Concomitant double valve replacement confirmed its high-risk profile with 10.5% overall in-hospital mortality; double mechanical prostheses demonstrated superior unadjusted survival but significantly higher stroke risk compared to double biological prostheses, while combined prosthesis-patient mismatch was highly prevalent after biological replacement and emerged as a univariable mortality predictor.
Key Findings
Results
Overall in-hospital mortality for concomitant double valve replacement was 10.5%, confirming its high-risk surgical profile.
The study examined ten years of concomitant aortic and mitral valve replacement.
In-hospital mortality differed substantially by prosthesis type: 1.9% for double mechanical prostheses (DMP) vs. 15.2% for double biological prostheses (DBP).
The difference in in-hospital mortality between groups was statistically significant (P = 0.010).
The authors note that 'baseline differences precluded definitive prosthesis-type recommendations after multivariable adjustment.'
Results
Double mechanical prostheses recipients had superior unadjusted 7-year survival compared to double biological prostheses recipients.
7-year survival was 91.3% for DMP vs. 67.7% for DBP (P = 0.003).
This survival advantage was observed on unadjusted analysis.
Baseline differences between groups precluded definitive prosthesis-type recommendations after multivariable adjustment.
The survival difference remained consistent with the in-hospital mortality difference between the two groups.
Results
Double mechanical prostheses recipients had significantly higher stroke rates compared to double biological prostheses recipients.
Stroke rates were 32.2% in DMP recipients vs. 5.0% in DBP recipients (P = 0.023).
Despite the higher stroke risk, there were no significant differences in major bleeding rates at follow-up between the two groups.
Major bleeding rates were 8.2% (DMP) vs. 11.3% (DBP) (P = 0.478).
The markedly higher stroke rate in DMP recipients represents a clinically significant tradeoff against their survival advantage.
Results
Combined prosthesis-patient mismatch (PPM) was highly prevalent after double biological prostheses replacement, occurring in 64.6% of DBP recipients compared to 14.8% of DMP recipients.
The difference in combined PPM prevalence between DBP and DMP was statistically significant (P < 0.001).
The cumulative hemodynamic burden of simultaneous prosthesis-patient mismatch at both aortic and mitral positions had never been systematically assessed prior to this study.
Combined PPM was defined in an exploratory manner, and the authors acknowledge collinearity between cPPM and prosthesis type.
The high prevalence of combined PPM in biological prostheses recipients (64.6%) was identified as a clinically important finding.
Results
Combined prosthesis-patient mismatch emerged as a univariable predictor of mortality with a hazard ratio of 1.97.
The hazard ratio for combined PPM as a mortality predictor was 1.97 (P = 0.046) on univariable analysis.
The authors characterized this finding as 'hypothesis-generating' given the exploratory nature of the combined PPM definition.
Collinearity between cPPM and prosthesis type limited the ability to independently assess the mortality contribution of PPM.
The authors stated that this finding 'warrants validation in larger, ideally multicenter, cohorts.'
This was the first systematic assessment of cumulative hemodynamic burden from simultaneous PPM at both aortic and mitral positions.
Background
Contemporary comparative data on double mechanical versus double biological prostheses for concomitant aortic and mitral valve replacement were identified as scarce prior to this study.
The study addressed a gap in the literature regarding simultaneous aortic and mitral valve replacement outcomes by prosthesis type.
No prior study had systematically assessed the cumulative hemodynamic burden of simultaneous prosthesis-patient mismatch at both aortic and mitral positions.
The study spanned ten years of experience, providing a longitudinal perspective on trends and outcomes.
The authors used multivariable adjustment to attempt to account for baseline differences between DMP and DBP recipients.
What This Means
This research examined ten years of data from patients who underwent simultaneous replacement of both the aortic and mitral heart valves, comparing outcomes between those who received two mechanical valves versus two biological (tissue) valves. The study found that this type of double valve surgery carries substantial risk overall, with about 1 in 10 patients dying in the hospital. However, the type of valve used significantly affected outcomes: patients receiving mechanical valves had much lower in-hospital death rates (about 2% vs. 15%) and better long-term survival at 7 years (91% vs. 68%), but faced a dramatically higher risk of stroke (32% vs. 5%). Bleeding complications at follow-up were similar between the two groups.
The study also introduced and examined a new concept called 'combined prosthesis-patient mismatch' (PPM), which occurs when the replacement valves are too small relative to the patient's body size — at both valve positions simultaneously. This was found to be very common after biological valve replacement (nearly 65% of patients) compared to mechanical valves (about 15%). When analyzed in a straightforward statistical comparison, having combined PPM was associated with nearly double the risk of death. However, because the biological valve group had many more older and higher-risk patients at baseline, it was not possible to cleanly separate the effect of valve type from the effect of mismatch on survival outcomes.
This research suggests that mechanical double valve replacement may offer a survival advantage but comes with a substantially higher stroke burden, presenting a difficult clinical tradeoff. The high prevalence of valve-patient size mismatch in biological valve recipients, and its potential link to worse survival, is a newly highlighted concern that the authors say needs confirmation in larger, multi-center studies before firm clinical conclusions can be drawn. The findings are relevant for surgical planning discussions, particularly regarding valve sizing in patients undergoing this complex procedure.
Azzola Guicciardi N, Lorusso R, Pavan S, Del Forno B, Margonato D, Rizza V, et al.. (2026). Ten years of concomitant aortic and mitral replacement: trends, outcomes and the role of patient-prosthesis mismatch.. Journal of cardiovascular medicine (Hagerstown, Md.). https://doi.org/10.2459/JCM.0000000000001948