Body temperature, systemic inflammation and risk of adverse events in patients with acute coronary syndromes

Background Inflammatory processes can trigger acute coronary syndromes (ACS) which may increase core body temperature (BT), a widely available low‐cost marker of systemic inflammation. Herein, we aimed to delineate baseline characteristics of ST‐segment elevation myocardial infarction (STEMI) and non‐ST‐segment elevation ACS (NSTE‐ACS) patients stratified by initial BT and to assess its predictive utility towards major adverse cardiovascular events (MACE) after the index ACS. Methods From 2012 until 2017, a total of 1044 ACS patients, 517 with STEMI and 527 with NSTE‐ACS, were prospectively recruited at the University Hospital Zurich. BT was measured by digital tympanic thermometer along with high‐sensitivity C‐reactive protein (hs‐CRP) and cardiac troponin‐T (hs‐cTnT) levels prior to coronary angiography. Patients were stratified according to initial BT and uni‐ and multivariable regression models were fit to assess associations of BT with future MACE risk. Results Among patients with STEMI, BT was not predictive of 1‐year MACE, but a U‐shaped relationship between BT and MACE risk was noted in those with NSTE‐ACS (p = .029), translating into a 2.4‐fold (HR, 2.44, 95% CI, 1.16–5.16) increased 1‐year MACE risk in those with BT >36.8°C (reference: 36.6–36.8°C). Results remained robust in multivariable‐adjusted analyses accounting for sex, age, diabetes, renal function and hs‐cTnT. However, when introducing hs‐CRP, the BT‐MACE association did not prevail. Conclusions In prospectively recruited patients with ACS, initial BT shows a U‐shaped relationship with 1‐year MACE risk among those with NSTE‐ACS, but not in those with STEMI. BT is a broadly available low‐cost marker to identify ACS patients with high inflammatory burden, at high risk for recurrent ischaemic events, and thus potentially suitable for an anti‐inflammatory intervention. Registration ClinicalTrials.gov Identifier: NCT01000701.