Association of left ventricular strain with 30-day mortality and readmission in patients with heart failure

Abstract

Background: Heart failure (HF) readmissions are a common and serious problem of heterogeneous etiology. Left ventricular (LV) ejection fraction has not been found to be a consistent risk marker. However, LV strain has been shown to predict outcomes in other settings, so the aim of this study was to determine the association of LV strain with 30-day HF readmission, independent of and incremental to clinical and basic echocardiographic parameters.

Methods: A total of 468 patients who underwent echocardiography at the time of the first admission for HF from July 2009 to June 2012 were retrospectively studied. Clinical parameters were comprehensively assessed, and standard echocardiographic parameters and two strain parameters (global longitudinal strain [GLS] and global circumferential strain) were measured using speckle-tracking. Patients were followed for all-cause 30-day hospital readmission or death after discharge, and the associations of parameters with outcome were assessed using Cox proportional hazards models.

Results: Readmission within 30 days (n = 92 patients [20%]) was associated with greater impairment of LV GLS (-8.6% [interquartile range, -10.9% to -5.9%] vs -11.1% [interquartile range, -14.6% to -7.7%], P < .01). The association of GLS with readmission (hazard ratio, 1.13; 95% confidence interval, 1.07-1.19; P < .01) was independent of age, male gender, systolic blood pressure, angiotensin-converting enzyme inhibitor or angiotensin receptor blocker use, and comorbidity, as well as renal function, sodium, hematocrit, LV mass, left atrial size, and mitral regurgitation. Global circumferential strain was associated with outcome but not was independent after adjustment with echocardiographic parameters. In sequential models for 30-day outcome, GLS added incremental information to clinical parameters and LV ejection fraction and significantly improved reclassification (categorical net reclassification improvement, 0.34; P = .04) when LV ejection fraction was >50%.

Conclusions: GLS is associated with HF readmission, independent of and incremental to clinical and basic echocardiographic parameters.

Keywords: Heart failure; Readmission; Strain.