Impact of Arteriovenous Fistula for Hemodialysis on Clinical Outcomes of Coronary Artery Bypass

Impact of coronary-subclavian steal after surgical myocardial revascularization with internal thoracic artery in chronic hemodialysis patients: A meta-analysis

Patients in hemodialysis with an arm arteriovenous fistula undergoing coronary artery bypass grafting (CABG) with an internal thoracic artery have been reported to suffer from coronary-subclavian steal (CSS) during dialysis session. However, its occurrence is still debated. A systematic literature review was performed to identify all studies investigating the occurrence of a CSS event in this subset of patients. The primary endpoint was the analysis of CSS and the following early and late survival outcomes. Independent determinants of CSS and the impact of the distance between the arteriovenous fistula (upper arm vs forearm) and the ipsilateral internal thoracic artery graft on CSS events and mortality were studied. Early and late survival outcomes were analyzed by comparing ipsilateral versus contralateral arteriovenous fistula. Of the 1,383 retrieved articles, 10 were included (n = 643 patients). The pooled event rate of CSS was 6.46% [95%CI=2.10-18.15], while of symptomatic CSS incidence was 3.99% [95%CI=0.95-15.25]. No survival differences were noted when comparing ipsilateral to contralateral arteriovenous fistula-internal thoracic artery combinations. On meta-regression, the upper arm was associated with more CSS events, while the forearm to lower late mortality rates. Independently from arteriovenous fistula-internal thoracic artery combination, CSS was not associated to higher mortality rates. Particular attention is warranted when selecting the type of conduits for CABG in patients with an arteriovenous fistula or if highly expected to need one in the near future after surgery. A contralateral arteriovenous fistula-internal thoracic artery combination is preferable. If this is not possible, a forearm arteriovenous fistula position should be preferred.

Influence of Ipsilateral Graft Inflow to Arteriovenous Fistula for Hemodialysis in Coronary Bypass Surgery

In coronary artery bypass grafting (CABG) for patients on hemodialysis, there has been concern about “coronary steal”. This study aims to evaluate the influence of using an in situ internal thoracic artery (ITA) ipsilateral to a preexisting arteriovenous fistula (AVF) in dialysis-dependent patients undergoing CABG. Between 2004 and 2018, dialysis-dependent patients with AVFs who underwent CABG were enrolled. According to the locational relationship of AVFs and in situ ITA grafts, the patients were divided into the ipsilateral group (n = 22) and the contralateral group (n = 21). Inverse probability weighting analysis was used to estimate and compare the late clinical outcomes. The late cardiac-related adverse events were not significantly different between the two groups: “major adverse cardiovascular and cerebrovascular events (MACCE)” (p = 0.090), “composite outcome of recurrent angina and coronary re-intervention” (p = 0.600). The in situ ITA graft of CABG on the ipsilateral side to AVF was not a significant risk factor for MACCE or the composite outcome of recurrent angina and coronary re-intervention. There was no statistically significant difference in the graft patency between the groups. Therefore, it might not be necessary to avoid using an in situ ITA on the ipsilateral side of an upper-arm AVF for optimal coronary artery bypass grafting in dialysis-dependent patients.

Internal thoracic artery graft ipsilateral to the arteriovenous fistula in haemodialysis patients

OBJECTIVES

The aim of this study was to investigate the impact of in situ internal thoracic artery (ITA) grafting ipsilateral to the arteriovenous fistula (AVF) on postoperative outcomes in haemodialysis patients undergoing isolated coronary artery bypass grafting (CABG).

METHODS

We reviewed 132 haemodialysis patients who underwent isolated CABG between January 2002 and December 2019. With a difference between the left and right upper arms blood pressure measurement of ≥20 mmHg, we did not use the ITA on the lower value side. We categorized patients into 55 patients (41.7%, ipsilateral group) whose left anterior descending artery was revascularized using the in situ ITA ipsilateral to the AVF, and 77 patients (58.3%, contralateral group) whose left anterior descending artery was revascularized using the ITA opposite the AVF. We compared patients' postoperative outcomes after adjusting for their backgrounds using weighted logistic regression analysis and inverse probability of treatment weighting.

RESULTS

No patients developed coronary steal postoperatively, and there was no significant difference in 30-day mortality between the groups (P = 0.353). The adjusted 5-year estimated rates of freedom from all-cause and cardiac death in the ipsilateral vs contralateral groups were 52.3% vs 54.0% and 78.2% vs 88.6%, respectively; survival curves were not statistically significantly different (P = 0.762 and P = 0.229, respectively).

CONCLUSIONS

In situ ITA grafting ipsilateral to the AVF was not associated with postoperative early and mid-term worse outcomes in haemodialysis patients undergoing isolated CABG.

Translational Sciences in Cardiac Failure Secondary to Arteriovenous Fistula in Hemodialysis Patients

High-output cardiac failure is a rare form of heart failure associated with the formation of arteriovenous fistula (AVF) in hemodialysis patients. The pathophysiology underlying the HOCF is complex and multifactorial. Presence of AVF can cause long term hemodynamic changes that ultimately lead to increased cardiac output and consequently cardiac failure. A number of risk factors have been associated with the development of HOCF post-AVF construction, including male sex, a proximally located AVF and a state of volume overload. Dysregulation of tissue inhibitor of matrix metalloproteinase 4, Sirtuin-1 and Sirtuin-3 gene expression have been associated with the development of heart failure. The differences observed between genders have been attributed to altered activity of the β-adrenoceptor system. Numerous biomarkers including cardiac troponin T and I, atrial natriuretic peptide, brain natriuretic peptide among others have shown both prognostic and diagnostic potential; however further research is needed to establish their utility in clinical practice for patients with AVF associated HOCF. In recent years risk stratification models have been developed to help identify patients at the highest risk of developing HOCF post AVF which could be revolutionary in its identification and management. Potential options for managing HOCF post-AVF include AVF ligation, banding and anastoplasty however these procedures are not without their own associated risks. In this review, we discuss the pathophysiology, risk stratification and management of patients with AVF associated HOCF.