Incidence, outcome and prediction of early clinical events following percutaneous transluminal coronary angioplasty. A comparison between treatment with reviparin and unfractionated heparin/placebo (results of a substudy of the REDUCE trial).

BACKGROUND

Unfractionated heparin and its low molecular weight fragments possess antithrombotic properties, properties that are routinely exploited in coronary angioplasty (PTCA).

OBJECTIVES

In the setting of the REDUCE trial, a randomized, double-blind, multicentre trial, the occurrence of acute or early clinical events was compared in patients treated with either unfractionated heparin/placebo or low molecular weight heparin (reviparin).

METHODS AND RESULTS

Six hundred and twelve patients with native coronary artery obstructions randomized between unfractionated heparin/placebo and reviparin, were analysed. Baseline characteristics were similar in both groups. Using the intention-to-treat analysis, major acute or early events (myocardial infarction, re-PTCA, bypass surgery, death) occurred in 42 patients (7%), 29 in the control group and 13 in the treatment group (P=0.027). In order to develop a predictive model for the risk of early events following coronary balloon angioplasty, clinical as well as pre-PTCA and procedural characteristics were analysed. Thrombi at the treated lesion site (P=0.02), dissection (P<0.001), lesion type B2 and C according to the NHLBI classification (P<0.001), diameter stenosis >50% post-PTCA (P<0.001), and length of stenosis >20mm (P=0.005) were significantly associated with the occurrence of acute events. By multiple logistic regression analysis, in which these variables and the treatment regimen were entered, dissection (P=0.042), diameter stenosis >50% (P<0.028) and lesion type B2 and C (P=0.017) were found to be independently predictive of early adverse events. Bleeding complications were similar in the two treatment groups.

CONCLUSIONS

Reviparin, given in a very early stage of vascular injury, compares favourably with unfractionated heparin/placebo, by reducing abrupt closure and acute-phase adverse outcome following PTCA. With respect to the evaluated risk factors for acute events, the positive effect of reviparin on early adverse outcome after PTCA may be due to improved antithrombotic properties as compared to unfractionated heparin.