In-Hospital ACEI Use and Long-Term Prognosis in Discharged Type 2 Myocardial Infarction Patients

ObjectiveTo explore the relationship between angiotensin-converting enzyme inhibitor (ACEI) use during hospitalization and both short-term and long-term prognosis of type 2 myocardial infarction (T2MI) patients after discharge. MethodsThis was a retrospective cohort study based on Medical Information Mart for Intensive Care IV(MIMIC-IV). Adult critically ill patients with T2MI were included in the analysis. The exposure was ACEI use during ICU stay. The primary outcome measure was 3-year all-cause mortality. Propensity score matching (PSM) was performed at a 1:1 ratio. Multivariate analysis was used to adjust for confounding factors. ResultsA total of 1086 T2MI patients were included. The PSM cohort included 590 patients, with 295 patients in each group. ACEI use significantly reduced the 3-year all-cause mortality (hazard ratio [HR], 0.55; 95% confidence interval [CI], 0.41-0.74; P<0.001). Both univariate and multivariate Cox proportional hazards analyses indicated that ACEI use reduced the risk of 3-year all-cause mortality (univariate HR, 0.55; multivariate HR, 0.59; all P<0.001). Sensitivity analysis using the entire cohort also showed that ACEI use significantly reduced 3-year all-cause mortality (HR, 0.58; 95% CI, 0.42-0.80; P<0.001). In addition, ACEI use significantly reduced 180-day all-cause mortality (HR, 0.43; 95% CI, 0.29-0.64; P<0.001). Both univariate Cox proportional hazards model analysis (HR, 0.43; 95% CI, 0.29-0.65; P<0.001) and multivariate Cox proportional hazards model analysis (HR, 0.49; 95% CI, 0.33-0.72; P<0.001) indicated that ACEI use reduced the risk of 180-day all-cause death in patients. The study results also showed that ACEI use had no effect on the risk of 3-year all-cause readmission (HR, 1.003; 95% CI, 0.776-1.295; P=0.984) and 3-year T2MI recurrence risk (HR, 1.14; 95% CI, 0.64-2.05; P=0.654). ConclusionACEI use significantly reduces both short-term and long-term all-cause mortality in discharged T2MI patients, while it does not affect patients readmission rates or T2MI recurrence rates. These findings expand the clinical applications of ACEI in populations with myocardial infarction of different pathogenesis. Further prospective studies are needed to determine the optimal administration strategy of ACEI. Key QuestionDoes ACEI use during hospitalization affect the long-term prognosis of T2MI patients after discharge? Key FindingIn discharged T2MI patients, ACEI use significantly reduced the 3-year and 180-day all-cause mortality, but had no effect on the risk of 3-year all-cause readmission or T2MI recurrence. Take Home MessageACEI use significantly reduces both short-term and long-term all-cause mortality in discharged T2MI patients; nevertheless, it does not affect readmission or T2MI recurrence rates. These findings broaden the clinical use of ACEI to include patients with myocardial infarction caused by different pathophysiological mechanisms.