Cardiac impact of arteriovenous fistulas: what tools to assess?

Abstract

The relationship between arteriovenous access flow (Qa) and cardiovascular changes is complex. Several studies have shown cardiac remodeling and symptoms of heart failure for high-flow arteriovenous fistulas (AVF). To evaluate the early cardiovascular impact of AVF. Forty-seven patients with an AVF, hospitalized for the evaluation of high-flow AVF or a pre-kidney transplant assessment were included. We collected clinical and biological data. We also collected data of the assessment by transthoracic echocardiography, functional evaluation by 6-min-walk test and peak oxygen consumption, and measurement of coronary flow reserve by dynamic myocardial perfusion imaging. The measurement of Qa was performed by color Doppler ultrasound and then indexed to the body surface area (Qai) and to the cardiac output (CO) (Qa/CO). Patients were poorly symptomatic (18 and 1 patients NYHA stage 2 and 3, respectively). There was no correlation between Qa, Qai, or Qa/CO and functional status, assessed by peak oxygen consumption (P = 0.891; P = 0.803; P = 0.939, respectively). Symptomatic patients did not have higher Qa, Qai or Qa/CO than asymptomatic (2260 vs 2197 mL/min, P = 0.402; 1257 vs 1256 mL/ min/m 2 , P = 0.835; and 34% vs 37%, P = 0.701, respectively). There was no correlation between Qa, Qai or Qa/CO and left ventricular end-diastolic volume or left ventricular ejection fraction. There was no correlation between coronary flow reserve and these 3 parameters of vascular access flow. However, the global longitudinal strain (GLS) was correlated with Qa and Qa/ CO (R = 0.331, P = 0.023 and R = 0.380, P = 0.008, respectively). Increase of Qa or Qa/CO was associated with an alteration of the GLS. A cut-off value of 2250 mL/min for Qa allowed 83% sensitivity and 63% specificity for detecting an alteration of the GLS > − 18%. A cut-off value of 33% for Qa/CO allowed 92% sensitivity and 65% specificity. Impact of AVF on cardiac parameters is weak. However, GLS is the first parameter to be impacted by the flow of the fistula. Systematic transthoracic echocardiography evaluation with measurement of GLS should be proposed for all patients with Qa > 2250 mL/min or Qa/ CO > 33%, to detect those at higher risk of cardiac impact of the AVF.

Impact of Different Approaches to Kidney Transplant with and without Chronic Hemodialysis on Cardiac Function and Morphology: A Case–Control Study

“…Fourth, coronary angiography was performed only in the minority of cases and no noninvasive verification of coronary status was repeated at the time of inclusion to this study; therefore, we cannot definitely exclude the impact of ischemic heart disease on our results. Fifth, despite the absence of significant contribution from AVF in multivariable models, it is likely that the AVF-related volume overload, more frequent in the HD subset, might have contributed to the between-group differences in cardiac function and morphology [30].…”

Optimizing Arteriovenous Fistula Care in Kidney Transplant Recipients

“…A cutoff value of 33% for Qa/CO allowed the detection of significant alteration in GLS indicative of myocardial dysfunction with a sensitivity of 92% and specificity of 66%. 9 Moreover, although a specific fistula flow cutoff value conferring a high risk of cardiac failure is still debated, numerous studies have shown that AVF with a blood flow exceeding 1500 ml/min are at a heightened risk.…”