Prognostic value of cycle exercise testing prior to and after outpatient cardiac rehabilitation

Abstract

Background: The prognostic value of cycle exercise testing prior to and after outpatient cardiac rehabilitation (OCR) is not well established.

Methods: 2146 consecutive patients undergoing symptom-limited cycle exercise testing at OCR entry, of whom 1853 (86%) also had a test at end of OCR, were followed for a median of 33 months.

Results: All-cause and cardiovascular annual mortality rates were 1.2% and 0.8%, respectively. At OCR entry, older age, diabetes, lower left ventricular ejection fraction (LVEF), calcium channel blocker use, and lower workload [hazard ratio (HR) 2.38 if < or = 105 W; p<0.001] were independent predictors of death. Diabetes, diuretic use, and lower workload [HR 3.53 if < or = 105 W; p=0.001] were independently associated with cardiovascular death. At end of OCR, older age, lower LVEF, lower workload (HR 2.34 if <140 W; p=0.009), and lower increase in peak heart rate from entry to end of OCR (HR 2.46 if <4 bpm; p=0.002) were independently associated with all-cause mortality. Older age, lower LVEF, lower increase in systolic blood pressure (HR 2.97 if <54 mm Hg; p=0.02), and lower increase in peak heart from entry to end of OCR (HR 2.72 if <4 bpm; p=0.013) were independently associated with cardiovascular mortality. Failure to undergo a test at end of OCR was an additional independent predictor of all-cause (HR 2.51; p<0.001) and cardiovascular mortality (HR 2.56; p=0.003).

Conclusion: Symptom-limited cycle exercise testing prior to and after OCR provides important prognostic information.