Managing heart failure with reduced ejection fraction merged with myocardial infarction with non-obstructive coronary arteries: a case report.

Background: The concepts of myocardial infarction with non-obstructive coronary arteries (MINOCA) are now widely accepted. Calcium channel blockers (CCBs) are the first-line medication for coronary spastic angina (coronary spastic angina: CSA/vasospastic angina: VSA), while β-blockers sometimes do not improve CSA/VSA. However, β-blockers are essential for managing symptoms of coronary microvascular dysfunction and considered vital for treating heart failure with reduced ejection fraction (HFrEF).

Case summary: We present the case of an 83-year-old female admitted with shortness of breath persisting for over 1 year and worsening ejection fraction (EF) from 65% to 32%. On admission, she experienced chest pain at rest despite finding no significant stenosis on coronary angiography. Several days later, we performed functional coronary angiography (FCA), revealing diffuse epicardial coronary spasm upon injecting acetylcholine. The coronary flow reserve was 4.4 (≧2.0), and the microvascular resistance index was 20 (<25). We diagnosed the patient with a myocardial injury event induced by CSA/VSA and initiated dihydropyridine CCBs. A few months later, her chest pain resolved; the HF symptoms improved (NYHA: from Ⅲ to Ⅱ), accompanied by a reduction in B-type natriuretic peptide levels (from 4561.2 to 75.4 pg/mL) and EF improvement (from 32.0% to 62.6%).

Discussion: We managed a patient with HFrEF and MINOCA. Although CCBs are not routinely recommended for HFrEF, we added dihydropyridine CCBs to treat CSA/VSA based on comprehensive diagnostic procedures. This approach sedated chest pain and may have contributed to her EF improvement. Detailed examinations and tailored treatment strategies might be helpful for HF treatment.