Effectiveness of midodrine treatment in patients with recurrent vasovagal syncope not responding to non-pharmacological treatment (STAND-trial).

AIMS Initial treatment of vasovagal syncope (VVS) consists of advising adequate fluid and salt intake, regular exercise, and physical counterpressure manoeuvres. Despite this treatment, up to 30% of patients continue to experience regular episodes of VVS. We investigated whether additional Midodrine treatment is effective in these patients. METHODS AND RESULTS In our study, patients with at least three syncopal and/or severe pre-syncopal recurrences during non-pharmacological treatment were eligible to receive double-blind cross-over treatment starting either with Midodrine or placebo. Treatment periods lasted for 3 months with a wash-out period of 1 week in-between. At baseline and after each treatment period, we collected data about the recurrence of syncope and pre-syncope, side effects, and quality of life (QoL). Twenty-three patients (17% male, mean age 32) included in the cross-over trial received both Midodrine and placebo treatment. The proportion of patients who experienced syncopal and pre-syncopal recurrences did not differ significantly between Midodrine and placebo treatment (syncope: 48 vs. 65%, P= 0.22; pre-syncope: 74 vs. 78%, P> 0.99). The median number of syncopes and pre-syncopes per 3 months were also not significantly different during Midodrine and placebo treatment (0 vs. 1; P= 0.57; and 6 vs. 8; P= 0.90). The occurrence of side effects was similar during Midodrine and placebo treatment (48 vs. 57%; P= 0.75). Also, QoL did not differ significantly. CONCLUSION Our findings indicate that additional Midodrine treatment is less effective in patients with VVS not responding to non-pharmacological treatment than reported as first-line treatment.