Interventions aimed to increase average 24-hour systolic blood pressure reduce blood pressure drops in patients with reflex syncope and orthostatic intolerance

Systolic blood pressure (SBP) drops recorded by 24-hour ambulatory blood pressure (BP) monitoring (ABPM) identify patients with susceptibility to reflex syncope and orthostatic intolerance. We tested the hypothesis that treatments aimed to increase BP (reassurance, education & life-style measures plus pharmacological strategies) can reduce SBP drops.

Multicentre, observational proof-of-concept study performed in patients with reflex syncope and/or orthostatic intolerance and with SBP drops on a screening ABPM.

Among 144 eligible patients, 111 underwent a second ABPM on average 2.5 months after start of treatment. Overall, mean 24-hour SBP increased from 114.1±12.1 mmHg to 121.4±14.5 mmHg (p <0.0001). The number of SBP drops <90 mmHg and <100 mmHg decreased by 61%, 46% during daytime and by 48% and 37% during 24-hour period, respectively (p<0.0001 for all). The dose-response relationship between difference in 24-hour average SBP increase and reduction in number of SBP drops reached a plateau around approximately 15 mmHg increase of 24-hour SBP. The reduction in SBP drop rate was consistent and significant in patients who underwent deprescription of hypotensive medications (n=44) and in patients who received BP-rising drugs (n=67).

In patients with reflex syncope and/or orthostatic intolerance, an increase in average 24-hour SBP, regardless of the implemented strategy, significantly reduced the number of SBP drops and symptom burden. A 13 mmHg increase in 24-hour SBP appears to represent the optimal goal for aborting the maximal number of SBP drops, representing a possible target for future interventions.