Efficacy And Factors Affecting Cardiac Resynchronization Therapy In Patients With Heart Failure With Atrioventricular Block

Objective:The clinical benefits of cardiac resynchronization therapy(CRT)compared to right ventricular pacing(RVP)have been widely recognized in patients with heart failure(HF)combined with atrioventricular block(AVB).However,for such patients,there is currently a lack of unified conclusions on the factors that affect the efficacy of CRT,and the economic burden,surgical difficulty,and risk of complications of CRT still cannot be underestimated.Screening suitable populations is crucial.This study aims to explore the efficacy and influencing factors of CRT in patients with HF combined with AVB,in order to further clarify the beneficiaries.Methods:From September 1,2018 to January 1,2022,all patients with HF(Left ventricular ejection fraction,LVEF<50%)and AVB(pacing ratio>40%)who underwent CRT in our hospital were included.Based on whether major adverse cardiovascular events(MACE)occurred during follow-up,such as HF readmission and death.Divide into MACE group and non MACE group,and compare the changes in LVEF,Left ventricular end-diastolic diameter(LVEDD),N-terminal fragment of brain natriuretic peptide precursor(NT pro BNP),and New York Heart Association(NYHA)cardiac function grading at three time points after surgery at 3,6,and 12 months.Establish a multivariate logistic regression equation to further determine the factors affecting MACE events after CRT surgery.The restricted cubic spline plot was used to evaluate the relationship between basic LVEF and MACE events,while the Kaplan Meier curve was used to evaluate the differences in MACE event incidence between different levels of LVEF and different types of cardiomyopathy.Results:87 patients were ultimately included in this study,with an average follow-up of 29 ± 11 months.During this period,2 died and 16 experienced at least one HF readmission event,and were assigned to the MACE group.The remaining 69 patients were included in the non MACE group.The remaining 69 patients were included in the non MACE group.Male patients accounted for a larger proportion in the MACE group(77.8% vs 50.7%,P=0.039),NYHA grade,NT pro BNP,LVEDD,and left atrial diameter(LA)were higher(p<0.05),basic LVEF was lower(P<0.001),preoperative mean QRS wave duration was wider(P=0.003),the proportion of patients with diabetes was higher(p=0.001),and the proportion of patients with pacing induced cardiomyopathy(PICM)was lower(P<0.05).During the first half of the postoperative follow-up,LVEF increased in both groups(P<0.05),but no significant improvement was observed in the MACE group in the second half of the year(P=0.260);There was no significant improvement in postoperative LVEDD in the MACE group compared to before(60.56 ± 9.26 vs 58.83 ± 8.76,P=0 820),the postoperative LVEDD in the non MACE group decreased compared to before(P=0.013).NT-pro BNP in the non MACE group continued to decrease during follow-up(p=0.01),and the decrease was significant in the first three months(2347.45 ± 3830.58 vs 1373.13 ± 1486.78,p=0.028).NTpro BNP in the MACE group decreased in the first six months after surgery(p=0.048).The baseline NYHA grading of the MACE group was higher than that of the non MACE group(3.33 ± 0.69 vs 2.94 ± 0.75,p=0.047).At 6 months after surgery,the NYHA grading of the two groups improved to 2.78 ± 0.65(p=0.01)and 2.01 ± 0.58(p<0.001),respectively.In multivariate logistic regression,baseline LVEF was significantly correlated with MACE events(OR=0.850;95% CI: 0.741-0.974,p=0.02),and the risk of MACE events was significantly reduced when baseline LVEF ≥ 40%(HR=0.291;95% CI: 0.091-0.935,p=0.021).There are significant differences in the incidence of MACE events among different types of cardiomyopathy,and compared to patients with ischemic cardiomyopathy,PICM patients have a significantly reduced risk of MACE events(HR=0.231,95CI: 0.077-0.689,P=0.036).Conclusions:Patients with HF combined with AVB can experience some improvement in their heart function one year after CRT surgery.The main factors affecting the occurrence of long-term MACE events in patients with HF combined with AVB after CRT are basal LVEF and type of cardiomyopathy.Especially for patients with basal LVEF ≥ 40% or PICM,the relative risk of postoperative MACE will be significantly reduced.Considering the long-term benefits,CRT is worth actively recommending.