Natural History of Atrial versus Ventricular Secondary Tricuspid Regurgitation: Insights from the Bronx-Valve Registry.

Atrial secondary tricuspid regurgitation (A-STR) and ventricular secondary tricuspid regurgitation (V-STR) have unique physiological and anatomical differences, but long-term outcomes based on TR etiology remain poorly understood. This study aimed to assess the characteristics and outcomes of severe A-S and V-STR. Adults diagnosed with severe secondary TR between January 2017 and December 2019 in a quaternary-care health system were included. TR was classified into left-sided V-STR (left-sided cardiac diseases), right-sided V-STR (pulmonary/vascular diseases), and A-STR (atrial pathology). The primary endpoint was to assess survival at follow-up. Incidence of heart failure (HF) hospitalizations and cardiovascular mortality were secondary endpoints. Among 1,037 patients with STR, 125 (12%) had A-STR, 737 (71.1%) left-sided V-STR, and 175 (16.9%) right-sided V-STR. Survival was significantly higher for A-STR compared to left and right-sided V-STR (46.9% vs. 30.6% vs. 22.0%, log-rank p=0.042, respectively). At multivariable Cox regression analysis, left and right-sided V-STR were independently associated with worse survival compared to A-STR (HR: 1.439, p=0.039 and HR: 1.816, p=0.001, respectively). A-STR patients also experienced lower rates of HF hospitalizations and cardiovascular mortality. A-STR was associated with better survival and fewer HF hospitalizations than V-STR groups, with right-sided V-STR being the strongest independent predictor of all-cause mortality.