Aortic prosthesis-patient mismatch strongly affects early results of double valve replacement

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.

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.

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) < or = 0.85 cm2/m2) 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.

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.