Background: Intermediate saphenous vein graft (SVG) lesions have high rates of progression. The purpose of this study was to examine the impact of extended-release niacin (ER-niacin) vs placebo on intermediate SVG lesions.
Methods: Patients with intermediate (30%-60% diameter stenosis) SVG lesions were randomized to ER-niacin vs placebo for 12 months. Quantitative coronary angiography (QCA), intravascular ultrasonography (IVUS), and optical coherence tomography (OCT) were performed at baseline and at 12 months. The primary endpoint was change in percent atheroma volume (ΔPAV). Enrollment was planned for 138 patients for 90% power to detect ≥2.5% difference in the primary endpoint of ΔPAV, but stopped early after publication of two negative outcome trials of ER-niacin, with enrolled patients completing the 12-month trial protocol.
Results: Thirty-eight patients were randomized to niacin (n = 19) or placebo (n = 19), yielding power of 47% to detect the primary planned treatment effect of 2.5 ± 4.0% difference in ΔPAV. Between baseline and 12-month follow-up, no significant difference was found between study groups in ΔPAV (-1.31 ± 6.05% vs 1.05 ± 17.8%; P=.60). By OCT, the ER-niacin vs placebo group had less plaque rupture within the intermediate SVG lesion (0.0% vs 36.0%; P=.01).
Conclusion: Administration of ER-niacin did not significantly impact intermediate SVG disease, with the notable limitation of compromised statistical power due to early termination of enrollment.
Trial registration: ClinicalTrials.gov NCT01221402.