Device therapy in heart failure: do all treatment goals apply to all patients?

Abstract

Cardiac resynchronization therapy (CRT) through atrio-biventricular pacing has been first applied in the treatment of patients with severe heart failure (HF) in the year 1996.1 Since then, it has been shown to improve symptoms and quality of life (QoL), to reduce HF hospitalizations, and to induce a significant positive remodelling effect that persists over time.2–4 Before a life-saving effect of this therapy was ever demonstrated,5 CRT has gained acceptance for the treatment of patients with advanced symptomatic HF and a severely depressed left ventricular ejection fraction (LVEF) that presented with a broad QRS on the ECG. This was due to the high degree of disability, impairment in QoL, and need for frequent hospitalizations of this patient population, in whom modalities beyond drug therapy were desirable. However, a significant life-saving effect of CRT alone (CRT-P) or in combination with a defibrillator (CRT-D) was demonstrated recently.5,6 An implantable cardioverter-defibrillator (ICD) as standalone therapy has also clearly shown to improve outcomes in patients with severe left ventricular systolic dysfunction with or without symptoms of HF.7,8 Despite the recent advances of device therapy in the treatment of patients with HF, important unresolved issues remain. Around 30% of the patients who will undergo CRT implantation will never respond to this therapy, and only a similar proportion of patients implanted with an ICD will require appropriate therapies after long-term follow-up.7,9 The reasons leading to a lack of benefit of device therapy are complex and poorly understood. For the ICD, the main difficulty consists of identifying the patient at risk for arrhythmic death. For CRT, the response to therapy will depend on appropriate patient identification (phenotype) and adequate … *Corresponding author. Tel: +32 89 32 71 00, Fax: +32 89 32 79 18, Email: maximo.rivero{at}zol.be