Arteriovenous Fistulas May Increase Heart Failure Risk
Pre-emptive placement of an arteriovenous fistula (AVF) in pre-dialysis patients with advanced chronic kidney disease (CKD) may increase their risk of congestive heart failure (CHF), a study found.
Researchers studied 562 patients with stage 4-5 pre-dialysis CKD. Native AVFs were created in 160 patients who chose hemodialysis as the initial modality for renal replacement therapy. Acute decompensated CHF developed in 95 patients (17%). The incidence rate was 19 episodes per 1,000 patient-years. Creation of a successful AVF was associated with a significant 9.5 times increased risk of CHF, according to a report published online ahead of print in Nefrologia.
The risk of developing CHF during the period following AVF creation was significantly greater in patients with a proximal AVF than in those with a distal AVF, Rocío Martínez-Gallardo, MD, and colleagues at Hospital Infanta Cristina in Badajoz, Spain, found. The median time between AVF creation and a CHF episode was 51 days.
According to the researchers, the short time span between AVF creation and CHF development, along with the higher frequency of CHF in patients with a proximal AVF, support a connection between the two.
The mortality of patients with CHF was similar to that of the other study subjects, although unplanned dialysis initiation occurred significantly more frequently in patients who experienced CHF, Dr. Martínez-Gallardo's team stated.
The association between AVF and CHF in dialysis patients previously had been considered incidental, the authors observed. They explained, however, that creation of an AVF causes hemodynamic changes that can favor development of CHF. These changes include increased cardiac venous return, increased heart rate and contractility, and increased filling pressures, which lead to a greater cardiac output, increased plasma volume, and decreased peripheral resistance, they noted.
The researchers said the results of their study support a recommendation that vascular surgeons try to create distal AVFs in pre-dialysis patients, particularly in those with risk factors for developing CHF. In addition, the authors recommend strict follow-up of cardiovascular tolerance and response to the creation of AVF, which would allow for an early diagnosis of CHF.