Stress cardiac MRI tests may improve angina diagnosis and treatment, according to a new study. The research reveals that half of patients given the all-clear for angina may have been misdiagnosed, even when coronary angiogram testing shows clear main heart arteries. Using stress cardiac MRI testing to measure blood flow around the heart appears to improve diagnosis and patient quality of life. These findings were shared at the American Heart Association’s Scientific Sessions 2025, held in New Orleans from November 7th to 10th.
The study, led by Professor Colin Berry, M.B.Ch.B., Ph.D., from the University of Glasgow and Golden Jubilee University National Hospital, highlights a common issue: people may have real angina even when the main arteries appear wide open. By measuring blood flow with a stress cardiac MRI test, the study found that small vessel problems were common. This challenges the notion that an angiogram alone is sufficient to explain chest pain. Berry emphasizes the importance of considering a functional test of blood flow before sending people home, especially women, who are more likely to have small vessel angina that otherwise goes unrecognized.
The CorCMR trial enrolled 250 adults with chest pain but no blocked coronary arteries, based on testing. All participants had a coronary angiogram test within three months before enrollment, with results indicating suspected angina and no obstructive coronary arteries (ANOCA). The study participants were randomly assigned to two groups. Both groups underwent a stress cardiac MRI test. In one group, the results were shared with doctors and patients to guide diagnosis and treatment. In the other group, the MRI results were withheld, and treatment decisions were based solely on the angiogram results. Neither the participants nor their doctors knew which group they were in until the study ended.
After a 12-month follow-up, the analysis revealed significant findings. About half of the participants (53%) had their diagnosis changed after the stress cardiac MRI. Approximately 50% of participants experienced chest pain from small vessels in the heart (microvascular angina), while 48% had chest pain unrelated to the heart. A small percentage (2%) had other conditions. When doctors reviewed the MRI images, about 50% of participants were diagnosed with microvascular angina, compared to fewer than 1% when relying solely on angiogram tests. More than half of those diagnosed with microvascular angina were women.
The study also assessed quality-of-life scores using the Seattle Angina Questionnaire. The stress cardiac MRI group showed improved scores, with small improvements at six months that became more pronounced after a year. Participants in the MRI group improved by an average of 18 points at six months and 22 points at one year. In contrast, the angiogram-guided group showed minimal improvement. After one year, the difference in questionnaire results between the two groups was approximately 21 points.
Importantly, no serious side effects were reported from the stress cardiac MRI screening, and there were no deaths during the follow-up period. Berry concludes that the study opens new avenues for people with chest pain, suggesting that symptoms and well-being are better when diagnoses are made with MRI. He recommends that clinical practice should now include stress cardiac MRI tests for angina, especially for women with chest pain and no blockages in the main arteries. These findings may also inform future clinical recommendations and improve clinical outcomes.
The study had some limitations, including the need for further research to confirm these findings in different healthcare settings and to assess longer-term outcomes. The under-recognition of small vessel chest pain, particularly in women and historically underrepresented groups, is a concern. Future trials should ensure these populations are well-represented.
