Isolated Elevation of Lipoprotein(A) is Uncommon Among Patients Admitted to Coronary Care

Abstract

Elevated lipoprotein(a) [Lp(a)] is an important inherited cardiovascular disease (CVD) risk factor. However, levels are not routinely measured in coronary care units (CCU). The clustering of elevated Lp(a) with other conventional CVD risk factors in this setting is also unknown. We aimed to audit the frequency of elevated Lp(a) in patients admitted to the CCU at Royal Perth Hospital, and to assess the spectrum of CVD risk factors in patients with high levels. Plasma Lp(a) was measured in all patients admitted to the CCU for 6.5 months. Elevated Lp(a) was defined as ≥0.50 g/L based on previous associations with CVD. Hypertension, type-2 diabetes and smoking status were recorded, and LDL-cholesterol documented from discharge summaries. LDL-cholesterol was adjusted for the cholesterol content of Lp(a) and lipid-lowering therapy. Lp(a) was measured in 345 patients; 69.6% were male, and average age was 61.8 years (range = 23.0 to 90.8). Elevated Lp(a) was identified in 27% (n = 93) of patients. In patients with elevated Lp(a), 33.3% (n = 31) had type-2 diabetes, 53.8% (n = 50) hypertension, and 36.6% (n = 34) were current or previous smokers; 71.0% (n = 66) had an adjusted LDL-cholesterol exceeding the recommended guideline of 2.5 mmol/L. Of those with elevated Lp(a), 35.5% (n = 33) had one, 25.8% (n = 24) two, 25.8% (n = 24) three, and 7.5% (N = 7) four of these additional CVD risk factors. There were 5 patients (5.4%) with isolated elevated Lp(a). These findings indicate that elevated Lp(a) co-exists with conventional CVD risk factors in most patients admitted to the CCU, suggesting that elevated Lp(a) may be a conditional CVD risk factor.