Background: Sotalol is a class III antiarrhythmic drug used for the management of patients with atrial fibrillation to maintain sinus rhythm. Sotalol-induced QT interval prolongation can be proarrhythmic and is conventionally initiated in an inpatient setting where routine electrocardiographic (ECG) monitoring is available while sotalol reaches the steady state. The emergence of cellular-compatible home ECG devices, such as AliveCor's Kardia Mobile 6L, which offers 6-lead ECG, has made it possible to accurately measure QT intervals outside the hospital.
Objectives: This study aimed to evaluate the safety, feasibility, and patient adherence to protocol-driven, pharmacist-led outpatient sotalol initiation using the Kardia Mobile 6L for remote ECG monitoring and to compare these outcomes with patients completing inpatient sotalol protocol for initiation.
Methods: Patients who underwent outpatient sotalol initiation through an antiarrhythmic clinic for the treatment of both atrial and ventricular arrhythmias over a period of approximately 3 years, from September 1, 2020, to June 16, 2023, were retrospectively reviewed and compared with a cohort of inpatients initiated on sotalol. The outpatient cohort had a minimum longitudinal follow-up of 90 days.
Results: A total of 263 patients using the outpatient sotalol initiation protocol were compared with 28 age- and sex-matched inpatients who underwent inpatient sotalol initiation. The outpatient cohort included 179 men (68%), with an age of 68.8 ± 10.1 years, CHA2DS2-VASc score of 3.48 ± 1.43, baseline 12-lead QTc interval of 440.77 ± 33.42 ms, and a left ventricular ejection fraction of 57.4% ± 9.23%. Outpatients were started on a median (minimum-maximum) dose of 120 (80-160) mg of sotalol twice a day (120-mg dose; n = 227; 86.3%) and ended at a median (minimum-maximum) dose of 120 (60-160) mg twice a day (120-mg dose; n = 217; 82.5%). The proportions of patients prescribed low-, moderate-, or high-dose sotalol twice a day (60 mg, 80 mg, 120 mg, and 160 mg) at the end of initiation were similar between the inpatient and outpatient groups (P = 0.5). The majority (98.9%; 260 of 263) of patients completed the 3-day outpatient initiation. Outpatient adherence was high during the 3-day initiation period among patients with varied age and socioeconomic background; 258 patients (98.1%) completed the ECG on day 1, and 240 (91.3%) completed the ECG on day 3. No significant QTc interval prolongation was observed during the outpatient postinitiation study period. There were similar sotalol discontinuation rates within 30 days of initiation in the inpatient vs outpatient cohorts (7% vs 8%; P > 0.90). A total of 17 (6.5%) patients stopped sotalol because of symptomatic bradycardia, and 1 death was observed over a 90-day follow-up period in the outpatient cohort.
Conclusions: Outpatient initiation of sotalol through a protocol-driven, pharmacist-led antiarrhythmic clinic is feasible and safe, with high adherence rates in a diverse range of patients using personal remote ECG.
Keywords: QT prolongation; antiarrhythmic drug; atrial fibrillation; electrocardiographic (ECG) monitoring; outpatient loading; remote monitoring; sotalol.
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