Impaired Chronotropic Response to Exercise Stress Testing in Patients with Diabetes Predicts Future Cardiovascular Events
- P. Michael Ho, MD, PhD (Michael.ho{at}uchsc.edu)1,,2,,3,
- Thomas M. Maddox, MD1,,2,,3,
- SM Colleen Ross, MS3,
- John S. Rumsfeld, MD, PhD1,,2,,3 and
- David J. Magid, MD, MPH2,,3
- 1Denver VA Medical Center
- 2University of Colorado Denver
- 3Institute for Health Research, Kaiser Permanente of Colorado
Abstract
Objectives: To assess the association between impaired chronotropic response (CR) and adverse events among patients with diabetes referred for exercise treadmill testing (ETT).
Research design and methods: Impaired CR was defined as achievement of less than 80% of a patient's heart rate reserve. Multivariable Cox proportional hazards regression assessed the independent association between impaired CR and adverse outcomes adjusting for demographics, co-morbidities and treadmill variables including the Duke Treadmill score.
Results: Of 1,341 patients with diabetes, 35.7% (n=479) demonstrated impaired CR during ETT. Patients with impaired CR were at increased risk of all-cause mortality, myocardial infarction, or coronary revascularization procedures. In multivariable analyses, impaired CR remained significantly associated with adverse outcomes (HR 1.53; 95% CI 1.10-2.14).
Conclusions: Among patients with diabetes, impaired CR is common during ETT and is associated with adverse outcomes. Impaired CR can be used as another non-invasive tool to risk stratify patients with diabetes following ETT.
Footnotes
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- Received March 26, 2008.
- Accepted May 7, 2008.
- Copyright © American Diabetes Association
