Quality control assessment in cardiac surgery: Single center experience in aortic valve replacement by mechanical prosthesis

Abstract

Objectives For quality control purposes, we aimed to compare the observed event rate to the event rate according validated scores for mortality and in-hospital complications. Material and Methods A consecutive series of 690 patients (average age 63 years) undergoing an aortic valve replacement by a mechanical prosthesis from January 1998 to December 2012. The implantation was associated with coronary artery bypass grafting in 214 patients (31,0%), BENTALL operation in 80 patients (11,6%), Buse / plasty in 14 patients (2,0%), septal myomectomy in 23 patients (3,3%), carotid endarterectomy in 15 patients (2,2%), MAZE in 9 patients (1,3%) and closure of a patent foramen ovale for 10 patients (1,4%). The short and long term outcomes were retrospectively analyzed and compared with predictive scores (the logistic EuroSCORE, 2010 EuroSCORE and STS). Results Operative mortality observed was 4,3% versus 6,42% and 3,61% predicted by the log and 2010 EuroSCORE respectively. Postoperative complications were: myocardial infarction in 17 patients (2,5%), stroke in 12 patients (1,7%), dialysis in 25 patients (3,6%), implantation of a pacemaker in 37 patients (5,4%) and AF in 279 patients (40,4%). The observed rates of procedural complications were in accordance with the rates predicted by the STS score, except for prolonged ventilation (4,1% predicted vs 10,9%) and reoperation (4,2% predicted vs 7,4%, p<0.01). The overall survival rate (Kaplan-Meier) at 5 years was 84%. For the prediction of 1-year mortality, the log EuroSCORE offered the best ROC curve with an AUC of 0,77. Conclusions The observed mortality rate is similar to the values predicted by the log and 2010 EuroSCORE. The observed rates of procedural complications 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.