Research Of Clinical Characteristics Of Super Responders To Cardiac Resynchronization Therapy

Objectives:Cardiac resynchronization therapy(CRT)exerts clinical benefits to partial patients with heart failure(HF),that is so-called response,and even reached to super-response.However,about one-third of patients who implanted CRT according to the current guidelines are "non-responders".Because of its high price,it is particularly important to screen patients who are more likely to be super-responders through effective predictors before the procedure under the limited medical resources.In this study,we retrospectively analyzed the baseline,perioperative and follow-up data of general characteristics,combined diseases,electrocardiogram(ECG),and ultrasound parameters of patients with HF hospitalized in Tianjin Chest Hospital and implanted CRT,aiming to investigate the possible predictors of super-response to CRT.Methods:80 consecutive HF patients implanted with a CRT system from Tianjin Chest Hospital between 2004.03 and 2015.01 were selected.All surgical patients' baseline and perioperative data were collected through electronic medical records system or paper case,including age,sex,HF duration,ECG(preoperative and postoperative),cardiac ultrasound,and drug therapy and concomitant diseases(including dilated cardiomyopathy,ischemic cardiomyopathy,hypertension,diabetes,atrial fibrillation).After discharge,outpatient follow-up was conducted at 3 months,6 months and 12 months after CRT device implantation,asymptomatic patients were subsequently followed once a year.Each followed-up visit,patients' recent heart function grade of NYHA were assessed,patients were asked for HF exacerbation related cardiac events,routine recorded ECG,cardiac ultrasound and pacemaker parameters to guide and adjust the rational anti-chronic HF and antiarrhythmic drug treatment programs.The definition of super-response is that,12 months after CRT,the absolute increasing of LVEF was greater than or equal to 15%,and the grade of NYHA decreased greater than or equal to 1.The others who didn't meet the conditions are non-super-responders.Results:During the 12 months follow-up,26(32.5%)patients showed super-response to CRT.The HF duration in the super-response group was significantly shorter than that in the non-response group(34.84±42.30 vs.60.76±65.88,P=0.036).The proportion of women in the super-response group was significantly higher than that in the nonresponse group(42.0%vs.18.5%,P=0.024).The proportion of true LBBB in the super-response group was significantly higher than that in the non-response group(73.1.0 % vs.44.4 %,P=0.016).The proportion of HF due to non-ischemic cardiomyopathy was significantly higher in super-response group than in non-response group(88.5%vs.64.8%,P=0.027).Besides,baseline pulmonary artery systolic pressure(PASP)(36.08±10.04 mmHgvs.42.72±10.22 mmHg,P=0.008),left atrial diameter(LAD)(43.12±6.15 vs.46.50±7.16 mm,P=0.042)and left ventricular enddiastolic diameter(LVEDD)(70.12±9.36 mm vs.75.24±10.18 mm,P=0.034)were also predictive of the occurrence of post-implantation super-response.In addition,the postoperative QRS duration was significantly lower in the super-response group than in the non-response group(135.15±14.64 ms vs.149.89±17.96 ms,P<0.001).Together,these 8 indicators may be positive predictors for post-implantation super-response.In addition,all patients with poor cardiac outcomes were from the non-response group.The incidence of cardiac events such as cardiac death and HF was significantly lower in patients with super-response than in non-responsers(P=0.001).Conclusions:Female gender,with true LBBB,non-ischemic cardiomyopathy,shorter postoperative QRS duration,normal baseline PASP,smaller LAD and LVEDD,and shorter HF duration seemed to be associated with super-response after CRT device implantation.