Question explored with the scientific record
Is continued use of Clipidogrel more or less risky than aspirin for patients who have received stents? Is the standard 75mg dose of clipidogrel the only dose or is there a lower dose for preventative use (like aspirin)
The short version: after a stent, clopidogrel plus aspirin prevents more clots than aspirin alone, but the trade-off is more bleeding, and there is no lower-dose clopidogrel option for prevention.
The CURE trial of 12,562 patients showed that adding clopidogrel to aspirin reduced heart attack, stroke, and cardiovascular death by about 20% compared to aspirin alone, but major bleeding went from 2.7% to 3.7% [5]. That is one extra major bleed for roughly every 100 people treated. The CREDO trial in 2,116 PCI patients found a similar benefit over one year, with a trend toward more bleeding [5]. The NHLBI Dynamic Registry followed 3,130 DES patients and found that continuing dual antiplatelet therapy beyond one year cut four-year death from 14.5% to 10.5% and MI from 9.1% to 7.5% [12]. Stopping aspirin early, even years after stenting, can trigger stent thrombosis [1, 2].
Clopidogrel at 75 mg daily is the only dose studied for long-term prevention. There is no lower-dose option tested for that purpose. The 75 mg dose is the maintenance dose after a loading dose. Some patients are poor metabolizers due to CYP2C19 genetic variants, which raises their risk of stent thrombosis [4, 24, 26]. In those patients, switching to prasugrel or ticagrelor is the alternative, not a lower clopidogrel dose [4, 16, 18]. The 5 mg prasugrel dose exists for high-risk patients but has no endpoint data [16].
| Regimen | Ischemic benefit (death/MI/stroke) | Major bleeding |
|---|---|---|
| Aspirin alone | baseline | baseline |
| Aspirin + clopidogrel | ~20% relative reduction (CURE) | 3.7% vs 2.7% (CURE) |
| Aspirin + prasugrel | ~19% relative reduction (TRITON) | 2.4% vs 1.8% (TRITON) |
| Aspirin + ticagrelor | ~16% relative reduction (PLATO) | increased vs clopidogrel |
The bleeding risk is real and dose-dependent. Higher aspirin doses (325 mg vs 81 mg) increase bleeding without adding benefit [5]. The standard 75 mg clopidogrel dose is the minimum tested; going lower would likely lose the ischemic protection the drug is prescribed for.
My call: clopidogrel plus aspirin reduces stent thrombosis and death more than aspirin alone, at the cost of more bleeding. There is no lower clopidogrel dose for prevention. Confidence: high for the benefit and bleeding trade-off; moderate for the absence of a lower dose (the evidence simply does not test one).
Sources used 9
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Simultaneous very late angiographic stent thrombosis of 2 drug-eluting stents: a case report
This case report describes a 59-year-old white man who developed simultaneous very late angiographic stent thrombosis in two drug-eluting stents after stopping aspirin, highlighting the risk of premature dual antiplatelet therapy discontinuation and the need for prolonged dual a…
DOI: 10.1016/j.ajem.2008.04.027 -
VERY LATE STENT THROMBOSIS AFTER DRUG-ELUTING “CRUSH” AND “MINI-CRUSH” BIFURCATION STENTING IS PREVENTED BY PROLONGED DUAL ANTIPLATELET THERAPY
Retrospective, single-center follow-up of 108 patients who underwent crush/minicrush bifurcation drug-eluting stenting to assess whether prolonged dual antiplatelet therapy prevents very late stent thrombosis, finding VLST occurred only after DAPT was stopped and suggesting long…
DOI: 10.1016/s0735-1097(16)30438-7 -
Simultaneous Two-Vessel Subacute Stent Thrombosis Caused by Clopidogrel Resistance from CYP2C19 Polymorphism
A 76-year-old man developed simultaneous two-vessel in-stent thrombosis due to clopidogrel resistance from homozygous CYP2C19*2 polymorphism, successfully treated with ticagrelor, highlighting pharmacogenetic considerations in post-PCI antiplatelet therapy.
DOI: 10.1155/2016/2312078 -
Antithrombotic Approaches in Acute Coronary Syndromes: Optimizing Benefit vs Bleeding Risks
A contemporary narrative review synthesizing randomized trials and registries on antithrombotic therapy for acute coronary syndromes, detailing the trade-offs between ischemic protection and bleeding risk and outlining personalized treatment strategies and guideline-aligned reco…
DOI: 10.1016/j.mayocp.2016.06.013 -
Benefit of Long-Term Dual Anti-Platelet Therapy in Patients Treated With Drug-Eluting Stents: From the NHLBI Dynamic Registry
This study evaluates the impact of long-term dual antiplatelet therapy (DAPT) on clinical outcomes in patients treated with drug-eluting stents, finding that continued DAPT significantly reduces the risk of death and myocardial infarction over four years.
DOI: 10.1016/j.amjcard.2012.10.030 -
Prasugrel
Prasugrel plus aspirin reduces the primary ischemic endpoint in ACS patients undergoing PCI compared with clopidogrel plus aspirin, with additional reductions in stent thrombosis and recurrent CV events, but with higher major bleeding risk; dosing adjustments (5 mg/day) are reco…
DOI: 10.5482/hamo-12-05-0007 -
Efficacy and safety of ticagrelor and clopidogrel in East Asian patients with coronary artery disease undergoing percutaneous coronary intervention
In a large real-world East Asian cohort of coronary artery disease patients undergoing PCI and treated with dual antiplatelet therapy, ticagrelor reduced 1-year major adverse cardiovascular and cerebrovascular events (MACCEs) compared with clopidogrel but increased TIMI bleeding…
DOI: 10.1080/03007995.2020.1825364 -
Cytochrome P-450 Polymorphisms and Response to Clopidogrel
Genetic polymorphisms in cytochrome P-450 enzymes, particularly CYP2C19, reduce activation of the antiplatelet prodrug clopidogrel, leading to lower active-metabolite exposure and platelet inhibition in healthy subjects, and to higher risk of cardiovascular events including sten…
DOI: 10.1056/NEJMoa0809171 -
The Role of the Cytochrome P450 Polymorphisms in Clopidogrel Efficacy and Clinical Utility
A comprehensive review of how cytochrome P450 polymorphisms, particularly CYP2C19 variants, influence clopidogrel activation, platelet inhibition, and cardiovascular outcomes, with discussion of clinical utility, dose strategies, and future directions for personalized antiplatel…
DOI: 10.2174/092986711794839151