Circadian variations of infarct size in acute myocardial infarction

Abstract

BackgroundThe circadian clock influences a number of cardiovascular (patho)physiological processes including the incidence of acute myocardial infarction. A circadian variation in infarct size has recently been shown in rodents, but there is no clinical evidence of this finding. Objective To determine the impact of time-of-day onset of ST segment elevation myocardial infarction (STEMI) on infarct size. Methods A retrospective single-centre analysis of 811 patients with STEMI admitted between 2003 and 2009 was performed. Infarct size was estimated by peak enzyme release. The relationship between peak enzyme concentrations and time-of-day were characterised using multivariate regression splines. Time of STEMI onset was divided into four 6-hour periods in phase with circadian rhythms. Results Model comparisons based on likelihood ratio tests showed a circadian variation in infarct size across time-of-day as evaluated by peak creatine kinase (CK) and troponin-I (TnI) concentrations (p¼0.015 and p¼0.012, respectively). CK and TnI curves described similar patterns across time, with a global maximum in the 6:00enoon period and a local minimum in the noone18:00 period. Infarct size was largest in patients with STEMI onset in the dark-to-light transition period (6:00enoon), with an increase in peak CK and TnI concentrations of 18.3% (p¼0.031) and 24.6% (p¼0.033), respectively, compared with onset of STEMI in the 18:00emidnight period. Patients with anterior wall STEMI also had significantly larger infarcts than those with STEMI in other locations. Conclusions Significant circadian oscillations in infarct size were found in patients according to time-of-day of STEMI onset. The infarct size was found to be significantly larger with STEMI onset in the dark-to-light transition period (6:00enoon). If confirmed, these results may have a significant impact on the interpretation of clinical trials of cardioprotective strategies in STEMI.

Mechanical ventilation in the early phase of ST elevation myocardial infarction treated with mechanical revascularization

“…In our series MV is a strong independent predictor for mortality, since MV patients are older, with a larger infarct size (as indicated by peak TnI) [18][19][20], hemodynamic impairment (as inferred by advanced Killip class) and a higher incidence of multi-organ dysfunction (as indicated by lower eGFR and a higher use of devices, often simultaneously implanted).…”

On Circadian Variation of Myocardial Reperfusion Injury

“…Mukamal et al 19 reported that the highest peak creatine kinase levels occurred in patients with myocardial infarction whose symptoms commenced between midnight and 6 AM, and the highest incidence of heart failure was seen in patients whose symptoms began around midnight. In patients with acute ST-segment elevation myocardial infarction, Suarez-Barrientes 20 showed that maximum infarct size estimated by biomarker release, depression of left ventricular ejection fraction, and the incidence of clinical heart failure were all greater in patients whose infarcts occurred between 6 AM and noon. Arroyo Ucar et al 21 reported that infarct sizes were larger in patients with ST-segment elevation myocardial infarction whose symptoms began between midnight and noon than those occurring between noon and midnight.…”

Circadian rhythm and cardiovascular disorders

“…Two retrospective studies and one prospective study have independently demonstrated that a larger infarct size, estimated by biomarker release, in patients with ST-elevation MI undergoing primary percutaneous coronary intervention is associated with onset of symptoms in the sleep-wake transition. [53][54][55] However, a recent prospective multicenter, multiethnic cohort study did not find a clear circadian dependence of infarct size either in the entire data set or in each of the three participating countries separately. 56 Unlike symptoms of ischemia, infarct size is influenced not only by the circadian biology of the patient, but also by the circadian biology of their health care providers, who are shift workers themselves and under different levels of stress in a time-of-day-dependent manner.…”