The effect of antiaggregating drugs on the patency of grafts in the arterial system

Meta-analysis of multi-arm trials using empirical logistic transform

Meta-analysis of multi-arm trials has been used increasingly in recent years. The aim of meta-analysis for multi-arm trials is to combine evidence from all possible similar studies. In this paper we propose normal approximation models by using empirical logistic transform to compare different treatments in multi-arm trials, allowing studies of both direct and indirect comparisons. Additionally, a hierarchical structure is introduced in the models to address the problem of heterogeneity among different studies. The proposed models are performed using the data from 31 randomized clinical trials (RCTs) which determine the efficacy of antiplatelet therapy in maintaining vascular patency.

Improved patency of the aortocoronary bypass by antithrombotic drugs

A total of 1,017 bypasses were performed in 442 patients operated on in our department between January 1, 1981, and May 30, 1984. The overall early postoperative graft patency rate in our hospital was 91.5%. About 10% of the grafts had a flow rate of 40 ml/min or less, measured intraoperatively, and most occluded grafts were in this group. This article presents our experience with low-flow bypasses whose patency rates we attempted to improve. Patients with aortocoronary bypasses (ACBs) and with intraoperative blood flow rates of 40 ml/min or less were divided into two groups. The treated group was given, from day 0 onward, a 500-mg dose of acetylsalicylic acid twice a day and a 75-mg dose of dipyridamole three times a day. The control group was given no medication. Control coronary arteriography was performed at one month and then at one year after the operation. One month postoperatively, 34 out of 41 ACBs in the treated group were patent; in the control group, only 17 out of 37 were patent (p less than .001). One year after the operation, 24 out of 37 ACBs in the treated group were patent, whereas in the control group only 8 out of 38 ACBs were patent (p less than .001). We conclude that antiplatelet drugs have a beneficial effect on the short-term and long-term patency of ACBs.