1LMU Klinikum der Universität München Medizinische Klinik und Poliklinik I München, Deutschland; 2LMU Klinikum der Universität München Herzchirurgische Klinik und Poliklinik München, Deutschland
Background
Mitral valve regurgitation (MR) is commonly found in patients with aortic stenosis (AS) and more than mild MR is associated with increased mortality. Etiology of MR can be structural and functional. The latter may be due to atrial (afMR) or ventricular (vfMR) dilatation.
Aortic stenoses are split into different “flow groups”, such as classical and paradoxical low-flow low-gradient (LFLG) AS, which are linked to a worse prognosis than high-gradient (HG) AS.
The aim of this study was to investigate the prognostic impact of the different MR subtypes in different AS flow groups.
Methods
Echocardiography images of all consecutive patients undergoing transcather aortic valve replacement (TAVI) for severe AS (aortic valve area ≤1.0 cm2) at our center between 2013 and 2021 were evaluated. Patients were classified into groups according to severity and type of MR and flow type of AS (HG: dPmean ≥40 mmHg; classical LFLG: dPmean <40 mmHg and left-ventricular ejection fraction (LVEF) <50%; paradoxical LFLG: dPmean <40 mmHg, LVEF ≥50% and stroke volume index ≤35 ml/m2 body surface area). Patients with prior aortic or mitral valve interventions were excluded from the analysis.
Results
Moderate MR or higher was found in 23% (617 patients) of the entire cohort and varied significantly between flow groups: 15.3% of HG AS patients (236 patients), 34.5% of classical LFLG AS patients (214 patients), and 18.3% of paradoxical LFLG AS patients (105 patients) had more than mild MR (Figure A). MR etiologies differed significantly between AS flow groups (Figure B), with the majority of classical LFLG AS patients having vfMR (82%) while most paradoxical LFLG patients had either primary MR (43%) or afMR (41%).
Baseline characteristics differed in many aspects between MR etiologies as well as AS flow groups. Patients with vfMR were mostly male (62% vs. primary: 33%, vs. afMR: 43%, p<0.01) and had numerically higher rates of coronary artery disease and prior myocadial infarction. Atrial fibrillation was found in 26% (primary), 39% (afMR), and 34% (vfMR), respectively (p=0.03).
In the overall population, more than mild MR was associated with a 2-year all-cause mortality of 31.5% [95% confidence interval, 27.6-35.1%] compared to 20.3% [18.8-21.9%] with MR <2 (hazard ratio 1.7 [1.4-2.0], p<0.01). A significant difference in 2-year all-cause mortality was seen also among HG AS (HR 1.6 [1.2-2.1]) and paradoxical LFLG AS patients (HR 1.8 [1.2-2.5], but not among classical LFLG AS patients (HR 1.2 [0.9-1.6]).
Valve Academic Research Consortium 3 (VARC-3) composite endpoints technical failure and device failure occurred at statistically similar rates between the groups.
Conclusion
Concomitant valvular disease is an important finding in aortic stenosis patients and requires further evaluation. While mortality is generally increased in LFLG AS patients, more than mild MR is associated with an additional risk especially among paradoxical LFLG patients. These patients require more concise follow-up examinations.