Multivalvular heart disease represents one of the most challenging scenarios for the contemporary Heart Team. The most frequent left-sided valve combination is aortic stenosis with concomitant mitral valve disease, present in approximately 10% of patients with severe aortic stenosis. The haemodynamic interaction between both valve lesions is particularly harmful: mitral stenosis limits forward flow and may be unmasked or worsened after relief of aortic obstruction, because the increase in forward stroke volume after TAVI raises the transmitral gradient across a calcified valve with a fixed orifice.

Until recently, double valve surgery (DVS), combining surgical aortic valve replacement with mitral valve replacement, was the only feasible treatment for these patients. The expansion of TAVI has opened an important debate: what happens when only the aortic valve is treated and the mitral stenosis is left unaddressed? The scarcity of effective transcatheter mitral devices for degenerative stenosis has made isolated transcatheter aortic valve replacement (I-TAVR) a common solution in patients at high surgical risk. Long-term data on the efficacy and durability of this strategy remain limited, which supports the relevance of the study analysed here.

Tagliafierro et al. performed a retrospective analysis of patients treated at a single centre between 2015 and 2024 for severe aortic stenosis and at least moderate mitral stenosis, divided into two groups: DVS (n = 97) versus I-TAVR (n = 129). Patients eligible for transcatheter mitral repair or replacement and those with an indication for concomitant tricuspid, aortic, or coronary treatment were excluded. Propensity score matching based on 12 clinically relevant covariates yielded 43 comparable pairs. The primary end points were perioperative mortality, stroke, and heart failure readmissions; secondary end points included the same outcomes at 1, 3, and 5 years and postoperative valve function. Recurrent readmissions were analysed using the Wei-Lin-Weissfeld marginal Cox model.

Before matching, patients undergoing I-TAVR were significantly older (median age, 80 vs 73 years; p < .001) and had a higher comorbidity burden, whereas chronic obstructive pulmonary disease, heart failure, arrhythmias, and previous cardiac surgery were more frequent in the DVS group. After matching, both groups were balanced across all variables. The main finding was that, despite the greater invasiveness of surgery, there were no significant differences in perioperative mortality or stroke between the two strategies. However, the cumulative rate of heart failure readmissions was significantly higher in patients treated with I-TAVR throughout follow-up (p = .006 in the matched population). In the matched cohort, readmission rates at 1, 3, and 5 years were 0.0%, 0.0%, and 6.0% in the DVS group versus 7.2%, 29.6%, and 52.2% in the I-TAVR group. In multivariable analysis, I-TAVR was an independent predictor of heart failure readmission (p = .042). The authors conclude that, in patients with severe aortic stenosis and at least moderate mitral stenosis, treating only the aortic valve with TAVI is an independent predictor of higher heart failure readmission rates, and that DVS should be considered the preferred strategy in patients with an acceptable surgical risk.

COMMENTARY:

This study addresses an everyday and uncomfortable clinical reality for the Heart Team: the elderly, high-risk surgical patient with double valve stenosis and no complete transcatheter solution. The most relevant message is not simply that DVS is superior to I-TAVR, which may be intuitively expected when one valve lesion is left untreated, but that even patients with moderate mitral stenosis at the time of TAVI may progress to haemodynamically significant obstruction during follow-up. This has a clear pathophysiological explanation: once the aortic obstruction is relieved, forward stroke volume increases, and when this higher flow crosses a calcified mitral valve with a fixed orifice, the transmitral gradient rises. The finding that heart failure readmission rates at 5 years exceed 50% after I-TAVR compared with 6% after DVS should give pause to those who regard I-TAVR as a durable solution.

The debate on how to manage multivalvular disease is rapidly evolving. In 2025, the Heart Valve Collaboratory published a consensus document in JACC (Zaid et al.) summarizing the main unresolved questions regarding the combination of aortic stenosis and concomitant mitral valve disease, emphasizing the lack of evidence-based recommendations on the optimal timing and sequencing of interventions. One proposed approach is a staged strategy: TAVI followed by transcatheter edge-to-edge repair (TEER) or transcatheter mitral valve replacement (TMVR) at a later stage, compared with simultaneous or “one-stop” treatment. This staged strategy is attractive in inoperable patients, but in degenerative mitral stenosis—the model addressed in the present study—it faces a fundamental limitation: the absence of widely available transcatheter mitral devices for this type of disease, with current use remaining limited and off-label.

From the surgeon’s perspective, the study also raises another interesting point: the potential role of hybrid strategies. In selected intermediate-to-high-risk patients, an attractive option could be to perform TAVI first to treat the aortic valve without cardiopulmonary bypass, reserving mitral surgery for a second stage with substantially shorter ischaemic times. Although evidence for this strategy remains anecdotal, the growing development of transcatheter devices and the accumulated experience of valve teams may make this type of sequential approach feasible for patients with elevated surgical risk in whom mitral stenosis cannot be definitively treated by transcatheter means. In the study by Tagliafierro et al., the complete absence of differences in perioperative mortality and stroke between groups, despite the fact that DVS involves cardiopulmonary bypass, cardiac arrest, and intervention on two valves, reinforces the idea that, in expert centres and with careful patient selection, double valve surgery remains a procedure with acceptable perioperative safety.

Nevertheless, the study has the inherent limitations of any single-centre retrospective analysis. After matching, the sample size was reduced to 43 pairs, limiting statistical power. Detailed aetiological classification of mitral stenosis was not systematically available, and the median follow-up was less than 2 years in the matched cohorts; therefore, 5-year estimates should be interpreted with caution. Finally, the absence of commercially available TMVR devices during the study period means that these results may change in the future if new devices prove effective in this setting. Despite these limitations, the data provided by this study represent a solid starting point for the randomized, multicentre studies that are needed in this highly complex population.

REFERENCE: 

Tagliafierro M, Kanade R, Kirilina D, Mitchell W, Ott N, Kitada Y et al. Double Valve Surgery Reduces Heart Failure Readmissions Compared to Isolated Transcatheter Aortic Valve Replacement in High-Grade Multivalvular Stenosis. Eur J Cardiothorac Surg. 2026;68(3):ezag102. doi: 10.1093/ejcts/ezag102