Improvement in CRT: new strategies, better choices

Cardiac resynchronisation therapy (CRT) emerged more than a decade ago as a useful form of device therapy for heart failure associated with abnormal ventricular conduction indicated by a wide QRS complex [1, 2]. According to the Guidelines of the European Society of Cardiology (ESC) entitled Cardiac Pacing and Cardiac Resynchronization Therapy (ESC Clinical Practice Guidelines, 2013), CRT has currently a Class I indication in patients with 1) chronic heart failure (NYHA Class II-IV despite optimal medical treatment), 2) a left bundle branch block (LBBB) on the ECG with a QRS width >120 ms (preferably >150 ms), and 3) a left ventricular ejection fraction<35 % [3]. The magnitude of CRT benefit increases in females, in patients with non-ischaemic cardiomyopathy, and in patients with a wide QRS complex: the longer the QRS duration the more favourable the response. CRT consists of biventricular pacing with or without an internal cardioverter defibrillator (ICD): in combination with an ICD, CRT is called CRT-D (efibrillator); without an ICD, the treatment is called CRT-P (acing). According to Daubert et al. [4], the prescription of CRT-D is currently restricted to patients in need of secondary prevention of ventricular ar-rhythmias or, for primary prevention, in younger patients without major concomitant illnesses. The preferential choice of CRT-P for the remainder of the ambulatory patients in NYHA class III or IV is currently acceptable. Because of insufficient data regarding the performance of CRT-P in patients presenting in NYHA functional class I or II, CRT-D is currently the device of choice for this sub-population. In the choice between CRT-D and CRT-P, the 2013 ESC guidelines-endorsed by our national society, the NVVC-clearly state: Owing to the potential incremental survival benefit of CRT-D over CRT-P, the prevailing opinion among the members of this Task Force is in favour of a superiority of CRT-D in terms of total mortality and sudden death. However, no strict recommendations can be made, and the Task Force prefers to merely offer guidance regarding the selection of patients for CRT-D or CRT-P, based on overall clinical condition , device-related complications and cost. Speaking of device-related complications and costs, these are crucial issues to be considered as there are still 20–30 % non-responders to CRT despite following the appropriate guideline indication [5–7]. Therefore, new strategies and more appropriate CRT approaches have to be implemented providing higher rates of success. Recently, Vernooij et al. [8] from Maastricht (the Netherlands) proposed new strategies …