The Associations Between Heart Rate, Deformational Echocardiographic Parameters, and Outcomes in Patients With Atrial...

The relationship among heart rates, cardiac function, and outcomes in patients with atrial fibrillation (AF) remains unknown.

The purpose of this study was to investigate the association among heart rate, left atrial (LA) and left ventricular (LV) strain, and clinical outcomes in AF.

Two-dimensional speckle-tracking echocardiography were performed in 1,219 patients during AF. Clinical endpoints included ischemic stroke, heart failure (HF), all-cause mortality, and composite endpoint.

The mean follow-up duration was 3.3 ± 1.6 years. Patients were categorized into different heart rate groups, ranging from 40-59 to ≥120 beats/min. As heart rates increased, there was a stepwise decrease of peak atrial longitudinal systolic strain and LV strain. Compared with 60 to 69 beats/min, faster heart rates were associated with increased risk of ischemic stroke (adjusted HR [aHR]: 4.448 in ≥120 beats/min), HF (aHR: 1.909 in ≥120 beats/min), mortality (aHRs: 2.487, 2.810, 4.569, and 4.760 in 90-99, 100-109, 110-119, and ≥120 beats/min groups), and composite endpoint (aHRs: 2.034, 2.349, and 3.492 in 100-109, 110-119, and ≥120 beats/min groups, respectively) (all P < 0.05). Kaplan-Meier analyses demonstrated distinct survival curves when patients were grouped based on different combinations of peak atrial longitudinal systolic strain, LV strain, and heart rate (long-rank P < 0.001).

Faster heart rates were associated with worse LA/LV functions and increased clinical events independent from baseline risk profiles. Favorable outcomes were found at heart rates below 100 beats/min, with even greater LA/LV function at heart rates below 80 beats/min. The relationship between heart rate and LA/LV function should be considered for patient management and risk stratifications.