OBJECTIVETo compare the effects of clopidogrel combined with dihydropyridine calcium-channel blockers (CCBs) or non-dihydropyridine CCBs on coronary artery disease (CAD) in elderly patients.

METHODSThe study cohort was defined as all patients ≥60 years old hospitalized for CAD with the prescription of clopidogrel between January 2001 and February 2011. The primary endpoint was death of all causes, and the secondary endpoints were nonfatal myocardial infarction (MI), hospitalization for unstable angina, stroke, transient ischemic attack, or repeat revascularization (PCI or coronary artery bypass graft).

RESULTSA total of 1021 patients were enrolled, among whom 402 patients were prescribed with clopidogrel and 619 with clopidogrel combined with CCB (dihydropyridine in 547 and non-dihydropyridine in 72). In clopidogrel group and clopidogrel with CCB group, the incidence density of death was 50.55 per thousand and 42.02 per thousand, respectively. The crude RR was 0.83 (95%CI: 0.55-1.26), and the multivariable-adjusted RR was 0.47 (95%CI: 0.14-1.6), showing no statistical significance in the rate of deaths of call causes between the two groups (P>0.05); the incidence density of composite thromboembolic events showed no significant difference between the two groups, either (P>0.05). After weighting of the propensity score, the patients with clopidogrel coadministered with non-dihydropyridine CCB showed a significant increase in composite thromboembolic events than those taking dihydropyridine CCB, with a SMRW-adjusted OR of 1.97 (95%: 1.2-3.23, P=0.007). No significant difference was observed in death or composite thromboembolic events between Pgp-inhibiting CCBs and non-Pgp-inhibiting CCBs.

CONCLUSIONCompared with clopidogrel without CCB, clopidogrel with CCB does not increase the mortality or composite thromboembolic events in elderly CAD patients, but clopidogrel combined with non-dihydropyridine CCB is associated with significantly increased composite thromboembolic events in comparison with dihydropyridine CCB.