Impact of dapagliflozin on supraventricular and ventricular arrhythmias, assessed by Holter ECG, in patients with heart failure with reduced ejection fraction

Background & Introduction Dapagliflozin has significantly reduced morbidity & mortality in patients with heart failure with reduced ejection fraction (HFrEF) (1). Some studies reported supraventricular & ventricular arrhythmia suppression, but Holter ECG was underused, hindering precise assessment of arrhythmia burden. Purpose We aim to assess the impact of dapagliflozin on reduction of arrhythmia in HFrEF at 1 year follow-up (FU) by Holter ECG. Methods This is a single center, prospective study. We have screened 219 HFrEF patients, but only 156 patients were enrolled with LVEF <40% in sinus rhythm from December 2021 to July 2023. All patients had dapagliflozin 10 mg once/day tablet with the standard HF therapy. Clinical evaluation, NYHA evaluation, 6-minute walking test (6MWT), echocardiogram, 24-hours Holter ECG and laboratory work-up were done at baseline, and FU at 6 months and 12 months. Results Males constituted 61.5% of study population; mean± SD participants’ age was 56.8 ± 8.6 years. The most common comorbidities were: ischemic etiology (63.3%), dilated cardiomyopathy (28.1%), hypertension (27.3%), smokers (14.7%), and type II diabetes (31.4%). LVEF was ≤ 35% in 85.9% of patients. We have reported (7.69%) deaths during 1-year FU, and 4 patients (2.56%) didn't complete 1-year FU. Main clinical and echocardiographic findings (baseline vs. 1-year FU): NYHA FC III& ambulant IV dropped from (42.9 to 32.9%), P value<0.05. Distance walked in 6MWT improved from 191.52 ± 75.37 to 219.35 ± 71.51 mean± SD meters, P value<0.05. E/e improved (9.4 to 8.3 cm/s, P value <0.01), LVEF improved (31.3 to 36.4%, P value<0.05). HF emergency: [HF visits dropped (23.7 to 19.2%) and HF hospitalization dropped (11.1 to 7.8%)], P value<0.05. Holter ECG (baseline vs. 1-year FU): Supraventricular Arrhythmia: [Paroxysmal AF reduced (56.2 to 47.6%), frequent PACs (≥ 10%) dropped (3.8 to 1.4%) & Intermittent 1st degree heart block dropped (12.5 to 7.3%)] P value <0.01. Ventricular Arrhythmia: [PVCs >5%-<10% dropped (16% to 9.3%), Frequent PVCs >10% dropped (3.2 to 1.4%), and NSVT dropped (7.8 to 3.1%)], P value <0.01. Stepwise logistic regression multivariable model aiming to predict the occurrence of ventricular and supraventricular arrhythmias has indicated a direct linear correlation with male gender, smoking, body mass index, left atrial volume, and a history of myocardial infarction. Conversely, there is an inverse relationship with systolic blood pressure, 6MWT distance, LVEF, and the administration of dapagliflozin (OR 0.72 [0.61 - 1.07], P value <0.01) concerning the likelihood of supraventricular and ventricular arrhythmias. Conclusions Dapagliflozin has demonstrated significant improvement in functional and echocardiographic parameters in HFrEF patients. Furthermore, it has effectively decreased the incidence of supraventricular and ventricular arrhythmias, identified through 24-hour Holter ECG monitoring during 1-year follow-up.