Association between Estimated Small Dense Low-Density Lipoprotein Cholesterol and Occurrence of New Lesions after Percutaneous Coronary Intervention in Japanese Patients with Stable Angina and Receiving Statin Therapy.

Background: Low-density lipoprotein cholesterol (LDL-C) is considered the most important risk factor for coronary artery disease (CAD). Although lipid-lowering therapy using high-intensity statins for patients with stable CAD is one of the cornerstones of medication therapy, there is still a risk of residual cardiovascular events, even after controlling for LDL-C. Recently, attention has focused on the association between small dense LDL-C as a residual risk factor for CAD, and it has been reported that a formula can be used to calculate the small LDL-C.

Methods: We investigated the association between estimated small dense LDL-C (Esd LDL-C) and the occurrence of new lesions with myocardial ischemia $\le$ 2 years after percutaneous coronary intervention (PCI) in 537 patients with stable angina who underwent PCI. In this study, all patients had been prescribed statins. This study was based on previously reported data regarding the relationship between non-high-density lipoprotein cholesterol levels and stable angina pectoris after PCI.

Results: Revascularization, including new lesions and in-stent restenosis, and new lesions appeared in 130 and 90 patients, respectively, $\le$ 2 years after PCI. Age, diabetes mellitus (DM), LDL-C, and Esd LDL-C were associated with the occurrence of revascularization and new lesions $\le$ 2 years after PCI. Multivariate logistic regression analysis models revealed that Esd LDL-C [odds ratio (OR) 1.03, 95% confidence interval (CI) 1.004-1.048, p = 0.020; and OR 1.03, 95% CI 1.009-1.057, p = 0.007, respectively] were associated with the revascularization and occurrence of new lesions $\le$ 2 years after PCI.

Conclusions: As well as total cholesterol and LDL-C, Esd LDL-C was an independent risk factor for the revascularization and occurrence of new lesions $\le$ 2 years after PCI for stable angina in Japanese patients receiving statin therapy. In patients with stable angina who are on lipid-lowering therapy with statins, calculating the Esd LDL-C may provide useful information for predicting revascularization and the occurrence of new lesions.