Abstract 16946: The Association of Clinical Indication for Exercise Stress Testing With All-Cause Mortality
Background: Little is known about the association between the clinical indication for stress testing and all-cause mortality and the impact of exercise capacity on this relationship.
Method: We studied 54,662 patients without known CHF who were referred for a treadmill stress test due to symptoms or for pre-operative evaluation at a single center between 1991 and 2009. Exercise capacity was assessed as METs achieved. The association between test indication and all-cause mortality was assessed using multivariable Cox models. Chest pain, the most common reason for referral, was used as the reference. A subgroup analysis was performed for patients with and without known CAD.
Results: The mean age was 54 ± 13 years, 53% were men, the mean Framingham Risk Score was 14 ± 11%, and 12% had known CAD. 67% of the patients were referred for chest pain, 10% for SOB, 4% for palpitations, and 2% for pre-operative evaluation. Over a mean follow-up of 11 years, survival varied significantly by indication for stress test, with 94% survival for palpitations, 90% for chest pain, 86% for SOB and 58% for pre-operative evaluation. Compared to patients referred for chest pain, those referred for palpitations had a lower risk of mortality (HR 0.73, CI 0.61-0.87), whereas those referred for SOB (HR 1.11, CI 1.04-1.19) and pre-operative evaluation (HR 2.18, CI 2.00-2.38) had an increased risk. These associations remained significant after adjustment for exercise capacity (Table). In a subgroup analysis, the decreased risk for all-cause mortality for those referred for palpitations was found only in those without known CAD (HR 0.74, CI 0.60-0.90). Conversely, an increased risk of mortality for those referred for SOB was observed only in those with known CAD (HR 1.18, CI 1.05-1.38).
Conclusion: Overall, patients referred for pre-operative evaluation had the greatest risk for mortality, while those referred for palpitations had the lowest risk. These associations were independent of exercise capacity.
- © 2013 by American Heart Association, Inc.