Researchers have found that an existing heart failure drug can improve the symptoms associated with postural orthostatic tachycardia syndrome
Postural orthostatic tachycardia syndrome (POTS) is a complex debilitating disorder that affects the body’s autonomic nervous system, causing a high heart rate. Recently, POTS has been identified as a potential “long-hauler” symptom of COVID-19.
Researchers from the University of California San Diego School of Medicine investigated the drug ivabradine and its effects on heart rate, quality of life and plasma norepinephrine levels (stress hormone) in 22 patients living with POTS.
Pam Taub, MD, cardiologist at the Cardiovascular Institute at UC San Diego Health and associate professor of medicine at UC San Diego School of Medicine, said: “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. 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.”
In the study, patients were given either ivabradine or a placebo for one month and then underwent a washout period where neither drug nor placebo was taken for one week at the end of that month. After the washout period, the participants who had previously received ivabradine switched to placebo and vice versa for a further month.
Over the course of the two month study, patients met with researchers for seven different clinic visits in which plasma norepinephrine levels were measured and head-up tilt testing conducted to observe the patient’s heart rate when sitting, lying down or standing up.
After one month of taking ivabradine, participants experienced a reduction in heart rate, improvement in their symptoms and overall quality of life. The researchers also noted that the drug was well-tolerated and did not cause any significant side effects.
“Before the study, these patients would be living with elevated heart rates ranging between 100 to 115 beats per minute when standing. 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”, said Taub.
“In our contemporary practice, we are seeing patients who have previously been infected with COVID-19 present with symptoms consistent with POTS,” added Jonathan Hsu, MD, cardiologist at UC San Diego Health. “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.”
“Similar to patients with COVID-19, patients with POTS need to be followed carefully. 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”, Taub concluded.
Read the full study in the Journal of the American College of Cardiology.