ABSTRACT
Importance: Global longitudinal strain (GLS) is an emerging echocardiographic biomarker of cardiac function in heart failure (HF). Evidence from large-scale studies comprehensively investigating GLS for its association with clinical phenotypes and mortality in asymptomatic and symptomatic chronic HF is limited. Objective: To assess the factors associated with GLS and its prognostic value in patients with chronic HF. Design, Setting, and Participants: The observational, prospective MyoVasc cohort study enrolled 3289 individuals with asymptomatic to symptomatic HF between January 17, 2013, and April 27, 2018. The median follow-up was 3.2 years (interquartile range, 2.0-4.0 years). Participants with stages A to D HF according to American Heart Association (AHA) criteria were examined at a dedicated study center. Echocardiography was performed with GLS measurement by independent reviewers. Data were analyzed from September 2, 2019, to January 15, 2020. Main Outcomes and Measures: All-cause and cardiac mortality were recorded by structured follow-up and validated via death certificates. Results: In the study sample, data on GLS were available on 2440 individuals, of whom 2186 (mean [SD] age, 65.0 [10.5] years; 1418 [64.9%] men) were classified as having AHA HF stages A to D. Mean (SD) GLS worsened across AHA stages from stage A (n = 434; -19.44 [3.15%]) to stage B (n = 629; -18.01 [3.46%]) to stages C/D (n = 1123; -15.52 [4.64%]). Age (ß = -0.27; 95% CI, -0.47 to -0.067; per decade, P = .009), female sex (ß = -1.2; 95% CI, -1.6 to -0.77; per decade, P < .001), obesity (ß = 0.64; 95% CI, 0.25-1.0; P = .001), atrial fibrillation (ß = 1.2; 95% CI, 0.69-1.6; P < .001), myocardial infarction (ß = 1.5; 95% CI, 1.00-2.1; P < .001), and estimated glomerular filtration rate (ß = -0.53; 95% CI, -0.73 to -0.32; per SD, P < .001) were independently associated with GLS in multivariable regression analysis. Global longitudinal strain was associated with the severity of HF as reflected by N-terminal prohormone B-type natriuretic protein (NT-proBNP) levels after additionally adjusting for cardiac structure and function (P < .001). During follow-up, GLS was associated with all-cause mortality (hazard ratio [HR] per SD, 1.55; 95% CI, 1.19-2.01; P < .001) and cardiac death (HR per SD, 2.32; 95% CI, 1.57-3.42; P < .001) independent of image quality, observer variability, clinical profile, HF medications, NYHA class, and cardiac structure and function. After further adjustment for the NT-proBNP level, GLS remained associated with cardiac death (HR per SD, 1.60; 95% CI, 1.07-2.41; P = .02) but not all-cause mortality (HR per SD, 1.26; 95% CI, 0.95-1.66; P = .11). Conclusions and Relevance: In patients with chronic HF, GLS was associated with clinical and cardiac status, reflected neurohormonal activation, and was associated with cardiac mortality independent of clinical and cardiac status. These findings suggest that GLS may serve as a useful tool to improve risk stratification in patients with HF.
