Endothelial dysfunction and long-term outcomes in patients with myocardial infarction and non-obstructive coronary arteries.

BACKGROUND

There is little information regarding the characteristics of patients with myocardial infarction with non-obstructive coronary arteries (MINOCA) in terms of coronary endothelial function and prognosis, as compared to patients with angina and non-obstructive coronaries (ANOCA). We assessed differences in clinical profile, endothelial function and prognosis between patients undergoing acetylcholine (ACH) testing for MINOCA or ANOCA.

METHODS

We combined two cohorts of patients undergoing ACH testing - ENDOCOR (multicentre; 2015-2023) and FISIOTON (single-centre; 2018-2024) - totalling 723 patients. Endothelial dysfunction was defined as any epicardial vasoconstriction to ACH or endothelium-dependent coronary flow reserve ≤1.5.

RESULTS

MINOCA was diagnosed in 68 (9.4%) patients. Endothelial dysfunction was found in 57.4%, epicardial spasm in 7.05% and microvascular spasm in 1.94%, without differences between MINOCA and ANOCA. In multivariable regression, MINOCA was independently associated with resting chest pain (OR 3.63, 95% CI: 1.84-7.66), previous MI (OR 2.91, 95% CI: 1.29-6.30) and active smoking (OR 2.15, 95% CI: 1.04-4.30). Over a median follow-up of 3.0 years, major adverse cardiovascular events (MACE) occurred in 7.5% of patients. MINOCA (HR 2.81, 95% CI: 1.40-5.67, p = 0.004), endothelial dysfunction (HR 2.59, 95% CI: 1.29-5.21, p = 0.008) and male sex (HR 2.01, 95% CI: 1.13-3.58, p = 0.017) were independently associated with MACE. Patients with MINOCA and endothelial dysfunction had the highest event rate (19.4%).

CONCLUSIONS

In patients with non-obstructive coronary arteries undergoing ACH testing, endothelial dysfunction and a MINOCA presentation were independently associated with adverse events, whereas classical spasm endotypes were not.