Midodrine helps prevent recurrent syncope

Treatment with midodrine is associated with fewer recurrence of vasovagal syncope in healthy, younger patients with a high syncope burden, reports a recent study.

Twenty-five university hospitals in Canada, US, Mexico, and UK participated in this randomized, double-blind, placebo-controlled clinical trial on patients with recurrent vasovagal syncope and no serious comorbid conditions.

A total of 133 patients (median age 32 years, 73 percent female) who had had a median of six syncope episodes in the prior year were randomly assigned 1:1 to placebo or midodrine and followed for 12 months. The proportion of patients with at least one syncope episode during follow-up was the primary outcome measure.

Fewer patients on midodrine had at least one syncope episode compared with those receiving placebo (28 of 66 [42 percent] vs 41 of 67 [61 percent]; relative risk, 0.69, 95 percent confidence interval [CI], 0.49–0.97; p=0.035).

The absolute risk reduction stood at 19 percentage points (95 percent CI, 2–36), and the number needed to treat to prevent a patient from having syncope was 5.3 (95 percent CI, 2.8–47.6). The time to first syncope was longer with midodrine (hazard ratio, 0.59, 95 percent CI, 0.37–0.96; p=0.035; log-rank p=0.031). Of note, both groups showed comparable adverse effects.

This study was limited by its small sample size, relatively short observation period, young and healthy patients, and high proportion of participants from one centre.

“Recurrent vasovagal syncope is common, responds poorly to treatment, and causes physical trauma and poor quality of life,” the investigators said. “Midodrine prevents hypotension and syncope during tilt tests in patients with vasovagal syncope.”