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

Aims: To conduct a systematic review and meta-analysis with the aim of providing robust estimates of the association between diabetes and long-term (>= 1 year) mortality after acute myocardial infarction (AMI). Material and methods: Medline, Embase and Web of Science databases were searched (January 1985 to July 2016) for terms related to long-term mortality, diabetes and AMI. Two authors independently abstracted the data. Hazard ratios (HRs) comparing mortality in people with and without diabetes were pooled across studies using Bayesian random-effects meta-analysis. Results: A total of 10 randomized controlled trials and 56 cohort studies, including 714 780 patients, reported an estimated total of 202 411 deaths over the median (range) follow-up of 2.0 (1-20) years. The risk of death over time was significantly higher among those with diabetes compared with those without (unadjusted HR 1.82, 95% credible interval [CrI] 1.73-1.91). Mortality remained higher in the analysis restricted to 23/64 cohorts reporting data adjusted for confounders (adjusted HR 1.48, 95% CrI 1.43-1.53). 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, 95% CrI 1.70-1.95). Conclusions: Despite medical advances, individuals with diabetes have a 50% greater long-term mortality compared with 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.