The following is a summary of “Impact of intravenous calcium with diltiazem for atrial fibrillation/flutter in the emergency department,” published in the November 2022 issue of Emergency Medicine by Rossi, et al.

In patients with atrial fibrillation (AF) or flutter (AFL) with a rapid ventricular response (RVR) in the Emergency Department (ED), researchers sought to evaluate the effects of early intravenous (IV) calcium on systolic blood pressure (SBP) when given with IV diltiazem.

The multicenter retrospective cohort research assessed persons who had been hospitalized in the ED with verified AF or AFL, heart rate (HR) > 120 bpm, and SBP 90 to 140 mmHg and who had been given IV diltiazem for rate control. The major result was a change in SBP 60 minutes (+/- 30 minutes) after the initial IV diltiazem dose. Time to first-rate control (HR< 100 bpm), time to sustained rate control (HR <100 bpm for 3 hours), change in HR, rates of hypotension, bradycardia, hypercalcemia, and line extravasation within 24 hours of the initial diltiazem treatment were secondary outcomes.

Over 56 participants receiving diltiazem with calcium and 198 subjects receiving diltiazem monotherapy all met the criteria for inclusion. The primary result was similar in all groups (-2 mmHg vs. -1.5 mmHg; P=0.642. However, the difference was not statistically significant. The secondary results were all discovered to be comparable between groups. Despite not being statistically significant, bradycardia and hypotension were more common in the diltiazem monotherapy group (4.5% vs. 0%; P=0.213) than they were in the diltiazem plus calcium group (20.2% vs. 32.1%). The time to initial rate control (1.4 h vs. 1.8 h; P=0.14) or time to sustained rate control (7.9 h vs. 7.7 h; P=0.570) compared to diltiazem alone were not statistically different after calcium delivery.

In comparison to IV diltiazem monotherapy, the administration of IV calcium together with IV diltiazem did not significantly affect clinical or safety results in the context of AF/AFL with RVR. While not statistically significant, bradycardia occurred more frequently in the diltiazem monotherapy group (4.5% vs. 0%; P = 0.213), and hypotension happened more frequently in the diltiazem plus calcium group (20.2% vs 32.1%). When it came to attaining rate control, the addition of calcium to diltiazem did not substantially affect either the time to initial rate control (1.4 h vs 1.8 h; P=0.141) or the time to sustained rate control (7.9 h vs 7.7 h; P=0.570) when compared to diltiazem alone.

Administration of IV calcium together with IV diltiazem in the context of AF/AFL with RVR did not demonstrate a meaningful difference in clinical or safety results when compared to IV diltiazem monotherapy.

Reference: sciencedirect.com/science/article/pii/S0735675722007161