Management of Tachycardia-Mediated Cardiomyopathy: Experience from the Vancouver General Hospital Cardiac Function Clinic (TMC-EXPLOR Study).

Background: Tachycardia-mediated cardiomyopathy (TMC) is a reversible form of heart failure with reduced ejection fraction (HFrEF), most commonly caused by atrial fibrillation or atrial flutter. Evidence for its management is scarce, and practice patterns are highly variable.

Objective: To describe management patterns for HFrEF and atrial arrhythmias in patients with TMC at a specialty heart failure clinic.

Methods: This retrospective cohort study involved adults with HFrEF and a physician-determined diagnosis of TMC, with an initial visit for this problem between October 2018 and October 2019. The 2 primary outcomes, evaluated at 1 year after the initial visit, were the proportion of patients receiving triple therapy (combination of angiotensin receptor-neprilysin inhibitor [or angiotensin-converting enzyme inhibitor/angiotensin II receptor blocker if ejection fraction improved to > 40% by 1 year], ß-blocker, and mineralocorticoid receptor antagonist at any dose) and the proportion receiving or with a plan to receive rhythm control.

Results: A total of 59 participants met the inclusion criteria. The mean age was 73 years, 39 patients (66%) were male, and 42 (71%) had hypertension. At 1-year follow-up, 42 (71%) were receiving triple therapy, and rhythm control was attempted or planned for 20 (34%). Among the 17 patients (29%) not receiving triple therapy, a mineralocorticoid receptor antagonist was the agent most commonly omitted.

Conclusions: In a specialty heart failure clinic, most patients with TMC were receiving triple therapy, with a mineralocorticoid receptor antagonist being the agent most commonly missing among those not receiving triple therapy. One-third of patients with TMC had received a rhythm-control strategy. These gaps in HFrEF therapy and rhythm control represent key areas for quality improvement initiatives in the management of patients with TMC.