Average Exercise Capacity in Men and Women >75 Years of Age Undergoing a Bruce Protocol Exercise Stress Test

Abstract

Exercise stress testing is routinely performed to evaluate suspected coronary artery disease in older adults. However, the available data to predict and compare relative exercise capacity in the general population were developed using predominantly younger, healthy cohorts with few or no women. This study aimed to describe the exercise capacity of patients older than 75 years who underwent a clinically indicated Bruce protocol exercise stress test. This was a retrospective, cross-sectional study of 2,041 consecutive patients older than 75 years who performed a Bruce protocol exercise stress echocardiogram that was terminated because of maximal effort without ischemia at Columbia University Medical Center between April 10, 2009, and July 30, 2020. The analytic sample included 2,041 exercise stress tests in 786 women (median [interquartile range] age 79 [77 to 81] years) and 1,255 men (median [interquartile range] age 79 [77 to 82] years). Cardiovascular risk factors and clinical coronary disease were common and more prevalent in men than women. The median exercise time for men aged 76 to 80 years was 7:22 (minutes:seconds) and for women was 6:00 and significantly decreased in both genders as age increased (p <0.001). The mean (SD) METs achieved for women and men were 6.5 (1.6) and 7.7 (1.7), respectively. Most women (85%) and men (95%) completed the first stage, whereas only 32% of women and 64% of men completed the second stage. It was uncommon for women (3%) or men (15%) to complete the third stage. Fewer than 1% of patients completed the fourth stage, and none completed the fifth stage. At all ages, women had a lower exercise capacity than men. These data allow physicians to compare the exercise capacity of older patients who underwent a Bruce protocol exercise stress test more accurately to a representative sample of similarly aged adults.

Figure 1.

Patient Selection and Inclusion Flowchart Abbreviations: Echo, echocardiogram; HR, heart rate; MPHR, age predicted maximum heart rate as defined by (220-age); TTE, transthoracic echocardiogram.

Figure 2.

Percent Completing Each Stage of the Bruce Protocol Stratified by Sex The distribution of the stages of the Bruce protocol exercise stress test completed is shown separately for women and men.

Figure 3.

Distribution of Metabolic Equivalents of Task (METs) Stratified by Age Category for Women and Men Sex specific distributions of METs are shown for each age category. Dots represent outliers. Horizontal dashed lines indicate achieved METs estimated based on the FRIEND registry data and also correspond to the achieved stages of the Bruce protocol. Abbreviations: ACSM, American College of Sports Medicine; CAD, coronary artery disease; FRIEND, Fitness Registry and the Importance of Exercise National Database; MET, metabolic equivalents of task.

Figure 4.

Distribution of Exercise Time by Age for Women and Men The fitted mean values (95% confidence interval) of exercise time across the spectrum of age are shown stratified by sex. Light horizontal lines indicate the three-minute stages of the Bruce protocol. Abbreviations: CI, confidence interval.