Determinants of false ST-segment depression during exercise echocardiography according to hypertensive response to exercise
H ChungAbstract
Background
Exercise echocardiography is a valuable noninvasive modality for evaluating patients with suspected coronary artery disease (CAD). However, false-positive findings, particularly ST-segment depression (STD) without ischemic wall motion abnormalities, may cause diagnostic confusion in clinical practice. We previously reported an association between hypertensive response to exercise (HTR) and false STD.
Purpose
Given that false STD may be influenced by loading conditions, this study aimed to identify determinants of false STD according to the presence or absence of HTR.
Methods
A total of 710 patients who underwent supine bicycle exercise echocardiography without exercise-induced regional wall motion abnormalities (RWMA) were analyzed. Indications for stress testing included CAD detection and evaluation of coronary patency after prior revascularization. Stepwise graded supine bicycle exercise was performed with simultaneous electrocardiographic monitoring and echocardiography following comprehensive resting echocardiography. False STD was defined as newly developed ST-segment depression >1 mm during exercise in the absence of RWMA. HTR was defined as a peak systolic blood pressure ≥210 mmHg in men and ≥190 mmHg in women. Patients were stratified into HTR (n = 182) and non-HTR (n = 525) groups for analysis.
Results
The mean age of the study population was 64 ± 9 years; 41.5% were women, 76.6% had hypertension, and 25.2% had diabetes. HTR was observed in 25.6% (182/710) of patients. Within the HTR group, patients with false STD were older (67 ± 9 vs. 64 ± 8 years, p = 0.047) and had lower diastolic blood pressure (73 ± 10 vs. 80 ± 11 mmHg, p = 0.002) and mean arterial pressure (92.5 ± 11 vs. 97 ± 12 mmHg, p = 0.041) than those without STD. Tricuspid regurgitation velocity (2.3 ± 0.3 vs. 2.2 ± 0.3 m/s, p = 0.024) and right ventricular systolic pressure (RVSP) (27.4 ± 5.8 vs. 24.7 ± 5.3 mmHg, p = 0.012) were significantly higher in patients with false STD. In contrast, no clinical or echocardiographic parameters were associated with STD in the non-HTR group. On multivariate logistic regression analysis, RVSP was independently associated with the presence of false STD in the HTR group (odds ratio 1.077, 95% confidence interval 1.005–1.155; p = 0.037).
Conclusions
Elevated RVSP was independently associated with false ST-segment depression in patients exhibiting a hypertensive response to exercise, whereas no such association was observed in patients without HTR. These findings suggest that altered loading conditions may contribute to exercise-induced ST-segment changes in patients with HTR and should be carefully considered when interpreting stress test results in clinical practice.