Prevalence and prognostic significance of chronic hyperglycaemia post acute myocardial infarction in a multiethnic UK population

Background: Coronary heart disease (CHD) and chronic hyperglycaemia (type 2 diabetes (T2DM) and impaired glucose regulation) are highly prevalent and associated with premature and excess mortality in the South Asian (SA) compared with the White European (WE) population. Further knowledge about chronic hyperglycaemia in SA patients with acute myocardial infarction (AMI) would help develop strategies to reduce the burden of CHD in this ethnic group. Aims: 1) To undertake a systematic review and meta-analysis to establish the association between diabetes and long-term mortality post AMI. 2) To investigate the relative prognostic significance of admission hyperglycaemia and prior diabetes in SA and WE patients admitted with AMI. 3) To compare survival in SA and WE patients presenting with AMI 4) To compare the prevalence of undiagnosed chronic hyperglycaemia in SA and WE patients admitted with AMI. 5) To evaluate the diagnostic yield and utility of oral glucose tolerance test (OGTT) versus HbA1c in screening for chronic hyperglycaemia in AMI. Key findings: 1) Diabetes increased long-term mortality post AMI by 50%. 2) Admission glucose was strongly associated with short- and long-term mortality post AMI, irrespective of prior diabetes diagnosis. 3) Adjusted survival following AMI was similar for SA and WE patients in the UK. 4) SA patients with AMI had up to six-fold higher risk of having undiagnosed T2DM than WE patients. 5) In AMI, use of HBA1c increased the prevalence of undiagnosed T2DM by over 1.5 fold (6.0% to 8.5%) in comparison with OGTT. Conclusion: This thesis established the higher prevalence of T2DM (diagnosed and undiagnosed) in UK SA patients presenting with AMI. This programme of work will help establish methods of screening for chronic hyperglycaemia in the setting of AMI. Early detection of T2DM in the SA population is extremely important to curb the higher incidence of CHD and related mortality in this population

All-cause mortality in relation to glycated haemoglobin in individuals with newly diagnosed type 2 diabetes: a retrospective cohort study

Aims: To explore the effect of glycated haemoglobin A1C (HbA1C) on all cause mortality in individuals newly diagnosed with type 2 diabetes, with and without previous cardiovascular disease. Methods: We identified a total of 110,372 of individuals aged 18 to 80 years newly diagnosed with type 2 diabetes (including 9721 (8.8%) with established cardiovascular disease before diagnosis of diabetes) from the UK General Practice Research Database from 1990 to 2005. Primary outcome was all cause mortality. Cox proportional hazards models were used to assess the impact of HbA1C on survival. Results: Over a median follow up of 5.2 years (interquartile range 2.9 to 8.1 years) there were 20,481 deaths. The hazard ratios for all cause mortality in individuals without cardiovascular disease, using the category of 6-6.49% as reference, were 1.28 (1.08 to 1.52), 1.16 (1.00 to 1.39), 1.43 (1.20 to 1.72), 1.62 (1.35 to 1.95), 1.80 (1.52 to 2.23), and 2.43 (2.01 to 2.97) for HbA1C categories of 9.0% respectively. In individuals with established cardiovascular disease a significant increased risk of mortality was observed for HbA1C categories above 8.00%; hazard ratios 1.91 (1.30-2.83) for HbA1C 8.00-8.99% and 1.95 (1.30-2.90) for HbA1C > 9.0%. Conclusions: A target of HbA1C between 6.0 and 6.5% is appropriate for individuals newly diagnosed with type 2 diabetes without cardiovascular disease. However, a target of < 8.0% may be less beneficial in individuals with established cardiovascular disease

Survival in South Asian and white European patients after acute myocardial infarction; a UK historical cohort study.

Objective To examine the association between ethnicity and survival following acute myocardial infarction (AMI) in White European (WE) and South Asian (SA) patients from a multiethnic UK population. Methods Retrospective, cohort study of 4111 (N=730, 17.8% of SA ethnicity) hospitalised patients, with AMI from a tertiary coronary care centre in the UK, admitted between October 2002 and September 2008. The primary end point was all-cause mortality. The association of ethnicity with survival post AMI was assessed using the Cox regression analysis. Results Compared with WE patients, SA patients were on average younger (62.0 years vs 67.3 years) and had higher prevalence of cardiovascular risk factors including diabetes (39.7% vs 16.1%). During follow-up (median 912, range 1–2556, days), crude mortality rate was 22.6% in SA patients and 26.0% in WE patients (p=0.061). SA ethnicity did not show univariate (HR 0.85 (0.72 to 1.01)) or multivariate (HR, 1.12 (0.94 to 1.34)) association with mortality. Findings were similar for mortality during 0–30 days (1.30 (0.99 to 1.70)), >30 days−1 year (0.97 (0.67 to 1.40)), >1 year–3 years (1.21 (0.83 to 1.76)), >3 years (0.82 (0.47 to 1.41)), and for long-term mortality in survivors from 30 days (1.02 (0.81 to 1.29)). Conclusions When adjusted for differing prevalence of cardiovascular risk factors in the two ethnic groups, survival following AMI was similar for SA and WE patients in the UK

Long-term mortality following acute myocardial infarction among those with and without diabetes: A systematic review and meta-analysis of studies in the post reperfusion era.

Aims: Considerable medical advances have seen an improved survival following an acute myocardial infarction (AMI), whether these benefits extend to those with diabetes remains less clear. This systematic review and meta-analysis aim to provide robust estimates of the association between diabetes and long-term mortality (≥one year) following AMI. Material and Methods: Medline, Embase and Web of Science databases were searched (January 1985 - July 2016) for terms related to long-term mortality, diabetes and AMI. Two authors independently abstracted the data. Hazard ratios (HR) comparing mortality in people with and without diabetes were pooled across studies using Bayesian random effects metaanalysis. Results: Ten randomised controlled trials and 56 cohort studies, including 714,780 patients, reported an estimated total of 202,411 deaths over the median follow-up of 2.0 years (range 1 to 20). The risk of death over time was significantly higher among those with diabetes compared to those without (unadjusted Hazard Ratio (HR) 1.82; 95% Credible Interval (CrI) 1.73 to 1.91). Mortality remained higher in the analysis restricted to 23/64 cohorts which had adjusted for confounders (adjusted HR 1.48 (1.43 to 1.53)). The excess long-term mortality in diabetes was evident irrespective of the phenotype and modern treatment of AMI, and persisted in early survivors (unadjusted HR 1.82 (1.70 to 1.95)). Conclusions: Despite medical advances, individuals with diabetes have a 50% increased long-term mortality compared to those without. Further research to understand the determinants of this excess risk are important for public health, given the predicted rise in global diabetes prevalence