Outcomes of Direct Current Cardioversion (DCCV) for Atrial Fibrillation (AF) in a South Auckland Population

Abstract

Elective direct current cardioversion (DCCV) is recommended in symptomatic patients with persistent atrial fibrillation (AF) as part of rhythm control therapy, but little is known about its efficacy in our population. Between 2017 to 2019, we identified and analysed 100 consecutive patients admitted for elective DCCV. We followed them retrospectively over one year to observe rhythm control, medication use and complications. The mean age was 64 yrs (41yrs to 83 yrs), 68% were male and one third identified as Māori (14%) or Pacific (19%). Risk factors: Previous DCCV, 18%, or ablation, 2%; mean BMI, 33 (16-62); smoking, 8%; hypertension, 46%; previous stroke, 3%; heart failure, 23%; cardiovascular disease, 16%; and type 2 diabetes, 26%. The mean CHADS2-VASc score was 2 (0-6). The majority (80%) had a left ventricular ejection fraction (LVEF) >40%. The most common anticoagulant was dabigatran 150mg BD (77%) and dabigatran 110mg BD (15%); also, rivaroxaban (2%) and warfarin (6%). The most common rate limiting therapy was beta blocker (84%); also, diltiazem (22%), amiodarone (33%) and digoxin (4%). At follow up review (mean 64 days, 7-421 days), 61% were in sinus rhythm (Māori/Pacific, 48% vs others, 67%) and after nearly 2 years of follow up, 74% had a further review with 42% in sinus rhythm (SR), 32% in AF/atrial flutter and 26% unknown. Over the study period, 5% of patients died (4% non-cardiac), and 8% had ablation. At 2 years of follow up over 1/3 of patients were in SR. Funded support around lifestyle change, to impact on obesity and hypertension rates, needs to be available.