Original Investigation
Associations of Cardiac Mechanics With Exercise Capacity: The Multi-Ethnic Study of Atherosclerosis

https://doi.org/10.1016/j.jacc.2021.04.082Get rights and content
Under an Elsevier user license
open archive

Abstract

Background

Lower exercise capacity, as measured by 6-minute walk distance (6MWD), is associated with incident heart failure (HF). Among those without HF, the associations of measures of cardiac function with 6MWD are unclear, and may provide insight regarding the risk of incident HF.

Objectives

The purpose of this study was to understand the relationships between cardiac function and exercise capacity.

Methods

This study evaluated the associations of cardiac mechanics with 6MWD in the sixth examination of the Multi-Ethnic Study of Atherosclerosis. Echocardiography (2-dimensional, Doppler, and speckle-tracking) was performed at rest and after passive leg raise to evaluate functional reserve after intravascular volume challenge.

Results

Of 2,096 participants without HF (mean age 73 years, 48% men, 58% non-White), individuals with lower (worse) left atrial (LA) reservoir strain were older and had higher blood pressure. Lower resting LA reservoir strain (β coefficient per SD decrease: −5.0; 95% confidence interval [CI]: −8.8 to −1.3 m; p = 0.009), inability to augment LA reservoir strain after passive leg raise (β coefficient per SD decrease: −5.8; 95% CI: −9.1 to −2.5 m; p < 0.001), and lower right atrial reservoir strain (β coefficient per SD decrease: −4.4; 95% CI: −7.8 to −1.1 m; p = 0.01) were associated with shorter 6MWD. Worse left ventricular (LV) diastolic function was also associated with lower 6MWD. There were no independent associations of measures of LV systolic function (global longitudinal strain, circumferential strain, ejection fraction) with 6MWD.

Conclusions

Among individuals without HF, worse biatrial function, lack of LA functional reserve, and worse LV diastolic function were associated with reduced submaximal exercise capacity. Therapies aimed to improve these functional domains may increase exercise capacity and prevent HF.

Key Words

6-min walk test
cardiac structure and function
echocardiography
heart failure
subclinical

Abbreviations and Acronyms

6MWD
6-minute walk distance
AF
atrial fibrillation
GLS
global longitudinal strain
LA
left atrial
LV
left ventricular
PASP
pulmonary artery systolic pressure
RV
right ventricular
SV
stroke volume
TAPSE
tricuspid annular plane systolic excursion

Cited by (0)

Listen to this manuscript's audio summary by Editor-in-Chief Dr. Valentin Fuster on JACC.org.

The authors attest they are in compliance with human studies committees and animal welfare regulations of the authors’ institutions and Food and Drug Administration guidelines, including patient consent where appropriate. For more information, visit the Author Center.