A review of factors contributing to health related quality of life achieved with cardiac resynchronization therapy for heart failure.

Unlabelled: Electrical cardiac resynchronization therapy (CRT) with biventricular pacing improves the impaired left ventricular function in selected patients and reduces mortality, morbidity and the number of hospitalizations for heart failure. Reversed left ventricular remodelling following CRT has been documented by various imaging

Methods: Application of CRT involves many factors as selection, implantation procedure, pacing site, programming of the atrioventricular and interventricular pacing intervals, optimal medical and anti-arrhythmic treatment and counselling of the patient with congestive heart failure (CHF). The contribution of various components of CRT to the hemodynamic response and to the left and right ventricular function has been extensively documented. Large prospective studies also demonstrated improvement of health related quality of life (QoL) compared to control patients. The cost-effectiveness of CRT and CRT/implantable cardioverter defibrillators (ICD) in terms of quality adjusted life year appears satisfying provided life expectancy of the recipient is enlarged. However, the follow up of most studies is rather short and QoL is always compared with the baseline condition. Furthermore, the clinical relevance of the reported numerical improvement of QoL and its persistence are fully unknown. The individual improvement of QoL of the CRT recipient cannot be predicted from clinical variables. Literature shows that the contribution of the various CRT factors to the hemodynamic response and to the left and right ventricular function and clinical benefit are extensively studied but not their contribution to health related QoL. For this purpose the contribution to QoL of all factors that are related to CRT response, was stepwise reviewed. Literature showed for several reasons no clear association with any individual CRT component and QoL. It can be concluded that prospective serial QoL studies of CRT patients in conjunction with studies of the cardiac function are requested to identify not only the contribution of CRT factors to QoL but also (sub)groups that benefit most. In these trials the methods and relevance of regular re-examination of the left ventricular function and of reprogramming of the device parameters to obtain a sustained positive CRT responsiveness, need to be established. Finally, because CRT has become a multidisciplinary therapy for chronic heart failure, the professional influence on QoL of the CRT recipient has to be studied.