Platelet AggregationPhase 2NCT03039205
Platelet Aggregation in Patients With Coronary Artery Disease and Kidney Dysfunction Taking Clopidogrel or Ticagrelor
A Phase 2 study testing Clopidogrel and Ticagrelor in people with Platelet Aggregation and Adenosine, run by University of Sao Paulo at 1 site in Brazil.
Trial summary
About 35% of patients hospitalized with Acute Coronary Syndromes (ACS) have some degree of renal dysfunction. Chronic kidney disease (CKD) is not only associated to worse prognosis in ACS patients, but leads also to an increased risk of bleeding, which may importantly influence the risk-benefit ratio of antiplatelet… Read more about this study
- Who is it for?
- Ages 18 years and older
- Conditions the study is for
- Platelet Aggregation, Adenosine, Coronary Artery Disease
- What is being tested?
- Clopidogrel and Ticagrelor
- Could I receive a placebo?
- No, everyone receives an active treatment
- How many people
- 90 participants
- Where
- 1 siteBrazil
- Study dates
- 7 Nov 2017to 19 Dec 2019
- Phase
- Phase 2
- Are there results?
- None posted in the registry
Key requirements
Who can take part, as listed by the sponsor. Only the study team can confirm whether you are eligible, so take this list to your doctor.
- Ages 18 years and older
- All sexes
- No healthy volunteers
- Adult, Older adult
Who may be able to join
- Patients in use of aspirin for at least 7 days prior to randomization;
- Documented obstructive coronary artery disease by angiography;
- At least 12 months from the last episode of myocardial infarction (MI);
- Agree to sign the Informed Consent.
Who cannot join
- Prior ischemic or hemorrhagic stroke;
- Prior intracranial bleeding;
- Use of oral anticoagulant in the past month;
- Use of dual antiplatelet therapy in the last 30 days;
- Use of NSAIDs and / or dipyridamole in the past month;
- Mandatory use of proton pump inhibitor;
Show all 14Show fewer
- Known platelet dysfunction or platelets <100,000 or >450,000/μL;
- End-stage renal disease undergoing hemodialysis;
- Terminal illness;
- Known liver disease or coagulation disorder;
- Known pregnancy, breast-feeding, or intend to become pregnant during the study period;
- Hypersensitivity to clopidogrel, ticagrelor or any excipients;
- Refusal to sign the Informed Consent;
- Active pathological bleeding.
Trial locations and contacts
1 site in 1 country.
Brazil1 site
Instituto do Coração (InCor) - Hospital das Clínicas da FMUSP
São Paulo
About this study
Official title: Evaluation of Platelet Aggregation and Adenosine Levels in Patients With Coronary Artery Disease and Chronic Kidney Dysfunction Taking Dual Antiplatelet Therapy With Aspirin and Clopidogrel or Ticagrelor
About 35% of patients hospitalized with Acute Coronary Syndromes (ACS) have some degree of renal dysfunction. Chronic kidney disease (CKD) is not only associated to worse prognosis in ACS patients, but leads also to an increased risk of bleeding, which may importantly influence the risk-benefit ratio of antiplatelet therapy in this population. The responsible mechanisms for increased rate of ischemic events in this population are not completely elucidated.
Antiplatelet therapy is of paramount importance in the treatment of ACS, but its benefit in CKD patients is not well established. This population is often excluded or underrepresented in large clinical trials, and the indication of antiplatelet therapy is often extrapolated from studies in patients with preserved renal function. In recent meta-analysis, Palmer et al. sought to evaluate the benefits and risks of antiplatelet agents in patients with CKD and concluded that in patients with ACS or scheduled for angioplasty already taking aspirin, the addition of clopidogrel or glycoprotein IIb / IIIa inhibitors have little or no impact in reducing the incidence of myocardial infarction, death or need for revascularization.
Read more
In the PLATO trial, ticagrelor (a new reversible inhibitor of P2Y12 receptor with faster onset of action and greater platelet inhibition) was compared to clopidogrel in patients with high risk ACS and was associated to a 16% risk reduction on the occurrence of death from vascular causes, myocardial infarction, or stroke. In a pre-specified sub-analysis, data from patients with CKD were compared to those obtained from the population with normal renal function and suggests that the benefit of ticagrelor may be even greater in patients with CKD. Two hypotheses were considered to explain these results:
- Greater and more consistent platelet inhibition achieved with ticagrelor would be more effective in reducing ischemic events in this population at increased thrombotic risk;
- Pleiotropic effects of ticagrelor besides inhibition of the P2Y12 receptor. Ticagrelor might be associated with an elevation in serum levels of adenosine. This could improve myocardial perfusion through coronary vasodilation, and this effect would be more pronounced in patients with renal dysfunction.
This project aims to validate (or not) these hypotheses, analyzing platelet aggregation and circulating adenosine levels in patients taking dual antiplatelet therapy with aspirin and clopidogrel or ticagrelor.
Read the detailed description
Previous publications demonstrated that about 35% to 40% of patients hospitalized with Acute Coronary Syndromes (ACS) have some degree of renal dysfunction. On the other hand, chronic kidney disease (CKD) is not only associated to worse prognosis in ACS patients, but leads also to an increased risk of bleeding, which may importantly influence the risk-benefit ratio of antiplatelet therapy in this population. Even at early stages, CKD increases the risk of myocardial infarction and death among different spectra of ACS, and the risk increase is directly proportional to the degree of renal dysfunction. The responsible mechanisms for the increased rate of ischemic events in this population are not completely elucidated. However, accelerated atherosclerosis, oxidative stress, inflammation and increased platelet aggregation, as well as underutilization of therapies such as antithrombotic agents and invasive procedures, are some of the proposed mechanisms.
