Advantages of using Genetically Elevated Lipoprotein(a) Levels in Predicting 5-Year Major Adverse Cardiovascular Events Relating to Coronary Artery Disease in Women.

BACKGROUND

This study aimed to investigate major adverse cardiovascular events (MACE) in patients with coronary artery disease (CAD) over 5 years, in general, and depending on sex, lipoprotein(a) level, and number of kringle IV type 2 (KIV-2) repeats in the Lipoprotein(A) (LPA) gene.

METHODS

This study comprised 216 patients (120 women and 96 men) hospitalized with a diagnosis of "CAD, unstable angina IIB class". The three-point risk of MACEs was assessed over 5 years: cardiovascular death, non-fatal myocardial infarction, and stroke. The number of KIV-2 repeats in the LPA gene was determined by quantitative real-time polymerase chain reaction (qPCR).

RESULTS

The relative risk of MACE in patients with elevated lipoprotein(a) (Lp(a)) was 2.0 (95% CI 1.04-3.87, p < 0.05) for quartile 4 (Q4) ≥ 48 mg/dL versus quartile 1 (Q1) ≤ 6 mg/dL. This was mainly attributable to an increase in men-relative risk (RR) 2.6 (95% CI 1.10-6.16, p < 0.05)-but not in women: RR 1.4 (95% CI 0.50-3.92). Mean lipoprotein(a) levels were inversely correlated with 42.5 and 7.5 for Q1 and Q4 KIV-2 repeat numbers, respectively. The relative risks of MACE for Q1 vs. Q4 KIV-2 repeats were as follows: 3.0 (95% CI 1.48-6.08, p < 0.001) for all patients; 3.0 (95% CI 1.20-6.55, p < 0.01) for men; 3.3 (95% CI 1.02-10.4, p < 0.05) for women.

CONCLUSIONS

Quantifying kringle IV type 2 repeat copy number in the LPA gene using qPCR more accurately reflects the risk of major adverse cardiovascular events within 5 years in women with coronary artery disease.