Long-term use of the blood-thinning agent clopidogrel did not alter the risk of death in people with heart disease or at risk of developing heart disease, nor did the drug appear to affect cancer risk, according to a statement from the U.S. Food and Drug Administration.
The FDA’s meta-analysis looked at results from 12 trials enrolling a total of 56,799 patients to evaluate the effect of long-term clopidogrel use on all-cause mortality. The incidence of all-cause mortality was 6.7% for the long-term clopidogrel plus aspirin arm and 6.6% for the comparator, resulting in a Mantel Haenszel Risk Difference (MH RD) of 0.04% (95% confidence interval, –0.35%-0.44%).
“The results indicate that long-term (12 months or longer) dual-antiplatelet therapy with clopidogrel and aspirin do not appear to change the overall risk of death, compared with short-term (6 months or less) clopidogrel and aspirin, or aspirin alone,” the agency said in its statement.
The FDA also conducted a meta-analysis looking at nine of these trials (n = 45,374) that had enrolled patients with coronary artery disease or patients at risk of CAD. This also suggested no difference in the risk of all-cause mortality (MH RD –0.07%; 95% CI, –0.43%- 0.29%).
The meta-analysis included results from the Dual-Antiplatelet Therapy Trial (DAPT), whose results included a worrisome safety signal for extended use of clopidogrel (N Engl J Med 2014; 371:2155-66). Patients in the DAPT underwent percutaneous coronary intervention and placement of a drug-eluting stent, after which they received 1 year of clopidogrel or prasugrel plus aspirin. About 1,000 patients were then randomized to 18 additional months of one of the dual-antiplatelet therapies or to aspirin plus placebo. Extended (30-month) use of clopidogrel plus aspirin was associated with a significantly increased risk of death (2.2% for 30 months vs. 1.5% for 12 months), whereas no increased risk was seen for prasugrel plus aspirin. A higher risk of death was mainly due to noncardiovascular causes, including cancer and trauma.
The DAPT did not show an increased risk of cancer-related adverse events related to treatment duration. However, the FDA performed two meta-analyses of other trials, with about 40,000 patients included in each analysis, to determine whether a signal could be found for either cancer-related adverse events or cancer-related death. Neither revealed an increased risk related to long-term clopidogrel use.