The Prevalence and Impact of Atrial Fibrillation on 1-Year Outcomes in Patients Undergoing Transcatheter Mitral Valve Repair: Results From the Society of Thoracic Surgeons/American College of Cardiology Transcatheter Valve Therapy Registry.

OBJECTIVES

The aim of this study was to compare 1-year outcomes following transcatheter mitral valve (MV) repair in patients with and without atrial fibrillation (AF).

BACKGROUND

The development of AF in degenerative mitral regurgitation (MR) is considered a sign of MR progression and is associated with adverse clinical events. However, the impact of AF in patients undergoing transcatheter MV repair remains uncertain.

METHODS

The TVT (Transcatheter Valve Therapy) Registry was used to identify patients undergoing transcatheter MV repair with the MitraClip between November 2013 and June 2016. Using Centers for Medicare and Medicaid Services-linked data, the 1-year rate of death, heart failure hospitalization, stroke, and bleeding following transcatheter MV repair was compared in patients with and without AF. Outcomes were analyzed using multivariate Cox regression modeling.

RESULTS

A total of 5,613 patients underwent commercial transcatheter MV repair in the United States during the study period, including 3,555 (63%) with pre-existing AF. Compared with patients without AF, patients with AF were older, were more likely to be male and Caucasian, had more comorbidities, and had higher Society of Thoracic Surgeons Predicted Risk of Mortality scores (median 7% vs. 5%; p < 0.0001). Acute procedural success (post-procedural ≥2+ MR, 37.4% vs. 35.0%; p = 0.20) and in-hospital mortality were similar, but length of hospital stay was longer for patients with AF (mean 4.91 days vs. 4.37 days; p = 0.0004). A total of 3,261 patients were linked to Centers for Medicare and Medicaid Services claims data. After adjustment, patients with AF had a higher 1-year rate of death or HF (hazard ratio [HR]: 1.27; 95% confidence interval [CI]: 1.11 to 1.44; p < 0.001). Patients with AF had higher rates of mortality (HR: 1.44; 95% CI: 1.22 to 1.70; p < 0.001), HF hospitalization (HR: 1.17; 95% CI: 1.00 to 1.36; p = 0.05), stroke (HR: 1.63; 95% CI: 1.01 to 2.64; p = 0.047), and bleeding (HR: 1.34; 95% CI: 1.10 to 1.64; p = 0.004) at 1 year as well. Among those with AF, the risk for stroke was lower (HR: 0.55; 95% CI: 0.32 to 0.93; p = 0.026) among those on anticoagulation.

CONCLUSIONS

In patients undergoing transcatheter MV repair, AF is common and is associated with worse clinical outcomes at 1 year despite similar acute procedural success. Further study is needed to investigate if early treatment of MR reduces the future risk for developing AF and to identify therapies that improve outcomes in these patients.