Vitis Vinifera Seed Extract Versus Micronized Purified Flavonoid Fraction for Patients with Chronic Venous Disease: A Randomized Noninferiority Trial

Background: Venoactive drugs (VADs) based on Vitis vinifera extract are widely used in Korea. However, studies on the clinical effects and head-to-head comparisons with other groups of VADs are limited. This trial aimed to evaluate whether Vitis vinifera seed extract was noninferior to the micronized purified flavonoid fraction (MPFF) in relieving venous symptoms and improving quality of life in patients with chronic venous disease. Methods: In this double-blind prospective randomized trial, patients from 13 hospitals, who were diagnosed with venous incompetence by duplex ultrasound and classified as clinical class 1, 2, or 3 in the Clinical, Etiological, Anatomical, and Pathophysiological classifications were enrolled. The primary outcome was the change in the Chronic Venous Disease Quality of Life Questionnaire (CIVIQ-20) score at 8 weeks from baseline. Secondary outcomes included changes in the Aberdeen Varicose Vein Questionnaire, visual analog scale, and Venous Clinical Severity Score at 4 and 8 weeks from baseline. Moreover, the change in leg circumferences was measured at 8 weeks and compared to baseline. Results: In total, 303 patients were enrolled and randomly assigned to receive either Vitis vinifera seed extract (n = 154) or MPFF (n = 149). The CIVIQ-20 scores at 8 weeks were significantly reduced compared to those at baseline in both groups. No significant intergroup difference in the change of CIVIQ-20 at 8 weeks from baseline was observed (−8.31 ± 14.63 vs. −10.35 ± 14.38, P = 0.29, 95% confidence interval −1.65 to 5.72). The lower limit of the 95% confidence interval was within the predefined noninferiority margin of 6.9. Furthermore, the Aberdeen Varicose Vein Questionnaire, visual analog scale, and Venous Clinical Severity Score scores significantly decreased at 4 and 8 weeks after randomization compared with baseline in both groups. No significant differences were observed in the reduction of each score between groups. The calf circumference measured at 8 weeks was significantly reduced compared to that at baseline in patients receiving Vitis vinifera seed extract. Conclusions: Vitis vinifera seed extract was noninferior to MPFF in relieving venous symptoms and improving the quality of life in patients with chronic venous disease.