Background and aims of the study: Despite many significant improvements in cardiac surgical technique, the operative risk for combined aortic and mitral valve surgery remains between 5% and 12%. Identification of high-risk patients will allow surgeons to develop strategies to improve these results.
Methods: The 30-day postoperative mortality and complication rates were analyzed in a group of 206 patients operated on over a 16-year period with cold crystalloid cardioplegia. Thirty-three possible risk factors for death and low output syndrome (LOS) were entered into univariate and multivariate logistic regression analysis.
Results: There were 10 perioperative deaths (4.9%). Major complications occurred in 38 patients (18.4%), 19 with LOS. On univariate analysis, right atrial pressure (RAP) > or = 8 mmHg (p = 0.001), aortic stenosis (p = 0.009) and systolic pulmonary artery pressure > or = 60 mmHg (p = 0.095) were found to be risk factors for death, as were RAP > or = 8 mmHg (p = 0.001), previous heart surgery (p = 0.007), serum creatinine > or = 120 mumol/l (p = 0.03), tricuspid valve disease (p = 0.038) and aortic stenosis (p = 0.09) for LOS. On multivariate analysis, RAP > or = 8 mmHg (p < 0.001) and aortic stenosis (p = 0.002) were identified as independent risk factors for death, as were RAP > or = 8 mmHg (p = 0.001) and previous heart surgery (p = 0.008) for LOS.
Conclusions: Mitro-aortic valve surgery involves complex procedures with substantial mortality and morbidity. The risk factors point toward the importance of operating before the stage of advanced heart failure and toward the key role of better myocardial protection techniques in these compromised hearts with limited reserves.