Cardiac resynchronization therapy with or without an implantable defibrillator: only indicated when everything else has failed?

Abstract

Cardiac resynchronization therapy (CRT) is potentially an important new treatment for patients with heart failure due to left ventricular systolic dysfunction and cardiac dyssynchrony. There is growing evidence that CRT can improve symptoms although it is possible that similar benefits could be obtained by skillful manipulation of pharmacological therapy. There is also preliminary but inconclusive evidence to suggest that CRT alone or in synergy with an implantable cardiac defibrillator (ICD) may reduce morbidity and mortality. However, fashion is in danger of overtaking facts and it is important to ensure that benefits are not only statistically proven but clinically meaningful and cost-effective. Optimal timing of intervention and patient selection will be essential to ensure that treatment is deployed efficiently. If CRT with or without ICD becomes part of mainstream therapy for heart failure this will have far-reaching consequences for heart failure management. Implantation is a skilled and often time-consuming procedure. Long-term management of both CRT and ICD is likely to provide challenges in terms of lead technology, pacing thresholds and device management. Heart failure physicians will have to learn new skills and collaborate more closely with electrophysiologists. Such developments, in addition to the need for complex pharmacological interventions will accelerate the move away from general practice and towards specialist care for this most common of malignant diseases. If CRT does reduce mortality, it will graduate from an adjunctive therapy which could be used to an essential one that should be used as part of routine therapy for appropriate patients. Currently, CRT is a symptomatic therapy for patients with severe heart failure resistant to intensive pharmacological therapy delivered by a heart failure specialist.