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Clinical significance of the hemodynamic gain index in patients undergoing exercise stress testing and coronary
Mohamad Jihad Mansour1,2, Elie Chammas1, Michael Winkler3
1Division of Cardiovascular Medicine, Clemenceau Medical Center Affiliated with Johns Hopkins International, PO Box 11-2555, Beirut, Lebanon.
Insights
Severely blunted Hemodynamic Gain Index (HGI) independently predicts obstructive coronary artery disease (CAD) in patients undergoing exercise stress testing and coronary computed tomography angiography (CCTA). This finding aids in diagnosing CAD, especially with suboptimal exercise.
Area of Science:
- Cardiology
- Diagnostic Imaging
- Medical Technology
Background:
- Obstructive coronary artery disease (CAD) diagnosis during exercise stress testing can be limited by suboptimal exercise.
- Hemodynamic Gain Index (HGI) is a sensitive indicator of ischemia and mortality.
- Evaluating HGI's clinical impact alongside coronary computed tomography angiography (CCTA) is crucial.
Purpose of the Study:
- To assess the clinical significance of HGI in patients undergoing both exercise stress testing and CCTA.
- To determine if HGI can independently predict obstructive CAD.
- To explore the utility of HGI in conjunction with advanced analytical methods.
Main Methods:
- Retrospective analysis of 284 patients from an executive health program (2010-2018).
- Calculation of HGI, Framingham Risk Score (FRS), and Duke treadmill score (DTS).
- Utilized multivariate analysis and artificial neural networks with CCTA as the reference standard.
Main Results:
- Severely blunted HGI (≤1.25) was associated with older age, higher FRS, and worse DTS.
- Patients with obstructive CAD had significantly lower HGI compared to those without.
- Severely blunted HGI independently predicted obstructive CAD, showing a threefold increased odds (P=0.05).
Conclusions:
- Severely blunted HGI is an independent predictor of obstructive CAD in patients who underwent exercise stress testing and CCTA.
- HGI provides valuable prognostic information beyond traditional risk factors.
- Artificial intelligence models demonstrated HGI's strong predictive capability for obstructive CAD.
Background:
Many hemodynamic parameters provide limited information regarding obstructive coronary artery disease (CAD) during exercise stress testing particularly when exercise is suboptimal. Hemodynamic gain index (HGI) is a recent sensitive indicator of ischemia and has been associated with increased mortality. This study evaluated the clinical impact of HGI in patients who underwent concomitant exercise stress testing and coronary computed tomography angiography (CCTA).
Methods:
A total of 284 consecutive patients from the executive health program between 2010 and 2018 were identified. Resting and peak heart rate (HR) as well as systolic blood pressure (SBP) measurements were recorded. Framingham risk score (FRS), Duke treadmill score (DTS) and HGI [Formula: see text] were calculated. The latter was divided into quartiles. CCTA was used as a reference test to detect any CAD. Multivariate analysis and artificial neural network were used to determine the independent predictors of obstructive CAD.
Results:
Mean age was 53 ± 12 years with 83% male. Mean HGI was 1.74 ± 0.67, with cut-off value of severely blunted HGI ≤ 1.25 (Quartile 4). Patients with severely blunted HGI were older, had higher FRS, and worse DTS. Patients with obstructive CAD had lower HGI when compared to those with normal CCTA/non-obstructive CAD (1.36 ± 0.53 vs. 1.77 ± 0.67, P = 0.005), and showed a higher prevalence of severely blunted HGI (44% vs. 22%, P = 0.019). After adjusting for traditional risk factors, HGI remained an independent predictor of obstructive CAD while severely blunted HGI was associated with threefold increased odds of having obstructive CAD (P = 0.05). Using artificial intelligence analysis, severely blunted HGI independently predicted obstructive CAD with an area under the curve of 0.83 and 0.96, and normalized importance of HGI of 100% and 63%, respectively for different models.
Conclusions:
Among patients who underwent concomitant exercise stress testing and CCTA, severely blunted HGI independently predicted obstructive CAD after multivariate adjustment for traditional risk factors.
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