Left ventricular strain-volume loops in bicuspid aortic valve disease: new insights in cardiomechanics

By combining temporal changes in left ventricular (LV) global longitudinal strain (GLS) with LV volume, LV strain-volume loops can assess cardiac function across the cardiac cycle. This study compared LV strain-volume loops between bicuspid aortic valve (BAV) patients and controls, and investigated the loop's prognostic value for clinical events.

From a prospective cohort of congenital heart disease patients, BAV patients were selected and compared with healthy volunteers, who were matched for age and sex at group level. GLS analysis from apical views was used to construct strain-volume loops. Associations with clinical events, i.e. a composite of all-cause mortality, heart failure, arrhythmias, and aortic valve replacement, were assessed by Cox regression. A total of 113 BAV patients were included (median age 32 years, 40% female). BAV patients demonstrated lower Sslope (0.21%/mL, [Q1-Q3: 0.17-0.28] vs. 0.27%/mL [0.24-0.34], P < 0.001) and ESslope (0.19%/mL [0.12-0.25] vs. 0.29%/mL [0.21-0.43], P < 0.001) compared with controls, but also greater uncoupling during early (0.48 ± 1.29 vs. 0.05 ± 1.21, P = 0.04) and late diastole (0.66 ± 1.02 vs. -0.07 ± 1.07, P < 0.001). Median follow-up duration was 9.9 [9.3-10.4] years. Peak aortic jet velocity (HR 1.22, P = 0.03), enlarged left atrium (HR 3.16, P = 0.003), E/e' ratio (HR 1.17, P = 0.002), GLS (HR 1.16, P = 0.008), and ESslope (HR 0.66, P = 0.04) were associated with the occurrence of clinical events.

Greater uncoupling and lower systolic and diastolic slopes were observed in BAV patients compared with healthy controls, suggesting presence of altered LV cardiomechanics. Moreover, lower ESslope was associated with clinical events, highlighting the strain-volume loop's potential as prognostic marker.