Elevated lipoprotein(A) has incremental prognostic value in type 2 diabetic patients with symptomatic coronary artery disease

Abstract

Aim: In addition to type 2 diabetes, an elevated Lp(a) level is known to be a surrogate biomarker of cardiovascular disease. However, recent studies have demonstrated that the Lp(a) levels are lower in type 2 diabetic patients than in non-diabetic subjects. Therefore, we sought to evaluate the prognostic value of elevated lipoprotein(a) [Lp(a)] in type 2 diabetic patients with symptomatic coronary artery disease (CAD). Methods: A total of 1494 diabetic patients with CAD (62.3% men, mean age: 63.5±10.3 years) were enrolled. CAD was diagnosed using invasive coronary angiography, and laboratory values for lipid parameters, including Lp(a), were obtained on the day of coronary angiography. The patients were divided into tertile groups according to the individual Lp(a) level. The baseline characteristics, coronary angiographic findings, duration of follow-up and major adverse cardiovascular events (MACEs) were recorded. Results: Over a mean follow-up period of 4.4±2.6 years, there were 59 MACEs (35 cardiac deaths and 24 cases of non-fatal myocardial infarction), for an event rate of 3.9%. A survival probability plot according to the Lp(a) tertile revealed that an elevated Lp(a) level was associated with a worse prognosis (p= 0.008), after adjusting for age, gender, hypertension, hyperlipidemia, smoking and the extent of CAD. Furthermore, the addition of an elevated Lp(a) level to the reference model improved the integrated discrimination improvement (0.0216, p＜0.001), continuous net reclassification improvement (NRI) (0.5721, p=0.012) and NRI (0.1549, p=0.004) values. Conclusions: In terms of the prognosis, elevated Lp(a) is associated with worse outcomes in type 2 diabetic patients with symptomatic CAD. Furthermore, an elevated Lp(a) level has incremental prognostic value in type 2 diabetic patients with symptomatic CAD.