Application Of His Bundle Pacing In Patients With Heart Failure And Indication Of Pacemaker Implantation

Objective:Cardiac conduction disease is a kind of diease which can be a serious,potentially life-threatening problem.Whereas the pathophysiological mechanisms underlying cardiac conduction disease are diverse,cardiac pacing is the only effective treatment for patients with bradycardia that cause severe symptoms.However,traditional right ventricular pacemaker implantation has been confirmed to result in reduced left ventricular synchrony,decreased left ventricular function,enhanced valvular regurgitation,increased incidence of heart failure,and increased hospitalization rate and mortality.Moreover,no matter the right ventricular apex,right ventricular septum or atrial-ventricular dual-chamber pacing,the traditional right ventricular pacing sites will not lead to the reduction in these pathophysiological changes.Although the following synchronous biventricular pacing has changed in the traditional pacing mode,its application in patients combined with heart failure is always limited due to the complex operation,high cost,and low success rate and response rate of patients to pacemaker after surgery.There is no stagnation in the research on pacing sites.The pacing in the His bundle region has been widely concerned in recent years due to its physiological pacing characteristics.From the current studies,compared with the traditional right ventricular pacing,His bundle pacing can improve left ventricular synchrony and reduce the incidence of heart failure.However,for patients combined with heart failure,it is unclear whether His bundle pacing can improve the prognosis.Methods:In this study,the patients with chronic heart failure and indications of pacemaker implantation in our hospital from 2015 to 2017 were included for implantation of His bundle pacing.The left ventricular ejection fraction(LVEF),left ventricular end-diastolic diameter(LVEDd),tricuspid regurgitation,pulmonary artery systolic pressure and NT-pro BNP level were followed up before His bundle pacing,and 1 month,6 months and 1 year after His bundle pacing.The changes in related indexes before and after surgery were analyzed using the paired t-test.According to age,arrhythmia type and other factors,the patients with chronic heart failure were matched with right ventricular apical pacing at 1 : 3 of the previous cases in our hospital.Comparison with His bundle pacing was carried out using the Chi square test combined with related clinical indexes.The results of 6-min walking test of the eligible patients were observed before and after surgery,so as to explore the effects of right ventricular apical pacing and His bundle pacing on patients with chronic heart failure.Results:Finally,28 patients were included in this study,including 7 patients(3 males and 4 females)undergoing implantation of His bundle pacing.According to the matching at 1 : 3,there were 21 patients receiving right ventricular apical pacing,including 9 males and 12 females.The average age of the His bundle pacing group was 75.5 ± 11.2 years,and the average age of the right ventricular apical pacing group was 76.5 ± 9.7 years.In the His-bundle pacing group,LVEF increased from 0.51±0.09 preoperatively to 0.53±0.09,0.57±0.11 and 0.57±0.1,respectively,at 1 month,6 months and 1 year postoperatively(P=0.04,<0.001 and <0.001,respectively);LVEDd reduced from 53.86±6.91 mm preoperatively to 50.86±5.43 mm,50.14±4.95 mm,and 9.6±6.22 mm,respectively,at 1 month,6 months and 1 year postoperatively(P=0.01,0.02 and 0.01,respectively);neither extent of tricuspid regurgitation(P=0.46,0.20 and 0.36,respectively)nor pulmonary artery systolic pressure(P=0.15,0.21 and 0.36,respectively)showed significant changes from preoperatively to 1 month,6 months or 1 year postoperatively;whereas NT-pro BNP showed significant improvements from 5487(406,31140)preoperatively to 2541(196,15280),1297(425,13257)and 1109(587,1296),respectively,at 1 month,6 months and 1 year postoperatively(P=0.018,0.028 and 0.046,respectively).In the RVAP group,compared to 0.61±0.05 preoperatively,LVEF showed significant difference only at 6 months postoperatively(0.59±0.04,P=0.03),yet no significant differences at 1 month or 1 year postoperatively(P=0.19 and 0.67,respectively);LVEDd showed no significant improvements from 48.90±4.21 mm preoperatively to 1 month(48.95±5.62),6 months(48.1±3.69)or 1 year(48.71±3.65)postoperatively(P=0.96,0.02 and 0.58,respectively);neither extent of tricuspid regurgitation nor pulmonary artery systolic pressure showed statistically significant differences from preoperatively to 1 month,6 months or 1 year postoperatively(P=0.33,0.33 and 0.16,respectively,for tricuspid regurgitation;P=0.60,0.38 and 0.86,respectively,for pulmonary artery systolic pressure);NT-pro BNP showed significant improvements from 141(989,7782)preoperatively to 1203(509,6892),1191(167,5804)and 1109(409,5012),respectively,at 1 month,6 months and 1 year postoperatively(P=0.001,0.002 and 0.002,respectively).A comparative study on the data validity of the 2 groups showed that ΔLVEF was 0.05 ± 0.012 in HBP Group,which was significantly different from the ΔLVEF-0.03 ± 0.36 in RVAP Group,P= 0.001.ΔLVEDd was-4.33±2.73 mm in HBP Group,which was significantly different from the ΔLVEDd-2±1.57 mm in RVAP Group,P= 0.012.ΔPASP was-6.5±15.77 mm in HBP Group,which was not significantly different from the ΔPASP-0.15±7.74 mm in RVAP Group,P= 0.359.ΔNT-pro BNP was-3088.3± 3315.58pg/ml in HBP Group,which was significantly different from the ΔNT-pro BNP 1077±1560pg/ml in RVAP Group,P= 0.046.In terms of the validity before and 1 year after operation,HBP Group showed a better improvement on LVEF and LVEDd than those in RVAP Group,with a P value of 0.038 and 0.023,respectively.There was no significant difference in the improvement of tricuspid regurgitation,PASP and NT-pro BNP between the 2 groups,with P values of 0.25,0.59 and 0.37,respectively.Four patients in His-bundle pacing group completed the 6 minutes walk test.There were significant improvements in the test results from respectively 239 m,123m,347 m and 214 m preoperatively to respectively 376 m,243m,458 m and 426 m at 1 year postoperatively.Conclusion:In this follow-up study comparing the His-bundle pacing group and RVAP group,it was noted that for patients with heart failure indicated for cardiac pacing,His-bundle pacing might provide a superior approach over RVAP.