Comparison of supine bicycle exercise versus treadmill exercise echocardiography in a cycling-naive population

Abstract

Abstract Introduction Exercise echocardiography is a useful diagnostic test for the evaluation of coronary artery disease. Supine bicycle exercise echocardiography has the advantage of continuous monitoring of wall motion during exercise. On the contrary, the heart rate and workload is usually lower compared to treadmill exercise, especially between patients not used to cycling as is the case of many old adults. The aim of this study is to compare both exercise modalities. Methods A group of consecutive patients with chest pain underwent supine bicycle exercise echocardiography under a protocol adapted to the individual requirements. The operator chose between three protocols: light (5 watts every minute), medium (5 watts every 30 seconds) or intensive (10 watts every 30 seconds) according to age, sex and physical condition. The other group underwent treadmill exercise echocardiography using the Ball State University/Bruce Ramp protocol. Results A total of 902 patients were included. Of them, 258 patients underwent supine bicycle exercise echocardiography and 644 patients underwent treadmill exercise echocardiography. Mean age was 62.1 years (SD=13.4) and 48.5% of patients were women. Baseline characteristics were comparable in both groups, without significant differences regarding age, sex, body mass index, pre-test probability or image quality. There were no significant differences in the percentage of positive tests (5.0 vs. 5.3%, p = 0.883). However, the percentage of patients that achieved at least 85% of the predicted workload was significantly higher in the group of treadmill exercise echocardiography (91.3 vs. 45.0%, p < 0.001). The percentage of patients that achieved at least 85% of the age-predicted maximum heart rate was also significantly higher in the group of treadmill exercise echocardiography (76.7 vs. 44.2%, p < 0.001). Conclusions This study suggests that in a population not used to cycling, the use of supine bicycle exercise echocardiography, as opposed to the use of treadmill, hinders the achievement of an adequate maximum heart rate and workload, which can lead to inconclusive results. This should be considered while selecting the ischemic test to use.