The Natural History of Atrial Functional Mitral Regurgitation.

BACKGROUND: The natural history of moderate/severe atrial functional mitral regurgitation (AFMR) is unknown. OBJECTIVES: The authors sought to study the incidence of left ventricular (LV) systolic dysfunction (LVSD), progression or regression of ≥mild-moderate AFMR, and impact on mortality. METHODS: Adults with left atrial (LA) volume index ≥40 mL/m2, ≥mild-moderate AFMR, and follow-up echocardiogram were followed for incident LVSD (ejection fraction <50% and ≥10% lower than baseline), progression of mild-moderate/moderate AFMR to severe, and persistent regression of AFMR to no/trivial. Relation of AFMR progression or regression as time-dependent covariates with all-cause mortality was studied. Incidence of LVSD was compared with patients with no/mild AFMR matched on age, sex, comorbidities and ejection fraction. Patients were followed until mitral intervention, myocardial infarction, or last follow-up. RESULTS: A total of 635 patients (median age 75 years, 51% female, 96% mild-moderate/moderate AFMR, 4% severe AFMR) were included. Over a median 2.2 years (Q1-Q3: 1.0-4.3 years), incidence rates per 100 person-years were 3.2 for LVSD (P = 0.52 vs patients with no/mild AFMR), 1.9 for progression of AFMR, and 3.9 for regression. Female sex and larger LA volume index were independently associated with progression, whereas younger age, male sex, absent atrial fibrillation, and higher LA emptying fraction were independently associated with regression. Neither AFMR progression nor regression was independently associated with mortality. Instead, independent risk factors for mortality included older age, concentric LV geometry, and higher estimated LV filling and pulmonary pressures. CONCLUSIONS: In patients with predominantly mild-moderate/moderate AFMR, regression of MR was more common than progression, but neither was associated with mortality. Instead, diastolic function abnormalities were more important. Over a median 2-year follow-up, LVSD risk was not increased.

Impact on Kidney Function and Medium-Term Outcomes of Transcatheter Aortic Valve Replacement in Patients With Chronic Kidney Disease.

Transcatheter aortic valve replacement (TAVR) is now widely approved for the treatment of aortic stenosis, regardless of the patients' surgical risk. However, the outcomes of TAVR and their determinants in patients with chronic kidney disease (CKD) beyond 1 year of follow-up are unknown. We aimed to assess the medium-term outcomes of TAVR in CKD, develop a risk score to estimate the 2-year mortality in patients with CKD, and evaluate the changes in kidney function at discharge after TAVR. Adults who underwent TAVR were retrospectively identified. The CKD stage was determined using the Chronic Kidney Disease Epidemiology 2021 creatinine formula. Improved kidney function was defined as post-TAVR creatinine ≤50% of pre-TAVR creatinine or decrease in creatinine of ≥0.3 mg/100 ml compared with pre-TAVR creatinine. Overall, 1,523 patients (median age 82 years; 59% men; 735 with CKD stage II or less, 661 with CKD III, 83 with CKD IV, and 44 with CKD V [of whom 40 were on dialysis]) were included. The all-cause mortality was higher in CKD stages IV and V on the multivariable analysis (p <0.001) at median follow-up of 2.9 (interquartile range 2.0 to 4.2) years. Moderate or severe tricuspid regurgitation, anemia, right ventricular systolic pressure >40 mm Hg and CKD stages IV and V were independent predictors of 2-year mortality and were used to develop a risk score. At hospital discharge, persisting acute kidney injury after TAVR occurred in 88 of 1,466 patients (6%), whereas improved kidney function occurred in 170 of 1,466 patients (12%). In conclusion, CKD stage was an independent determinant of mortality beyond 2 years after TAVR. Kidney function was more likely to improve than worsen at the time of hospital discharge after TAVR.

Incidence, risk factors, and outcomes of atrial functional mitral regurgitation in patients with atrial fibrillation or sinus rhythm.

AIMS: Atrial functional mitral regurgitation (AFMR) has been associated with atrial fibrillation (AF) and heart failure with preserved ejection fraction. However, data on incident AFMR are scarce. We aimed to study the incidence, risk factors, and clinical significance of AFMR in AF or sinus rhythm (SR). METHODS AND RESULTS: Adults with new diagnosis of AF and adults in SR were identified. Patients with >mild MR at baseline, primary mitral disease, cardiomyopathy, left-sided valve disease, previous cardiac surgery, or with no follow-up echocardiogram were excluded. Diastolic dysfunction (DD) was indicated by ≥2/4 abnormal diastolic function parameters [mitral medial e', mitral medial E/e', tricuspid regurgitation velocity, left atrial volume index (LAVI)]. Overall, 1747 patients with AF and 29 623 in SR were included. Incidence rate of >mild AFMR was 2.6 per 100 person-year in new-onset AF and 0.7 per 100 person-year in SR, P < 0.001. AF remained associated with AFMR in a propensity score-matched analysis based on age, sex, and comorbidities between AF and SR [hazard ratio: 3.80 (95% confidence interval 3.04-4.76)]. Independent risk factors associated with incident AFMR were age ≥65 years, female sex, LAVI, and DD in both AF and SR, in addition to rate (vs. rhythm) control in AF. Incident AFMR was independently associated with all-cause death in both groups (both P < 0.001). CONCLUSIONS: AF conferred a three-fold increase in the risk of incident AFMR. DD, older age, left atrial size, and female sex were independent risk factors in both SR and AF, while rhythm control was protective. AFMR was universally associated with worse mortality.