Abstract 12738: Elevated Sympathetic Activity, Impaired Endothelial Function, and Late Hypertension After Repair of Coarctation of the Aorta
Introduction: There is a high prevalence of hypertension late after repair of coarctation of the aorta but its exact mechanism is unknown. Elevated sympathetic tone may contribute to the development of late hypertension. This study aims to investigate the neural profile of coarctation patients including the use of muscle sympathetic nerve activity (MSNA) testing, a direct method of measuring sympathetic activity.
Methods: Twenty-three patients aged ≥18 years with a coarctation repair underwent transthoracic echocardiography (TTE) and measurements of resting and 24-hour ambulatory blood pressures (BP), MSNA, sympathetic and cardiac baroreflex functions, digital endothelial function, and pulse wave velocity (PWV). Median age at repair was 1.2 months (interquartile range: 0-9 months). Patients were compared to 18 healthy controls matched for age, gender, weight, and waist/hip circumference ratio.
Results: After a follow-up of 26 ± 5 years, 6% (1/18) and 44% (8/18) had clinic resting hypertension and prehypertension, respectively. On 24-hour BP monitoring, 15% (3/20) and 20% (4/20) had hypertension and prehypertension, respectively. Left ventricular hypertrophy on TTE was present in 43% (6/14), and was more prevalent in patients with prehypertension/hypertension on 24-hour BP monitoring compared to those with normal 24-hour BP (75% [3/4] vs. 30% [3/10], p=0.2). Coarctation patients had elevated MSNA compared with controls (50 ± 25 vs. 29 ± 14 bursts/100 heartbeats, p=0.01), decreased sympathetic baroreflex function (-2.2 ± 2.1 vs. -7.0 ± 5.6 bursts/100 heartbeats·mmHg-1, p=0.007), normal cardiac baroreflex function (41.9 ± 30.4 vs. 35.7 ± 21.1 ms·mmHg-1, p=0.6), decreased endothelial function (pulse amplitude tonometry ratio: 0.4 ± 0.3 vs. 0.8 ± 0.5, p=0.004), and normal PWV (5.8 ± 1.1 vs. 5.5 ± 0.4 m/s, p=0.7).
Conclusions: After coarctation repair patients have increased MSNA, impaired sympathetic baroreflex response, and impaired endothelial function, all of which may contribute to the development of late hypertension. Agents targeting sympathetic activity and endothelial function may be the ideal antihypertensive therapies after coarctation repair. Regular monitoring for late hypertension after coarctation repair is warranted.
Author Disclosures: M.G. Lee: None. J.P. Mynard: None. E. Lambert: None. M.M. Cheung: None. G. Lambert: None. Y. d’Udekem: Consultant/Advisory Board; Modest; MSD, Actelion.
- © 2016 by American Heart Association, Inc.