The prognostic value of right ventricular longitudinal strain in heart failure: a systematic review and meta-analysis

Background: Right ventricular (RV) dysfunction is a well-recognized adverse prognostic feature in patients with heart failure (HF). Recently, many single-center studies have demonstrated that RV longitudinal strain assessed using speckle tracking echocardiography might be a powerful prognosticator in HF. Objectives: To systematically appraise and quantitatively synthesize the evidence of the prognostic value of echocardiographic RV longitudinal strain, across the entire spectrum of left ventricular ejection function (LVEF) in HF. Methods: A systematic literature review was conducted in electronic databases to identify every study reporting the predictive role of RV global longitudinal strain (RV GLS) and RV free wall longitudinal strain (RV FWLS) in HF subjects. A random-effects meta-analysis was conducted to quantify the adjusted and unadjusted hazard ratios [(a)HRs] for all-cause-mortality and for the composite outcome of all-cause mortality or HF-related hospitalization for both indices. Results: Twenty-four studies were deemed eligible and 15 of these provided appropriate quantitative data for the meta-analysis, encompassing 8,738 patients. Each 1% worsening in RV GLS and RV FWLS was independently associated with increased risk of all-cause mortality (pooled aHR = 1.08 [1.03–1.13]; p < 0.01; I² = 76% and 1.05 [1.05–1.06]; p < 0.01; I² = 0%, respectively) and the composite outcome (pooled aHR = 1.10 [1.06–1.15]; p < 0.01; I² = 0% and 1.06 [1.02–1.10]; p < 0.01; I² = 69%, respectively) for patients with HF. The subgroup analysis of HF patients with LVEF < 45% yielded similar results, with worsening in RV GLS and RV FWLS retaining strong association with the two outcomes. Conclusion: Echocardiographic RV GLS and RV FWLS appear to have powerful prognostic value across the range of HF.