Ventilatory efficiency is reduced in people with hypertension during exercise

Hope, Katrina; Chant, Ben; Hinton, Thomas; Kendrick, Adrian H.; Nightingale, Angus K.; Paton, Julian F.R.; Hart, Emma C.

Abstract

BACKGROUND: An elevated ventilatory efficiency slope during exercise (minute ventilation/volume of expired CO2; VE /VCO2 slope) is a strong prognostic indicator in heart failure. It is elevated in people with heart failure with preserved ejection, many of whom have hypertension. However, whether the VE /VCO2 slope is also elevated in people with primary hypertension versus normotensive individuals is unknown. We hypothesize that there is a spectrum of ventilatory inefficiency in cardiovascular disease, reflecting an increasingly abnormal physiological response to exercise. The aim of this study was to evaluate the VE /VCO2 slope in patients with hypertension compared with age-, peak oxygen consumption–, and sex-matched healthy subjects. METHODS AND RESULTS: Ramped cardiovascular pulmonary exercise tests to peak oxygen consumption were completed on a bike ergometer in 55 patients with primary hypertension and 24 normotensive controls. The VE /VCO2 slope was assessed from the onset of exercise to peak oxygen consumption. Data were compared using unpaired Student t test. Age (mean±SD, 66±6 versus 64±6 years; P=0.18), body mass index (25.4±3.5 versus 24±2.4 kg/m2; P=0.13), and peak oxygen consumption (23.2±6.6 versus 24±7.3 mL/min per kg; P=0.64) were similar between groups. The VE /VCO2 slope was elevated in the hypertensive group versus controls (31.8±4.5 versus 28.4±3.4; P=0.002). Only 27% of the hypertensive group were classified as having a normal VE /VCO2 slope (20–30) versus 71% in the control group. CONCLUSIONS: Ventilatory efficiency is impaired people with hypertension without a diagnosis of heart failure versus normotensive individuals. Future research needs to establish whether those patients with hypertension with elevated VE /VCO2 slopes are at risk of developing future heart failure.

• Journal Article Type: Article
• Acceptance Date: Mar 6, 2023
• Online Publication Date: Jun 22, 2023
• Publication Date: Jul 4, 2023
• Deposit Date: Mar 12, 2024
• Publicly Available Date: Mar 12, 2024
• Journal: Journal of the American Heart Association
• Electronic ISSN: 2047-9980
• Publisher: Wiley Open Access
• Peer Reviewed: Peer Reviewed
• Volume: 12
• Issue: 13
• Article Number: e024335
• DOI: https://doi.org/10.1161/JAHA.121.024335
• Public URL: https://uwe-repository.worktribe.com/output/11793943