Not in the guidelines
“To date, it is unclear whether potassium and magnesium administration might be reasonable in the acute treatment of AF and AFL, and although this intervention may be common practice in some EDs, it is not part of the treatment recommendations in current guidelines,” Dr. Cacioppo and colleagues write.
“Our findings suggest that intravenous potassium and magnesium administration may increase the chance of SCV in patients with AF with either hypokalemia or with plasma potassium levels in the range of 3.50 to 3.99 mEq/L. In patients with AFL, however, potassium and magnesium administration may not be associated with SCV probability,” they write.
Dr. Cacioppo and associates add that in their study IV administration of potassium and magnesium was associated with SCV only in patients with symptom onset of less than 48 hours, suggesting a time-dependent outcome. However, they caution, “because only a limited number of patients with SCV had symptom onset greater than or equal to 48 hours, this finding warrants further investigation.”
A Band-Aid approach
“I’m a little skeptical about this study,” Georgios Syros, MD, director of arrhythmia services at Mount Sinai Queens and Mount Sinai Brooklyn, New York, said in an interview.
“Atrial fibrillation is a chronic disease. The natural history of this disease is that it is paroxysmal in the beginning, and at some point the episodes become more frequent and longer in duration. For some people, at some point, it becomes permanent,” Dr. Syros said.
“Suppose I cut my finger while slicing bread. I put a Band-Aid on the cut. That doesn’t mean I have fixed it, it means I’ve helped it temporarily. Atrial fibrillation in this paper is very analogous,” he said. “The patient may have episodes, goes to the emergency room, you give them medication, and temporarily alleviate the situation so that the patient does not have to be admitted. It’s simple, inexpensive, you make the heart rate go back to normal, not permanently, with few side effects, except perhaps for some pain at the injection site, but that doesn’t mean you have fixed the AFib permanently. But for someone who has had a first incidence, or doesn’t want to stay in the hospital because it’s the weekend, yes, you can use this as a Band-Aid,” he said.
Intravenous potassium and magnesium, as proposed in the current study, is similar to a medication currently in use in Europe, called vernakalant, Dr. Syros said.
“Vernakalant is not FDA approved in the U.S. It is not meant to treat atrial fibrillation permanently, so we have to inform the public about the limitations of what we are doing,” he said. “Vernakalant is similar to IV potassium and magnesium, as given in this study, but it is more expensive. It temporarily allows people to go back to sinus rhythm, but it’s not going to be there forever and you may go back to permanent AFib, so this is not magic, unfortunately.”
Dr. Syros emphasized that the current study results apply only to cases of paroxysmal atrial fibrillation of less than 48 hours duration. “This is a very important distinction,” he said.
“For example, a patient who drank a lot and the day after is in AFib, with what we call holiday heart, would be a good candidate for the treatment in this study. He’s young, without any heart damage, no diabetes, no hypertension, no prior stroke, so sure, help him out with potassium and magnesium, provided that he can prove to us that this started within 48 hours,” Dr. Syros said.
Dr. Cacioppo and colleagues and Dr. Syros report no relevant financial relationships. Study corresponding author Jan Niederdoeckl, MD, PhD, obtained funding for the study.
A version of this article first appeared on Medscape.com.