Benefit of adding low molecular weight heparin to the conventional treatment of stable angina pectoris. A double-blind, randomized, placebo-controlled trial.

BACKGROUND Patients with chronic coronary artery disease exhibit a dysfunctioning endothelium, which may be responsible for exercise-induced platelet activation and expression of a procoagulant moiety. In this study, we evaluated the therapeutic efficacy of a low molecular weight heparin (Parnaparin) in patients with stable angina pectoris. METHODS AND RESULTS According to a double-blind, randomized, placebo-controlled trial, 29 patients with stable exercise-induced angina pectoris and angiographically proven coronary artery disease received a single daily subcutaneous injection of Parnaparin or placebo on top of aspirin and conventional antianginal medication over 3 months. Patients randomized to Parnaparin showed a significant decrease in the fibrinogen level (P = .035) and an improvement in both the time to 1-mm ST segment depression (P = .008) and the peak ST segment depression (P = .015). The Canadian Cardiovascular Society class for angina pectoris was also improved by Parnaparin (P = .016). Parnaparin did not affect ADP and collagen-induced platelet aggregation, whereas thrombin-induced aggregation was reduced (P = .0001). The bleeding time was slightly prolonged, but this was not associated with any significant bleeding. CONCLUSIONS Patients with stable angina pectoris may be treated with Parnaparin in addition to aspirin and conventional antianginal medication. Side effects are negligible, and compliance is excellent.