Comparative efficacy of once daily parnaparin and unfractionated heparin in unstable angina pectoris: PRIME CARE study.

ABSTRACT

BACKGROUND: This study sought to compare the efficacy of low molecular weight heparin, parnaparin and unfractionated heparin in Indian patients presenting with unstable angina pectoris. METHODS AND RESULTS: In this randomized, prospective and multicentre trial 897 adult patients of both sexes suffering from unstable angina were included. All patients also received oral aspirin and adequate anti-anginal treatment as per their individual needs. Patients in unfractionated heparin group received unfractionated heparin as an intravenous bolus of 5000 IU followed by an intravenous infusion of 800 to 1000 IU/hour for 48 hours, followed by 5000 IU subcutaneously every 6 hours for 5 days. The patients in the other group were treated with parnaparin sodium 6400 IU subcutaneously once daily for 7 days. In the unfractionated heparin group there were 446 patients (310 males, 136 females) with a mean age of 55.9 + 12.27 years and in parnaparin group 451 patients (312 males, 139 females) with a mean age of 57.6 +/- 11.19 years. Both the groups were similar with respect to age and sex (p = 0.89 and 0.068, respectively). The associated cardiovascular risk factors such as diabetes, hypertension, dyslipidemia, previous myocardial infarction and previous coronary artery bypass grafting/percutaneous transluminal coronary angioplasty were similar in both the groups. At the end of 7 days, the primary end points (death, myocardial infarction, or need for myocardial revascularization) were reported in 33 (7.32%) patients in parnaparin group and 51 (11.43%) patients in unfractionated heparin group. This difference was statistically significant. At the end of 30 days, data from 330 patients from parnaparin group and 334 patients from unfractionated heparin group was available for analysis. The cumulative event rate of primary end points at the end of 30 days was reported in 40 (12.12%) patients in parnaparin group and in 73 (21.86%) patients in unfractionated heparin group. This difference was statistically significant. Two episodes of major bleeding each were reported in both the groups. Minor bleeding was reported by 12 (2.66%) patients in parnaparin group and by 115 (25.8%) patients in unfractionated heparin group. This difference was statistically significant. CONCLUSIONS: Addition of parnaparin to the standard treatment of unstable angina significantly reduced the incidence of combined triple end points of death, myocardial infarction and need for revascularization when compared to unfractionated heparin. This benefit was observed at 7 days as well as at 30 days of follow-up. The incidence of minor bleeding was significantly less in patients treated with parnaparin. Thus, once daily administration of parnaparin 6400 IU as a fixed dose is a safe and effective alternative to unfractionated heparin in the treatment of unstable angina.