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Abnormal heart-rate response during cardiopulmonary exercise testing identifies cardiac dysfunction in symptomatic
Sundeep Chaudhry1, Naresh Kumar2, Hushyar Behbahani2
1Research and Development, MET-TEST, Inc., Atlanta, GA, United States.
Insights
A new heart-rate response measure during cardiopulmonary exercise testing (CPET) shows higher accuracy than stress ECG for detecting under-treated atherosclerosis. This method may help identify cardiac dysfunction in symptomatic patients with normal routine testing.
Area of Science:
- Cardiology
- Exercise Physiology
- Diagnostic Imaging
Background:
- Symptomatic non-obstructive coronary artery disease presents a diagnostic challenge.
- Current testing methods offer limited clinical utility for identifying cardiac dysfunction.
- Novel approaches are needed to accurately assess coronary artery disease.
Purpose of the Study:
- To compare the diagnostic performance of a novel heart-rate response parameter against stress ECG.
- To evaluate the sensitivity and specificity of the ΔHR-WR Slope in detecting coronary artery disease.
- To assess the utility of CPET-derived heart-rate response for identifying cardiac dysfunction.
Main Methods:
- Prospective observational cohort study involving symptomatic and healthy participants.
- Cardiopulmonary exercise testing (CPET) was used to measure heart-rate responses.
- The change in heart-rate as a function of work-rate (ΔHR-WR Slope) was analyzed.
- Comparison with stress ECG for detecting atherosclerosis.
Main Results:
- The ΔHR-WR Slope demonstrated significantly higher sensitivity than stress ECG for detecting under-treated atherosclerosis.
- The parameter showed improved accuracy in identifying both non-obstructive and obstructive coronary artery disease.
- Reclassification rates for abnormal studies were substantially higher with ΔHR-WR Slope.
Conclusions:
- Abnormal heart-rate response during CPET is a more effective indicator of under-treated atherosclerosis than stress ECG.
- This novel parameter holds potential for identifying cardiac dysfunction in symptomatic individuals.
- The findings suggest a valuable role for CPET in patients with normal routine cardiac evaluations.
Background:
Symptomatic non-obstructive coronary artery disease is a growing clinical dilemma for which contemporary testing is proving to be of limited clinical utility. New methods are needed to identify cardiac dysfunction.
Methods And Results:
This is a prospective observational cohort study conducted from December 2013 to August 2015 in two outpatient cardiology clinics (symptomatic cohort) and 24 outpatient practices throughout the US (healthy cohort) with centralized methodology and monitoring to compare heart-rate responses during cardiopulmonary exercise testing (CPET). Participants were 208 consecutive patients (median age, 61; range, 32-86years) with exercise intolerance and without prior heart or lung disease in whom coronary anatomy was defined and 116 healthy subjects (median age, 45; range, 26-66years). Compared to stress ECG, the novel change in heart-rate as a function of work-rate parameter (ΔHR-WR Slope) demonstrated significantly higher sensitivity to detect under-treated atherosclerosis with similar specificity. In men, area under the ROC curve increased from 60% to 94% for non-obstructive CAD and from 64% to 80% for obstructive CAD. In women, AUC increased from 64% to 85% for non-obstructive CAD and from 66% to 90% for obstructive CAD. ΔHR-WR Slope correctly reclassified abnormal studies in the non-obstructive CAD group from 22% to 81%; in the obstructive CAD group from 18% to 84% and in the revascularization group from 35% to 78%.
Conclusion:
Abnormal heart-rate response during CPET is more effective than stress ECG for identifying under-treated atherosclerosis and may be of utility to identify cardiac dysfunction in symptomatic patients with normal routine cardiac testing.
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