Lipoprotein(a), Atherosclerotic Plaque Burden, and Long-term Cardiovascular Outcomes in Patients With Coronary Artery Disease.

BACKGROUND & AIMS: Although lipoprotein(a) [Lp(a)] is an established independent risk factor for atherosclerotic cardiovascular disease (ASCVD) in primary prevention settings, it remains unclear whether Lp(a) contributes to an increased risk of adverse cardiovascular events in patients with established ASCVD. METHODS: The current analysis combines the ATHEROREMO and IBIS-3 observational studies, which together enrolled 798 patients undergoing coronary angiography for stable angina pectoris or acute coronary syndrome. Intravascular ultrasound (IVUS) and near-infrared spectroscopy were performed to assess coronary plaque characteristics in a non-culprit study segment. Regression models were applied to relate Lp(a) to coronary plaque characteristics and long-term (up to 10 year) clinical outcomes. Lp(a) was analysed both as a continuous and categorical variable (using 75 nmol/L and 125 nmol/L as threshold). RESULTS: Mean age of the patients was 61.6 years (10.8); 75% were male; 19% had elevated Lp(a) levels (>125 nmol/L). Patients with Lp(a) > 125 nmol/L had a significantly higher prevalence of hypercholesterolemia and prior percutaneous coronary intervention. These patients demonstrated higher IVUS-derived plaque burden (40.7% (±11.5) vs. 38.6% (±10.7), p = 0.028), though no associations were found with other plaque characteristics, e.g. minimum lumen area, lipid core burden index and thin-cap fibroatheroroma. No association was found between Lp(a) and -5-year major adverse cardiac events (HR 1.06, 95% CI: 0.70-1.60, p = 0.78) and 10-year all-cause mortality (HR 0.63, 95% CI: 0.38-1.06, p = 0.78). CONCLUSIONS: Among patients with established ASCVD, Lp(a) was associated with plaque burden, supporting evidence that relates Lp(a) to atherosclerotic disease. However, Lp(a) was not associated with long-term mortality or cardiac adverse events in these patients.