Empagliflozin Versus Placebo on the Rate of Arrhythmic Events in Heart Failure Patients

Background and rationale: Empagliflozin is an orally available inhibitor of the sodium-glucose co-transporter 2 (SGLT-2), that promotes enhanced glucose excretion in the urine, thereby lowering blood glucose concentrations in patients with type 2 diabetes mellitus (T2DM). The EMPA-REG OUTCOME study demonstrated a significant reduction in both heart failure hospitalization and cardiovascular death in type 2 diabetes patients with high risk for cardiovascular events. A potential mechanism underlying the pleiotropic and explaining the remarkable early reduction in cardiovascular mortality may be related to the effect of empagliflozin on arrhythmic events.

Multiple potential mechanisms have been suggested to mediate the positive cardiovascular effect of empagliflozin (altered cardiomyocyte metabolism, anti-arrhythmic effect, improved glycemic control, positive effect on myocardial contractility).

Ventricular arrhythmias and the associated sudden cardiac death (SCD) is the leading cause of mortality in patients with heart failure. The risk for the occurrence of SCD in heart failure patients is closely related to the etiology (ischemic versus non-ischemic) and the left ventricular EF. The introduction of defibrillation therapy for primary prevention of SCD in HF patients has revolutionized the field during the last 2 decades. Nevertheless, ventricular arrhythmias remain a major cause of mortality for HF patients given the limited ability for risk stratification, and the dreadful prognosis associated with ventricular arrhythmias treated by defibrillation therapy. The burden of premature ventricular Complexes (PVCs) has been shown as an independent risk factor for ventricular tachyarrhythmia and SCD for healthy, ischemic and heart failure patients (with and without resynchronization and/or defibrillator therapy). Anti-arrhythmic drugs (AAD) are efficient in suppressing the occurrence of PVCs but for certain drugs, the associated with profile of adverse events and cardiotoxicity may paradoxically increase the rate of sudden cardiac death as learned by the remarkable CAST study. Be that as it may, easily suppressed PVC burden (without the associated adverse profile of AADs) has been suggested to correlate with reduction of the likelihood for SCD. Furthermore, the growing field of PVC ablation has been shown to have beneficial effect on cardiac function and the risk for ventricular arrhythmia. In summary, PVC suppression, a once neglected strategy, is now considered a promising strategy for evaluating the effect of therapeutic strategies on the risk for SCD.

Empagliflozin treatment in high cardiovascular risk patients has been shown to have a relatively rapid powerful capability in reducing cardiovascular mortality. Among the suggested mechanisms mediating this effect of empagliflozin, anti-arrhythmic effect (AAE) has the highest potential to translate into a rapid clinical beneficial effect on cardiovascular mortality, while other mechanisms are known to have a lag in their clinical effect based on data from previous studies. Based on this assumption, the study driving hypothesis is that the effect of empagliflozin on the rate of cardiovascular death may be mediated by a direct effect on the risk for arrhythmic events (via a direct or an indirect effect on the myocardium). The current study aims at assessing the effect of empagliflozin on arrhythmias in diabetic patients with HF with reduced EF and relatively high arrhythmic burden.

Study Objectives The objective of the current study is to demonstrate the effect of empagliflozin compared to placebo on the rate of ventricular arrhythmic events in type 2 diabetes patients with heart failure with reduced ejection fraction and high risk arrhythmic profile.

Primary endpoint:

The primary endpoint is the burden of premature ventricular complexes, defined as the PVCs percentage of all beats in a pre-specified period captured on implantable cardioverter-defibrillator ( ICD ) or CRTD/P device.

Secondary endpoint:

1. The number of non-sustained ventricular tachycardia (NSVT) episodes.
2. A composite cumulative endpoint of ventricular arrhythmia load (number of: sustained ventricular tachycardia, ventricular fibrillation, antitachycardia pacing (ATP) or delivery of shock therapy episodes.
3. The change in blood level of NT-Pro Brain Natriuretic peptide (BNP) from baseline to the end of any of the treatment periods.
4. The change in Left ventricular end diastolic diameter on echocardiography from baseline to the end of any of the treatment periods.
5. The change in left ventricular ejection fraction (EF) on echocardiography from baseline to the end of any of the treatment periods.
6. Safety endpoints (as detailed bellow).

Study Design:

The present study is a randomized, prospective, controlled, double blind, cross-over, pairwise, add on standard therapy, event driven study, comparing empagliflozin versus placebo on the ventricular arrhythmia burden in a blocked randomization stratified by ischemic versus non-ischemic cardiomyopathy and PVC burden at screening of< or > to 4%. Potential study subjects will sign an informed consent prior to undergoing any study related procedure. Number of patients to be enrolled is 128.

This study encompass 4 periods for each study subject: screening period of 8 weeks, first treatment period of 8 weeks, washout period of 4 weeks and a second treatment period of 8 weeks. Expected duration of subject participation is 6-7 months.

Duration of study:

The duration of the treatment period is approximately 6 months. This time span is required for completing the therapy and determining the safety profile of the drug combination and the response rate.

Estimated accrual duration: 12 months. Estimated total trial duration: 18 months (for each center).