Related Experiment Videos
Correlations between coronary flow reserve measured with a Doppler guide wire and treadmill exercise testing
D S Schulman1, D Lasorda, T Farah
1Department of Medicine, Medical College of Pennsylvania, and Hahnemann University, Allegheny General Hospital, Pittsburgh 15212, USA.
Insights
Exercise stress tests, including ST-segment depression and reduced exercise time, effectively predict coronary flow reserve (CFR) in patients with coronary artery disease. These findings highlight the value of non-invasive exercise testing for assessing stenosis severity.
Area of Science:
- Cardiology
- Diagnostic Imaging
- Exercise Physiology
Background:
- Coronary artery disease (CAD) diagnosis often relies on assessing stenosis severity.
- Coronary flow reserve (CFR) measured invasively provides a physiologic index of stenosis severity.
- Non-invasive exercise testing is widely used but its correlation with CFR needs further elucidation.
Purpose of the Study:
- To compare exercise test results with invasive CFR measurements in patients with single-vessel coronary disease.
- To determine the predictive value of exercise test variables for abnormal CFR.
- To assess the relationship between ST-segment depression, exercise duration, and CFR.
Main Methods:
- 35 patients with single-vessel CAD underwent exercise testing (Bruce protocol) and CFR measurement using a Doppler guide wire.
- Exercise treadmill time was normalized to age- and sex-predicted values.
- Statistical analysis, including stepwise logistic regression, was used to evaluate predictors of abnormal CFR.
Main Results:
- Patients with abnormal CFR (Group 1) showed significantly higher rates of ST-segment depression (14/21 vs 3/14) and reduced normalized exercise time (0.82 vs 1.25) compared to those with normal CFR (Group 2).
- ST-segment depression or normalized exercise time <1 demonstrated 95% sensitivity and 86% predictive accuracy for abnormal CFR.
- Exercise time and ST-segment depression were significant predictors of CFR (r²=0.51), while minimal lumen diameter was not.
Conclusions:
- Exercise test variables, specifically ST-segment depression and reduced exercise time, are valuable non-invasive predictors of the physiologic significance of coronary stenoses.
- These findings support the utility of exercise stress testing in evaluating the functional impact of coronary lesions.
- Non-invasive exercise parameters can effectively predict abnormal coronary flow reserve, aiding in clinical decision-making.
Abstract:
We compared exercise test results to a physiologic depiction of stenosis severity, coronary flow reserve (CFR), measured with a Doppler guide wire in 35 patients with single-vessel coronary disease. Group 1 (n = 21) had abnormal CFR, and group 2 (n = 14) had normal CFR. In group 1, 14 of 21 had ST-segment depression versus 3 of 14 in group 2 (p < 0.01). Exercise treadmill time (Bruce protocol) was normalized to the age- and sex-predicted time. Exercise time and normalized exercise time were less in group 1 (5.6 +/- 2.3 vs 9.9 +/- 1.8 min and 0.82 +/- 0.32 vs 1.25 +/- 0.23, p < 0.00001). Having either ST-segment depression or a normalized exercise time <1 during exercise had a 95% sensitivity, 71% specificity, and 86% predictive accuracy in identifying abnormal CFR. Coronary stenoses and minimal lumen diameter were similar in groups 1 and 2. By using stepwise logistical regression analysis, exercise time and ST-segment depression predicted CFR with a total r2 of 0.51. Minimal lumen diameter did not significantly add to the model. Exercise test variables, ST-segment depression, and exercise time are predictive of the physiologic significance of coronary lesions.