Impact of elevated lipoprotein(a) on coronary artery disease phenotype and severity

Abstract

Aims A thorough characterization of the relationship between elevated lipoprotein(a) [Lp(a)] and coronary artery disease (CAD) is lacking. This study aimed to quantitatively assess the association of increasing Lp(a) levels and CAD severity in a real-world population. Methods This non-interventional, cross-sectional, LipidCardio study included patients aged ≥21 years undergoing angiography and results (October 2016−March 2018) at a tertiary cardiology centre, who have at least one Lp(a) measurement. The association between Lp(a) and CAD severity was determined by synergy between PCI with taxus and cardiac surgery (SYNTAX)-I and Gensini scores and angiographic characteristics. Overall, 975 patients (mean age: 69.5 years) were included; 70.1% were male, 97.5% had Caucasian ancestry, and 33.2% had a family history of premature atherosclerotic cardiovascular disease. Median baseline Lp(a) level was 19.3 nmol/L. Patients were stratified by baseline Lp(a): 72.9% had < 65 nmol/L, 21.0% had ≥100 nmol/L, 17.2% had ≥125 nmol/L, and 12.9% had ≥150 nmol/L. Compared with the normal (Lp(a) < 65 nmol/L) group, elevated Lp(a) groups (e.g. ≥ 150 nmol/L) had a higher proportion of patients with prior CAD (48.4% vs. 62.7%; P < 0.01), prior coronary revascularization (39.1% vs. 51.6%; P = 0.01), prior coronary artery bypass graft (6.0% vs. 15.1%; P < 0.01), vessel(s) with lesions (68.5% vs. 81.3%; P = 0.03), diffusely narrowed vessels (10.9% vs. 16.5%; P = 0.01) or chronic total occlusion lesions (14.3% vs. 25.2%; P < 0.01), and higher median SYNTAX-I (3.0 vs. 5.5; P = 0.01) and Gensini (10.0 vs. 16.0; P < 0.01) scores. Conclusion Elevated Lp(a) was associated with a more severe presentation of CAD. Awareness of Lp(a) levels in patients with CAD may have implications in their clinical management. Lay summary Patients with coronary artery disease (CAD) suffer with progressive plaque buildup in the walls of coronary blood vessels, which restricts blood flow and may result in serious cardiovascular outcomes such as chest pain (angina) and heart attacks (myocardial infarction). In this study, we assessed whether elevated levels of lipoprotein(a) [Lp(a)-a lipoprotein found in blood] are associated with more severe illness. We observed that elevated Lp(a) was associated with a higher proportion of patients with prior CAD, prior interventions on coronary blood vessels, and more diseased blood vessels. These collectively form what is considered a 'severe' clinical presentation of CAD, meaning a greater likelihood of adverse clinical outcomes.