Outcome of left heart mechanical valve replacement in West African children - A 15-year retrospective study

BACKGROUND The West African sub-region has poor health infrastructure. Mechanical valve replacement in children from such regions raises important postoperative concerns; among these, valve-related morbidity and complications of lifelong anticoagulation are foremost. Little is known about the long-term outcome of mechanical valve replacement in West Africa. We sought to determine the outcome of mechanical valve replacement of the left heart in children from this sub-region. METHOD We conducted a retrospective review of all consecutive left heart valve replacements in children (< 18 years old) from January 1993 - December 2008. The study end-points were mortality, valve-related morbidity, and reoperation. RESULTS One hundred and fourteen patients underwent mitral valve replacement (MVR), aortic valve replacement (AVR) or mitral and aortic valve replacements (MAVR). Their ages ranged from 6-18 years (13.3 ± 3.1 years). All patients were in NYHA class III or IV. Median follow up was 9.1 years. MVR was performed in 91 (79.8%) patients, AVR in 13 (11.4%) and MAVR in 10 (8.8%) patients. Tricuspid valve repair was performed concomitantly in 45 (39.5%) patients. There were 6 (5.3%) early deaths and 6 (5.3%) late deaths. Preoperative left ventricular dysfunction (ejection fraction < 45%) was the most important factor contributing to both early and late mortality. Actuarial survival at 1 and 15 years were 98.1% and 94.0% respectively. Prosthetic valve thrombosis occurred in 5 patients at 0.56% per patient-year. There was 1(0.9%) each of major bleeding event and prosthetic valve endocarditis. Two reoperations were performed at 0.22% per patient-year. Actuarial freedom from reoperation was 99.1% at 1 and 10 years, and 85.1% at 15 years. CONCLUSION Mechanical valve replacement in West African children has excellent outcomes in terms of mortality, valve-related events, and reoperation rate. Preoperative left ventricular dysfunction is the primary determinant of mortality within the first 2 years of valve replacement. The risk of valve-related complications is acceptably low. Anticoagulation is well tolerated with a very low risk of bleeding even in this socioeconomic setting.