This study aimed to analyze the short- and long-term prognosis of patients subjected to aortic valve replacement using a mechanical prosthesis. For quality control purposes, we compared the incidence of observed events to the incidence of events predicted by validated scores for mortality and other short- and long-term complications. Furthermore, the predictive performance of these validated scores regarding 1-year mortality was assessed.
Material and methods
The study was based on a consecutive series of 690 patients (mean age 63 years) who underwent aortic valve replacement with mechanical prosthesis from January 1998 to December 2012. The implantation was associated with coronary artery bypass in 214 patients (31.0%), BENTALL procedure in 80 (11.6%), intervention on the thoracic aorta (tube/plasty) in 14 (2.0%), septal myomectomy in 23 (3.3%), carotid endarterectomy in 15 (2.2%), MAZE procedure in 9 (1.3%), and patent foramen ovale closure in 10 (1.4%). Short- and long-term outcomes were retrospectively analyzed and compared with predictive scores like the logistic EuroSCORE (I), 2010 EuroSCORE (II), and STS score (STS).
The observed operative mortality was 4.3% as compared to predicted mortality rates of 6.42% and 3.61% using the EuroSCORE I and II, respectively. Postoperative complications were the following: myocardial infarction in 17 patients (2.5%), stroke in 12 (1.7%), dialysis in 25 (3.6%), pacemaker implantation in 37 (5.4%), and atrial fibrillation in 279 (40.4%). Long-term complications over a mean follow-up duration of 3.4 years comprised 39 bleeding events (5.7%), 24 strokes (3.5%), 8 reoperations for sternal wound infection (1.2%), 6 reinterventions (0.9%), 4 valvular dysfunctions (0.6%), 2 bacterial endocarditis (0.3%), and 2 peripheral embolisms (0.3%). The observed procedural complication rates were in line with the rates predicted by the STS score, except for prolonged ventilation (observed: 4.1%; predicted: 10.92%) and reoperation (observed: 4.2%; predicted: 7.41%). Using the Kaplan-Meier method, the estimated 5- and 10-year overall survival rates were 84% and 60%, respectively. Regarding 1-year mortality prediction, the EuroSCORE I offered the best ROC curve, with an AUC of 0.77.
The observed mortality rate was similar to the values predicted by the EuroSCOREs I and II. Procedural complication rates were in accordance with the rates predicted by the STS score, except for prolonged ventilation and reoperation where much lower event rates were observed in our series.
Service de cardiologie et chirurgie cardiovasculaire, CHU UCL Namur