Relation of heart rate response to exercise with prognosis and atherosclerotic progression after coronary artery bypass grafting.

Pubmed ID: 19427433

Journal: The American journal of cardiology

Publication Date: May 15, 2009

Affiliation: Division of Cardiovascular Medicine, University of Iowa Hospitals and Clinics, Iowa City, Iowa, USA. saket-girotra@uiowa.edu

MeSH Terms: Humans, Male, Female, Risk Factors, Middle Aged, Proportional Hazards Models, Disease Progression, Prospective Studies, Prognosis, Double-Blind Method, Coronary Angiography, Coronary Artery Bypass, Heart Rate, Coronary Artery Disease, Exercise, Exercise Test

Authors: Mukamal KJ, Girotra S, Mittleman MA, Keelan M, Weinstein AR

Cite As: Girotra S, Keelan M, Weinstein AR, Mittleman MA, Mukamal KJ. Relation of heart rate response to exercise with prognosis and atherosclerotic progression after coronary artery bypass grafting. Am J Cardiol 2009 May 15;103(10):1386-90. Epub 2009 Mar 25.

Studies:

Abstract

Impaired heart rate response to exercise is associated with adverse clinical outcomes in healthy adults and those with established coronary artery disease. It is unclear whether this association persists in subjects who have undergone coronary artery bypass grafting (CABG). In this study, 920 subjects enrolled in the Post CABG trial who had undergone CABG with patent saphenous vein grafts at baseline and known to have discontinued beta blockers before exercise were studied. A maximal symptom-limited exercise treadmill test was performed on study entry. Chronotropic variables were measured at peak exercise. Participants were followed for a composite end point of death, myocardial infarction, stroke, or revascularization. Quantitative coronary angiography was performed at follow-up and compared with baseline angiography, with prespecified angiographic end points of the substantial progression of graft disease and complete occlusion. In multivariate analysis, a low chronotropic index was strongly associated with an increased risk for the composite clinical end point (p for trend = 0.04) and angiographic complete occlusion (p for trend = 0.007) but only weakly associated with angiographic substantial progression (p for trend = 0.07). In conclusion, impaired chronotropic response to exercise identifies subjects at risk for clinical outcomes and graft occlusion, even after revascularization with CABG.