Promotion of Cardiac Resynchronisation Therapy in the Future
The development of CRT keeps evolving, and is now applied in hypertrophic cardiomyopathy; congenital heart disease with different phenotypes of HF (systemic LV failure, RV failure and single ventricular failure); RV failure due to pulmonary hypertension and in patients with HF with preserved ejection fraction.29 The effectiveness of CRT is attenuated in atrial fibrillation, therefore a multimodal therapeutic approach, such as AV junction ablation30 or pulmonary vein isolation combined with CRT, may accentuate the response to CRT by means of rate control. In order to overcome technical hurdles to the wide application of CRT, the development of new technology is required. Access route of LV leads need to be improved in difficult patients including transventricular passage or percutaneous subxiphoid approach. The implantation of CRT using a sensor-based electromagnetic tracking system to facilitate LV placement has proven safe and successful.31 Multisite stimulation has emerged as a method of potentially overcoming non-response; this may be achieved by means of multiple leads or multipolar (quadripolar) LV leads.32 A leadless ultrasound-based technology for LV endocardial resynchronisation showed promising results in a pilot study.33 Safer and more effective lead and system extraction will be required in the event of system infection or dislodgement for CRT system. Last but not least, stand-alone devices with lower cost and remote monitoring will further consolidate the advantages of CRT. In summary, from proof-of-concept studies to clinical trials, CRT is undoubtedly an important therapy for a subgroup of HF patients. Further studies and initiatives are required to increase its utilisation in eligible patients.