This article is more than 5 years old. Information may no longer be current.
Exercise stress testing predicts high-risk CAD in abnormal ECGs
Conditional use of myocardial perfusion imaging in patients with abnormal stress ECG and/or low functional capacity reduced radiation exposure and cost, according to a study published in The American Journal of Cardiology.
“The majority of exercise stress testing performed in this country includes additional imaging, which increases radiation burden and cost, although American College of Cardiology/American Heart Association guidelines recommend standard exercise treadmill testing without additional imaging as a class I indication for the evaluation of chest pain in subjects with interpretable ECGs,” Adrián I. Löffler, MD, cardiovascular imaging fellow at University of Virginia School of Medicine in Charlottesville, and colleagues wrote. “In an era of increasing attention to cost-effective health care, maximizing the utility of noninvasive and invasive cardiovascular testing is becoming increasingly important.”
The researchers analyzed data from 412 patients with chest pain who underwent coronary angiography within 3 months of exercise stress testing from 2007 to 2011. Electronic medical records were reviewed, which included information on medical comorbidities, baseline demographics, medications, angiographic data and exercise functional capacity.
High-risk CAD was defined as at least 70% diameter stenosis in three major epicardial arteries, diameter stenosis at least 70% in the proximal left anterior descending artery or at least 50% diameter stenosis in the left main artery.
Coronary angiography showed that one-quarter of patients had high-risk CAD.
Independent predictors of high-risk CAD included abnormal stress imaging, positive stress ECG, male sex and left ventricular ejection. Positive stress ECG was the strongest predictor (HR = 3.16; 95% CI, 1.9-5.27), although functional capacity alone was not an independent predictor.
When 10 or more metabolic equivalents were achieved with a negative stress ECG, sensitivity was 94% and negative predictive value was 97% in identifying those with high-risk CAD.
“[This supports] the strategy of provisional use of stress imaging for patients with low functional capacity and/or abnormal stress ECG changes to minimize cost and radiation exposure,” Löffler and colleagues wrote. – by Darlene Dobkowski
Disclosures: The authors report no relevant financial disclosures.