Author + information
- Pelbreton Balfour,
- George Beller and
- Jamieson Bourque
Background: Exercise stress electrocardiography (ECG) alone is underutilized despite guideline recommendations in part due to poor diagnostic accuracy. High frequency QRS analysis (HF-QRS) is a novel tool to supplement standard ST-analysis during stress ECG. We sought to compare the diagnostic accuracy of HF-QRS compared with standard ST-analysis for the identification of moderate to severe myocardial ischemia by exercise SPECT myocardial perfusion imaging (MPI).
Methods: We analyzed the diagnostic accuracy of HF-QRS versus ST-depression in 389 consecutive patients who underwent exercise SPECT MPI at the Cleveland Clinic Foundation, Minneapolis Heart Institute Foundation, and the University of Virginia Health System, respectively. An ischemic HF-QRS pattern was defined as an absolute reduction of ≥1 μV and a relative reduction of ≥50% between maximal and minimal values of the mean root square of the 150-250 Hz band signal in ≥3 leads. Semi-quantitative gated SPECT MPI was the gold standard for the diagnosis of moderate to severe ischemia. Statistical analysis was performed using chi-square and logistic regression analysis.
Results: The study cohort was 71% male and 84% Caucasian with a mean age of 58 ± 12. ST segment and HF-QRS analyses were positive in 106 (23%) and 126 (28%) patients, respectively. HF-QRS had a substantially higher sensitivity than ST-analysis for moderate-severe ischemia (66.7% vs. 40.0%, p < 0.0001). There was no statistically significant difference in specificities for HF-QRS vs ST-analysis for moderate-severe ischemia. (70.5% vs 75.7%, p=0.08). HF-QRS demonstrated incremental diagnostic value to ST-analysis and clinical risk factors and increased the model discrimination (AUC 0.751 vs 0.783, p<0.005).
Conclusions: HF-QRS analysis substantially improves detection of moderate-severe ischemia over ST-segment analysis in patients undergoing exercise stress ECG. This novel noninvasive adjunct may improve CAD risk stratification and encourage use of stress ECG without imaging, reducing costs and radiation exposure.
Moderated Poster Contributions
Acute and Stable Ischemic Heart Disease Moderated Poster Theater, Poster Hall, Hall C
Saturday, March 18, 2017, 9:45 a.m.-9:55 a.m.
Session Title: Blips, Trops, and Chips: New Ways to Diagnose CAD
Abstract Category: 2. Acute and Stable Ischemic Heart Disease: Clinical
Presentation Number: 1217M-03
- 2017 American College of Cardiology Foundation