Thromboembolism, major bleeding and mortality in patients with mechanical heart valves- a population-based cohort study

IntroductionLow incidences of thromboembolism (TE) and bleeding in patients with mechanical heart valves (MHV) have previously been reported. This study assesses the incidence of and clinical risk factors predicting TE, major bleeding and mortality in a clinical setting.Methods and resultsAll 546 patients undergoing anticoagulation treatment due to MHV replacement at hospitals in Malmö and Sundsvall in Sweden were monitored during 2008-2011 and the incidence of TE, major bleeding and mortality was prospectively followed. There were 398, 122 and 26 patients in the aortic group (AVR), mitral (MVR) group and the combined aortic/mitral valve group respectively. The incidence of TE was 1.8 and 2.2 per 100 patient-years in the AVR group MVR group respectively. The corresponding incidences of bleeding were 4.4 and 4.6, respectively. Independent predictor of thromboembolism was vascular disease (Odds ratio {OR}: 4.2; 95% CI: 1.0-17.4). Predictor of bleeding was previous bleeding (OR: 2.7; 95% CI: 1.4-5.3). Independent predictors of mortality was age (Hazard ratio {HR}: 1.03; 95% CI: 1.00-1.05), hypertension (HR: 2.4; 95% CI: 1.3-4.5), diabetes (HR: 2.4; 95% CI: 1.3-4.3) and alcohol overconsumption (HR: 5.2; 95% CI: 1.7-15.9). Standardized mortality/morbidity ratio for mortality and AMI was 0.99 (95% CI: 0.8-1.2) and 0.87 (95% CI: 0.5-1.2) respectively.ConclusionThe incidence of TE and major bleeding in this unselected clinical population exceeds that of previously reported retrospective and randomized trials. Despite this, mortality is equal to that of the general population.