A new study published in American Heart Journal Plus - Cardiology and Practice sheds light on persistent chest pain in women despite having no blocked coronary arteries—a syndrome known as INOCA (Ischemia with No Obstructive Coronary Artery disease). The research, part of the Women's Ischemia Syndrome Evaluation - Coronary Vascular Dysfunction (WISE-CVD) study, identifies key drivers of refractory angina and offers clues to possible treatment strategies.

Conducted between 2008 and 2015, the study analyzed 198 women who underwent repeat cardiac MRI scans and completed the Seattle Angina Questionnaire (SAQ-7) at baseline and again one year later. Refractory angina was defined as persistently low SAQ-7 scores (below 75) with minimal improvement after a year.

Thirty percent of the participants (n = 60) experienced refractory angina. They were more likely to have lower income, high blood pressure, and require nitrate medications. Physiologically, these women had impaired coronary blood flow (CBF) response to acetylcholine. Their myocardial perfusion reserve index did not differ significantly from that of the non-refractory group.

Symptomatically, those with refractory angina continued to report no significant improvements in physical functioning, angina stability, or overall disease perception after one year. Statistically, hypertension increased the odds of refractory angina by over four times, and abnormal CBF tripled the risk, even after adjusting for age.

These findings highlight the burden of cardiovascular symptoms in women with INOCA, which is generally overlooked.