High Rate of Obstructive CAD Seen in Patients With Typical Angina Symptoms but Negative Stress Test
Patients who present with typical symptoms of angina but who have a negative precardiac catheterization stress-test result have the highest rate of obstructive coronary artery disease, according to a new analysis of patients undergoing elective coronary angiography. For patients with atypical angina but a positive stress-test result, just one in four have obstructive coronary artery disease.
The results, say researchers, highlight the importance of clinical judgment and intuition when assessing a patient’s symptoms.
“In the era of modern diagnostic testing, there is still a tremendous role for clinical assessment and the use of bedside judgement to identify those who are at risk for having coronary artery disease,” lead investigator John Vavalle, MD (University of North Carolina, Chapel Hill), told TCTMD.
The study, published as a research letter on March 16, 2016, in JAMA: Cardiology, included 15,888 patients with no history of coronary artery disease who underwent elective angiography between 1996 and 2010 at Duke University Medical Center. Typical symptoms of angina were present in 36.9% of patients, atypical symptoms in 38.8%, and no symptoms of angina in 24.3%. A total of 4,994 patients underwent a cardiac stress test before coronary catheterization, including 3,812 who had a negative stress test result and 1,182 who had a positive result indicative of ischemia.
To TCTMD, Vavalle noted that more than two-thirds of patients were referred directly for elective coronary angiography without first undergoing a stress test.
“As we’re taught in medical school, if you have a very high clinical suspicion for something, and an intermediary-type of test, like a stress test, isn’t going to change what you’re going to ultimately do, then you shouldn’t do it,” said Vavalle. “If your clinical suspicion is so high based on their symptoms or their non–stress-test finding, such as changes on an electrocardiogram, then you should go straight to cardiac catheterization.”
In the present analysis, patients with typical angina had the highest rates of obstructive coronary artery disease. In total, 74.3% of patients with typical angina but a negative stress test had obstructive disease. “What this means is that despite having a negative stress test, the referring physician felt—based on their clinical intuition—that the symptoms were so convincing they did not believe the stress test and referred them for coronary angiography,” said Vavalle.
For patients who had typical symptoms of angina but didn’t undergo a stress test, nearly 70% had obstructive coronary disease identified on angiography. For those with typical angina and a positive stress test, approximately 60% had obstructive coronary artery disease.
Rates of obstructive and nonobstructive disease identified by angiography were much lower among patients with atypical angina symptoms and patients with no chest pain (these patients had other symptoms of ischemia, such as exercise intolerance, for example). Of note, the lowest rate of obstructive coronary artery disease occurred in patients with atypical symptoms of angina but a positive stress test. In these atypical angina patients, Vavalle said the physicians were “fooled” by the positive stress test, with ultimately just 24.6% of these patients having obstructive coronary disease on coronary angiography.
The bottom line, he said, is that despite the availability of multiple imaging tools to assess coronary perfusion, there is a role for clinical acumen.
“You don’t always need a stress test,” said Vavalle. “The message here is not that there isn’t a role for stress testing. Of course, clearly, there’s a role. It’s in the guidelines, and it’s in the appropriate use criteria. I use stress testing all the time, but we can’t rely solely on it. We can’t rely solely on noninvasive stress testing. There’s a very important role for clinical assessment using clinical judgement and clinical intuition to make decisions.”
- Vavalle JP, Shen L, Broderick S, et al. Effect of the presence and type of angina on cardiovascular events in patients without known coronary artery disease referred for elective coronary angiography. JAMA Cardiology 2016;Epub ahead of print.
- The study was funded by an unrestricted educational grant from Gilead Sciences.
- Authors report no conflicts of interest.