Ivabradine as a treatment for postural orthostatic tachycardia syndrome: A systematic review

Ivabradine is one of several off-label treatments for patients with postural orthostatic tachycardia syndrome (POTS). We conducted a systematic review of the literature to identify studies which evaluate ivabradine treatment in patients with POTS. The results were narratively synthesized given methodological heterogeneity among the identified studies. There were 11 studies included in the analysis with 305 participants between 2008 to 2020. The only randomized trial of 22 patients showed that ivabradine improved heart rate compared to placebo and there were symptomatic benefits in terms of physical functioning, and social functioning. All studies suggested a reduction in heart rate with ivabradine treatment; the proportion of patients with symptomatic benefit ranged from 67% to 100%. One study using the Malmo POTS score found that ivabradine improved the total score, including key components such as light-headedness with standing, feeling faint, feeling rapid heart rate, and chest pain. While two studies did not report side effects and two studies described no side effects, others reported adverse effects including bradycardia, nausea, worsening syncope, palpitations, flushing, light sensitivity, headache, light-headedness, fatigue, scalded tongue, itching and burning, and visual disturbance. In conclusion, there is low-quality evidence derived from small observational studies and one small randomized trial that ivabradine is effective in reducing heart rate and improving symptoms in patients with POTS. The exact role of ivabradine in treatment of POTS needs to be clarified in further randomized trials and more robust evidence.