What is the clinical evidence from this study?

Study design: Cohort. Population: Myocardial infarction (n=768). Intervention: Newly diagnosed diabetes mellitus (NDM) vs. Normal glucose tolerance (NGT). Primary outcome: First occurrence of major adverse cardiovascular events (MACE) including cardiovascular death, non-fatal MI, severe heart failure or non-haemorrhagic stroke (HR 2.15, 95% CI 1.42-3.24, p=0.003).

November 16, 2015Open Access

Impaired Glucose Tolerance or Newly Diagnosed Diabetes Mellitus Diagnosed during Admission Adversely Affects Prognosis after Myocardial Infarction: An Observational Study

Key Result

Newly diagnosed diabetes mellitus (HR 2.15) and impaired glucose tolerance (HR 1.54) independently increased the risk of major adverse cardiovascular events compared to normal glucose tolerance post-myocardial infarction.

Study Design

Type

Cohort (n=768)

Multicenter

Structured PICO

Does newly diagnosed diabetes mellitus or impaired glucose tolerance increase the risk of major adverse cardiovascular events in patients post-myocardial infarction?

Population

768 patients without preexisting diabetes mellitus admitted with myocardial infarction, followed for a mean of 47.2 months.

Exposure

Newly diagnosed diabetes mellitus (NDM) or impaired glucose tolerance (IGT) diagnosed on pre-discharge oral glucose tolerance test (OGTT)

Comparator

Normal glucose tolerance (NGT) diagnosed on pre-discharge oral glucose tolerance test (OGTT)

Outcome

First occurrence of major adverse cardiovascular events (MACE) including cardiovascular death, non-fatal MI, severe heart failure (HF) or non-haemorrhagic strokecomposite

Newly diagnosed diabetes mellitus and impaired glucose tolerance identified via pre-discharge OGTT are strong independent predictors of major adverse cardiovascular events in patients post-myocardial infarction.

Main Result

Hazard Ratio: 2.15 (95% CI 1.42–3.24)

Absolute Event Rate: 32.2% vs 14.2%

p-value: p=0.003

Limitations

Retrospective analysis of prospectively collected data from a single centre
Did not explore the interaction between acute revascularisation and post-challenge hyperglycaemia or post-discharge management
OGTT was not repeated pre- or post-discharge, so random fluctuation or stress-associated hyperglycaemia could not be ruled out

Abstract

OBJECTIVE: To investigate the prognostic effect of newly diagnosed diabetes mellitus (NDM) and impaired glucose tolerance (IGT) post myocardial infarction (MI). RESEARCH DESIGN AND METHODS: Retrospective cohort study of 768 patients without preexisting diabetes mellitus post-MI at one centre in Yorkshire between November 2005 and October 2008. Patients were categorised as normal glucose tolerance (NGT n = 337), IGT (n = 279) and NDM (n = 152) on pre- discharge oral glucose tolerance test (OGTT). Primary end-point was the first occurrence of major adverse cardiovascular events (MACE) including cardiovascular death, non-fatal MI, severe heart failure (HF) or non-haemorrhagic stroke. Secondary end-points were all cause mortality and individual components of MACE. RESULTS: Prevalence of NGT, impaired fasting glucose (IFG), IGT and NDM changed from 90%, 6%, 0% and 4% on fasting plasma glucose (FPG) to 43%, 1%, 36% and 20% respectively after OGTT. 102 deaths from all causes (79 as first events of which 46 were cardiovascular), 95 non fatal MI, 18 HF and 9 non haemorrhagic strokes occurred during 47.2 ± 9.4 months follow up. Event free survival was lower in IGT and NDM groups. IGT (HR 1.54, 95% CI: 1.06-2.24, p = 0.024) and NDM (HR 2.15, 95% CI: 1.42-3.24, p = 0.003) independently predicted MACE free survival. IGT and NDM also independently predicted incidence of MACE. NDM but not IGT increased the risk of secondary end-points. CONCLUSION: Presence of IGT and NDM in patients presenting post-MI, identified using OGTT, is associated with increased incidence of MACE and is associated with adverse outcomes despite adequate secondary prevention.

Bookmark

View Full Paper