Comparison of all-cause and cause-specific mortality after myocardial infarction - a Hungarian registry study

Despite advances, myocardial infarction remains a significant public health concern, with survival being a crucial outcome measure. While all-cause mortality is well-studied, less is known about causes of death following an infarction. This study aimed to analyse cause-specific mortality after myocardial infarction and to compare it with the analysis of all-cause mortality.

Data from a nationwide Hungarian myocardial infarction registry from January 2020 to June 2022 were linked with official cause of death information. Cumulative incidence functions and multivariable modelling of subdistribution hazard were used for cause-specific survival analysis, accounting for competing risks. Standard all-cause survival analysis (Cox proportional hazards model) was also carried out as a comparison.

Among 27,965 patients with acute myocardial infarction, 25.0 % died during follow-up (of a median of 661 days). Myocardial infarction was the primary cause of death in 38.6 % of cases, followed by other cardiovascular causes (37.5 %). Factors associated with higher cause-specific mortality for infarction included older age, male sex, ST-elevation infarction, diabetes, prior stroke, peripheral artery disease, and heart failure. Percutaneous coronary intervention and hypertension was associated with lower hazard. Results largely matched all-cause survival analysis, except for ST-elevation, where hazard was much higher in cause-specific analysis.

While overall and cause-specific analyses aligned in this large registry study, a notable difference was observed for ST-elevation infarction, where hazard was substantially higher in the cause-specific analysis. This highlights the potential relevance of distinguishing between causes of death for a more precise understanding of outcomes.