A new study suggests that stress cardiac MRI tests can help diagnose and treat chest pain even when coronary angiograms show no blockages in the main arteries. The findings, presented at the American Heart Association’s Scientific Sessions 2025 in New Orleans, indicate that approximately half of patients with suspected angina but no obstructive coronary artery disease (ANOCA) actually have microvascular angina, a condition involving small heart vessels that is often missed by standard angiograms.
“People may have real angina even when the main arteries appear wide open,” said study author Colin Berry, M.B.Ch.B., Ph.D., professor of cardiology at the University of Glasgow. “By measuring blood flow with a stress cardiac MRI test, we found that small vessel problems were common.” The study, known as the CorCMR trial, enrolled 250 adults with chest pain and no blocked coronary arteries based on prior angiogram testing. Participants were randomly assigned to two groups: one where stress cardiac MRI results were shared with doctors to guide diagnosis and treatment, and another where the results were not disclosed.
The analysis found that about half of all participants had a diagnosis change after the stress cardiac MRI. Among them, 48% were diagnosed with microvascular angina, compared to fewer than 1% when doctors relied only on angiograms. More than half of those diagnosed with microvascular angina were women. After six and twelve months, patients in the stress cardiac MRI group reported significant improvements in quality of life, as measured by the Seattle Angina Questionnaire. The group improved by an average of 18 points at six months and 22 points at one year, while the angiogram-guided group improved by less than 1 point.
“The results of our study open a new path for people with chest pain,” Berry said. “It indicates that symptoms and well-being are worse when diagnoses are made based only on an angiogram. Clinical practice should now change to include a stress cardiac MRI test for angina, especially for women.” The study had no serious side effects from the stress cardiac MRI and no deaths during follow-up.
According to the American Heart Association, chest pain is the second most common reason adults visit U.S. hospital emergency departments, accounting for over 6.5 million visits annually. The findings highlight the need for functional testing of blood flow beyond angiograms, particularly for women who are more likely to have unrecognized small vessel angina. The study was funded by the British Heart Foundation and coordinated by an independent clinical trials unit. More research is needed to confirm these findings in different healthcare settings and to assess longer-term outcomes.
