Left Atrial Reservoir Strain-Based Left Ventricular Diastolic Function Grading and Incident Heart Failure in Hypertrophic Cardiomyopathy

Abstract

Background: The echocardiographic assessment of left ventricular (LV) diastolic dysfunction (LVDD) in patients with hypertrophic cardiomyopathy is complex and not well-established. We investigated whether the left atrial reservoir strain (LARS) could be used to categorize LVDD and whether this grading is predictive of heart failure (HF) events in hypertrophic cardiomyopathy. Methods: A total of 414 patients with hypertrophic cardiomyopathy (aged 58.3±12.8 years; 65.7% male) were categorized using LARS-defined LVDD (LARS-DD) grades: ≥35% (grade 0), ≥24% to <35%, ≥19% to <24%, and <19% (grade 3). Patients were followed for a median of 6.9 years to assess hospitalization for HF or HF-related death. Results: An increase in LARS-DD grade was associated with worse conventional echocardiographic parameters of LVDD, such as lower e′, higher E/e′ ratio, greater maximum tricuspid regurgitation velocity, and restrictive mitral inflow pattern. Higher LARS-DD grade was also associated with parameters reflecting increased LV filling pressure, such as greater LV wall thickness, greater extent of fibrosis, obstructive physiology, and decreased LV longitudinal strain. Furthermore, higher LARS-DD grade was associated with worse HF-free survival (log-rank P <0.001). Patients with LARS-DD grades 0, 1, 2, and 3 showed 10-year HF-free survival of 100%, 91.6%, 84.1%, and 67.5%, respectively. LARS-DD grade was an independent predictor of HF events after adjusting for clinical and echocardiographic variables (hazard ratio, 1.53 [95% CI, 1.03–2.28], per 1-grade increase). The LARS-DD grade also had incremental prognostic value for incident HF events over the traditional echocardiographic LVDD parameters and grading system. The prognostic value of advanced LARS-DD grade was consistent in sensitivity analyses and various patient subgroups. Conclusions: LARS can be used as a simple single or supplemental index to categorize LV diastolic function and predict HF events in hypertrophic cardiomyopathy.