Comparison of clinical characteristics and long-term prognosis between isolated mitral regurgitation and isolated tricuspid regurgitation in patients with atrial fibrillation

Introduction

With the growing understanding and clinical emphasis on tricuspid regurgitation (TR), the management of isolated TR has become increasingly proactive. Atrial fibrillation (AF) is a major contributor to isolated TR; however, the mechanisms by which AF predisposes to isolated mitral regurgitation (MR) versus isolated TR remain unclear. Furthermore, comparative data on the long-term prognosis of AF-associated isolated MR and isolated TR are limited. This study sought to delineate the clinical characteristics and outcomes of these two conditions.

Method

We performed a single-center retrospective cohort study in Taiwan utilizing the integrated medical database of a tertiary medical center, which compiles electronic health records and mortality data from the Taiwan Death Registry. Institutional Review Board approval was obtained.

Patients with atrial fibrillation, who underwent echocardiography between June 1, 2010, and December 31, 2022 (index date), were screened for three mutually exclusive groups: (1) isolated TR: TR ≥2+ with MR <2+, (2) isolated MR: MR ≥2+ with TR <2+, and (3) control: MR <2+ and TR <2+.

Exclusion criteria included prior valvular surgery, aortic dissection, rheumatic heart disease, infective endocarditis, cardiac surgery, and dilated cardiomyopathy. The primary endpoint was all-cause mortality.

Result

A total of 3,622 patients were included: 295 with isolated MR, 846 with isolated TR, and 2,481 controls. Mean age was 71.2 years, and 64.5% were male.

•Isolated MR patients exhibited higher prevalence of coronary artery disease, prior stroke, as well as higher hemoglobin, and NT-proBNP. They more frequently received amiodarone, digoxin, and beta-blockers, and reported alcohol consumption.

•Isolated TR patients were older (mean 74.0 years), more often female (43%), and demonstrated higher rates of cirrhosis, chronic obstructive pulmonary disease, malignancy, and cardiac implantable electronic device implantation. They more frequently received calcium channel blockers.

•Both regurgitation groups had greater use of proton pump inhibitors and diuretics compared with controls.

Five-year all-cause mortality was significantly higher in both regurgitation groups: 42.0% in isolated MR and 44.2% in isolated TR, compared with 29.7% in controls. Mortality did not differ significantly between MR and TR groups (p=0.125).

Conclusion

In patients with AF, isolated TR was associated with adverse prognosis comparable to isolated MR. These findings underscore the need for heightened clinical attention, longitudinal surveillance, and tailored therapeutic strategies for isolated TR.Kaplan-Meier (KM) survival curveCharacteristic profiles