Key Points:
- Stress cardiac MRI (CMR) enhanced diagnostic accuracy for patients with angina but no obstructive coronary artery disease, identifying microvascular angina often missed by standard angiography.
- In the CorCMR trial, MRI-guided management improved chest pain and quality of life over 12 months, with participants reporting a 21-point higher Seattle Angina Questionnaire score versus angiography-guided care.
- Findings highlight the need for functional testing in unexplained chest pain, especially in women, who represent more than half of those with microvascular angina.
The (NCT04805814), presented at the 2025 American Heart Association Scientific Sessions, demonstrated that stress cardiac magnetic resonance (CMR)-guided management substantially improved diagnostic accuracy, angina relief, and quality of life in patients with angina and nonobstructive coronary arteries (ANOCA). The trial design was published in American Heart Journal in 2023. The randomized, double-blind study enrolled 250 adults (mean age 63 years, 51% women) who had undergone recent coronary angiography showing no obstructive disease but continued to experience angina. Participants were assigned to either stress CMR-guided care, where myocardial blood flow results were disclosed to treating physicians, or angiography-guided care, where results were withheld.
At 12 months, 53% of participants in the CMR-guided group had their diagnosis reclassified to microvascular angina, compared with fewer than 1% in the angiography-only group. Investigators noted that microvascular angina was frequently misdiagnosed as noncardiac chest pain when angiography was used alone, particularly among women. “By measuring blood flow with a stress cardiac MRI test, we found that small vessel problems were common,” said Colin Berry, MB ChB, PhD, principal investigator. “Our findings show that an angiogram alone is not always enough to explain chest pain. A functional test of blood flow should be considered before sending people home, especially women, who are more likely to have small vessel angina that otherwise goes unrecognized.”
The benefits of CMR-guided management extended beyond diagnosis. At one year, participants who received stress CMR-guided care experienced an average 21-point higher Seattle Angina Questionnaire score compared with those treated based on angiography alone (70.9 vs 52.1; p<0.001), alongside higher EuroQoL-5D-5L scores. MRI-guided patients were also more likely to receive appropriate anti-anginal therapy, including nitrates, statins, and aspirin, reflecting improved therapeutic targeting. No deaths or adverse events occurred during the study, and follow-up was achieved in 100% of participants.
The CorCMR findings reinforce the clinical value of functional testing for myocardial blood flow in patients with angina and nonobstructive coronary arteries, an often-overlooked population, particularly women. By providing both diagnostic clarity and symptom relief, stress CMR imaging offers a promising new pathway for managing microvascular angina and redefining the care of patients historically told their hearts were “normal.”