Antiplatelet therapy is of paramount importance in the treatment of ACS, but its benefit in CKD patients is not well established. The fact that this population is often excluded or underrepresented in large clinical trials, makes the indication for its use be very often extrapolated from studies in patients with preserved renal function.
In recent meta-analysis, Palmer et al. sought to summarize the benefits and risks of antiplatelet agents in patients with CKD, focusing on the occurrence of cardiovascular events (including mortality) and bleeding. The results led them to conclude that: 1) the evidence for the use of antiplatelet agents in patients with CKD and cardiovascular disease is of low quality, 2) in patients with ACS or scheduled for angioplasty already taking acetylsalicylic acid (ASA), the addition of clopidogrel or glycoprotein IIb / IIIa inhibitors have little or no impact in reducing the incidence of myocardial infarction, death or need for revascularization, and 3) there was a significant 40% increase in the incidence of major bleeding.
In the PLATO trial - "Ticagrelor versus Clopidogrel in Patients with Acute Coronary Syndromes" - ticagrelor, a new reversible inhibitor of the P2Y12 receptor with faster onset of action and greater platelet inhibition power was compared to clopidogrel in over 18,000 patients with high risk ACS. In this publication, patients receiving ticagrelor had a 16% risk reduction on the occurrence of primary composite endpoint (death from vascular causes, myocardial infarction or stroke) without significant increase in the incidence of major bleeding. In a secondary outcome analysis, it was found a significant reduction in mortality from vascular causes and mortality from any cause in patients treated with ticagrelor. Among the high-risk criteria used in the selection of patients for this study, a creatinine clearance <60 ml/min/1.73 m2 was included.
In a following article, considering a pre-specified sub-analysis from the PLATO trial, the results of 3,237 patients who had this high-risk criterion were compared to those obtained for the population with normal renal function. The developed comparisons suggest that the benefit of ticagrelor may be even greater in patients with CKD: when considering the MDRD equation to estimate renal function, the hazard-ratio (HR) for the primary outcome of the study was 0.71 for patients with renal impairment (creatinine clearance <60 ml/min/1.73m2) and 0.90 for those without renal dysfunction (p = 0.03 for interaction). Furthermore, the HRs for mortality were, respectively, 0.79 and 0.91 for patients with and without renal dysfunction (P = 0.02 for interaction). Interestingly, no significant difference between groups relatively to major bleeding was observed, and the incidence of dyspnea was higher in the population without renal dysfunction.
Two hypotheses were considered to explain these results. The first suggests that a greater and more consistent platelet inhibition achieved with ticagrelor would be more effective in reducing ischemic events in this population at increased thrombotic risk. The second hypothesis considers possible pleiotropic effects of ticagrelor besides the reversible inhibition of the P2Y12 receptor. Ticagrelor might be associated with an elevation in serum levels of adenosine through the inhibition of its reuptake by erythrocytes and by increased release of adenosine triphosphate (ATP) from the same erythrocytes, subsequently converted in adenosine by ecto-ATPases. An increase in the concentrations of circulating adenosine could improve myocardial perfusion through coronary vasodilation, and this effect would be more pronounced in patients with renal dysfunction.
Thus, this project aims to validate (or not) these hypotheses, analyzing platelet aggregation and circulating adenosine levels in patients taking dual antiplatelet therapy with aspirin and clopidogrel or ticagrelor.
# Safety: as this protocol was designed for a short-term duration, we do not expect to have many adverse events (AE). An AE is any untoward medical occurrence in a participant that does not necessarily have a causal relationship with the study intervention. An AE can therefore be any unfavorable or unintended sign (including an abnormal laboratory finding), symptom or disease temporally associated with the use of a medical treatment or procedure regardless of whether it is considered related to the medical treatment or procedure. AEs will be reported as soon as possible.
Serious adverse events (SAE) are defined as any untoward medical occurrence that meets any one of the following criteria:
- Results in death or is life-threatening at the time of the event;
- Requires inpatient hospitalization, or prolongs a hospitalization;
- Results in a persistent or significant disability/incapacity;
- Is a congenital anomaly/birth defect (in a participants offspring); or
- Is medically judged to be an important event that jeopardized the subject and, for example, required significant measures to avoid one of the above outcomes.
SAEs will be reported within 24 hours of its information received. The causality of SAEs (their relationship to all study treatment/procedures) will be assessed by the investigator(s) and the investigator is responsible for informing the local authorities and ethical committees, of any serious adverse events as per local requirements.
