Compared with ventricular functional mitral regurgitation (VFMR), atrial functional mitral regurgitation (AFMR) is more common in elderly patients, female patients, and patients with atrial fibrillation, is less often accompanied by heart failure symptoms, and is associated with lower all-cause mortality and lower cardiovascular death or heart failure hospitalization.
Among 269 patients with significant functional mitral regurgitation, 22.7% had AFMR and 77.3% had VFMR.
AFMR patients differed clinically from VFMR patients: they were more often female and older, had more atrial fibrillation, and had less coronary artery disease.
AFMR patients less often had heart failure symptoms and less often had previously visited cardiovascular departments.
On echocardiography, the AFMR group had larger left atrial anteroposterior, right atrial transverse, and right ventricular transverse diameters, a higher LVEF, and more frequent moderate or greater tricuspid regurgitation than the VFMR group.
All-cause mortality was lower in the AFMR group than in the VFMR group.
The composite of cardiac death and heart failure hospitalization was lower in the AFMR group.
Kaplan-Meier analysis showed higher cumulative event-free survival in the AFMR group than in the VFMR group.
In multivariate Cox regression, age, cerebrovascular disease, moderate or greater tricuspid regurgitation, and AFMR were independent predictors of all-cause mortality in functional MR, with AFMR protective.
This study looked at 269 hospitalized patients in China who had significant mitral valve leakage that was not caused by a structural problem in the valve itself. In some, the leak was driven by an enlarged left atrium (atrial functional mitral regurgitation, AFMR; 61 patients). In most, it was driven by problems in the left ventricle (ventricular functional mitral regurgitation, VFMR; 208 patients). Patients were followed for a median of about 2 years. Patients with AFMR tended to be older, were more often women, and more often had atrial fibrillation. They were less likely to have coronary artery disease or heart failure symptoms. Their left ventricular pumping function (LVEF) was higher. They died less often than VFMR patients (21.3% vs. 38.9%) and less often had cardiac death or heart failure hospitalization (24.6% vs. 42.8%). After accounting for other factors, AFMR was linked to a lower risk of death (HR 0.341). Older age, prior cerebrovascular disease, and moderate or greater tricuspid valve leakage were linked to higher risk of death. This research suggests that AFMR is a distinct form of functional mitral regurgitation with a better outlook than the ventricular type. It was a single-hospital retrospective study, so it shows associations rather than proving cause, and the findings may not apply to all populations.
Wang P, Lin M, Wei Y, Liu Y, Zheng S, Wang J, et al.. (2026). [Clinical characteristics and prognosis of patients with atrial functional mitral regurgitation].. Zhonghua xin xue guan bing za zhi. https://doi.org/10.3760/cma.j.cn112148-20260901-00549