High LDL cholesterol confers greater risk of STEMI than NSTEMI in statin-treated patients with ischemic heart disease

Background and Aims Low-density lipoprotein cholesterol (LDL-C) is causally associated with myocardial infarction (MI). However, MI covers two clinically different entities: ST-segment elevation MI (STEMI) and non-STEMI (NSTEMI). We aimed to assess whether high LDL-C confers greater risk of STEMI than NSTEMI in statin-treated patients with ischemic heart disease (IHD). Methods We included statin-treated patients with IHD determined by coronary angiography from the Western Denmark Heart Registry between 2011-2020. LDL-C and non-high-density lipoprotein cholesterol (non-HDL-C) levels were measured within 1 year after coronary angiography. The risk of STEMI and NSTEMI was estimated as adjusted hazard ratios (aHR). The comparison of STEMI versus NSTEMI and 30-day mortality after STEMI versus NSTEMI was estimated as adjusted odds ratios (aOR). Results The study included 36,739 statin-treated patients with IHD: 26,178 (71%) men, median age 66 years. During median follow-up of 4.9 years, 531 STEMI and 1,614 NSTEMI events occurred. Per 1 mmol/L higher LDL-C, the aHRs of STEMI and NSTEMI were 1.43 (95% CI: 1.30-1.57) and 1.23 (95% CI: 1.16-1.31), corresponding to an aOR of 1.18 (95% CI: 1.04-1.32) for STEMI versus NSTEMI. Patients at LDL-C goal ≤1.4 mmol/L versus >2.2 mmol/L had a lower risk of STEMI and NSTEMI, with 22% lower odds of STEMI than NSTEMI. Results were similar for non-HDL-C. STEMI was associated with higher 30-day mortality than NSTEMI: aOR 1.62 (95% CI: 1.02-2.57). Conclusions High LDL-C confers greater risk of STEMI than NSTEMI in statin-treated patients with IHD. This is important given the higher early mortality associated with STEMI.