Ambient temperature and coronary plaque rupture risk in STEMI: Insights from OCT analysis.

BACKGROUND AND AIMS: Cold weather is associated with an increased risk of cardiovascular events, but its impact on culprit plaque characteristics in ST-segment elevation myocardial infarction (STEMI) remains unclear.

METHODS

This study included 647 STEMI patients who underwent optical coherence tomography (OCT) to assess untreated culprit lesions. Participants were grouped based on ambient temperature on the day of admission or mean ambient temperatures over the preceding 7-, 14-, 21-, and 28-day periods. Restricted cubic spline curves and regression models explored associations between ambient temperature and plaque characteristics.

RESULTS

A U-shaped relationship was observed between the mean ambient temperature over the 21 days preceding admission and plaque rupture risk. After covariate adjustment, participants in the coldest (Tertile-1) and hottest (Tertile-3) temperature tertiles had a 105 % (OR: 2.05, 95 % CI: 1.31-3.22) and 24 % (OR: 1.24, 95 % CI: 0.82-1.90) higher risk of plaque rupture, respectively, compared with those in the intermediate tertile (Tertile-2). The optimal temperature minimizing plaque rupture risk was 12.7 °C. Cold exposure was also associated with a higher prevalence of lipid-rich plaques and larger lipid plaque dimensions. Similar patterns were observed for the ambient temperature on the day of admission and the mean temperatures over the preceding 7-, 14-, and 28-day periods.

CONCLUSIONS

Extreme cold and hot temperatures are associated with increased coronary plaque rupture risk, with cold exposure linked to more lipid-rich and extensive plaque morphology. These OCT-based findings provide quantitative evidence of temperature-dependent vulnerability in coronary atherosclerosis.