Amyloid β1-40 Predicts Long-Term Mortality Rate in Patients With Acute Myocardial Infarction

Background: Amyloid β1-40 (Aβ1-40) contributes to atherosclerosis, being involved in plaque formation and destabilization. The prognostic role of Aβ1-40 in patients with acute myocardial infarction is currently limited to non-ST-segment-elevation myocardial infarction (NSTEMI). We examined the prognostic value of Aβ1-40 in a real-world cohort of patients with acute myocardial infarction (both ST-segment-elevation myocardial infarction [STEMI] and NSTEMI) and identified predictors for its elevated levels. Methods and results: Our population included 1119 consecutive patients (mean age, 67 years; 72% men; and STEMI, 68%). The median Aβ1-40 concentration on admission was 86.9 (interquartile range, 54.5-128.9) pg/mL, and there was no difference in Aβ1-40 levels between NSTEMI and STEMI (P=0.1). Higher Aβ1-40 levels were predicted by older age, lower left ventricular ejection fraction, glycated hemoglobin >39 mmol/mol and glomerular filtration rate <60 mL/min per m2. From the final multivariable model, a nomogram was computed to determine probability of high Aβ1-40. During the median follow-up of 57 months, 193 patients (17.2%) died. Kaplan-Meier analysis revealed higher mortality risk in patients with Aβ1-40 levels above the median (P<0.01), consistent across STEMI (P<0.01) and NSTEMI (P=0.01) subgroups. At Cox multivariable analysis including the entire cohort, Aβ1-40 levels were predictive of death (hazard ratio, 1.03; P=0.01), together with older age, higher high-sensitivity C-reactive protein levels, smoking, glomerular filtration rate <60 mL/min per m2, worse left ventricular ejection fraction, and previous ischemic events. In the STEMI subcohort, Aβ1-40 remained a significant predictor, along with advanced age, worse left ventricular ejection fraction, smoking, and elevated high-sensitivity C-reactive protein. No such association was found in patients with NSTEMI (P=0.17), likely due to the smaller cohort size and low event rate. Conclusions: Aβ1-40 is an independent predictor of death and improves risk stratification in patients with acute myocardial infarction.