CMR feature-tracking derived left atrial late diastolic strain rate is associated with long-term outcomes in non-ischemic heart failure patients with severely reduced LVEF

Abstract

Heart failure (HF) patients with LVEF ≤ 35% remain at high risk of adverse outcomes. Cardiac magnetic resonance (CMR) feature-tracking (FT) enable the assessment of left atrial (LA) deformation, but the long-term prognostic value of LA strain parameters in this high-risk population remains unclear. This study evaluated whether CMR-derived LA strain and strain-rate parameters are associated with long-term outcomes in HF patients with LVEF ≤ 35%. This retrospective study included 214 consecutive patients with non-ischemic HF and LVEF ≤ 35% who underwent CMR between March 2018 and December 2020. Conventional CMR parameters and FT derived strain parameters were assessed. The primary endpoint was a composite of all-cause death or heart transplantation. The secondary endpoint was unplanned hospitalization for worsening heart failure. Cox proportional hazards models, Kaplan-Meier survival analysis, and model discrimination assessed by C-index were used to evaluate the prognostic value of LA strain parameters. During a median follow-up interval of 61 months (IQR, 52 - 68.25), 32 patients reached the primary endpoint and 96 patients reached the secondary endpoint. After adjustment for clinical and CMR parameters, SRa remained associated with the primary endpoint [hazard ratio (HR), 2.761; 95% confidence intervals (CI), 1.120 - 6.804; P = 0.027] and the secondary endpoint (HR, 1.862; 95% CI, 1.163 - 2.981; P = 0.010). Hemoglobin and LV end-diastolic volume index (LVEDVi) were additionally associated with the primary endpoint, while atrial fibrillation history and LVEDVi were associated with the secondary endpoint. In HF patients with LVEF ≤ 35%, CMR-FT derived SRa was associated with the risks of all-cause death or heart transplantation and heart failure worsening hospitalization. SRa may serve as a potential complementary prognostic marker in severe LV systolic dysfunction.