Effects of flecainide on left ventricular pressure gradient and symptoms in obstructive hypertrophic cardiomyopathy: a comparison of flecainide and disopyramide

Abstract

It remains unclear whether flecainide, a Class I antiarrhythmic drug, improves left ventricular pressure gradient (LVPG) or symptoms in patients with obstructive hypertrophic cardiomyopathy (HCM). Our study evaluated the long-term efficacy of flecainide, compared to disopyramide, when administered orally, on LVPG and symptoms in obstructive HCM patients. Among 164 obstructive HCM patients, 15 were administered oral flecainide therapy and 33 administered oral disopyramide therapy. LVPG declined from 79.8 ± 36.6 to 39.2 ± 36.7 mmHg (p = 0.003) after flecainide therapy and from 74.5 ± 26.4 to 31.4 ± 24.8 mmHg (p < 0.001) after disopyramide therapy. The percent reduction in LVPG was -47.9 ± 43.2 % in patients treated with flecainide, comparable to the results for those treated with disopyramide (-57.1 ± 33.0 %; p = 0.425). We found no significant differences in improvement in NYHA functional class between patients treated with flecainide and those treated with disopyramide (p = 0.331). Patients treated with flecainide exhibited no significant adverse side effects, and there was no need for myectomy or alcohol septal ablation to reduce LVPG and symptoms. Improvements in LVPG and symptoms were similar in patients treated with flecainide and patients treated with disopyramide, suggesting that flecainide is a potentially useful alternative for symptomatic obstructive HCM patients, particularly those with disopyramide-induced vagolytic side effects, narrow angle glaucoma, or prostatic hyperplasia and pre-existing urination difficulties. Our data must be viewed with caution, however, in view of the small number of study patients. Flecainide therapy will require further proof of safety before it can be routinely recommended in patients with symptomatic obstructive HCM.

Flecainide in Ventricular Arrhythmias: From Old Myths to New Perspectives

“…In addition, Chung, in a study involving patients with the widespread clinical condition of LV hypertrophy (ventricular wall thickness ≥ 1.4 cm), highlighted that treatment with IC AADs did not increase mortality in AF patients in comparison with patients receiving amiodarone [74]. Moreover, even in patients with hypertrophic obstructive cardiomyopathy, flecainide, in a mean follow-up of 9 years, clearly demonstrated its efficacy in the reduction of LV pressure gradient and symptoms and the burden of non-sustained VT compared with disopyramide, with a ratio of 1:11 [75].…”

Disopyramide for Hypertrophic Cardiomyopathy: A Pragmatic Reappraisal of an Old Drug

“…Both patients had urinary hesitancy or retention requiring drug discontinuation. There were no reported anticholinergic AEs with disopyramide in the 2015 study …”

“…The third study, published in 2015, was a single‐center, retrospective study that assessed symptom improvement and reduction in LVOT gradient in patients with HCM treated with flecainide or disopyramide . Of 164 patients with evidence of obstruction, 15 (9.1%) were treated with flecainide and 33 (20.1%) were treated with disopyramide.…”

“…These AEs occur in 10–32% of patients and include dry mouth, urinary retention, blurred vision, and constipation . However, the rate of discontinuation because of these anticholinergic AEs was relatively low at 6.7% or less in the three clinical studies in patients with HCM . In the 2005 study, eight (6.7%) patients treated with disopyramide discontinued therapy due to AEs .…”

Next Generation Sequencing and Linkage Analysis for the Molecular Diagnosis of a Novel Overlapping Syndrome Characterized by Hypertrophic Cardiomyopathy and Typical Electrical Instability of Brugada Syndrome

“…Recently, Haruki et al, 37 reported that oral flecainide administration may be considered a useful therapy to improve left ventricular pressure gradient and symptoms in patients with obstructive HCM, particularly for those with disopyramideinduced vagolytic side effects. Although the authors did not observed any flecainide-induced Brugada phenomenon or proarrhythmic events in treated patients, their data must be viewed with caution given the small number of patients enrolled and in light of our data.…”