Positive Stress ECG + Normal Stress Echo = Slightly Increased Heart Risk

By Amy Orciari Herman

Edited by Jaye Elizabeth Hefner, MD

Patients with positive results on exercise stress electrocardiography (ECG) but normal results on stress echocardiography may be at increased risk for adverse cardiovascular (CV) events, suggests a JAMA Internal Medicine study.

Researchers followed 15,000 patients who underwent treadmill stress ECG and stress echo for suspected heart disease at a single medical center. Roughly 86% had negative findings on both tests, while 9% had a positive ECG and negative echo.

During roughly 7 years' follow-up, major adverse CV events occurred more often in patients with a positive ECG and negative echo than in those with negative results on both (15% vs. 9%). After multivariable adjustment, patients with a positive ECG and negative echo were at significantly increased risk for CV events both in the 30 days after testing (hazard ratio, 8.1) and over the long term (HR, 1.3).

The researchers say the "slightly increased risk ... was not previously recognized." Dr. Harlan Krumholz of NEJM Journal Watch Cardiology weighs in: "It is not surprising that a positive ECG might have prognostic importance, but the question that is looming is, when does a stress test provide actionable information that will improve patient outcomes? We are increasingly asking whether and when tests really make a difference."