University of Calgary, Calgary, Alberta, Canada (R.S., P.F., C.A.M., D.R., S.S., C.M.).
University of Western Ontario, London, Ontario, Canada (A.T.).
Ann Intern Med. 2021 Oct;174(10):1349-1356. doi: 10.7326/M20-5415. Epub 2021 Aug 3.
Recurrent vasovagal syncope is common, responds poorly to treatment, and causes physical trauma and poor quality of life. Midodrine prevents hypotension and syncope during tilt tests in patients with vasovagal syncope.
To determine whether midodrine can prevent vasovagal syncope in usual clinical conditions.
Randomized, double-blind, placebo-controlled clinical trial. (ClinicalTrials.gov: NCT01456481).
25 university hospitals in Canada, the United States, Mexico, and the United Kingdom.
Patients with recurrent vasovagal syncope and no serious comorbid conditions.
Patients were randomly assigned 1:1 to placebo or midodrine and followed for 12 months.
The primary outcome measure was the proportion of patients with at least 1 syncope episode during follow-up.
The study included 133 patients who had had a median of 6 syncope episodes in the prior year (median age, 32 years; 73% female). Compared with patients receiving placebo, fewer patients receiving midodrine had at least 1 syncope episode (28 of 66 [42%] vs. 41 of 67 [61%]). The relative risk was 0.69 (95% CI, 0.49 to 0.97; = 0.035). The absolute risk reduction was 19 percentage points (CI, 2 to 36 percentage points), and the number needed to treat to prevent 1 patient from having syncope was 5.3 (CI, 2.8 to 47.6). The time to first syncope was longer with midodrine (hazard ratio, 0.59 [CI, 0.37 to 0.96]; = 0.035; log-rank = 0.031). Adverse effects were similar in both groups.
Small study size, young and healthy patients, relatively short observation period, and high proportion of patients from 1 center.
Midodrine can reduce the recurrence of syncope in healthy, younger patients with a high syncope burden.
The Canadian Institutes of Health Research.
血管迷走性晕厥反复发作较为常见，对治疗反应不佳，可导致身体创伤和生活质量下降。米多君可预防血管迷走性晕厥患者倾斜试验时的低血压和晕厥。
确定米多君是否可预防血管迷走性晕厥的常规临床情况下发生。
随机、双盲、安慰剂对照临床试验。（ClinicalTrials.gov：NCT01456481）。
加拿大、美国、墨西哥和英国的 25 所大学医院。
反复发生血管迷走性晕厥且无严重合并症的患者。
患者以 1:1 的比例随机分配至安慰剂或米多君组，并随访 12 个月。
随访期间至少发生 1 次晕厥发作的患者比例。
该研究纳入 133 例患者，这些患者在过去 1 年中平均发生 6 次晕厥发作（中位年龄 32 岁，73%为女性）。与接受安慰剂的患者相比，接受米多君的患者中至少发生 1 次晕厥的患者更少（28/66 [42%] vs. 41/67 [61%]）。相对风险为 0.69（95%CI，0.49 至 0.97；P=0.035）。绝对风险降低 19 个百分点（95%CI，2 至 36 个百分点），预防 1 例患者发生晕厥所需的治疗人数为 5.3（95%CI，2.8 至 47.6）。米多君组首次发生晕厥的时间更长（风险比，0.59 [95%CI，0.37 至 0.96]；P=0.035；对数秩检验=0.031）。两组的不良反应相似。
研究规模较小，患者年轻且健康，观察期相对较短，且大多数患者来自 1 个中心。
米多君可减少健康、年轻且晕厥负担较高的患者的晕厥复发。
加拿大卫生研究院。
