Association Between Renal Insufficiency And Prognosis Of Heart Failure Patients Treated By Cardiac Resynchronization Treatment

Background:Renal insufficiency(RI)is an independent risk factor for clinical prognosis in patients with heart failure(HF),but there are few studies on the relationship between RI and clinical prognosis of HF patients undergoing cardiac resynchronization therapy(CRT).Objective:To explore the association between RI and postoperative CRT patients’ response and prognosis by long-term follow-up of HF patients treated with CRT in our hospital.Methods:In a retrospective comparative analysis method,patients with HF having a complete follow-up data were selected in this study,who were successfully implanted CRT/CRT-D from March 2007 to August 2015 either in the Department of Cardiology of the sixth affiliated hospital of Kunming Medical University or in the adjacent hospital but conducted regular review in our hospital.Also,after their surgery follow-up data for them were completely recorded.Preoperative and postoperative patient history and clinical data were collected.In addition,general conditions,echo-cardiograms,electrocardiogram,laboratory test results,and medication status were recorded.After the long-term follow-up of the hand-operated patients,the primary end result is all-cause mortality and HF re-admissions.The glomerular filtration rate(GFR)estimated by the MDRD method divided the patients into 3 groups:moderate to severe decline in renal function(GFR<60 ml/min/1.73m2)in group A,and mild decline in renal function in group B(GFR was 60-89 ml/min/1.73m2),group C had normal renal function(GFR>90 ml/min/1.73m2).The responses of patients after CRT and the reversal of left ventricular remodeling were compared among different groups.Single factor analysis and multivariate logistic regression analysis were used to investigate the relationship between renal function and other factors and postoperative CRT reactivity.The Kaplan-Meier method was used to analyze the association between all-cause death events and re-hospitalization events in different groups.Univariate and multi-factor COX proportional hazards regression models were used to study the relationship between renal function and other factors and prognosis of patients after CRT treatment.Results:1.A total of 83 patients meeting the criteria were enrolled.All patients were followed up for 6 months.Both their clinical data before surgery and 6 months after surgery were collected.2.There were 58(66.3%)patients with chronic renal insufficiency who underwent CRT.The GFR of the three groups before surgery was statistically significant(P<0.001);other clinical baselines were of no statistical significance.3.51(61.4%)patients have responses after undergoing CRT.The response rate was 35.7%in group A,73.3%in group B,and 76.0%in group C.The differences in reactivity between group A and group B,group A and group C were statistically significant(P<0.05).There was no significant difference between group B and group C(P>0.05).4.The left ventricular ejection fraction(LVEF)and left ventricular end-diastolic dimension(LVEDD)were reversed at different degrees after 6 months in all three groups;the reversals of A and B,A and C were relatively statistically significant(P<0.05).There was no significant difference between Group B and Group C(P>0.05).5.The renal function levels of the three groups were reversed at different levels after 6 months.The change in GFR of responders with CRT was significantly higher than that of non-responders.In groups A and B,there was a statistically significant difference in responder’s GRF change and non-responder’s GRF change(P<0.001,P=0.001),6.Univariate analysis(chi-square test and T-test)was performed on response and non-response groups in CRT,showing there exists relationship between response and GRF,complete left bundle branch block(CLBBB),and Ischemic Heart Disease(IHD);Multivariate logistic regression analysis was used to predict postoperative CRT response,showing that the higher GFR and the combined CLBBB are independent predictor of CRT postoperative response,and IHD is an independent influencing factor of postoperative CRT.7.Through a follow-up of 28.73± 10.37 months,16 deaths(19.3%)were caused by all-cause deaths,of which 8(9.6%)died of HF aggravation,4(4.8%)died of sudden cardiac death(SCD)and another four people(4.8%)died from other causes.At the same time,a total of 24(28.9%)patients were re-hospitalized because of HF aggravation after CRT.The total number of deaths and re-hospitalization was 27(32.5%).8.Kaplan-Meier survival analysis was used to test the differences in distribution of all-cause mortality and HF re-hospitalization after CRT among the three groups of patients.Log rank results showed a statistically significant difference among the three groups(P<0.001).Using the Log-rank method again,the three groups were compared in pairs.The results showed that the difference in the distribution of primary end points after CRT was statistically significant between group A and group B and C(P=0.007,P=0.003).There was no significant difference between group B and groupC(P=0.696).Single factor COX regression analysis was used to predict the influencing factors of the primary endpoint of postoperative CRT,showing that GFR,combined LBBB,IDH were related to the primary end point event.Multivariate COX regression analysis showed that higher GFR,and the combined CLBBB were independent factors in the decline of all-cause death combined with HF re-hospitalization events,Suffering from IHD was an independent factor affecting therise of these events.Conclusion:About 3/5 of HF patients undergoing CRT have RI.Their cardiac function was improved after CRT.About 2/3 of them had postoperative response and heart function improved significantly.The renal function of patients after CRT was also improved,and the postoperative renal function improved significantly in responders.GFR were an independent predictor of CRT postoperative reactivity,all-cause death events in combination with HF rehospitalization events.Patients with GFR<60 ml/min/1.73m2 had poor postoperative reactivity and high incidence of all-cause deaths in combination with HF rehospitalization after CRT.At the same time,patients with IHD or CLBBB were also independent risk factors for the above events.