Heart rate and left ventricular remodeling after repaired coarctation of the aorta: a cross-sectional study.

Abstract

Background: Patients with repaired coarctation of the aorta (CoAo) remain at risk for left ventricular hypertrophy (LVH) even in the absence of hypertension. Alterations in wave reflection and the timing of reflected pressure waves may contribute to ventricular remodeling beyond pressure load alone.

Methods: We performed a cross-sectional analysis of patients with repaired CoAo. Office and ambulatory blood pressure (ABPM), non-invasive central hemodynamics, and echocardiographic indices of left ventricular structure were assessed. Linear and multivariable regression models evaluated associations with posterior wall thickness in diastole (PWTd) and interventricular septal thickness in diastole. Computational simulations were conducted to examine the impact of heart rate on ventricular remodeling.

Results: Fifty-seven patients (median post-repair follow-up 11 years) were included. LVH prevalence was 15.2% (95% confidence interval [CI], 4.8, 25.6). Although 42% met criteria for hypertension based on ABPM, no patients exhibited elevated central blood pressure and LVH. Heart rate-adjusted augmentation index (AIX@75) was inversely associated with PWTd and remained independently associated after multivariable adjustment (R² = 0.40, P < 0.01). Replacing AIX@75 by heart rate improved model performance (R² = 0.44), with lower heart rate independently associated with greater PWTd. Simulation modeling showed that a 10% increase in heart rate reduced mean PWTd and decreased posterior wall hypertrophy prevalence from 30.9% to 2.4% (odds ratio, 0.10; 95% CI, 0.01, 0.44).

Conclusions: Ventricular remodeling occurs despite normal central blood pressure in CoAo. A lower heart rate associates with increased ventricular mass. Heart rate-mediated modulation of wave reflection timing represents a potential mechanistic and therapeutic target.