Comparison of outcome among type 2 vs type 1 myocardial infarction: a systematic review and meta-analysis

To date, there were limited studies available on myocardial infarction (MI), and consequently, the outcomes of patients with type 1 myocardial infarction (T1MI) compared to type 2 myocardial infarction (T2MI) remained inconclusive. We aimed to compare the outcomes of T1MI and T2MI patients in terms of mortality and adverse cardiovascular outcomes. We performed a systematic literature search on PubMed, Embase, and Scopus for relevant articles from inception until March 20, 2022. 341,049 patients had T1MI, while the remaining 67,537 patients had T2MI. Mean age was similar between both groups (T1MI: 67.3 years, T2MI: 71.03 years), while the proportion of females was lower in T1MI (37.81% vs 47.15%). Our analysis revealed that patients with T1MI had significantly lower odds of all-cause mortality (OR 0.45, 95% CI 0.36-0.56, p < 0.001), in-hospital mortality (OR 0.63, 95% CI 0.46-0.86, p < 0.001), 1-year mortality (OR 0.35, 95% CI 0.25-0.47, p < 0.001), and major adverse cardiovascular events (MACE) (OR 0.59, 95% CI 0.39-0.91, p = 0.02). There was no significant difference in terms of 30-day mortality (OR 0.58, 95% CI 0.25-1.36, p = 0.21), cardiovascular mortality (OR 0.95, 95% CI 0.68-1.32, p = 0.74), all-cause readmission (OR 0.84, 95% CI 0.62-1.14, p = 0.26), and readmission due to MI (OR 1.22, 95% CI 0.66-2.27, p = 0.53) between both groups. Patients with T1MI had favorable outcomes in terms of mortality and MACE compared to that of T2MI patients. Further studies should aim at determining the optimal management strategy for these high-risk patients for better patient outcomes.