Investigators found significant decreases in heart rate among patients with postural orthostatic tachycardia syndrome who received ivabradine for 1 month.
A drug commonly used to treat heart failure may be effective in treating postural orthostatic tachycardia syndrome (POTS), which has been identified as a potential “long-hauler” symptom of coronavirus disease 2019 (COVID-19).
Investigators analyzed the drug ivabradine and its effects on heart rate, quality of life, and plasma norepinephrine levels in patients living with POTS, which is a complex disorder affecting the autonomic nervous system, causing a high heart rate when standing. Trial participants experienced a reduction in heart rate as well as improvement in their symptoms and overall quality of life 1 month after taking the drug, according to the study.
“Ivabradine is a novel agent that’s FDA-approved for heart failure but based on its mechanism we thought it could be helpful for patients with POTS as it reduces heart rate without impacting blood pressure,” said Pam Taub, MD, a cardiologist at the Cardiovascular Institute at the University of California San Diego, in a press release. “When we can lower the heart rate, we’re providing these patients with the ability to stand up, something they couldn’t do without difficulty before, due to their POTS diagnosis.”
The study included 22 individuals with an average age of 32 years. Each participant had been screened and recruited from cardiology clinics between 2018 and 2020. Investigators utilized a randomized, double-blinded, placebo-controlled crossover design in which patients started on either ivabradine or a placebo for 1 month.
At the end of the month, all participants underwent a washout period in which neither the drug nor the placebo were taken for 1 week. After that week, the participants who had previously received ivabradine switched to the placebo and vice versa for 1 month.
Patients also met with researchers for 7 different clinic visits, when they measured norepinephrine levels and conducted head-up tilt testing to observe the patient’s heart rate with sitting, lying down, or standing up. Taub said they found significant decreases in heart rate among patients taking ivabradine.
“Before the study, these patients would be living with elevated heart rates ranging between 100 to 115 beats per minute when standing,” Taub said in the statement. “After taking ivabradine twice a day for one month, the standing heart rate decreased significantly to around 77 beats per minute compared to the placebo group. Participants also reported improvement in quality of life measures when on the drug.”
The researchers said ivabradine was well-tolerated with no significant adverse effects, whereas other drugs used to lower heart rate can cause fatigue and decreased blood pressure. Additionally, Taub said this study was the first randomized clinical trial using ivabradine to treat POTS.
POTS is typically caused by a viral infection, trauma, surgery, or enforced bedrest, and it most commonly affects young women who are physically active. The condition can severely impact quality of life, although there is currently no FDA-approved treatment. Symptoms include “brain fog,” lightheadedness, palpitations, tremors, weakness, blurry vision, and fatigue, and it has recently been suggested as a potential long-term symptom of COVID-19.
“In our contemporary practice, we are seeing patients who have previously been infected with COVID-19 present with symptoms consistent with POTS,” said Jonathan Hsu, MD, cardiologist at UC San Diego Health, in a press release. “Given the similarities, this study leads to the question whether therapy with ivabradine may help patients who experience similar symptoms after a COVID-19 infection and provide an important area for future study as well.”
The press release said the researchers are hopeful that ivabradine will be considered as a possible treatment option for those with a confirmed diagnosis of POTS. Because it is not currently FDA-approved for the disease, it could be considered off-label use.
“Similar to patients with COVID-19, patients with POTS need to be followed carefully,” Taub concluded in the press release. “Treatment for POTS needs to be personalized for each individual and with this drug, paired with lifestyle therapy, including exercises specific for POTS, we hope we will see more individuals overcome this unfortunate condition.”
Existing Heart Failure Drug May Treat Potential COVID-19 Long-Hauler Symptom [news release]. UC San Diego; February 15, 2021. https://ucsdnews.ucsd.edu/pressrelease/existing-heart-failure-drug-may-treat-potential-covid-19-long-hauler-symptom. Accessed February 18, 2021.