Abstract
Type of funding sources: None.
The achievement of a maximal workload of 10 metabolic equivalents (METs) is associated to good outcome with hard cardiac events of just around 1%/year. However, there is no much information on common daily exercises that can be quantitatively measured and give information about this exercise performance. We aimed to assess the capacity of stepping up stairs in patients submitted for an exercise testing (ExT).
A total of 165 consecutive ambulatory patients submitted for a clinically indicated ExT with ECG (ExT-ECG, n = 15) or echocardiography (ExT-E, n = 150) were included. At least 15 minutes after the test patients were asked to step up 4 flights of stairs (60 stairs) at fast pace without stopping but also without running and the time to do it was counted.
Patients who achieved 10 METs during exercise (n = 69) made the stairs test in 46 ± 11 secs, those who achieved 8-10 METs (n = 37) in 58 ± 21 secs, and those who achieved <8 METs (n = 59) made it in 82 ± 41 secs (p < 0.001). Correlation between METs and stairs time test was 0.53 (Figure 1). The area under the curve ROC of stairs time for predicting an achievement of 10 METs was 0.79 (95% CI= 0.72-0.86, p < 0.001). A cut off value of 60 secs had high sensitivity (94%) and negative predictive value for 10 METs (93%) although specificity and positive predictive values were of 53% and 59%, respectively. A cut-off value of 90 secs had low sensitivity (34%) but high specificity (96%) and positive predictive value (83%) for predicting <8 METs. Abnormal results were seen in 58% of patients with limited exercise capacity, 30% with intermediate exercise capacity, and 29% with good exercise capacity (p = 0.002); and in 32% of patients that did the stairs test in at least 60 secs in comparison with 52% of those that lasted between 61-89 secs and 58% of those that lasted more (p = 0.018).
Most subjects able to step up 4 flights of stairs in 45 secs will perform well during exercise testing. On the contrary, those unable to make the stairs test in 1 and a half minutes are expected to have bad functional capacity and worse exercise test performance.
Abstract Figure.
