Comparison of sustained-release nifedipine and temperature biofeedback fortreatment of primary Raynaud phenomenon - Results from a randomized clinical trial with 1-year follow-up

Background: The efficacy and safety of sustained-release nifedipine for the treatment of primary Raynaud phenomenon (RP) has not previously been demon strated by a randomized, controlled trial. Temperature biofeedback has been studied in patients with primary RP but not in a large multicenter control led trial or compared with nifedipine therapy. Objective: To evaluate and compare the effectiveness of sustained-release n ifedipine and temperature biofeedback for the treatment of primary RP. Participants and Methods: This is a randomized, controlled clinical trial, double-masked for drug and placebo but not masked for temperature and contr ol biofeedback. It included 313 persons with primary RP as defined by medic al history, physical examination findings, normal nailfold capillaries, and a history of 2 or more attacks per day during the previous cold season. Pa rticipants were randomized to 1 of 4 treatment groups: (1) sustained-releas e nifedipine, (2) pill placebo, (3) temperature biofeedback, or (4) control (electromyographic) self-reported, color chart-verified RP attacks during 1 winter month approximately 1 year after initiation of treatment. Secondar y outcome measures included verified attacks at 2 months, all attacks at 2 months and 1 year, and quality of life. Results: Nifedipine-treated participants showed a 66% reduction in verified attacks compared with placebo recipients (P<.001); temperature biofeedback training did not reduce attacks significantly compared with control biofee dback (P = .37). Comparison of nifedipine and temperature biofeedback treat ments favored nifedipine use (P = .08); similar results were obtained for t he secondary end points. Adverse effects resulted in discontinuation of nif edipine treatment in 15% of participants. Conclusions: Temperature biofeedback is not better than its control treatme nt and is inferior to sustained-release nifedipine for treating primary RP, whereas sustained-release nifedipine is a safe and effective treatment for this disease.