Cardiac resynchronisation therapy (CRT) is an efficacious and cost-effective therapy in patients with highly symptomatic systolic heart failure and delayed ventricular conduction. Current guidelines recommend CRT as a class I indication for patients with sinus rhythm, New York Heart Association (NYHA) functional class III or ambulatory class IV, a QRS duration ├óÔÇ░─ä120ms, and left ventricular ejection fraction (LVEF) ├óÔÇ░┬ñ35%, despite optimal pharmacological therapy. Recent trials resulted in an extension of current recommendations to patients with mild heart failure, patients with atrial fibrillation, and patients with an indication for permanent right ventricular pacing with the aim of morbidity reduction. The effectiveness of CRT in patients with narrow QRS, patients with end-stage heart failure and cardiogenic shock, and patients with an LVEF >35% still needs to be proved. This article reviews current evidence and clinical applications of CRT in heart failure and provides an outlook on future developments.
Cardiac resynchronisation therapy, heart failure, biventricular pacemaker, cardiomyopathy, indications
Disclosure: Charlotte Eitel has no conflicts of interest to declare. Gerhard Hindricks has received modest lecture honoraria from St Jude Medical, Biotronik, Medtronic, and Biosense and is a member of the St Jude Medical and Biosense advisory boards. Christopher Piorkowski has received modest lecture honoraria from St Jude Medical and Biotronik and is a member of the St Jude Medical advisory board.
Received: 12 November 2010 Accepted: 8 February 2011 Citation: Eurpoean Cardiology, 2011;7(1):29├óÔé¼ÔÇ£33
Correspondence: Charlotte Eitel, University of Leipzig, Heart Center, Department of Electrophysiology, Str─é─¢mpellstrasse 39, 04289 Leipzig, Germany. E: firstname.lastname@example.org
Cardiac resynchronisation therapy (CRT) is an established therapy for patients with drug-refractory, highly symptomatic systolic heart failure (HF) and delayed ventricular conduction.1 CRT devices are designed to synchronise the mechanical activity within the left ventricle, between the left and the right ventricle and between the atria and ventricles. Resynchronisation induces reverse remodelling and reduces mitral regurgitation.2,3 This has been shown to improve cardiac function, resulting in an enhanced functional capacity and improved quality of life.4 Finally, large randomised trials have shown significant reductions in all-cause mortality and hospital admissions with CRT versus usual care.5,6 Thus, current guidelines recommend CRT combined with a pacemaker (PM; CRT-P) or implantable cardioverter├óÔé¼ÔÇ£defibrillator (ICD; CRT-D) as a class I indication for patients with sinus rhythm (SR), New York Heart Association (NYHA) functional class III or ambulatory IV, a QRS duration ├óÔÇ░─ä120ms, and left ventricular ejection fraction (LVEF) ├óÔÇ░┬ñ35% despite optimal pharmacological therapy.7├óÔé¼ÔÇ£9
Given the high morbidity and mortality in chronic HF, efforts are being made to explore new indications with the aim of extending the beneficial effects of CRT to selected subgroups of patients who do not fulfill current selection criteria. Nevertheless, the high number of patients not deriving any demonstrable benefit despite fulfilling current guidelines should be kept in mind, requiring careful assessment of evidence.
Data from multicentre clinical trials have recently been published and resulted in an update of the European Society of Cardiology (ESC) guidelines, further extending CRT indications to selected patients. The aim of this article is to give an overview of these recent trials and the respective changes to the guidelines. Furthermore, emerging indications and ongoing trials are reported and discussed.
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