- Conditions
- Platelet Aggregation, Adenosine, Coronary Artery Disease, Kidney Dysfunction, Antiplatelet Therapy
- Being tested
- Clopidogrel, Ticagrelor
- Keywords
- Platelet aggregation, Adenosine, Coronary artery disease, Kidney dysfunction, Ticagrelor, Clopidogrel
- Medical subject headings
- Coronary Artery Disease
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
ClopidogrelDrug
Also called Plavix
Clopidogrel 600 mg loading dose + 75 mg q.d. for 7 to 9 days
TicagrelorDrug
Also called Brilinta
Ticagrelor 180 mg loading dose + 90 mg b.i.d. for 7 to 9 days
| Study group | Role | What they receive |
|---|---|---|
| Chronic kidney dysfunction Clopidogrel | Active comparator | Patients with creatinine clearance <60ml/min/m2 (estimated by MDRD formula) randomized to clopidogrel group Receives: Drug: Clopidogrel |
| Chronic kidney dysfunction Ticagrelor | Active comparator | Patients with creatinine clearance <60ml/min/m2 (estimated by MDRD formula) randomized to ticagrelor group Receives: Drug: Ticagrelor |
| Normal kidney function Clopidogrel | Active comparator | Patients with creatinine clearance ≥60ml/min/m2 (estimated by MDRD formula) randomized to clopidogrel group Receives: Drug: Clopidogrel |
| Normal kidney function Ticagrelor | Active comparator | Patients with creatinine clearance ≥60ml/min/m2 (estimated by MDRD formula) randomized to ticagrelor group Receives: Drug: Ticagrelor |
What is being measured
The primary outcome is the main question the study is designed to answer.
Platelet aggregation evaluated by VerifyNow® P2Y12 (difference between clopidogrel and ticagrelor) in patients with and without renal dysfunction randomized to treatment with either clopidogrel or ticagrelor
Compare the level of inhibition of platelet aggregation evaluated by VerifyNow® P2Y12 (difference between clopidogrel and ticagrelor) in patients with coronary artery disease with and without renal dysfunction undergoing treatment with ASA in combination with clopidogrel or ticagrelor.
Measured: 8 days (±1)
Secondary outcomes (2)
Adenosine plasma concentration evaluated by isocratic high-performance liquid chromatographic technique, in patients with and without renal dysfunction randomized to treatment with either clopidogrel or ticagrelor.
Compare adenosine plasma concentration evaluated by isocratic high-performance liquid chromatographic technique, in patients with coronary artery disease with and without renal dysfunction undergoing treatment with ASA in combination with clopidogrel or ticagrelor.
Measured: 8 days (±1)
Platelet aggregation (difference between clopidogrel and ticagrelor) evaluated by Multiple electrode platelet aggregometry (Multiplate®) in patients with and without renal dysfunction randomized to treatment with either clopidogrel or ticagrelor
Measured: 8 days (±1)
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted1 Feb 2017 (estimated)
- Study start7 Nov 2017
- Primary completion19 Dec 2019
- Study completion19 Dec 2019
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Publications (20)Papers the sponsor has linked to this study.
- Other trials for Platelet AggregationStudies of the same condition, open and under way.
- More trials run by University of Sao PauloThe sponsor's other registered studies.
- What the trial phases meanHow a treatment moves from first tests in people to approval.
More details
For doctors and researchers: how the study is designed, who runs it, and its registry IDs.
Study design
- Study type
- Interventional
- Phase
- Phase 2
- Primary purpose
- Treatment
- Allocation
- Randomised
- Intervention model
- Parallel groups
- Masking
- Triple blind
- Who is masked
- Participant, Care provider, Investigator
- Enrolment
- 90 participants (actual)
Sponsor and investigators
- Lead sponsor
- University of Sao Paulo
- Sponsor type
- University, hospital or other
- Collaborators
- Fundação de Amparo à Pesquisa do Estado de São Paulo
- Responsible party
- Principal investigator, Jose Carlos Nicolau, University of Sao Paulo
- Investigators
- José C Nicolau, M.D. / PhD, Study chair, Heart Institute (InCor) / University of São PauloAndré Franci, M.D., Principal investigator, Heart Institute (InCor) / University of São Paulo
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT03039205
- Sponsor's protocol ID
- FAPESP 2014/01021-4
- Other IDs
- 4086/14/066
- Status last verified
- Apr 2020
- First submitted
- 23 Jan 2017
- Last updated
- 24 Apr 2020
- Results posted
- No
- Data monitoring committee
- No
- FDA-regulated drug
- No
- FDA-regulated device
- No
- Individual data sharing
- Undecided
Publications
Al Suwaidi J, Reddan DN, Williams K, Pieper KS, Harrington RA, Califf RM, Granger CB, Ohman EM, Holmes DR Jr; GUSTO-IIb, GUSTO-III, PURSUIT. Global Use of Strategies to Open Occluded Coronary Arteries. Platelet Glycoprotein IIb/IIIa in Unstable Angina: Receptor Suppression Using Integrilin Therapy; PARAGON-A Investigators. Platelet IIb/IIIa Antagonism for the Reduction of Acute coronary syndrome events in a Global Organization Network. Prognostic implications of abnormalities in renal function in patients with acute coronary syndromes. Circulation. 2002 Aug 20;106(8):974-80. doi: 10.1161/01.cir.0000027560.41358.b3.
PubMed 12186803Freeman RV, Mehta RH, Al Badr W, Cooper JV, Kline-Rogers E, Eagle KA. Influence of concurrent renal dysfunction on outcomes of patients with acute coronary syndromes and implications of the use of glycoprotein IIb/IIIa inhibitors. J Am Coll Cardiol. 2003 Mar 5;41(5):718-24. doi: 10.1016/s0735-1097(02)02956-x.
