Prognostic impact of lipoprotein (a) on long-term clinical outcomes in diabetic patients on statin treatment after percutaneous coronary intervention

Abstract

BackgroundSerum levels of lipoprotein (a) [Lp(a)] have been reported as a residual risk marker for adverse events in patients with coronary artery disease (CAD). However, the prognostic impact of Lp(a) on long-term clinical outcomes among diabetic patients on statin therapy after percutaneous coronary intervention (PCI) remains unclear. MethodsThe present investigation was a single-center, observational, retrospective cohort study. Among consecutive patients with CAD who underwent first PCI in our institution from 2000 to 2016, we enrolled diabetic patients on statin treatment. As a result, 927 patients (81% men; mean age, 67 years) were enrolled and divided into 2 groups according to a median Lp(a) level of 19.5 mg/dL. The incidence of major adverse cardiac events (MACE), including all-cause death, non-fatal myocardial infarction (MI), and non-fatal cerebral infarction (CI), was evaluated. ResultNo significant differences were seen in age, sex, smoking habits, hypertension, chronic kidney disease, or body mass index between high and low Lp(a) groups. During follow-up (median, 5.0 years; interquartile range, 1.9–9.7 years), MACE occurred in 90 cases (17.6%), including 40 (7.9%) cardiac deaths, 18 (3.6%) non-fatal MI, and 37 (7.9%) non-fatal CI. Frequency of MACE was significantly higher in the high-Lp(a) group than in the low-Lp(a) group (log-rank test, p = 0.002). Higher Lp(a) level at the time of PCI was significantly associated with higher frequency of MACE, even after adjusting for other covariates, including other lipid profiles (hazard ratio, 1.91; 95% confidence interval, 1.20–3.09; p = 0.006). ConclusionOur results demonstrated that in diabetic patients with CAD on statin treatment, increased Lp(a) levels could offer a good residual lipid risk marker. Assessing Lp(a) levels may be useful for risk stratification of long-term clinical outcomes after PCI, especially in diabetic patients.