Aortic Prosthesis-Patient Mismatch Strongly Affects Early Results of Double Valve Replacement

Background and aim of the study: The aim of this retrospective single-center study was to assess the authors' results in mitral-aortic double valve replacement (DVR), with attention focused on the risk factors of in-hospital mortality (HM). As the initial results showed a strong relationship between HM and aortic prosthesis-patient mismatch (PPM), this led to an assessment of the impact of PPM on the early results of DVR. Methods: Data from 196 consecutive patients (mean age 60 10 years) who had undergone DVR between January 1996 and December 2011 at the authors' institution were analyzed. A statistical comparison was made of groups defined by the presence/absence of in-hospital death, postoperative complications, and aortic PPM. A logistic regression analysis of the factors associated with HM and their postoperative evolution was also conducted. Results: Surgery was mostly performed on an elective basis (89.3%), using mainly bileaflet mechanical valves (93.9%). The rate of associated coronary bypass (CABG) was 11.2%. Aortic PPM (i.e., an effective orifice area index (EOAI) <= 0.85 cm(2)/m(2)) was noted in 28.1% of patients. HM (6.63%) was significantly related to PPM (p <0.002), greater age (p <0.003), a smaller EOAI (p = 0.005), associated CABG (p <0.008), and a longer aortic cross-clamp time (p <0.03). Patients with aortic PPM had a significantly worse early outcome, with higher overall (p <0.0007) and cardiac (p <0.05) complication rates, a longer intensive care unit stay (p <0.03), and an almost six-fold higher rate of HM (16.4% versus 2.8%; p <0.002). PPM and age as risk factors were included in a predictive model of HM based on logistic regression; a similar model for postoperative complications highlighted PPM, age and cardiopulmonary bypass time as significant risk factors. Conclusion: Aortic PPM greatly affects the postoperative outcome of DVR, as it is related to an increased complication rate and a higher in-hospital mortality. A strategy of avoiding PPM but without taking additional risks might improve the early results of DVR.