“Less bradycardia in sinus rhythm with calcium blocker.”

Robert Thielmann, MD, a cardiologist at Groningen Martini Hospital and co-author of the study, noted that the use of calcium channel blockers to control heart rate in patients with atrial fibrillation has declined significantly in recent decades. Prescribers have developed a preference for beta-blockers, although there is no scientific basis for this. It is assumed that beta blockers are the most well-known and calcium channel blockers have simply been forgotten. Doctors don't think about it anymore.

International guidelines We recommend both calcium blockers and beta blockers as the first choice of maintenance medications in patients with atrial fibrillation to suppress symptoms and prevent heart failure. The risk of medications is that patients with paroxysmal atrial fibrillation may develop bradycardia during periods of sinus rhythm. Because calcium channel blockers selectively target the atrioventricular node and not the sinus node, bradycardia in sinus rhythm should theoretically occur less frequently.

To test this hypothesis, Tim Coldenhoff, Robert Tillman, and colleagues conducted a post hoc analysis using data from Confirm trial From 2002 (BMJ Heart. 2023;109:1759-64). From this, they selected data from 474 patients with paroxysmal atrial fibrillation (42% female, mean age 69 years; SD: 8), of whom 218 used calcium channel blockers (74% diltiazem, 26% verapamil) for rate control. . 256 Beta blockers. Patients who were also taking antiarrhythmic medications were also included. Additional use of antiarrhythmic medications was equally common in both treatment arms. Study participants were not randomized to a specific rate-control treatment; Patients received their medications as prescribed by their physician. No information was available on medication doses.

The patient groups achieved the target heart rate of 110/min or less equally often during atrial fibrillation episodes (92% in both groups). Patients taking calcium channel blockers had a mean heart rate in sinus rhythm compared to patients taking beta blockers (heart rate 66 (SD: 11) versus 69 (SD: 12). Patients taking calcium channel blockers in Sinus rhythm was less frequent. Bradycardia (<60/min) or severe bradycardia (<50/min) compared to patients taking beta blockers (odds ratio (OR): 0.41; 95% CI: 0.19-0.90). Bradycardia occurred in 32% of patients taking beta blockers.Beta blockers and in 17% of patients taking calcium blockers.Severe bradycardia occurred in 5% of beta blocker users and 1% of patients taking calcium blockers.

Based on this retrospective analysis with several limitations, no firm conclusions can be drawn, says doctoral student Tim Coldenhoff. “We do not have any definitive, conclusive evidence on which to base a preference for calcium channel blockers. But based on the mechanism of action of calcium channel blockers and the results of our research, bradycardia in sinus rhythm is likely to occur less often when these agents are used.”

Coldenhoff says this requires a personal approach. Beta blockers are reliable and safe medications, but they may not be suitable for every patient. Often, general practitioners and cardiologists prescribe them out of habit, while calcium channel blockers may be more suitable for a patient who lives an active lifestyle. It is important for doctors to know that there is a good alternative, especially if patients are experiencing side effects due to beta blockers.