Developing and Validating a Simple Risk Score for Patients with Acute Myocardial Infarction.

INTRODUCTION: Mortality from acute myocardial infarction (AMI) remains substantial. The current study is aimed at developing a novel simple risk score for AMI. METHODS: The Coronary Artery Tree description and Lesion EvaluaTion (CatLet) extended validation trial (ChiCTR2000033730) and the CatLet validation trial (ChiCTR-POC-17013536), both being registered with chictr.org, served as the derivation and validation datasets, respectively. Both datasets included 1,018 and 308 patients, respectively. They all suffered from AMI and underwent percutaneous intervention (PCI). The endpoint was 4-year all-cause death. Lasso regression analysis was used for covariate selection and coefficient estimation. RESULTS: Of 26 candidate predictor variables, the four strongest predictors for 4-year mortality were included in this novel risk score with an acronym of BACEF (serum alBumin, Age, serum Creatinine, and LVEF). This score was well calibrated and yielded an AUC (95% CI) statistics of 0.84 (0.80-0.87) in internal validation, 0.89 (0.83-0.95) in internal-external (temporal) validation, and 0.83 (0.77-0.89) in external validation. Notably, it outperformed the ACEF, ACEF II, GRACE scores with respect to 4-year mortality prediction. CONCLUSION: A simple risk score for 4-year mortality risk stratification was developed, extensively validated, and calibrated in patients with AMI. This novel BACEF score may be a useful risk stratification tool for patients with AMI.

Interaction of lipoprotein(a) with low-density lipoprotein cholesterol on first incident acute myocardial infarction.

OBJECTIVE: To evaluate the interaction effects between lipoprotein (a) (Lp(a)) and low-density lipoprotein cholesterol (LDL-C) on first incident acute myocardial infarction (AMI) among Chinese Han population. METHODS: 1522 cases and 1691 controls were retrospectively analyzed. All subjects were grouped by Lp(a) or LDL-C level. RESULTS: Compared with reference group (LDL-C < 2.6 mmol/L and in the 1st quintile of Lp(a)), multivariable-adjusted analysis revealed that OR(95%CI) of first incident AMI for higher LDL-C alone is 2.66(1.78-3.98); that ORs(95%CI) for higher Lp(a) alone are 1.51(1.07-2.15), 1.84(1.28-2.64), 1.86(1.30-2.67) and 2.66(1.88-3.76) across the Lp(a) quintiles; and that ORs(95%CI) for both higher LDL-C and higher Lp(a) are 3.95(2.64-5.92), 3.20(2.21-4.64), 5.64(3.80-8.36) and 7.48(4.90-11.44) which were greater than the sum of the risks of both alone across the Lp(a) quintiles. Relative excess risks due to interaction were 1.78(95% CI, 0.12-3.44, P = 0.036) and 3.01(0.58-5.44, P = 0.015) at the 4th and 5th quintile of Lp(a), confirming the presence of additive interaction between Lp(a) and LDL-C on initial AMI. CONCLUSIONS: Lp(a) interacts with LDL-C in first incident AMI on additive scale in Chinese Han population. The risk of initial AMI from exposure of elevated Lp(a) combined with elevated LDL-C is much greater than the sum of the risks from that of both alone.