Prevention of sudden death in heart failure with reduced ejection fraction: do we still need an implantable cardioverter-defibrillator for primary prevention?

Sudden death is a devastating complication of heart failure (HF). Current guidelines recommend an implantable cardioverter-defibrillator (ICD) for prevention of sudden death in patients with HF and reduced ejection fraction (HFrEF) specifically those with a left ventricular ejection fraction ≤35% after at least 3 months of optimized HF treatment. The benefit of ICD in patients with symptomatic HFrEF caused by coronary artery disease has been well documented; however, the evidence for a benefit of prophylactic ICD implantation in patients with HFrEF of non-ischaemic aetiology is less strong. Angiotensin-converting enzyme inhibitors or angiotensin receptor blockers, beta-blockers (BB), and mineralocorticoid receptor antagonists (MRA) block the deleterious actions of angiotensin II, norepinephrine, and aldosterone, respectively. Neprilysin inhibition potentiates the actions of endogenous natriuretic peptides that mitigate adverse ventricular remodelling. BB, MRA, angiotensin receptor-neprilysin inhibitor (ARNI) have a favourable effect on reduction of sudden cardiac death in HFrEF. Recent data suggest a beneficial effect of sodium-glucose cotransporter 2 inhibitors (SGLT2i) in reducing serious ventricular arrhythmias and sudden cardiac death in patients with HFrEF. So, in the current era of new drugs for HFrEF and with the optimal use of disease-modifying therapies (BB, MRA, ARNI and SGLT2i), we might need to reconsider the need and timing for use of ICD as primary prevention of sudden death, especially in HF of non-ischaemic aetiology.