Abstract 16400: The Diagnostic Value of Abnormal Heart Rate Recovery During Exercise Stress Testing in Predicting the Presence of Endothelial and Microvascular Dysfunction in Patients With Angina in the Absence of Obstructive Coronary Artery Disease
Introduction: It has been shown that conventional stress testing parameters are not helpful in identifying occult coronary abnormalities, such as endothelial and microvascular dysfunction (MVD), in patients with angina in the absence of obstructive coronary artery disease (CAD). Abnormal heart rate recovery (HRR) has been shown to be a predictor of all-cause and cardiovascular mortality in both women and men. Recent guidelines have also recommended integrating this parameter when analyzing a routine exercise stress test to improve its diagnostic value.
Hypothesis: We studied the ability of abnormal HRR during exercise stress testing to predict the presence of endothelial dysfunction and MVD in patients with angina in the absence of obstructive CAD.
Methods: We studied 139 patients with angina found to have no obstructive CAD on coronary angiography who underwent endothelial function and MVD testing. Endothelial dysfunction was defined as a decrease in epicardial coronary diameter by > 20% after intracoronary acetylcholine. MVD was defined as an index of microvascular resistance (IMR) ≥ 25. HRR was defined as peak heart rate during exercise minus heart rate at one minute into recovery. Abnormal HRR was defined as ≤ 12 bpm.
Results: The mean age of the population was 54.3 ± 11.5 years and 103 (74.3%) were women. Endothelial dysfunction was present in 93 (67.3%) patients, while 21 (15.3%) had MVD. On multiple variable logistic regression analysis, abnormal HRR independently predicted the presence of endothelial dysfunction and/or MVD (Table).
Conclusions: Heart rate recovery, a non-ECG stress testing parameter that is easily obtained during a routine exercise stress test, provides important diagnostic information about underlying occult coronary abnormalities like endothelial dysfunction and/or MVD. Adding HRR to conventional stress testing may help in the management of patients with angina in the absence of obstructive CAD.
Author Disclosures: V.S. Pargaonkar: None. Y. Kobayashi: Research Grant; Significant; Boston Scientific. Other; Modest; St. Jude Medical. T. Kimura: None. D.P. Lee: Honoraria; Modest; Abott Vascular, Boston Scientific, Medtronic. M.L. Stefanick: None. W.F. Fearon: Research Grant; Significant; Medtronic, St. Jude Medical. Honoraria; Significant; Medtronic. Consultant/Advisory Board; Significant; Heartflow. A.C. Yeung: Research Grant; Significant; Boston Scientific, Edwards, Medtronic. Honoraria; Significant; Abott Vascular, Medtronic. J.A. Tremmel: Honoraria; Modest; Boston Scientific, Medtronic, Recor, Terumo.
- © 2016 by American Heart Association, Inc.