Stratified treatment of myocardial infarction with non-obstructive coronary arteries: the PROMISE trial

Myocardial infarction with non-obstructive coronary arteries (MINOCA) is associated with a significant risk of mortality, rehospitalization, and angina burden. Despite its clinical impact, no randomized clinical trials have hitherto evaluated optimal management strategy for MINOCA. The PROMISE trial was designed to assess whether a stratified treatment improves clinical outcomes in patients with MINOCA as compared to standard care.

PROMISE is a multicentre randomized trial. Patients with MINOCA were randomized 1:1 to either a stratified treatment based on a comprehensive diagnostic workup aimed at identifying the underlying aetiology, or to standard care. The primary endpoint was the between-group difference in the change in angina status at 12 months, assessed by the Seattle Angina Questionnaire summary score (SAQSS). The secondary endpoint was the incidence of major adverse cardiovascular events (MACE), defined as the composite of all-cause mortality, myocardial infarction, stroke, heart failure hospitalization and repeated coronary angiography. The trial was terminated early upon recommendation by the Data and Safety Monitoring Board due to clear benefits observed in the intervention group and potential harm in the control group.

Of 101 randomized patients, 92 were confirmed as MINOCA and included in the final analysis (mean age 62 ± 13 years, 48% women; stratified treatment n = 45; standard care n = 47). At 12-month follow-up, SAQSS was significantly higher in the stratified treatment than in standard care group, with a mean between-group difference of +9.38 in favour of the stratified treatment (95% confidence interval 6.81 to 11.95; P < .001). MACE occurred in 1 patient (2.2%) in the stratified treatment and in 4 patients (8.5%) in the standard care group, though the difference was not statistically significant (P = .18).

In this first randomized trial of treatment strategies in MINOCA, a stratified treatment, based on comprehensive diagnostic assessment and aetiology-guided therapy, led to a significant improvement in angina-related health status. While the study findings provide the first evidence supporting individualized management in this heterogeneous and often under-recognized patient population, these results require confirmation in a larger prospective study with longer follow-up.