Predictors Of Super-response To Cardiac Resynchronization Therapy And The Effect Of Super-Response On Long-term Prognosis

BackgroundSince 1990 s,Cardiac Resynchronization Therapy(CRT)has become the standard treatment for chronic heart failure patients with ventricular systolic asynchrony and wide QRS besides the best drug treatment.Some previous large clinical trials have confirmed that CRT can reverse left ventricular remodeling,improve cardiac function,improve quality of life and reduce mortality.Certain patients realize near normal or normal of left ventricular ejection fraction(LVEF)after CRT,referred to as “super-responders(SRs)”.Unfortunately,about 30% patients after CRT were “non-responders”.Therefore,preoperative identification of heart failure patients to be SRs after CRT has important clinical significance for patients with heart failure to choose the appropriate treatment.Previous studies found that female,left bundle branch block(LBBB),smaller left atrial,smaller left ventricle,non-ischemic cardiomyopathy,shorter heart failure duration,lower pulmonary artery systolic pressure and wider QRS were independent predictors of Super-Response(SR)to CRT.However,the definitions of SR vary in previous studies,with different predictors of SR to CRT reported.Pulmonary hypertension is an abnormal hemodynamic state in which pulmonary artery pressure exceeds a certain threshold.Previous studies found about 2/3 chronic heart failure patients had pulmonary hypertension.Few studies involved the predictive value of pulmonary artery systolic pressure on CRT SR and the effect of pulmonary artery systolic pressure on long-term prognosis of patients after CRT.The purpose of this study was to explore the predictive factors of CRT SR and the effect of SR on long-term prognosis,also to explore the predictive value of preoperative pulmonary artery systolic pressure on CRT SR and the effect of pulmonary artery systolic pressure on long-term prognosis of patients after CRT.Objectives:1.To explore which clinical indicators can predict CRT SR and the impact of SR on long-term prognosis.2.To explore the value of pulmonary artery systolic pressure in predicting SR to CRT and the effect of pulmonary artery systolic pressure on long-term prognosis in patients after CRT.Methods:This study was divided into two parts.All data were from 73 patients who received CRT and had complete follow-up data from June 2014 to December 2017 in the Department of Cardiology of our hospital.Baseline data of all patients were collected,including age,sex,comorbidities,New York Heart Association(NYHA)functional class,echocardiography,electrocardiogram,medication for heart failure and 6-months follow-up data after CRT were collected,including echocardiography,electrocardiogram,NYHA class,combined end point(all-cause mortality or hospitalization for heart failure).1.The first part of the study was to explore the clinical indicators that could predict SR to CRT and the impact of SR on long-term prognosis.According to the definition of CRT SR in the study of Gasparini et al.and Castellant et al.,we also define CRT SR as after 6-month follow-up when NYHA class reduction to I or II combined with LVEF ? 50% were observed.According to the occurrence of SR after CRT,the patients were divided into SRs and non-SRs(NSRs)group.2.The second part of the study was to explore the value of pulmonary artery systolic pressure in predicting SR to CRT and the effect of pulmonary artery systolic pressure on long-term prognosis in patients after CRT.According to pulmonary artery systolic pressure estimated by echocardiogram,the patients were divided into two groups: Pulmonary artery hypertension group(pulmonary artery systolic pressure ? 50 mmHg)and Non-pulmonary artery hypertension group(pulmonary artery systolic pressure<50 mmHg).Results:1.Predictors and prognosis of SR to CRT(1)17 patients were considered SRs and 56 patients were considered NSRs.Heart failure duration,left atrial dimension(LAD)and LBBB were independent predictors of SR.(2)The area under curve(AUC)for heart failure duration was 0.789(95% CI: 0.67-0.91,P < 0.001),with heart failure duration ? 36 months having 88% sensitivity,70% specificity.LAD ? 42 mm was 82% sensitive and 71% specific for predicting SR to CRT(AUC 0.775;95% CI: 0.67-0.88;P < 0.001).For Combination of heart failure duration and LAD,the AUC was 0.899(95% CI: 0.83-0.98,P < 0.001),with heart failure duration ? 48 months together with LAD ? 42 mm having 88% sensitivity,79% specificity.Combination of heart failure duration and LAD significantly increased AUC compared with standalone heart failure duration(0.899 vs 0.789,Z = 2.207,P = 0.027)or standalone LAD(0.899 vs 0.775,Z = 2.487,P = 0.013).(3)The cumulative incidences of combined end point were significantly lower in the SRs group,LAD ? 42 mm group and combination of heart failure duration ? 48 months and LAD ? 42 mm group.(4)Compared with non-SRs group,SRs group had better improvement of cardiac function(P < 0.001),higher LVEF(P < 0.001),smaller left ventricular end-diastolic dimension(LVEDD,P < 0.001),and less mitral regurgitation area(P < 0.001).(5)LAD and LBBB were independent risk factors for the prognosis of heart failure patients after CRT.2.The value of pulmonary artery systolic pressure in predicting SR to CRT and the effect of pulmonary artery systolic pressure on long-term prognosis in patients after CRT.(1)There were 27 patients in pulmonary hypertension group and 46 patients in non-pulmonary hypertension group.Non-pulmonary hypertension group had better improvement of NYHA class,LVEF and LVEDD than pulmonary hypertension group.(2)The incidence of CRT response and CRT SR in pulmonary hypertension group was lower than that in non-pulmonary hypertension group.(3)There may exist a value for baseline pulmonary artery systolic pressure to predict CRT SR(AUC,0.709;95 % CI,0.575-0.843;P = 0.002),with pulmonary artery systolic pressure ? 35 mm having 76.5% sensitivity,64.3% specificity.(4)The cumulative incidence of combined end point was significantly lower in pulmonary hypertension group than that in non-pulmonary hypertension group.(5)Pulmonary hypertension and LBBB were independent risk factors for prognosis of patients after CRT.Conclusions:1.Heart failure duration,LAD and LBBB are independent predictors of SR.The combination of HF duration and LAD make more robust prediction of SR.The long-term prognosis of CRT SRs,patients with LAD ? 42 mm and patients with heart failure duration ? 48 months combined with LAD ? 42 mm are better.2.Patients with elevated pulmonary systolic pressure have worse improvement in NYHA class,LVEF and LVEDD,and have higher incidence of combined end point.The incidences of CRT response and SR are lower in patients with pulmonary hypertension.There may exist a value for baseline pulmonary artery systolic pressure ? 35 mm to predict CRT SR.3.LBBB,LAD and pulmonary hypertension are independent risk factors for long-term prognosis of heart failure patients after CRT.