PubMed 12628712Anavekar NS, McMurray JJ, Velazquez EJ, Solomon SD, Kober L, Rouleau JL, White HD, Nordlander R, Maggioni A, Dickstein K, Zelenkofske S, Leimberger JD, Califf RM, Pfeffer MA. Relation between renal dysfunction and cardiovascular outcomes after myocardial infarction. N Engl J Med. 2004 Sep 23;351(13):1285-95. doi: 10.1056/NEJMoa041365.
PubMed 15385655Best PJ, Lennon R, Ting HH, Bell MR, Rihal CS, Holmes DR, Berger PB. The impact of renal insufficiency on clinical outcomes in patients undergoing percutaneous coronary interventions. J Am Coll Cardiol. 2002 Apr 3;39(7):1113-9. doi: 10.1016/s0735-1097(02)01745-x.
PubMed 11923033Fox CS, Muntner P, Chen AY, Alexander KP, Roe MT, Cannon CP, Saucedo JF, Kontos MC, Wiviott SD; Acute Coronary Treatment and Intervention Outcomes Network registry. Use of evidence-based therapies in short-term outcomes of ST-segment elevation myocardial infarction and non-ST-segment elevation myocardial infarction in patients with chronic kidney disease: a report from the National Cardiovascular Data Acute Coronary Treatment and Intervention Outcomes Network registry. Circulation. 2010 Jan 26;121(3):357-65. doi: 10.1161/CIRCULATIONAHA.109.865352. Epub 2010 Jan 11.
PubMed 20065168Ezekowitz J, McAlister FA, Humphries KH, Norris CM, Tonelli M, Ghali WA, Knudtson ML; APPROACH Investigators. The association among renal insufficiency, pharmacotherapy, and outcomes in 6,427 patients with heart failure and coronary artery disease. J Am Coll Cardiol. 2004 Oct 19;44(8):1587-92. doi: 10.1016/j.jacc.2004.06.072.
PubMed 15489090Antithrombotic Trialists' Collaboration. Collaborative meta-analysis of randomised trials of antiplatelet therapy for prevention of death, myocardial infarction, and stroke in high risk patients. BMJ. 2002 Jan 12;324(7329):71-86. doi: 10.1136/bmj.324.7329.71.
PubMed 11786451Basra SS, Tsai P, Lakkis NM. Safety and efficacy of antiplatelet and antithrombotic therapy in acute coronary syndrome patients with chronic kidney disease. J Am Coll Cardiol. 2011 Nov 22;58(22):2263-9. doi: 10.1016/j.jacc.2011.08.051.
PubMed 22093501Palmer SC, Di Micco L, Razavian M, Craig JC, Perkovic V, Pellegrini F, Copetti M, Graziano G, Tognoni G, Jardine M, Webster A, Nicolucci A, Zoungas S, Strippoli GF. Effects of antiplatelet therapy on mortality and cardiovascular and bleeding outcomes in persons with chronic kidney disease: a systematic review and meta-analysis. Ann Intern Med. 2012 Mar 20;156(6):445-59. doi: 10.7326/0003-4819-156-6-201203200-00007.
PubMed 22431677Wallentin L, Becker RC, Budaj A, Cannon CP, Emanuelsson H, Held C, Horrow J, Husted S, James S, Katus H, Mahaffey KW, Scirica BM, Skene A, Steg PG, Storey RF, Harrington RA; PLATO Investigators; Freij A, Thorsen M. Ticagrelor versus clopidogrel in patients with acute coronary syndromes. N Engl J Med. 2009 Sep 10;361(11):1045-57. doi: 10.1056/NEJMoa0904327. Epub 2009 Aug 30.
PubMed 19717846James S, Budaj A, Aylward P, Buck KK, Cannon CP, Cornel JH, Harrington RA, Horrow J, Katus H, Keltai M, Lewis BS, Parikh K, Storey RF, Szummer K, Wojdyla D, Wallentin L. Ticagrelor versus clopidogrel in acute coronary syndromes in relation to renal function: results from the Platelet Inhibition and Patient Outcomes (PLATO) trial. Circulation. 2010 Sep 14;122(11):1056-67. doi: 10.1161/CIRCULATIONAHA.109.933796. Epub 2010 Aug 30.
PubMed 20805430Levey AS, Bosch JP, Lewis JB, Greene T, Rogers N, Roth D. A more accurate method to estimate glomerular filtration rate from serum creatinine: a new prediction equation. Modification of Diet in Renal Disease Study Group. Ann Intern Med. 1999 Mar 16;130(6):461-70. doi: 10.7326/0003-4819-130-6-199903160-00002.
PubMed 10075613Ohman J, Kudira R, Albinsson S, Olde B, Erlinge D. Ticagrelor induces adenosine triphosphate release from human red blood cells. Biochem Biophys Res Commun. 2012 Feb 24;418(4):754-8. doi: 10.1016/j.bbrc.2012.01.093. Epub 2012 Jan 27.
PubMed 22306816Montalescot G, Silvain J. Ticagrelor in the renal dysfunction subgroup: subjugated or substantiated? Circulation. 2010 Sep 14;122(11):1049-52. doi: 10.1161/CIRCULATIONAHA.110.974683. Epub 2010 Aug 30. No abstract available.
