Introduction:
Despite extensive studies, patient selection for cardiac resynchronization therapy (CRT) remains a challenge, as 20 to 40% fail to respond.Out of the non-responders, a small proportion will experience worsening.We sought to evaluate predictors for clinical worsening following CRT in a real-life cohort of CRT recipients and its correlation to subsequent long-term mortality.
Methods:
The study included 231 consecutive patients that were implanted with CRT systems between 2007 and 2011 and had complete follow-up at our institution. Clinical and echocardiographic assessment were available at baseline and during the first year after CRT. Clinical response (worsened, stable, improved) at one year was defined using a composite score based on NYHA class, 6-minute walk test and Quality of Life. Logistic regression modeling was used to identify predictors for worsening after CRT,in the entire cohort and in the left bundle branch morphology (LBBB) sub-group.Survival data were obtained up to 6 years post-implant.
Results:
Within one-year post-CRT implantation 60% of the patients improved, 20% remained stable and 20% experienced clinical worsening.Patients who clinically deteriorated were older compared to stable or improved status (71±9vs.66±10vs.68±10 years respectively;p=0.03) and had higher prevalence of coronary artery disease (78%vs.54% vs.70% respectively;p=0.04).Four-year mortality was higher in worsened patients (64%vs.24%vs.21%, in stable and improved patients respectively;P<0.001).In multivariate analysis age was the only independent predictor for worsening (OR 1.049;P=0.02). There was a trend for non LBBB morphology to be associated with clinical worsening (OR 1.9;P=0.07).Within LBBB patients, PR>200 ms and QRS
Conclusions
Older age at time of CRT implantation, as well as 1st-degree AVB and QRS
