Cardiac Resynchronization Therapy (CRT): Patient Selection and Guideline Adherence : An Analysis of CRT Practice in Europe Based on the European Society of Cardiology CRT Survey II with 11088 patients in 42 countries.

Background/Aims Cardiac Resynchronization Therapy (CRT) reduces morbidity and mortality in patients with heart failure and electrical dyssynchrony. Recommendations for which patients should receive a CRT device are outlined in cardiology society guidelines. However, these recommendations vary and for certain recommendations are imprecise. The purpose of this PhD is to explore why there are variations in international guideline recommendations and how these may contribute to differences in practice using the cohort of CRT Survey II with 11 088 patients in 42 European Society of Cardiology (ESC) member countries. Methods The recommendations provided by the major international guidelines were reviewed to identify areas of consistency and inconsistency in CRT recommendations. Data were collected on consecutive patients implanted with a CRT device in 42 ESC countries. These data were analysed to assess CRT practice and guideline adherence and relate them to variations in guideline recommendations. Results There was mainly consistency in the international guidelines regarding who should receive a device. However, some inconsistencies were identified. These included patients with non-left bundle branch block (LBBB) and patients with heart failure and a pacemaker requirement, implanted with a CRT to avoid right ventricular pacing dependence. Some of these inconsistencies could be explained by the timing of the release of the guidelines. However, others appeared to be related to CRT trial evidence being interpreted differently by different societies. In the European CRT population we found that implanters adhered well to European guidelines with only 2% of patients being implanted outside guideline recommendations. However, practice did vary in the different countries and these variations were more pronounced in areas where guideline recommendations are inconsistent or undetermined. Discussion Adherence to guidelines for CRT in Europe is high. However, in areas where there is limited CRT trial evidence this results in imprecise and inconsistent recommendations in international guidelines and may contribute to promoting variations in CRT practices in different countries