Among MI patients revascularized by CABG, only 27 percent received clopidogrel (Plavix, Bristol-Myers Squibb/Sanofi-Aventis) after discharge, according to a nationwide Danish study, published in the March 8 issue of the Journal of the American College of Cardiology.

Clinical practices and the effect of clopidogrel treatment in real-life MI patients revascularized by CABG “remain unclear,” according to the study authors.

Therefore, Rikke Sorensen, MD, from the department of cardiology at Copenhagen University Hospital Gentofte in Copenhagen, Denmark, and colleagues conducted a nationwide study to investigate the use and the effect of clopidogrel treatment on mortality and recurrent MI among 3,545 MI patients revascularized by CABG. The mean follow-up was 466 days.

Nationwide administrative registers identified all patients admitted with first-time MI between 2002 and 2006, treated with CABG within 180 days after admission. The researchers determined clopidogrel treatment by claimed prescriptions after discharge from surgery. They assessed the risk of death or recurrent MI, and a combined endpoint of the two, by cumulative incidence and Cox proportional hazards model.

Of the 3,545 patients, 27 percent were treated with clopidogrel after CABG, Sorenson and colleagues reported. Among patients treated with clopidogrel, 4.1 percent died or experienced a recurrent MI, whereas that occurred in 7.8 percent of patients without clopidogrel. 

By propensity score, of 945 patients with or without clopidogrel treatment who were matched, death or recurrent MI occurred in 4 percent of patients with clopidogrel and 6 percent without clopidogrel, according to the study authors. Corresponding hazard ratio was 0.67 for clopidogrel users, with no-clopidogrel as reference.

For patients without pre-CABG clopidogrel, the researchers reported that predictors of lower initiation were use of vitamin K antagonists, time to CABG and the lowest income group. For patients with pre-CABG clopidogrel, use of vitamin K antagonists and aspirin predicted low initiation. “We found no excess of bleeding among the patients treated with clopidogrel compared with patients not treated with clopidogrel, but this result should be interpreted with caution as more patients in the group without clopidogrel received vitamin K antagonists,” they wrote.

They also found that once started on a regimen of clopidogrel, adherence with treatment improved over time, with 47 percent continuing treatment for 180 days in 2002 and 74 percent in 2006.

As a recommendation, Sorensen and colleagues said that a greater focus on discharge clopidogrel treatment of these patients should be made.