Background N-terminal pro β-type natriuretic peptide （NT pro BNP） has been shown to predict the prognosis and could guide the treatment of heart failure. We aimed to investigate the values of NT pro BNP in predicting the clinical response to cardiac resynchronization therapy （CRT）. Methods A total of 44 patients with chronic heart failure （34 male and 10 female, mean age of （58±13） years, New York Heart Association （NYHA） class 3.3±0.5, QRS duration （150±14） milliseconds） who underwent successful implantation of a CRT system were enrolled in this study. Pharmacotherapy remained stable during the first 3 months of follow-up. Plasma levels of NT pro BNP were evaluated before and 3 months after implantation. Clinical, echocardiographic and exercise parameters were monitored at each clinical visit after CRT implantation. Receiver operating characteristic analysis and a paired ttest were performed to analyze the data. Results After a mean of （16.3±5.5） months of follow-up, 11 nonresponders were identified. CRT resulted in a significant reduction in NT pro BNP （（1.70±1.28） vs （1.07±0.88） pmol/ml, P 〈0.001） in responders. Percentage change in NT pro BNP level （△BNP%） was a statistically significant predictor of long term clinical improvement at 3 months of follow-up. Conclusions △BNP% from baseline to 3 months of follow-up is a predictor of long term response to CRT. NT pro BNP may be a simple method for monitoring the effects of CRT.
Background Although cardiac resynchronization therapy （CRT） is already an established treatment, the characteristics of patients who have an excellent response to CRT and those who get no benefit remain to be determined. The purpose of this study was to search for potential predictors of both non-response and super-response to CRT.Methods Seventy-six consecutive patients who received CRT treatment were divided into group A （non-responders）,group C （super-responders） and group B （responders exclusive of super-responders）. Student＇s t test, Mann-Whitney test, Logistic regression and receiver operating characteristic curve were employed to identify potential predictors among the patients＇ demographic characteristics, clinical features, several electrocardiographic parameters before and after CRT implantation, and their pre-implant echocardiographic parameters.Results Group A had the lowest 3-month left ventricular ejection fraction （LVEF）. Group C had the smallest pre-implant left ventricular end-diastolic dimension （LVEDD）, the shortest post-implant QRS duration, the smallest 3-month LVEDD and the highest 3-month LVEF. In addition, there was a trend of gradual change in percent of left bundle branch block,severity of pre-implant mitral regurgitation, pre-implant QRS dispersion, post-implant QRS duration as well as post-implant QRS dispersion from group A to group B and from group B to group C. Multivariable Logistic analysis revealed that only pre-implant LVEDD could predict CRT super-response. A pre-implant LVEDD of 68.5 mm was the cut-off value that identified super-responders with 87.5% sensitivity and 79.7% specificity. A pre-implant LVEDD of 62.5mm identified super-responders with 50.0% sensitivity and 89.8% specificity.Conclusions Predictors of a CRT non-response remain unclear at present. But it is credible that patients with a smaller left ventricle would have a better chance to become super-responders to CRT.
QIAO Qing DING Li-gang HUA Wei CHEN Ke-ping WANG Fang-zheng ZHANG Shu
