Clinical Significance of Postinfarct Fever in ST-Segment Elevation Myocardial Infarction: A Cardiac Magnetic Resonance Imaging Study

Little is known about causality and pathological mechanism underlying association of postinfarct fever with myocardial injury in patients with ST-segment elevation myocardial infarction. In 276 patients undergoing primary percutaneous coronary intervention for ST-segment elevation myocardial infarction, cardiac magnetic resonance imaging was performed a median of 3.4 days after the index procedure. Forty-five patients had postinfarct fever (peak body temperature within 4 days after primary percutaneous coronary intervention ≥37.7°C; Fever group) whereas 231 did not (no-Fever group). Primary outcome was myocardial infarct size as assessed by cardiac magnetic resonance imaging. Secondary outcomes were extent of area at risk, myocardial salvage index, and microvascular obstruction area. In cardiac magnetic resonance imaging analysis, myocardial infarct size (25.6% [19.7-32.4] in the Fever group versus 17.2% [11.8-25.4] in the no-Fever group;