[Coumarin combined with low-dose acetylsalicylic acid in the prevention of thromboembolic complications in patients with mitral and aortic valve prostheses].
Authors studied the effect of coumarin, and its combination with low-dose (125 mg/day) acetylsalicylic acid in the prevention of thromboembolic complication during a 10-year period (average 4.7 years) in a randomized trial of 296 patients aged 18-60 year with tilting disc type prosthetic heart valve (159 mitral and 137 aortic) in sinus rhythm. In the group treated with coumarin (152 patients, 743.4 patient-years) 4 cases (2 of them fatal) of valve thrombosis, 12 cases of peripheral embolism and 9 cases (3 intracranial, 3 among them fatal) of major bleeding were observed; in the group treated with coumarin plus acetylsalicylic acid (144 patients, 638.7 patient-years) 2 cases (1 of them fatal) of valve thrombosis, 4 cases of peripheral embolism and 14 cases (3 of them fatal) of major bleeding were observed. In the case of valve thromboses the difference between the two groups was non-significant but still clinically remarkable; peripheral embolism occurred in significantly higher number (p < 0.05). There was no statistically significant difference of bleeding complications between the two groups. The results suggest that the combination of coumarin plus low-dose acetylsalicylic acid is more effective in the prevention of thromboembolic complications in patients with mitral and aortic prosthetic heart valve than coumarin alone; the danger of bleeding complications seems to be acceptable with adequate control.