Characteristics, Determinants, and Prognostic Impact of Severe Tricuspid Regurgitation in Patients with Atrial Functional Mitral Regurgitation: Insights from the REVEAL-AFMR Registry

AIMS: Tricuspid regurgitation (TR) is often seen in patients with atrial functional mitral regurgitation (AFMR). The aim of this study was to investigate the characteristics, determinants, and prognostic impact of severe TR coexisting with AFMR. METHODS AND RESULTS: In 26 facilities in Japan, patients with significant AFMR defined with moderate or severe functional mitral regurgitation with dilated left atrium and preserved left ventricular function were enrolled. The primary endpoint was a composite of heart failure hospitalization and all-cause mortality. The secondary endpoint was all-cause mortality. In 792 patients with AFMR (mean age 77 ± 9 years, 55% female), the prevalence of severe TR was 14.9% (n = 118) overall, and 34.6% in severe AFMR. Patients with severe TR were older, mostly with atrial fibrillation, and had more severe heart failure symptoms and more advanced left atrial and right heart remodelling than those with non-severe TR. Age >75 years, permanent atrial fibrillation, chronic obstructive pulmonary disease, and higher right atrial pressure appeared as independent determinants of severe TR. Severe TR was associated with both the primary and secondary endpoints after adjusted for covariates including the severity of AFMR (adjusted hazard ratio 1.65 [95% confidence interval 1.09-2.47], p = 0.017 and 1.80 [1.06-3.06], p = 0.029 for the primary and secondary endpoints, respectively). Atrial and ventricular functional TR accounted for 41% and 59% of significant TR. Despite more advanced right heart remodelling in ventricular TR, these groups showed similar prognosis. CONCLUSIONS: Severe TR coexisting with AFMR was common and was associated with increased event rates. Further study is warranted to establish therapeutic strategies.