New atrioventricular valve regurgitation emerges after transcatheter aortic valve replacement

The rise of transcatheter aortic valve replacement, or TAVR, has transformed the treatment of severe aortic stenosis, offering a minimally invasive alternative to open-heart surgery for patients who were once considered inoperable or too frail to survive a sternotomy. Each year, hundreds of thousands of people worldwide receive a replacement aortic valve delivered through a catheter, most often via the femoral artery, and the procedure’s success rates continue to improve as device technology and operator experience mature. Yet a new study from researchers at LMU University Hospital in Munich suggests that fixing the aortic valve does not always fix the heart. Their findings, published in Clinical Research in Cardiology, reveal that roughly one in nine patients who enter the catheterization laboratory with clean mitral and tricuspid valves emerge with clinically significant leakage in those very valves within the follow-up period—and that this new-onset regurgitation is associated with a striking increase in mortality.

Aortic stenosis is the most common valve disease requiring intervention in the aging populations of Europe and North America. As calcium deposits stiffen the aortic valve leaflets, the left ventricle must generate ever higher pressures to push blood through the narrowed orifice. Over time, this chronic pressure overload thickens the ventricular wall, impairs relaxation, and can set off a cascade of downstream consequences, including rising pressures in the left atrium, the pulmonary vasculature, and eventually the right side of the heart. Conventional wisdom has long held that when leakage of the mitral or tricuspid valves—so-called atrioventricular valve regurgitation—appears in patients with severe aortic stenosis, it is simply a late-stage manifestation of this domino effect: a stretched left ventricle distorts the mitral apparatus, pulmonary hypertension burdens the right ventricle, and the tricuspid annulus dilates in response.

The Munich team, led by first author Kornelia Löw and senior author Simon Deseive, challenged that assumption. If atrioventricular valve regurgitation were purely a marker of advanced heart damage, one might expect it to be present before treatment, and one might further expect the relief of the aortic obstruction to halt or even reverse its progression. Instead, the researchers suspected that in many patients, regurgitation of the mitral or tricuspid valve develops as an independent disease entity—driven by its own mechanisms and carrying its own prognostic weight, even after the aortic valve has been successfully replaced.

To test this hypothesis, the investigators assembled a cohort of 1,034 patients with severe aortic stenosis who underwent TAVR at their center between January 2016 and December 2021 and who had no relevant regurgitation of the mitral or tricuspid valves before the procedure. This deliberately “clean baseline” design is what sets the study apart. Previous work on multivalvular disease in TAVR patients has largely focused on those who already had combined lesions at the time of intervention, making it impossible to distinguish pre-existing disease from disease that emerges afterward. By excluding patients with any baseline atrioventricular valve regurgitation, the Munich group could observe, in effect, the natural history of valves left to their own devices once the aortic bottleneck was removed.

The results were unambiguous. During follow-up, 114 patients—11.0 percent of the cohort—developed new mitral and/or tricuspid regurgitation of at least grade 2 severity, the threshold at which leakage becomes clinically relevant. The pattern of involvement was revealing: 75 patients developed isolated mitral regurgitation, 22 developed isolated tricuspid regurgitation, and 17 experienced the combined form. Mitral regurgitation thus dominated the new-onset spectrum, accounting for the majority of cases whether alone or in combination. Echocardiographic assessments, performed according to established guidelines for chamber quantification and valvular regurgitation grading, allowed the team to track valve function over time and to classify severity consistently across the cohort.

The clinical consequences were severe. Patients who developed new atrioventricular valve regurgitation after TAVR had significantly higher three-year all-cause mortality compared with those whose mitral and tricuspid valves remained competent, with a hazard ratio of 1.87 (95 percent confidence interval 1.34–2.61, p < 0.01). The signal was even stronger for cardiovascular mortality, which was significantly elevated in the regurgitation group at p < 0.001. In other words, nearly nine out of ten patients in this cohort avoided new valve leakage after their aortic valve replacement—but for the minority who did not, the development of regurgitation essentially halved the expected survival benefit of the procedure over the following three years.

What might explain this counterintuitive phenomenon? The authors point to several plausible mechanisms. The relief of aortic obstruction changes the loading conditions of the left ventricle abruptly: afterload falls, and the ventricle begins to remodel, sometimes in ways that alter the geometry of the mitral annulus and the tethering forces acting on the leaflets. In some patients, underlying annular dilatation—particularly of the tricuspid annulus—may predate the TAVR procedure but remain hemodynamically silent until subtle shifts in ventricular size, pulmonary pressures, or rhythm unmask it. Atrial fibrillation, which is common in this elderly population and often develops or accelerates after valve intervention, can rapidly enlarge the atria and pull the valve leaflets apart, converting a functionally normal valve into a leaking one. The study’s findings on right ventricular to pulmonary artery coupling, tricuspid annular plane systolic excursion, and stroke volume index—parameters tracked in the analysis—suggest that both left- and right-sided hemodynamics contribute to which patients tip into regurgitation.

The clinical implications are considerable. TAVR volumes are expanding globally, and indications continue to broaden toward younger and lower-risk patients, guided in part by staging classifications of aortic stenosis that incorporate the extent of cardiac damage beyond the valve itself. If more than a tenth of patients without baseline atrioventricular valve disease can be expected to develop significant regurgitation after TAVR—and if that regurgitation carries a nearly twofold increase in mortality—then structured surveillance of the mitral and tricuspid valves after the procedure becomes not an academic nicety but a survival issue. Serial echocardiography, which is already routine in most TAVR follow-up programs, may need to place greater emphasis on quantitative assessment of the atrioventricular valves, and emerging transcatheter therapies for mitral and tricuspid regurgitation may find a new and growing patient population among TAVR survivors.

The study also reframes the interpretation of prior research. Earlier investigations from the same Munich group showed that tricuspid annular dilatation measured by computed tomography predicts both the persistence of tricuspid regurgitation after TAVR and increased two-year mortality, and that the underlying cause of mitral regurgitation influences outcomes after transcatheter aortic valve implantation. Meta-analytic evidence has likewise indicated that improvement of tricuspid regurgitation after TAVR is associated with better survival. Taken together with the new findings, a consistent picture emerges: the atrioventricular valves are not passive bystanders in aortic stenosis but active participants in the disease trajectory, capable of deteriorating independently of the aortic valve and of dragging prognosis down with them.

Several caveats temper the conclusions. The analysis comes from a single high-volume center, and although the cohort of more than a thousand patients is large by the standards of valve research, referral patterns and procedural techniques at LMU Munich may not generalize everywhere. Regurgitation grading by echocardiography remains inherently observer-dependent, particularly for the tricuspid valve, for which no universally accepted quantitative standard exists—a limitation the field has acknowledged in calls for new grading schemes. And as an observational study, the analysis demonstrates association, not causation: new-onset regurgitation may itself be a marker of adverse ventricular remodeling rather than a direct killer. Even so, the strength and consistency of the mortality signal, maintained across both all-cause and cardiovascular endpoints, argue that this is more than statistical noise.

For patients and clinicians alike, the message is one of vigilant follow-up rather than alarm. A successful TAVR remains one of the most effective interventions in modern cardiology, capable of relieving debilitating symptoms and extending life in a population with few alternatives. But the heart is an integrated system, and correcting one valve does not guarantee the health of its neighbors. The Munich study suggests that the mitral and tricuspid valves deserve the same attentive, quantitative scrutiny after aortic valve replacement that the aortic valve itself receives—because in a meaningful minority of patients, the story of valve disease does not end in the catheterization laboratory. It continues, quietly and sometimes lethally, in the valves downstream.