Author + information
- R. Baggen-Santos,
- M. Trêpa,
- I. Silveira,
- B. Brochado,
- M.J. Sousa,
- C. Roque,
- A.P. Vieira,
- V. Lagarto,
- V.A. Dias,
- H. Reis and
- S. Torres
Cardiac resynchronization therapy (CRT) has become increasingly important in the treatment of advanced heart failure (HF). However, variable responses have been observed between patients who meet ESC criteria for CRT implantation. We aimed to assess the predictors of clinical and echocardiographic response to CRT.
Unicentric retrospective study including 316 patients with advanced heart failure who underwent cardiac resynchronization therapy (CRT) between 2002 and 2016. Clinical, laboratory, electrocardiographic and echocardiographic variables were included. We defined response as obtaining both clinical and echocardiographic improvement: global response. Clinical response was defined as improvement in ≥1 NYHA class and echocardiographic response as ≥ 5% increase in left ventricular ejection fraction (LVEF) observed 6-12 months after device implantation. Only variables with p<0.1 in univariate regression analysis were included in the multivariate model.
The study population had a mean age of 69±10 years, 65% of patients were male and 67% had HF of non-ischemic etiology. Previously to CRT implantation, most patients (77%) were in NYHA class III, 18% in class II and 6% in class IV. The mean LVEF was 27±6% and mean QRS duration was 160±24ms. We observed clinical response in 211 patients (73%) and echocardiographic response in 177 (56%). 50% of patients obtained global response.
Compared to the non-responder group, global responders were more likely to be women (44 vs 31%, p= 0.024), have non ischemic etiology (69% vs 51%, p=0.002). Previously to CRT implantion, global responders were more frequently in sinus rhythm (SR) (71% vs 58%, p=0.018), had more often left bundle block pattern (81 vs 67%, p=0.013) and longer QRS duration (QRS>140 ms: 75 vs 91%, p=0.005). There were no significant differences between the groups regarding age, lead placement in coronary sinus, type of lead or previous presence of another device (pacemaker or implantable cardioverter-defibrillator).
In multivariate analysis, non-ischemic etiology (OR 2.5; p=0.013), QRS>140 ms (OR 3.0; p=0.04) and SR (OR 2.4; p=0.04) were independent predictors of global response.
In this study, non ischemic etiology, QRS duration and sinus rhythm previously to implantation were strongly associated with joint clinical and echocardiographic response to CRT. Combining this data with the classical criteria for CRT implantation may help predicting which patients derive greater benefit from resynchronization.