Hyperglycaemia, adverse outcomes and impact of intravenous insulin therapy in patients presenting with acute ST‐elevation myocardial infarction in a socioeconomically disadvantaged urban setting: The Montefiore STEMI Registry

BACKGROUND: Hyperglycaemia occurs frequently in ST‐elevation myocardial infarction (STEMI) and is associated with poor outcomes, for which continuous insulin infusion therapy (CIIT) may be beneficial. Information is limited regarding hyperglycaemia in acute STEMI affecting urban minority populations, or how CIIT fares in such real‐world settings. METHODS AND RESULTS: We assembled an acute STEMI registry at an inner‐city health system, focusing on patients with initial blood glucose ≥180 mg/dL to determine the impact of CIIT vs usual care. Clinical and outcomes data were added through linkage to electronic records. Inverse‐probability‐of‐treatment weighting using propensity scores (PS) was used to compare CIIT vs no CIIT. The 1067 patients included were mostly Hispanic or African American; 356 had blood glucose ≥180 mg/dL. Such pronounced hyperglycaemia was related to female sex, minority race‐ethnicity and lower socioeconomic score, and associated with increased death and death or CVD readmission. CIIT was preferentially used in patients with marked hyperglycaemia and was associated with in‐hospital hypoglycaemia (21% vs 11%, P = .019) and, after PS weighting, with increased in‐hospital (RR 3.23, 95% CI 0.94, 11.06) and 1‐year (RR 2.26, 95% CI 1.02, 4.98) mortality. No significant differences were observed for death at 30 days or throughout follow‐up, or death and readmission at any time point. CONCLUSIONS: Pronounced hyperglycaemia was common and associated with adverse prognosis in this urban population. CIIT met with selective use and was associated with hypoglycaemia, together with increased mortality at specific time points. Given the burden of metabolic disease, particularly among race‐ethnic minorities, assessing the benefits of CIIT is a prerogative that requires evaluation in large‐scale randomized trials.