At this year’s EndoVascular Access (EVA; 24–25 June, Patras, Greece) meeting, the design and intentions of the EVA DROP study—which will seek to evaluate blood pressure changes associated with device-created arteriovenous fistulas (AVFs) for haemodialysis—were presented by Georgia Georgopoulou (University Hospital of Patras, Greece).
At the outset of her presentation, Georgopoulou noted that previous studies have indicated that surgically created AVFs lower blood pressure by decreasing peripheral resistance, but that they also lead to renin-angiotensin-aldosterone system (RAAS) activation and stimulation of the sympathetic system, increasing cardiac output and subsequently causing left ventricular hypertrophy (LVH).
As such, the EVA DROP study was set up to evaluate possible decreases in blood pressure following minimally invasive AVF creation with the WavelinQ system (BD)—as well as assessing potential early effects on other factors like cardiac output and arrhythmias.
This prospective, single-centre, single-arm proof-of-concept study intends to enrol 20 pre-dialysis chronic kidney disease (CKD) patients, according to Georgopoulou. She also noted that the study represents a multidisciplinary team effort, with investigators spanning interventional radiology, nephrology and cardiology departments. The study’s principal investigator is Panagiotis Kitrou (Assistant professor of Interventional Radiology, University Hospital of Patras, Greece).
Among the most important aspects of the trial’s inclusion criteria, Georgopoulou continued, is the fact that all patients have established, non-reversible kidney failure and are set to start haemodialysis within six months of recruitment in EVA DROP.
“Our primary endpoints are blood pressure changes [defined as the level of mean blood pressure change] and the possible impact of endoAVF creation to the increased output,” she said, “while secondary endpoints are the arrhythmic risk profile and the evaluation of possible independent factors that may influence our primary endpoints.”
She went on to report that the investigators will record 24-hour blood pressure measurements in the contralateral arm intended to undergo endoAVF creation, adding: “We will collect several blood pressure datapoints with a very sophisticated blood pressure-measurement device.” These various datapoints range from peripheral and central aortic blood pressure, to augmentation index (AIx) and pressure, to pulse wave velocity (PWV) and ‘arterial stiffness’.
Georgopoulou noted that a number of cardiac rhythm measurements are also set to be monitored over a 24-hour period in the study, and patients will undergo an echocardiogram and, “as we are talking about vascular access”, flow and vessel diameter measurements will be examined both before AVF creation and at follow-up, as well.
Elaborating further, the speaker noted three key timepoints for these assessments: prior to AVF creation; six weeks after AVF creation; and at a third timepoint that will depend on whether or not the fistula has matured (two months if non-matured), and also whether it will ultimately be required for dialysis.
Speaking to Renal Interventions recently, principal investigator Kitrou said: “This is a proof-of-concept study with a small number of patients and a short follow-up. However, we believe that this is a good step forward and will help us to better understand the systemic blood pressure and cardiovascular changes following percutaneous fistula creation. It is important to explore the clinical impact these percutaneous fistulas have, with the aim to improve the service provided to our patients.”
