Refining the Role of Left Atrial Strain in Heart Failure with Reduced Ejection Fraction

Incremental prognostic utility of left ventricular and left atrial strains in coronary artery disease patients with reduced systolic function

OBJECTIVE

This study aimed to investigate the predictive value of left ventricular global longitudinal strain (GLS) and left atrial reservoir strain (LARS) on adverse events in chronic coronary artery disease (CAD) patients with reduced systolic function.

METHODS

A total of 192 consecutive patients clinically diagnosed with chronic CAD and left ventricular ejection fraction (LVEF) ≤ 50% were finally included. Multiple strain parameters were analyzed with speckle tracking echocardiography. The composite endpoint included all-cause mortality, rehospitalization due to heart failure, myocardial infarction, and stroke.

RESULTS

Patients experiencing the endpoint showed lower LVEF, lower absolute GLS and LARS than those without events. Both GLS (AUC = 0.82 [GLS] vs. 0.58 [LVEF], p < 0.001) and LARS (AUC = 0.71 [LARS] vs. 0.58 [LVEF], p = 0.033) were superior to LVEF in predicting adverse events. Multivariate cox regression analysis showed that both GLS (hazard ratio, 0.71; 95% CI, 0.63-0.79; p < 0.001) and LARS (hazard ratio, 0.96; 95% CI, 0.93-0.98; p < 0.001) were independent predictors for the endpoint. The addition of LARS (global chi-squared, 35.7 vs. 17.4; p < 0.05), GLS (global chi-squared, 58.6 vs. 17.4; p < 0.05) or both LARS and GLS (global chi-squared, 79.6 vs. 17.4; p < 0.05) to LVEF in the prediction model significantly improved its performance. The same significant improvement was also shown in the subgroups of mild (30% < LVEF ≤ 50%) and severe (LVEF ≤ 30%) reduced systolic function.

CONCLUSIONS

Regarding CAD patients with reduced LVEF, both GLS and LARS are superior to LVEF in predicting adverse events, providing significant incremental value to LVEF.

Peak left atrial longitudinal strain is associated with all-cause mortality in patients with ventricular functional mitral regurgitation

PURPOSE

Chronic mitral regurgitation promotes left atrial (LA) remodeling. However, the significance of LA dysfunction in the setting of ventricular functional mitral regurgitation (FMR) has not been fully investigated. Our aim was to assess the prognostic impact of peak atrial longitudinal strain (PALS), a surrogate of LA function, in patients with FMR and reduced left ventricular ejection fraction (LVEF).

METHODS

Patients with at least mild ventricular FMR and LVEF < 50% under optimized medical therapy who underwent transthoracic echocardiography at a single center were retrospectively identified in the laboratory database. PALS was assessed by 2D speckle tracking in the apical 4-chamber view and the study population was divided in two groups according to the best cut-off value of PALS, using receiver operating characteristics (ROC) curve analysis. The primary endpoint-point was all-cause mortality.

RESULTS

A total of 307 patients (median age 70 years, 77% male) were included. Median LVEF was 35% (IQR: 27 - 40%) and median effective regurgitant orifice area (EROA) was 15mm² (IQR: 9 - 22mm²). According to current European guidelines, 32 patients had severe FMR (10%). During a median follow-up of 3.5 years (IQR 1.4 - 6.6), 148 patients died. The unadjusted mortality incidence per 100 persons-years increased with progressively lower values of PALS. On multivariable analysis, PALS remained independently associated with all-cause mortality (adjusted hazard ratio 1.052 per % decrease; 95% CI: 1.010 - 1.095; P = 0.016), even after adjustment for several (n = 14) clinical and echocardiographic confounders.

CONCLUSION

PALS is independently associated with all-cause mortality in patients with reduced LVEF and ventricular FMR.

Left atrial strain determinants and clinical features according to the heart failure stages. New insight from EACVI MASCOT registry

Few studies analyzed left atrial (LA) peak atrial longitudinal strain (PALS) determinants, particularly across heart failure (HF) stages. We aimed to analyze the pathophysiological and clinical PALS correlates in a large multicentric prospective study. This is a multicenter prospective observational study enrolling 745 patients with HF stages. Data included PALS and left ventricular global longitudinal strain (LV-GLS). Exclusion criteria were: valvular prosthesis; atrial fibrillation; cardiac transplantation; poor acoustic window. Median global PALS was 17% [24–32]. 29% of patients were in HF-stage 0/A, 35% in stage-B, and 36% in stage-C. Together with age, the echocardiographic determinants of PALS were LA volume and LV-GLS (overall model R2 = 0.50, p < 0.0001). LV-GLS had the strongest association with PALS at multivariable analysis (beta: −3.60 ± 0.20, p < 0.0001). Among HF stages, LV-GLS remained the most important PALS predictor (p < 0.0001) whereas age was only associated with PALS in lower HF-stage 0/A or B (R = − 0.26 p < 0.0001, R = − 0.23 p = 0.0001). LA volume increased its association to PALS moving from stage 0/A (R = − 0.11; P = 0.1) to C (R = − 0.42; P < 0.0001). PALS was the single most potent echocardiographic parameter in predicting the HF stage (AUC for B vs. 0/A 0.81, and AUC vs. 0/A for C 0.76). PALS remained independently associated with HF stages after adjusting for ejection fraction, E/e′ ratio, and mitral regurgitation grade (p < 0.0001). Although influenced by LV-GLS and LA size across HF stages, PALS is incrementally and independently associated with clinical status. LA function may reflect a substantial part of the hemodynamic consequences of ventricular dysfunction.

Quantified mitral regurgitation and left atrial function in heart failure with reduced ejection fraction: interplay and outcome implications

AIMS

The clinical and prognostic importance of functional mitral regurgitation (FMR) in heart failure patients with reduced ejection fraction (HFrEF) has been highly debated. This study aims to define FMR linkage to cardiovascular (CV) outcomes and the interplay with left atrial (LA) function in a prospective cohort of consecutive HFrEF outpatients.

METHODS AND RESULTS

Overall, 286 consecutive outpatients with chronic HFrEF were prospectively enrolled. FMR was quantified by effective regurgitant orifice area (EROA). Global peak atrial longitudinal strain (PALS) was measured by speckle tracking echocardiography. The primary endpoint was a composite of congestive heart failure hospitalization or CV death. During a mean follow-up of 4.1 ± 1.5 years, the primary endpoint occurred in 99 patients (35%). The spline modelling of the risk by FMR severity showed an excess event risk starting at about the EROA value of 0.1 cm2 . There was a remarkable graded association between the EROA strata, even if tested per 0.1 cm2 increase, and the risk of CV events (hazard ratio [HR] EROA per 0.10 cm2 increase: 1.42, 95% confidence interval [CI] 1.19-1.68; p < 0.0001). EROA ≥0.30 cm2 was associated with CV events regardless of LA function (HR 2.34, 95% CI 1.29-4.19; p = 0.005). Less severe FMR (EROA ≥0.10 cm2 ) was associated with a dismal outcome only in patients with reduced LA function (PALS <14%) (5-year CV event rate 51 ± 4%); conversely, the risk of events was relative reduced when preserved global PALS and FMR coexisted (5-year CV event rate 38 ± 6%).

CONCLUSIONS

Our results refine the independent association between FMR and CV outcome among HFrEF outpatients. Within a moderate EROA range, LA function mitigates the clinical consequences of mitral regurgitation, providing measurable proof of the interplay between regurgitation and LA compliance.