The reliability and prognosis of in-hospital diagnosis of metabolic syndrome in the setting of acute myocardial infarction

Abstract

Objectives: This study sought to examine the reliability and prognostic importance of an in-hospital diagnosis of metabolic syndrome (MetS) in the setting of acute myocardial infarction (AMI).

Background: Because the factors that comprise MetS are believed to be altered in the setting of AMI, the diagnosis of MetS during AMI hospitalization and its prognostic significance have not been studied.

Methods: We assessed patients within a multicenter registry for metabolic factors at baseline and 1 month post-AMI and followed them for mortality and rehospitalizations. The accuracy of an inpatient diagnosis of MetS was calculated using a 1-month follow-up as the gold standard. Patients were categorized based on MetS diagnosis at baseline and 1 month, and the combined endpoint of death or rehospitalization over 12 months was compared between groups.

Results: Of the 1,129 patients hospitalized for AMI, diagnostic criteria for MetS were met by 69% during AMI hospitalization and 63% at 1 month. Inpatient MetS diagnosis had a sensitivity and specificity for outpatient diagnosis of 87% and 61%, respectively, and was associated with an 11 times increased odds of an outpatient diagnosis (C-index 0.74). Compared with patients without MetS during hospitalization and follow-up, patients classified as MetS during AMI but not follow-up had worse outcomes, whereas those classified MetS at follow-up had the worst outcomes (rates for combined endpoint 27% vs. 37% vs. 38%; log-rank p = 0.01).

Conclusions: In a large cohort of patients with AMI, the diagnosis of MetS is common and can be made with reasonable accuracy during AMI. MetS is associated with poor outcomes, regardless of whether the diagnosis is confirmed during subsequent outpatient visit, and identifies a high-risk cohort of patients that may benefit from more aggressive risk factor modification.

Keywords: AMI; CAD; MetS; acute myocardial infarction; coronary artery disease; long-term outcomes; metabolic syndrome; myocardial infarction.

Copyright © 2013 American College of Cardiology Foundation. Published by Elsevier Inc. All rights reserved.

Figures

Figure 1. Flowchart of Patients in Study Cohort

Patients could opt for 1-month follow-up by telephone or in-home visit, which allowed for collection of additional clinical and laboratory data. Only patients with baseline and 1-month assessments sufficient to determine the presence or absence of MetS were included.

Figure 2. Prevalence of the Components of Metabolic Syndrome During and After AMI Hospitalization

Number of patients who met diagnostic criteria for MetS and each of the individual components during AMI hospitalization and at 1-month follow-up.

Figure 3. Survival Free from Death or Rehospitalization Across Metabolic Groups

MetS−/MetS−=No MetS at baseline and 1-month (n=256). MetS+/MetS−=MetS at baseline but not at 1 month (n=162). MetS+/MetS+ and MetS−/MetS+=true MetS patients (i.e., MetS diagnosed as an outpatient; n=711).