Rapid ventricular response (RVR) and atrial fibrillation (Afib) are treated promptly with intravenous push (IVP), metoprolol (MET) or diltiazem (DIL). Diltiazem is contraindicated in people with heart failure (HF) because of its unfavorable inotropic effects. HF is frequently excluded from studies comparing the management of atrial fibrillation. Hirschy et al. assessed the efficacy and safety of IVP metoprolol or diltiazem in HF patients with concurrent Afib and RVR. They discovered comparable safety and efficacy results between the 2 groups.

From January 1, 2018, to July 31, 2021, patients who presented to the emergency center (EC) with Afib with RVR and HF were assessed in the retrospective, IRB-approved research. Patients who received IVP metoprolol or diltiazem in the EC and had a documented baseline ejection fraction (EF) were included if they were at least 18 years old. The key efficacy outcome was successful heart rate (HR) control, which was defined as HR <100 beats per minute (bpm) 30 min after therapy with either IVP metoprolol or diltiazem. Secondary efficacy objectives were HR control at EC discharge or transfer and at 60 minutes after IVP, and HR reductions of greater than 20% at 30 minutes, 60 minutes, and at the time of discharge or transfer. Time to satisfactory HR control, the total amount of IVP metoprolol or diltiazem administered, the administration of any additional rate-controlling medications, and crossover between metoprolol and diltiazem were among the other secondary outcomes. All safety-related events are Bradycardia, hypotension, shortness of breath, increased oxygen needs, a change in EF, acute kidney damage, or renal replacement treatment.

A total of 193 individuals, aged 73.3±12.2 years and 63% female, were included from the 2,580 patients assessed (134 DIL vs. 59 MET). About 30% of patients had heart failure with reduced ejection fraction (HFrEF), whereas 64% had a heart failure with preserved ejection fraction (HFpEF), with an average EF of 48.2±14.2%. Effective heart rate regulation was comparable across the two groups 30 min after IVP (55% DIL vs. 41% MET, P = 0.063). DIL was able to regulate HR more quickly than MET (13 [9, 125] DIL vs. 27 [5, 50] MET, min, P = 0.009). At 30 minutes (33.2 ± 25.4 DIL vs. 19.7 ± 19.7 MET, bpm, P < 0.001) and 60 minutes (31 ± 23.5 DIL vs. 19.6 ± 19.1 MET, bpm, P = 0.002), DIL led to larger HR decreases. At 30 min, DIL was more commonly associated with an HR drop of 20% or more (63% DIL vs. 27% MET, P< 0.001), at 60 min post-IVP (59% DIL vs. 41% MET, P = 0.019), and at the time of patient release or transfer from the EC (70% DIL vs. 49% MET, P = 0.005). There were no discernible variations in the safety results.

It might be difficult to acutely treat people who have Afib with RVR and HF. Diltiazem and metoprolol achieved effective rate control at 30 minutes, but there were no differences in safety outcomes. IVP diltiazem lowered HR more quickly and by 20% or more frequently than IVP metoprolol. Further research was required to assess the safety of diltiazem in patients with HF and Afib.

Reference: sciencedirect.com/science/article/pii/S0735675722006313