Prolonged Fever After ST‐Segment Elevation Myocardial Infarction and Long‐Term Cardiac Outcomes

BACKGROUND The biphasic inflammation after ST-segment elevation myocardial infarction (STEMI) plays an important role in myocardial healing and progression of systemic atherosclerosis. The purpose of this study is to investigate the impact of fever during the first and second phases of post-STEMI inflammation on long-term cardiac outcomes. METHODS AND RESULTS A total of 550 patients with STEMI were enrolled in this study. Axillary body temperature (BT) was measured and maximum BTs were determined for the first (within 3 days: max-BT1-3d) and second (from 4 to 10 days after admission: max-BT4-10d) phases, respectively. Patients were followed for cardiac events (cardiovascular death, acute coronary syndrome, and rehospitalization for heart failure) for a median 5.3 years. During the follow-up period, 80 patients experienced cardiac events. A high max-BT4-10d was strongly associated with long-term cardiac events (hazard ratio, 95% CI) for a 1°C increase in the max-BT4-10d: 2.834 (2.017-3.828), P<0.0001, whereas the max-BT1-3d was not associated with cardiac events (1.136 [0.731-1.742], P=0.57). Even after adjustment for coronary risk factors, estimated glomerular filtration rate, infarct size, pericardial effusion, and medications on discharge, fever during the second phase (max-BT4-10d ≥37.1°C) was significantly associated with future cardiac events (hazard ratio [95% CI] 2.900 [1.710-5.143], P<0.0001). CONCLUSIONS Fever during the second phase but not the first phase of post-STEMI inflammation was a strong associated factor with worse long-term cardiac outcomes in patients after STEMI, suggesting the need to consider the optimal timing for anti-inflammatory strategies after STEMI.