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

Abstract

ObjectiveTo investigate the prognostic effect of newly diagnosed diabetes mellitus (NDM) and impaired glucose tolerance (IGT) post myocardial infarction (MI).Research Design and MethodsRetrospective 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.ResultsPrevalence 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.ConclusionPresence 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.

Glucose abnormalities detected by oral glucose tolerance test in patients with acute myocardial infarction: clinical significance, epidemiology, natural course and therapeutic concerns

“…The analysis of particular MACE which occurred during long-term observation showed that there were no significant differences between patients with normal glucose tolerance and IFG, IGT, or DM with respect to recurrent AMI, percutaneous coronary intervention, coronary artery by-pass grafting or stroke [17]. The adverse role of IGT in AMI patients was also confirmed in a study by George et al in which 42% of the study population was treated invasively [18]. Impaired glucose tolerance, as well as newly detected DM, were independent predictors MACE.…”

“…Newly detected diabetes was also associated with a higher risk of nonfatal AMI. The authors compared readmission due to heart failure, however, no significant differences between the glucometabolic groups were noted [18]. To the authors' knowledge, there is only one study which showed that newly detected dysglycemia in AMI patients had no impact on the prognosis.…”

“…Impaired fasting glycemia (isolated or coexisting with impaired glucose tolerance) was observed in 10-15%, but it was reported infrequently. In patients with coronary artery disease, 2h-PG has a similar diagnostic and prognostic usefulness as in other populations [12,13,14,15,16,17,18]. Tamita et al classified AMI patients with respect to fasting glucose as subjects with normal or impaired fasting glycemia and showed that there were no significant differences in the major adverse cardiovascular events (MACE) between those groups.…”

“…Nevertheless, early performance of OGTT, the exclusion of high-risk patients with heart failure and renal failure, which were shown to be independent risk factors of death in patients with glucose abnormalities [17], could have had a major impact on the obtained results. In published studies, the clinical characteristics of patients with AMI and newly detected abnormal glucose tolerance are not equivocal, however, those patients are generally more likely to be older, female, hypertensive, overweight or obese, they have a worse left ventricle ejection fraction and renal function, higher glycemia measured on hospital admission, higher fasting glucose levels, higher glycosylated hemoglobin and insulin, proinsulin, and triglycerides than patients with normoglycemia [12, 13,14,15,16,17,18,19,20,21]. In the majority of studies there were no differences in cardiovascular medical history with respect to different glucose abnormalities, except a study by Bartnik et al which showed that patients with abnormal glucose tolerance had a trend towards more heart failure history [21].…”

What does the Acarbose Cardiovascular Evaluation (ACE) trial tell us?

“…[1][2][3] Observational studies have also shown that impaired glucose tolerance (IGT) is associated with increased cardiovascular morbidity and mortality, although to a lesser degree than in patients with T2DM. [4][5][6] These observational associations suggest the possibility that lowering postprandial glucose lowering levels in people with postprandial hyperglycemia and/or IGT could reduce their risk of T2DM, and may also reduce their risk of premature death. The Study to Prevent NIDDM (STOP-NIDDM), was a placebo-controlled double-blind trial that compared an α-glucosidase inhibitor, acarbose 100 mg three times daily, with placebo in 1429 individuals with IGT who were thought to be at relatively low cardiovascular risk.…”