Diurnal, weekly and seasonal variations of chest pain in patients transported by emergency medical services.

OBJECTIVES: Chest pain is among the leading causes for emergency medical services (EMS) activation. Acute myocardial infarction (MI) is not only one of the most critical aetiologies of chest pain, but also one of few conditions encountered by EMS that has been shown to follow a circadian pattern. Understanding the diurnal relationship between the inflow of chest pain patients and the likelihood of acute MI may inform prehospital and emergency department (ED) healthcare providers regarding the prediction, and hence prevention, of dire outcomes. METHODS: This was a secondary analysis of previously collected data from an observational prospective study that enrolled consecutive chest pain patients transported by a large metropolitan EMS system in the USA. We used the time of EMS call to determine the time-of-day of the indexed encounter. Two independent reviewers examined available medical data to determine our primary outcome, the presence of MI, and our secondary outcomes, infarct size and 30-day major adverse cardiac events (MACE). We estimated infarct size using peak troponin level. RESULTS: We enrolled 2065 patients (age 56±17, 53% males, 7.5% with MI). Chest pain encounters increased from 9:00 AM to 2:00 PM, with a peak at 1:00 PM and a nadir at 6:00 AM. Acute MI had a bimodal distribution with two peaks: 10 AM in ST-elevation MI, and 10 PM in non-ST-elevation MI. ST-elevation MI with afternoon onset was an independent predictor of infarct size. Acute MI with winter and early spring presentation was an independent predictor of 30-day MACE. CONCLUSIONS: EMS-attended chest pain calls follow a diurnal pattern, with the most vulnerable patients encountered during afternoons and winter/spring seasons. These data can inform prehospital and ED healthcare providers regarding the time of presentation where patients are more likely to have an underlying MI and subsequently worse outcomes.

Perioperative stroke associated in-hospital morbidity and in-hospital mortality in common non-vascular non-neurological surgery.

Perioperative stroke in non-vascular, non-neurological surgery is a potential cause of high levels of in-hospital morbidity and mortality. Although, perioperative stroke following non-vascular and non-neurological surgery is a relatively infrequent event; high surgical volume results in thousands of patients experiencing neurological deficits. We aim to determine if perioperative stroke is an independent risk factor for 30-day in-hospital morbidity and mortality following common non-vascular non-neurological surgery. This is a retrospective analysis of 4,264,963 surgical procedures identified in the Nationwide Inpatient Sample (NIS) from the years 2000 through 2011. The exposure of interest was stroke within 30 days of total knee arthroscopy, total hip arthroscopy, lung segmentation and resection, appendectomy, hemicolectomy, cholecystectomy, and lysis of peritoneal adhesions. Study outcomes were in-hospital mortality and in-hospital morbidity. Our study found an in-hospital morbidity, in-hospital mortality, and perioperative stroke rate of 5.5%, 0.8%, and 0.2%, respectively. Multivariable analysis revealed perioperative stroke to be a significant independent predictor (p < 0.001) of length of stay exceeding 14 days (OR = 4.55, 95% CI: 4.21-4.91), cardiovascular complications (OR = 1.96, 95% CI: 1.75-2.19), pulmonary complications (OR = 2.07, 95% CI: 1.89-2.27). The impact of perioperative stroke on in-hospital mortality was (OR = 8.53, 95% CI: 7.87-9.25), whereas cardiovascular complications impact on in-hospital mortality was (OR = 8.36, 95% CI = 7.67-9.10, p < 0.001). This study identified perioperative stroke as an independent predictor of 30-day in-hospital morbidity and mortality following non-vascular, non-neurological surgery.