PubMed 20805425Park SH, Kim W, Park CS, Kang WY, Hwang SH, Kim W. A comparison of clopidogrel responsiveness in patients with versus without chronic renal failure. Am J Cardiol. 2009 Nov 1;104(9):1292-5. doi: 10.1016/j.amjcard.2009.06.049.
PubMed 19840579
Study at a glance
From the registry record, last updated by the sponsor on 24 Apr 2020. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- Evaluation of Platelet Aggregation and Adenosine Levels in Patients With Coronary Artery Disease and Chronic Kidney Dysfunction Taking Dual Antiplatelet Therapy With Aspirin and Clopidogrel or Ticagrelor
- ClinicalTrials.gov ID
- NCT03039205
- Acronym / sponsor ID
- FAPESP 2014/01021-4
- Conditions
- Platelet Aggregation, Adenosine, Coronary Artery Disease, Kidney Dysfunction, Antiplatelet Therapy
- Keywords
- Platelet aggregation, Adenosine, Coronary artery disease, Kidney dysfunction, Ticagrelor, Clopidogrel
- Phase
- Phase 2
- Study type
- Interventional
- Recruitment status
- Completed
- Enrolment
- 90 participants (actual)
- Lead sponsor
- University of Sao PauloUniversity, hospital or other
- Collaborators
- Fundação de Amparo à Pesquisa do Estado de São Paulo
- Study start
- 7 Nov 2017 (actual)
- Primary completion
- 19 Dec 2019 (actual)
- Study completion
- 19 Dec 2019 (actual)
- First posted
- 1 Feb 2017 (estimated)
- Results
- Not posted in the source record
Clinical summary
The research question as the sponsor registered it. This describes what the study plans to test, not what it found.
About 35% of patients hospitalized with Acute Coronary Syndromes (ACS) have some degree of renal dysfunction. Chronic kidney disease (CKD) is not only associated to worse prognosis in ACS patients, but leads also to an increased risk of bleeding, which may importantly influence the risk-benefit ratio of antiplatelet therapy in this population. The responsible mechanisms for increased rate of ischemic events in this population are not completely elucidated.
Antiplatelet therapy is of paramount importance in the treatment of ACS, but its benefit in CKD patients is not well established. This population is often excluded or underrepresented in large clinical trials, and the indication of antiplatelet therapy is often extrapolated from studies in patients with preserved renal function. In recent meta-analysis, Palmer et al. sought to evaluate the benefits and risks of antiplatelet agents in patients with CKD and concluded that in patients with ACS or scheduled for angioplasty already taking aspirin, the addition of clopidogrel or glycoprotein IIb / IIIa inhibitors have little or no impact in reducing the incidence of myocardial infarction, death or need for revascularization.
In the PLATO trial, ticagrelor (a new reversible inhibitor of P2Y12 receptor with faster onset of action and greater platelet inhibition) was compared to clopidogrel in patients with high risk ACS and was associated to a 16% risk reduction on the occurrence of death from vascular causes, myocardial infarction, or stroke. In a pre-specified sub-analysis, data from patients with CKD were compared to those obtained from the population with normal renal function and suggests that the benefit of ticagrelor may be even greater in patients with CKD. Two hypotheses were considered to explain these results:
- Greater and more consistent platelet inhibition achieved with ticagrelor would be more effective in reducing ischemic events in this population at increased thrombotic risk;
- Pleiotropic effects of ticagrelor besides inhibition of the P2Y12 receptor. Ticagrelor might be associated with an elevation in serum levels of adenosine. This could improve myocardial perfusion through coronary vasodilation, and this effect would be more pronounced in patients with renal dysfunction.
This project aims to validate (or not) these hypotheses, analyzing platelet aggregation and circulating adenosine levels in patients taking dual antiplatelet therapy with aspirin and clopidogrel or ticagrelor.
Detailed description
Previous publications demonstrated that about 35% to 40% of patients hospitalized with Acute Coronary Syndromes (ACS) have some degree of renal dysfunction. On the other hand, chronic kidney disease (CKD) is not only associated to worse prognosis in ACS patients, but leads also to an increased risk of bleeding, which may importantly influence the risk-benefit ratio of antiplatelet therapy in this population. Even at early stages, CKD increases the risk of myocardial infarction and death among different spectra of ACS, and the risk increase is directly proportional to the degree of renal dysfunction. The responsible mechanisms for the increased rate of ischemic events in this population are not completely elucidated. However, accelerated atherosclerosis, oxidative stress, inflammation and increased platelet aggregation, as well as underutilization of therapies such as antithrombotic agents and invasive procedures, are some of the proposed mechanisms.
Antiplatelet therapy is of paramount importance in the treatment of ACS, but its benefit in CKD patients is not well established. The fact that this population is often excluded or underrepresented in large clinical trials, makes the indication for its use be very often extrapolated from studies in patients with preserved renal function.
In recent meta-analysis, Palmer et al. sought to summarize the benefits and risks of antiplatelet agents in patients with CKD, focusing on the occurrence of cardiovascular events (including mortality) and bleeding. The results led them to conclude that: 1) the evidence for the use of antiplatelet agents in patients with CKD and cardiovascular disease is of low quality, 2) in patients with ACS or scheduled for angioplasty already taking acetylsalicylic acid (ASA), the addition of clopidogrel or glycoprotein IIb / IIIa inhibitors have little or no impact in reducing the incidence of myocardial infarction, death or need for revascularization, and 3) there was a significant 40% increase in the incidence of major bleeding.
