Prognostic value of left atrial strain by speckle tracking echocardiography in acute and chronic heart failure: a meta-analysis and meta-regression analysis

Abstract Funding Acknowledgements Type of funding sources: None. Background Heart failure (HF) is a global health burden which prognostic assessment is currently challenging. Speckle tracking echocardiography (STE) has gained increasing importance for the diagnostic and prognostic assessment of HF. Left atrial (LA) strain by STE is widely recognized as an index of diastolic function and left ventricular (LV) filling pressures and fibrosis. Moreover, many studies have investigated its prognostic value in HF with reduced, mildly reduced and preserved ejection fraction (HFrEF, HFmrEF and HFpEF). Objective our aim was to systematically investigate the prognostic value of peak atrial longitudinal strain (PALS) for cardiovascular (CV) events in HF and its variation in acute/chronic HF and according to LV function, age and gender. Methods A systematic literature search of medical databases including Pubmed, Scopus, Ovid Online, EMBASE, Web of Science, Cochrane Central Register, Scopus was performed using PRISMA principles. All relevant studies in English language reporting the predictive value of LA strain for mortality and/or CV events (CV death, hospitalization for HF, cardiac transplant, ventricular assist device implant) in HFrEF, HFmrEF and HFpEF, with follow up >6 months were identified. All-cause mortality and HF hospitalizations were considered as primary endpoint. Hazard ratios (HR) were performed using a random effect model reporting on the association of global PALS and outcome and described as pooled estimates with 95% confidence intervals (CI). Results Eight studies (5767 patients, median [IQR] age=66.3 [65;68.6], 37% female) satisfied the inclusion criteria (5 studies chronic HF, 2 studies acute HF, 1 study in acute and chronic HF). Overall, 6 studies included patients with HFrEF, 3 studies patients with HFmrEF and 5 patients with HFpEF. Median global PALS value was 17.6 [14.9;26.8]%, median LVEF was 36 [30;56]% and median LV global longitudinal strain (GLS) was −9 [−7;-16.9]%. Over a median follow up of 903 [321;1062] months, 2688 patients reached the primary endpoint (944 all-cause mortality, 1963 HF hospitalization). Each unit decrease in Global PALS was independently associated with a 5% increase for the primary endpoint (meta-analytic HR 1.05; 95% CI [1.02–1.07]; p<0.01). Subgroup analysis conducted in patients with acute and chronic HF showed no differences (p = 0.18). Meta-regression analysis showed that the prognostic value of global PALS was higher for lower LVEF values (beta=-0.0023), a similar trend was observed for worse LV GLS and lower age without reaching statistical significance. Funnel plot analysis showed no publication bias (Egger’s p = 0.45). Conclusions Global PALS may be used as a useful prognostic tool in HF, both in acute and chronic setting and especially in patients with HFrEF, providing an additional independent value for risk stratification of these patients in clinical practice.