The association of lipoprotein(a) with patient characteristics and mortality in a primary prevention cohort: data from our clinic database

Abstract

Abstract Background Lipoprotein(a) [Lp(a)] has emerged as a causal risk factor for development of cardiovascular (CVD) and valvular heart disease. However, not much is known about the gender differences and Lp(a). The aim of our study was to investigate gender differences in clinical and laboratory characteristics of primary prevention patients with elevated Lp(a) and to study the associations between Lp(a) and all-cause mortality by gender. Method We analyzed data obtained from the Preventive Cardiology Information System (PreCis), a database of clinical and laboratory information on 8,136 consecutive primary prevention patients seen at our clinic preventive cardiology clinic from 1999-2018. Primary prevention was defined as having no history of coronary artery disease (CAD), coronary and peripheral arterial revascularization, nor atherosclerosis. Data regarding mortality were gathered from a combination of sources including the Social Security Death Index (SSDI), the Ohio State Department of Health Vital Statistics, and electronic medical record. All-cause mortality was assessed using time to event analyses, and adjusted Cox proportional hazards models. All statistical analyses were conducted using SAS version 9.4. Result In the overall cohort (n=8,136), 57% were female at a median age of 54 years and 43% were male at a median age of 52 years. Median Lp(a) was 24 (IQR 8-63) mg/dL in females and 18.6 (IQR 7-51) mg/dL in males. The proportion of females increased with increasing Lp(a) values from 54% with Lp(a) <30 mg/dL to 69% with Lp(a) ≥90mg/dL. Female patients with Lp(a) ≥50 mg/dL were significantly more likely to have dyslipidemia (40.5% vs 34.1%; p>0.001) and hypertension (27.3% vs 23.3%; p>0.001) compared to <50 mg/dL. There was a trend toward increased all-cause mortality in elevated Lp(a) group among female patients (<50 mg/dL vs ≥50 mg/dL; (HR (95%CI): 1.22 (0.98-1.52); p=0.083). Conclusion In this primary prevention population, a higher proportion of females had elevated Lp(a) than males. Females with elevated Lp(a) presented with more comorbidities and a trend towards increased all-cause mortality. These findings suggest a gender difference in the distribution of Lp(a) and all-cause mortality in the primary prevention setting, which warrants further investigation.