In the PLATO trial - "Ticagrelor versus Clopidogrel in Patients with Acute Coronary Syndromes" - ticagrelor, a new reversible inhibitor of the P2Y12 receptor with faster onset of action and greater platelet inhibition power was compared to clopidogrel in over 18,000 patients with high risk ACS. In this publication, patients receiving ticagrelor had a 16% risk reduction on the occurrence of primary composite endpoint (death from vascular causes, myocardial infarction or stroke) without significant increase in the incidence of major bleeding. In a secondary outcome analysis, it was found a significant reduction in mortality from vascular causes and mortality from any cause in patients treated with ticagrelor. Among the high-risk criteria used in the selection of patients for this study, a creatinine clearance <60 ml/min/1.73 m2 was included.
In a following article, considering a pre-specified sub-analysis from the PLATO trial, the results of 3,237 patients who had this high-risk criterion were compared to those obtained for the population with normal renal function. The developed comparisons suggest that the benefit of ticagrelor may be even greater in patients with CKD: when considering the MDRD equation to estimate renal function, the hazard-ratio (HR) for the primary outcome of the study was 0.71 for patients with renal impairment (creatinine clearance <60 ml/min/1.73m2) and 0.90 for those without renal dysfunction (p = 0.03 for interaction). Furthermore, the HRs for mortality were, respectively, 0.79 and 0.91 for patients with and without renal dysfunction (P = 0.02 for interaction). Interestingly, no significant difference between groups relatively to major bleeding was observed, and the incidence of dyspnea was higher in the population without renal dysfunction.
Two hypotheses were considered to explain these results. The first suggests that a greater and more consistent platelet inhibition achieved with ticagrelor would be more effective in reducing ischemic events in this population at increased thrombotic risk. The second hypothesis considers possible pleiotropic effects of ticagrelor besides the reversible inhibition of the P2Y12 receptor. Ticagrelor might be associated with an elevation in serum levels of adenosine through the inhibition of its reuptake by erythrocytes and by increased release of adenosine triphosphate (ATP) from the same erythrocytes, subsequently converted in adenosine by ecto-ATPases. An increase in the concentrations of circulating adenosine could improve myocardial perfusion through coronary vasodilation, and this effect would be more pronounced in patients with renal dysfunction.
Thus, this project aims to validate (or not) these hypotheses, analyzing platelet aggregation and circulating adenosine levels in patients taking dual antiplatelet therapy with aspirin and clopidogrel or ticagrelor.
# Safety: as this protocol was designed for a short-term duration, we do not expect to have many adverse events (AE). An AE is any untoward medical occurrence in a participant that does not necessarily have a causal relationship with the study intervention. An AE can therefore be any unfavorable or unintended sign (including an abnormal laboratory finding), symptom or disease temporally associated with the use of a medical treatment or procedure regardless of whether it is considered related to the medical treatment or procedure. AEs will be reported as soon as possible.
Serious adverse events (SAE) are defined as any untoward medical occurrence that meets any one of the following criteria:
- Results in death or is life-threatening at the time of the event;
- Requires inpatient hospitalization, or prolongs a hospitalization;
- Results in a persistent or significant disability/incapacity;
- Is a congenital anomaly/birth defect (in a participants offspring); or
- Is medically judged to be an important event that jeopardized the subject and, for example, required significant measures to avoid one of the above outcomes.
SAEs will be reported within 24 hours of its information received. The causality of SAEs (their relationship to all study treatment/procedures) will be assessed by the investigator(s) and the investigator is responsible for informing the local authorities and ethical committees, of any serious adverse events as per local requirements.
Study design
- Primary purpose
- Treatment
- Allocation
- Randomised
- Intervention model
- Parallel groups
- Masking
- Triple blind (participant, care provider, investigator)
- Number of arms
- 4
| Arm | Type | Receives |
|---|---|---|
| Chronic kidney dysfunction Clopidogrel | Active comparator | Drug: ClopidogrelPatients with creatinine clearance <60ml/min/m2 (estimated by MDRD formula) randomized to clopidogrel group |
| Chronic kidney dysfunction Ticagrelor | Active comparator | Drug: TicagrelorPatients with creatinine clearance <60ml/min/m2 (estimated by MDRD formula) randomized to ticagrelor group |
| Normal kidney function Clopidogrel | Active comparator | Drug: ClopidogrelPatients with creatinine clearance ≥60ml/min/m2 (estimated by MDRD formula) randomized to clopidogrel group |
| Normal kidney function Ticagrelor | Active comparator | Drug: TicagrelorPatients with creatinine clearance ≥60ml/min/m2 (estimated by MDRD formula) randomized to ticagrelor group |
Who may qualify
- Ages
- 18 years and older
- Sex
- All
- Healthy volunteers
- Not accepted
- Age groups
- Adult, Older adult
Key inclusion criteria (4 listed)
- Patients in use of aspirin for at least 7 days prior to randomization;
- Documented obstructive coronary artery disease by angiography;
- At least 12 months from the last episode of myocardial infarction (MI);
- Agree to sign the Informed Consent.
