Analysis of Medtronic’s IN.PACT AV Access Trial Reports Predictors of Thrombosis

October 31, 2023—A post hoc analysis reported differences in patients in the IN.PACT AV Access study who eventually had a thrombosis versus those who did not.

The IN.PACT AV Access study is a multicenter, single-blinded randomized controlled trial (RCT) that compared the In.Pact AV drug-coated balloon (DCB; Medtronic) to standard percutaneous transluminal angioplasty (PTA) in end-stage kidney disease patients with de novo or obstructive native arteriovenous fistulas (AVFs) from the United States, Japan, and New Zealand.

Serious adverse events, including access circuit thrombosis, were independently adjudicated. A multivariable analysis was conducted to assess factors associated with access-circuit thrombosis through 36 months. Thrombotic events in AVFs used for dialysis are associated with high rates of access loss, additional procedure cost, poor long-term patency, and higher mortality rates. However, patient, lesion, and procedural characteristics associated with thromboses are not well understood and are rarely reported in prospective RCTs.

Robert Lookstein, MD, presented the findings during a late-breaking clinical trial session at VIVA23, the Vascular InterVentional Advances annual vascular education symposium held by The VIVA Foundation on October 30 to November 2 in Las Vegas, Nevada.

As summarized in the VIVA press release, the cumulative incidence of access circuit thrombosis through 36 months in the IN.PACT AV Access study was 8.2% in the DCB group compared to 18.3% in the PTA group based on Kaplan-Meier estimates (log-rank P = .04).

The post hoc multivariable analysis of all participants suggested that predictors of a higher risk of access circuit thrombosis were two or more reinterventions in the year before the index procedure, upper arm AVF type, higher preprocedural diameter stenosis of the target lesion, and treatment with PTA.

In the IN.PACT AV Access trial, the cumulative incidence of thrombosis through 36 months was lower in the DCB group compared to the PTA group.

After conducting a multivariable analysis, four variables were retained and appear to be associated with higher access circuit thrombosis through 36 months. Dr. Lookstein advised in the VIVA press release that because of the costs and patient impact associated with access circuit thrombosis, as well as the post hoc approach, these results should be further studied in larger populations.