Safety of clopidogrel in older patients: a nonrandomized, parallel-group, controlled, two-centre study

The safety and efficacy of clopidogrel therapy in patients with stable coronary artery disease or acute coronary syndromes undergoing percutaneous coronary intervention (PCI) have been demonstrated.

To evaluate the safety (primary outcome, defined as any bleeding complication or thrombocytopenia) and adverse outcomes (secondary outcomes, defined as death from cardiovascular causes, myocardial infarction or stroke) of clopidogrel therapy in patients aged ≥75 years with stable or unstable coronary artery disease undergoing PCI, and to compare these outcomes with those in younger controls.

Patients with both stable coronary heart disease and acute coronary syndromes undergoing PCI were included in the study. Two groups were formed according to age at the time of admission. Patients aged ≥75 years (the study group, n = 149) formed one group; the other group included patients aged <75 years (the control group, n = 298). During an ad hoc PCI procedure, a 600 mg loading and 75 mg/day maintenance dose of clopidogrel in addition to aspirin (acetylsalicylic acid) therapy (300 mg/day) were administrated to both treatment groups. In-hospital outcomes were investigated during a mean ± SD follow-up period of 5.3 ± 3.9 days.

The first safety (primary) outcome of any bleeding event occurred in 16.1% of the patients in the study (older) group and 6.0% of the patients in the control (younger) group (odds ratio [OR] 2.987; 95% CI 1.565, 5.701; p = 0.001). The second safety outcome of TIMI (Thrombolysis in Myocardial Infarction) major bleeding occurred in 4.0% of the patients in the study group and 0.7% of the patients in the control group (OR 6.210; 95% CI 1.238, 31.151; p = 0.012). Other safety outcomes of TIMI minor/minimal bleeding and thrombocytopenia were not different between the two groups. The rate of the first adverse (secondary) outcome of the composite of death from cardiovascular causes, myocardial infarction or stroke was higher in older patients (12.1% vs 5.4%) [OR 2.422; 95% CI 1.197, 4.899; p = 0.012], primarily driven by stroke events (2.0% vs 0%; p = 0.014).

Any bleeding and TIMI major bleeding complications increase in patients aged ≥75 years treated with clopidogrel in addition to aspirin.