Key exclusion criteria (14 listed)
- Prior ischemic or hemorrhagic stroke;
- Prior intracranial bleeding;
- Use of oral anticoagulant in the past month;
- Use of dual antiplatelet therapy in the last 30 days;
- Use of NSAIDs and / or dipyridamole in the past month;
Eligibility is decided by the study team after screening; this overview does not establish that a patient qualifies. Full inclusion and exclusion criteria.
Interventions
| Intervention | Type | Arms |
|---|---|---|
| ClopidogrelAlso: PlavixClopidogrel 600 mg loading dose + 75 mg q.d. for 7 to 9 days | Drug | Chronic kidney dysfunction Clopidogrel, Normal kidney function Clopidogrel |
| TicagrelorAlso: BrilintaTicagrelor 180 mg loading dose + 90 mg b.i.d. for 7 to 9 days | Drug | Chronic kidney dysfunction Ticagrelor, Normal kidney function Ticagrelor |
Primary outcome
Platelet aggregation evaluated by VerifyNow® P2Y12 (difference between clopidogrel and ticagrelor) in patients with and without renal dysfunction randomized to treatment with either clopidogrel or ticagrelor
Time frame: 8 days (±1)
Compare the level of inhibition of platelet aggregation evaluated by VerifyNow® P2Y12 (difference between clopidogrel and ticagrelor) in patients with coronary artery disease with and without renal dysfunction undergoing treatment with ASA in combination with clopidogrel or ticagrelor.
2 secondary outcomes
Adenosine plasma concentration evaluated by isocratic high-performance liquid chromatographic technique, in patients with and without renal dysfunction randomized to treatment with either clopidogrel or ticagrelor.
Time frame: 8 days (±1)
Platelet aggregation (difference between clopidogrel and ticagrelor) evaluated by Multiple electrode platelet aggregometry (Multiplate®) in patients with and without renal dysfunction randomized to treatment with either clopidogrel or ticagrelor
Time frame: 8 days (±1)
Results and safety
The study is completed, but results are not available in the source record. That does not mean the treatment did or did not work.
Research links
- Official record on ClinicalTrials.govLast updated by the sponsor 24 Apr 2020.
- Background: PubMed 12186803Al Suwaidi J, Reddan DN, Williams K, Pieper KS, Harrington RA, Califf RM, Granger CB, Ohman EM, Holmes DR Jr; GUSTO-IIb, GUSTO-III, PURSUIT. Global Use of Strategies to Open Occluded Coronary Arteries. Platelet Glycoprotein IIb/IIIa in Unstable Angina: Receptor Suppression Using Integrilin Therapy; PARAGON-A Investigators. Platelet IIb/IIIa Antagonism for the Reduction of Acute coronary syndrome events in a Global Organization Network. Prognostic implications of abnormalities in renal function in patients with acute coronary syndromes. Circulation. 2002 Aug 20;106(8):974-80. doi: 10.1161/01.cir.0000027560.41358.b3.
- Background: PubMed 12628712Freeman RV, Mehta RH, Al Badr W, Cooper JV, Kline-Rogers E, Eagle KA. Influence of concurrent renal dysfunction on outcomes of patients with acute coronary syndromes and implications of the use of glycoprotein IIb/IIIa inhibitors. J Am Coll Cardiol. 2003 Mar 5;41(5):718-24. doi: 10.1016/s0735-1097(02)02956-x.
- Background: PubMed 15385655Anavekar NS, McMurray JJ, Velazquez EJ, Solomon SD, Kober L, Rouleau JL, White HD, Nordlander R, Maggioni A, Dickstein K, Zelenkofske S, Leimberger JD, Califf RM, Pfeffer MA. Relation between renal dysfunction and cardiovascular outcomes after myocardial infarction. N Engl J Med. 2004 Sep 23;351(13):1285-95. doi: 10.1056/NEJMoa041365.
- Background: PubMed 11923033Best PJ, Lennon R, Ting HH, Bell MR, Rihal CS, Holmes DR, Berger PB. The impact of renal insufficiency on clinical outcomes in patients undergoing percutaneous coronary interventions. J Am Coll Cardiol. 2002 Apr 3;39(7):1113-9. doi: 10.1016/s0735-1097(02)01745-x.
- Background: PubMed 20065168Fox CS, Muntner P, Chen AY, Alexander KP, Roe MT, Cannon CP, Saucedo JF, Kontos MC, Wiviott SD; Acute Coronary Treatment and Intervention Outcomes Network registry. Use of evidence-based therapies in short-term outcomes of ST-segment elevation myocardial infarction and non-ST-segment elevation myocardial infarction in patients with chronic kidney disease: a report from the National Cardiovascular Data Acute Coronary Treatment and Intervention Outcomes Network registry. Circulation. 2010 Jan 26;121(3):357-65. doi: 10.1161/CIRCULATIONAHA.109.865352. Epub 2010 Jan 11.
- Background: PubMed 15489090Ezekowitz J, McAlister FA, Humphries KH, Norris CM, Tonelli M, Ghali WA, Knudtson ML; APPROACH Investigators. The association among renal insufficiency, pharmacotherapy, and outcomes in 6,427 patients with heart failure and coronary artery disease. J Am Coll Cardiol. 2004 Oct 19;44(8):1587-92. doi: 10.1016/j.jacc.2004.06.072.
