Standard exercise stress testing attenuates peripheral microvascular function in patients with suspected coronary microvascular dysfunction

Massimo Nardone,Steven Miner,Mary Mccarthy,Heather Edgell

doi:10.1186/s13102-021-00246-8

Abstract

BackgroundThe effect of exercise on the microvasculature of patients with suspected coronary microvascular dysfunction (CMD), assessed by reactive hyperemia peripheral arterial tonometry (RH-PAT; EndoPAT), is unknown. The present study aimed to determine if standard clinical exercise stress testing (GXT) affected peripheral microvascular function, as determined by the reactive hyperemia index (RHI and LnRHI), in patients with suspected CMD.MethodsIn a cross-sectional study, patients (n = 76) were grouped based on whether the GXT was performed; 1) prior to (exercisers; n = 30), or 2) after the vascular assessment (non-exercisers; n = 46). Patients with an adenosine index of microvascular resistance > 25, adenosine coronary flow reserve (CFR) < 2.0, and/or acetylcholine CFR < 1.5 were considered to have CMD (n = 42). RHI and LnRHI quantified finger pulse amplitude hyperemia following 5 min of forearm ischemia.ResultsLnRHI was lower in patients with CMD compared to patients without CMD, while LnRHI was also lower in exercisers compared to non-exercisers (LnRHI: CMD Non-Exercisers: 0.63 ± 0.25; CMD Exercisers: 0.54 ± 0.19; No CMD Non-Exercisers: 0.85 ± 0.23; No CMD Exercisers: 0.63 ± 0.26; Condition and Exercise Main Effects: Both P < 0.01). In patients who did not exercise prior to the vascular assessment, the receiver operating characteristic curve (ROC) for LnRHI to predict CMD was 0.76 (95% CI: 0.62–0.91; P < 0.01). However, in patients who performed exercise prior to the vascular assessment, the ROC for LnRHI to predict CMD was 0.60 (95% CI: 0.40–0.81; P = 0.34).ConclusionsCMD is associated with impaired peripheral microvascular function and preceding acute exercise is associated with further reductions of LnRHI. Further, acute exercise abolished the capacity for RH-PAT to predict the presence of CMD in patients with chest pain and non-obstructive coronary arteries. RH-PAT measurements in patients with suspected CMD should not be conducted after exercise has been performed.

Highlights

The effect of exercise on the microvasculature of patients with suspected coronary microvascular dysfunction (CMD), assessed by reactive hyperemia peripheral arterial tonometry (RH-PAT; EndoPAT), is unknown
Such analyses may be relevant in patients with coronary microvascular dysfunction (CMD), a diseased characterized by abnormal coronary microvascular vasomotion and increased rates adverse cardiac outcomes [9,10,11]
We have recently demonstrated that poor peripheral microvascular function, using RH-PAT, identifies patients with CMD [6], supporting its utility within clinical settings

Summary

Introduction

The effect of exercise on the microvasculature of patients with suspected coronary microvascular dysfunction (CMD), assessed by reactive hyperemia peripheral arterial tonometry (RH-PAT; EndoPAT), is unknown. Studies quantifying endothelial function using flow-mediated dilation in healthy participants have highlighted that acute exercise briefly attenuates endothelial function, the magnitude of which is dependent on the duration, intensity, and type of exercise, as reviewed by Dawson et al [14]. These observations cannot necessarily be applied to RH-PAT, given that both flow-mediated dilation and RH-PAT are poorly correlated [15] and can be differentially influenced [15,16,17]

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Discussion

Conclusion