Systematic review of β blocker, aspirin, and statin in critically ill patients: importance of severity of illness and cardiac troponin

Abstract

Non-cardiac critically ill patients with type II myocardial infarction (MI) have a high risk of mortality. There are no evidence-based interventions to mitigate this risk. We systematically reviewed the literature regarding the use of medications known to reduce mortality in patients with cardiac troponin (cTn) elevation due to type I MI (β blockers, statin, and aspirin) in studies of critically ill patients without Type I MI. All PubMed publications between 1976–2/19/16 were reviewed. Search terms included: β blocker or aspirin or statin and intensive care unit (ICU) or critically ill or sepsis; 497 primary references were obtained. Inclusion criteria were as follows: (1) study population consisted of critically ill patients in the ICU with non-cardiovascular illnesses, (2) mortality end point, (3) severity of illness (or injury) was measured, and (4) the antiplatelet agent was primarily aspirin. Retrospective investigations, prospective observational studies, meta-analysis, systematic review, and randomized controlled trials were included; case reports were excluded. 25 primary references were obtained. The data were extracted and tabulated using data collection headings as follows: article title, first author/year/reference number, study type/design, population studied, outcome and intervention, and study question addressed. Evidence was not graded as the majority of studies were non-randomized (low-to-moderate quality). 11 studies were found through bibliography reviews for a total of 36 references. In conclusion, β blockers, statins, and aspirin may play a role in reducing mortality in non-cardiac critically ill patients. Benefit appears to be related to severity of illness, for which cTn may be a marker.