- Background: PubMed 11786451Antithrombotic Trialists' Collaboration. Collaborative meta-analysis of randomised trials of antiplatelet therapy for prevention of death, myocardial infarction, and stroke in high risk patients. BMJ. 2002 Jan 12;324(7329):71-86. doi: 10.1136/bmj.324.7329.71.
- Background: PubMed 22093501Basra SS, Tsai P, Lakkis NM. Safety and efficacy of antiplatelet and antithrombotic therapy in acute coronary syndrome patients with chronic kidney disease. J Am Coll Cardiol. 2011 Nov 22;58(22):2263-9. doi: 10.1016/j.jacc.2011.08.051.
- Background: PubMed 22431677Palmer SC, Di Micco L, Razavian M, Craig JC, Perkovic V, Pellegrini F, Copetti M, Graziano G, Tognoni G, Jardine M, Webster A, Nicolucci A, Zoungas S, Strippoli GF. Effects of antiplatelet therapy on mortality and cardiovascular and bleeding outcomes in persons with chronic kidney disease: a systematic review and meta-analysis. Ann Intern Med. 2012 Mar 20;156(6):445-59. doi: 10.7326/0003-4819-156-6-201203200-00007.
- Background: PubMed 19717846Wallentin L, Becker RC, Budaj A, Cannon CP, Emanuelsson H, Held C, Horrow J, Husted S, James S, Katus H, Mahaffey KW, Scirica BM, Skene A, Steg PG, Storey RF, Harrington RA; PLATO Investigators; Freij A, Thorsen M. Ticagrelor versus clopidogrel in patients with acute coronary syndromes. N Engl J Med. 2009 Sep 10;361(11):1045-57. doi: 10.1056/NEJMoa0904327. Epub 2009 Aug 30.
- Background: PubMed 20805430James S, Budaj A, Aylward P, Buck KK, Cannon CP, Cornel JH, Harrington RA, Horrow J, Katus H, Keltai M, Lewis BS, Parikh K, Storey RF, Szummer K, Wojdyla D, Wallentin L. Ticagrelor versus clopidogrel in acute coronary syndromes in relation to renal function: results from the Platelet Inhibition and Patient Outcomes (PLATO) trial. Circulation. 2010 Sep 14;122(11):1056-67. doi: 10.1161/CIRCULATIONAHA.109.933796. Epub 2010 Aug 30.
- Background: PubMed 10075613Levey AS, Bosch JP, Lewis JB, Greene T, Rogers N, Roth D. A more accurate method to estimate glomerular filtration rate from serum creatinine: a new prediction equation. Modification of Diet in Renal Disease Study Group. Ann Intern Med. 1999 Mar 16;130(6):461-70. doi: 10.7326/0003-4819-130-6-199903160-00002.
- Isocratic high-performance liquid chromatographic determination of plasma adenosineLink provided by the sponsor.
- Individual participant dataSharing planned: Undecided
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Cookies for Platelets
Blood Donation
Referral and contact
AzTrials does not enrol participants or take referrals. Contact the study team or a site listed below; they decide who can take part. This study is not recruiting at the moment.
José C Nicolau, M.D. / PhD study chair
Heart Institute (InCor) / University of São Paulo
André Franci, M.D. principal investigator
Heart Institute (InCor) / University of São Paulo
1 site in 1 country: see every site and its status.
Questions about this trial
What is this clinical trial studying?
A Phase 2 study testing Clopidogrel and Ticagrelor in people with Platelet Aggregation and Adenosine, run by University of Sao Paulo at 1 site in Brazil.
The full registered description is in the About this study section and the official record.
Who may be eligible to take part?
The sponsor lists 4 inclusion and 14 exclusion criteria. Eligibility is decided by the study team after screening, so read the full criteria and contact a listed site.
Is this clinical trial currently recruiting?
The record says: finished, as of the sponsor's last update on 24 Apr 2020. Status can change between updates, so confirm with the study contact before making plans.
Where is the study taking place?
The record lists 1 site in Brazil. Whether a site is taking part right now should be confirmed with that site. See every site.
What are the possible benefits and risks?
They depend on the study and the treatment, and no study can promise a benefit. The study team explains the known risks during informed consent, before anyone joins; the record itself does not list them.
What does this phase mean?
Phase 2 studies give the treatment to a larger group to see whether it has the intended effect and to keep checking safety.
Not every study follows the same path, and some studies (observational studies, device studies) have no phase.
Are results available for this study?
The study is completed, but results are not available in the source record. That does not mean the treatment did or did not work.
How can a doctor refer a patient or contact the research team?
The record lists no contact. The official record names the sponsor, who can be asked directly. AzTrials does not enrol participants or take referrals.
What does the primary outcome measure?
Platelet aggregation evaluated by VerifyNow® P2Y12 (difference between clopidogrel and ticagrelor) in patients with and without renal dysfunction randomized to treatment with either clopidogrel or ticagrelor (time frame: 8 days (±1)). It is what the study was designed to measure, not a finding.
Where can I read the original study information?
On the ClinicalTrials.gov record for NCT03039205, which also lists 20 linked publications.
Does a listing mean the treatment is approved or proven to work?
No. A listing means the study is registered. It does not show that the treatment is safe, works, or is approved by a regulator.
How often is this information updated?
AzTrials copies changed records from ClinicalTrials.gov every night and reloads the whole registry every week. The sponsor last updated this record on 24 Apr 2020.