Sex differences in left ventricular dilatation in patients with significant aortic regurgitation: prognostic implications

Abstract Background Left ventricular (LV) dilatation is a strong indicator of adverse outcome in patients with aortic regurgitation (AR). Accordingly, current guidelines recommend the use of LV end-systolic diameter index (LVESDi) as one of the criteria to trigger aortic valve surgery (AVS) in patients with severe AR, but with the same threshold regardless of gender. Purpose To assess sex differences in LV remodeling using both volumetric and linear measurements in a large cohort of patients with significant AR (moderate or greater) and to investigate their prognostic implications. Methods A total of 1070 patients (56 ± 18 years, 691 men) were included. The primary outcome was all-cause mortality. Results Women presented with older age (58 ± 19 vs. 55 ± 17, p=0.023) and more advanced heart failure (HF) symptoms than men (NYHA class III-IV 12% vs. 9%, p=0.017). Men showed significantly larger LVESDi (21 ± 5 vs. 20 ± 5 mm/m2, p=0.013) and LV end-systolic volume index (LVESVi 37 ± 28 vs. 26 ± 17 ml/m2 p<0.001). During a median follow-up of 89 (IQR, 54-132) months, 168 patients died. Women had lower survival rates at 3, 5, and 10 years of follow-up compared to men (92% vs. 94.3%; 85% vs. 89.7% and 75.3% vs. 84.1%, p=0.005) (Figure 1). Spline curve analysis revealed that the threshold of LVESDi associated with an increased risk of mortality was 20 mm/m2 for both sexes. In turn, the threshold for LVESVi was 40 ml/m2 for women and 45 ml/m2 for men. Univariable Cox regression models were constructed separately for men and women. The variables associated with all-cause mortality were age, NYHA class III-IV, and AVS as time-dependent covariate in women, and age, diabetes, AVS as time-dependent covariate, and LAVI (left atrial volume index) in men. These parameters were used as a basal multivariable Cox regression model on top of which LVESDi >20 mm/m2 (Model 1), LVESVi >40 ml/m2 for women and 45 ml/m2 for men (Model 2) were added (Table 1A). LVESVi >40 ml/m2 was not a significant univariate predictor in men. In women, LVESDi >20 mm/m2 (HR: 2.046, 95%CI 1.244-3.419; p=0.006) and LVESVi >40 ml/m2 (HR 1.758, CI 1.095-2.825; p=0.020) showed an independent association with all-cause mortality among other factors (Table 1A). In men, death was independently associated with LVESDi >20 mm/m2 (HR 1.979, 95%CI 1.255-3.121; p=0.003) and LVESVi >45 ml/m2 (HR 2.388, 1.522-3.746; p<0.001), among other factors (Table 1A). Moreover, when added to a basal model that included clinical and echocardiographic variables associated with prognosis, LV dilatation based on volumetric LV enlargement resulted in a greater discriminatory power for both genders (Table 1B). Conclusion Men and women have a similar LVESDi threshold of 20 mm/m2, which is associated with an increased risk of death. However, their respective cut-off values for LVESVi differ, with the optimal threshold for women being 40 ml/m2 and for men 45 ml/m2.