[Ineffectiveness of preventive low-dose heparin administration in pacemaker implantation].

In a prospective controlled trial the prophylactic efficacy of low-dose heparin was investigated in 41 patients undergoing transvenous pacemaker implantation. 20 of these patients were randomly selected to receive heparin (2 x 5000 units subcutaneously/day, first dose 1--2 hours before surgery). 21 did not receive prophylaxis and acted as a control group. The frequency of deep-vein thrombosis, determined by the 125I-fibrinogen test, was 14.3% in the control group and 25% in the treatment group. Independently of heparin administration, the incidence of thrombosis was significantly higher among the 20 patients with multiple factors known to predispose to deep venous thrombosis (39% versus 4.3%; p < 0.05). It is concluded that in patients undergoing transvernous pacemaker implantation low-dose heparin does not reduce the frequency of 125I-fibrinogen thrombosis. Conventional anticoagulation of patients selected on the grounds of risk factors is probably more appropriate.