Original Investigation
Randomized Trial of Ivabradine in Patients With Hyperadrenergic Postural Orthostatic Tachycardia Syndrome

https://doi.org/10.1016/j.jacc.2020.12.029Get rights and content
Under an Elsevier user license
open archive

Abstract

Background

Postural orthostatic tachycardia syndrome (POTS) is a complex, multifaceted disorder that impairs functional status and quality of life. Current pharmacological treatments are limited.

Objectives

This study investigated the effect of ivabradine (selective blocker of the Ifunny channel in the sinoatrial node) on heart rate, quality of life (QOL), and plasma norepinephrine (NE) levels in patients with hyperadrenergic POTS defined by plasma NE >600 pg/ml and abnormal tilt table test.

Methods

In total, 22 patients with hyperadrenergic POTS as the predominant subtype completed a randomized, double-blinded, placebo-controlled, crossover trial with ivabradine. Patients were randomized to start either ivabradine or placebo for 1 month, and then were crossed over to the other treatment for 1 month. Heart rate, QOL, and plasma NE levels were measured at baseline and at the end of each treatment month.

Results

The average age was 33.9 ± 11.7 years, 95.5% were women (n = 21), and 86.4% were White (n = 23). There was a significant reduction in heart rate between placebo and ivabradine (p < 0.001). Patients reported significant improvements in QOL with RAND 36-Item Health Survey 1.0 for physical functioning (p = 0.008) and social functioning (p = 0.021). There was a strong trend in reduction of NE levels upon standing with ivabradine (p = 0.056). Patients did not experience any significant side-effects, such as bradycardia or hypotension, with ivabradine.

Conclusion

Ivabradine is safe and effective in significantly improving heart rate and QOL in patients with hyperadrenergic POTS as the predominant subtype.

Key Words

hyperadrenergic
ivabradine
postural orthostatic tachycardia syndrome
randomized cross-over trial
tachycardia

Abbreviations and Acronyms

BP
blood pressure
HUTT
head-up tilt table test
NE
norepinephrine
OVM
orthostatic vitals monitoring
POTS
postural orthostatic tachycardia syndrome
QOL
quality of life
SA
sinoatrial node
SF-36
RAND 36-Item Health Survey 1.0

Cited by (0)

Listen to this manuscript's audio summary by Editor-in-Chief Dr. Valentin Fuster on JACC.org.

The authors attest they are in compliance with human studies committees and animal welfare regulations of the authors’ institutions and Food and Drug Administration guidelines, including patient consent where appropriate. For more information, visit the Author Center.

Dr. Taub and Ms. Zadourian contributed equally to this work.