You’ll start to hear about myocardial infarction with NO obstructive coronary atherosclerosis (MINOCA).
Up to 15% of heart attacks may be due to MINOCA. These are patients with typical heart attack symptoms...but who have less than 50% blockage of major heart vessels.
Explain that it’s more common in younger patients...and up to 5 times more likely in women. Increased diabetes and obesity in young people might explain the rising rates of CV disease.
Educate that in many cases, the cause is still cholesterol-related, such as atherosclerotic plaque disruption. But other conditions can lead to MINOCA, such as coronary vasospasm...or when small collateral vessels feeding the heart aren’t working properly.
While patients with MINOCA have better survival rates than patients with MI from obstructive CAD, it’s still important to pinpoint the exact cause to provide proper treatment.
Expect patients to need further tests (cardiac MRI, etc) to determine the etiology.
Be aware, there isn’t strong evidence to guide MINOCA treatment. But recommend standard heart meds based on the cause.
For example, for plaque disruption, recommend meds as you would after MI due to obstructive CAD...antiplatelets, statins, beta-blockers, etc.
For patients with coronary vasospasm, turn to calcium channel blockers (diltiazem, etc), long-acting nitrates, and possibly cilostazol. But avoid beta-blockers...they can worsen vasospasm.
And for patients with chest pain from small heart vessel dysfunction, suggest nitrates, beta-blockers, or CCBs first...and add on ranolazine as a second-line option.
Consider aspirin, statins, and ACEIs or ARBs when the cause is unknown. Avoid adding another antiplatelet (clopidogrel, etc) to aspirin in these cases...the combo may not add benefit.
At discharge, reinforce adherence. One-third of post-MI patients report poor adherence...increasing their risk of repeat symptoms and CV events.
Also watch for substances that may trigger MINOCA again, such as amphetamines...pseudoephedrine...cocaine...and triptans.
Refer to our resource, Optimizing Care of Patients With Coronary Artery Disease, for more guidance on the treatments for obstructive CAD and MINOCA.
- Pacheco C, Coutinho T, Bastiany A, et al. Canadian Cardiovascular Society/Canadian Women’s Heart Health Alliance Clinical Practice Update on Myocardial Infarction With No Obstructive Coronary Artery Disease (MINOCA). Can J Cardiol 2024 Jun;40(6):953-968.
- Tamis-Holland JE, Jneid H, Reynolds HR, et al. Contemporary Diagnosis and Management of Patients with Myocardial Infarction in the Absence of Obstructive Coronary Artery Disease: A Scientific Statement from the American Heart Association. Circulation 2019 Apr 30;139(18):e891-e908.
- Abdu FA, Mohammed AQ, Liu L, et al. Myocardial Infarction with Nonobstructive Coronary Arteries (MINOCA): A Review of the Current Position. Cardiology. 2020;145(9):543-552.
- Parwani P, Kang N, Safaeipour M, et al. Contemporary Diagnosis and Management of Patients with MINOCA. Curr Cardiol Rep. 2023 Jun;25(6):561-570.