Surgical PA-LAA Shunting: a Feasibility Study (PA-LAA)

Surgical PA-LAA Shunting for Management of Systemic Embolization in Patients With Atrial Fibrillation: a Feasibility Study

Atrial fibrillation is common and increases the risk of stroke. Traditionally patients are treated with blood thinning medications or at the time of surgery the part of the heart where blood clots form is cut out. Surgically cutting out the left atrial appendage can be difficult and complications can occur. An alternative strategy is to create a tunnel to increase blood flow and wash out the part of the heart where clots form.

This strategy has not been previously studied. The purpose of this study is to determine if creating a tunnel to increase blood flow is feasible and safe.

Study Overview

• Status: Withdrawn
• Conditions: LAA Thrombus Prevention
• Intervention / Treatment: Procedure: PA-LAA shunt

Detailed Description

The goal is to understand the potential avenues to increase Left Atrial Appendage (LAA) flow in patients with Atrial Fibrillation (AF) to minimize systemic embolization risk. Flow modeling demonstrates that the anatomy of the LAA results in decreased velocities in the LAA apex. Introduction of a 3-4mm shunt in the apex can result in increased velocity, less stasis and a lower propensity for thrombus formation. Small (<8mm) inter-chamber shunts can exist in humans with no long term hemodynamic consequences in otherwise structurally normal hearts - making a strategy of pulmonary artery (PA) to LAA shunt an attractive potential therapy given anatomic proximity and gradient differential between the cardiac chambers.

This will be a 5 patient first-in-human feasibility study. The population will include patients undergoing CABG or other cardiovascular surgery with AF and a CHADS2 score >1 in whom the treating team deems traditional therapy with anticoagulants is prohibitive or ineffective (dialysis or EGFR preoperatively <15, previous bleeding with non-reversible pathology, clinically deemed contraindicated to oral anticoagulant). The intervention will be PA-LAA shunt creation at the time of surgery. As this is a single arm study there will be no comparison group.

• Study Type: Interventional
• Phase: Not Applicable

Contacts and Locations

Study Locations

• Canada
  • Ontario
    • Ottawa, Ontario, Canada, K1Y4W7
      • University of Ottawa Heart Institute

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: 18 years and older (Adult, Older Adult)
• Accepts Healthy Volunteers: No
• Genders Eligible for Study: All

Description

Inclusion Criteria:

• Age ≥ 18 years undergoing CV surgery
• History of AF with a CHADS2 score >1

• Relative contraindication to OAC as determined by the heart team

  1. Dialysis or preoperative eGFR of <15
  2. Bleeding on DOAC/Coumadin with non-reversible pathology
  3. Other medical condition that makes the patient ineligible for OAC
• Anatomic proximity of LAA and PA on preoperative CT scan suitable for shunt creation

Exclusion Criteria:

• LVEF <40%
• History of VTE - either DVT or PE
• Resting baseline preoperative O2 sats <98%
• Inability of the patient to provide written informed consent
• Greater than moderate valvular heart disease which is not to be addressed during surgical intervention
• Documented mPA to PCWP <5mmHg

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Other
• Allocation: N/A
• Interventional Model: Single Group Assignment
• Masking: None (Open Label)

Number of Arms

1

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Experimental: Procedure arm; At the time of surgery a covered stent will be inserted through the atriotomy into the left pulmonary artery and balloon dilated to stabilize the device. The target shunt diameter will be 3.5-4 mm to minimize LAA stasis.	Procedure: PA-LAA shunt; At the time of surgery a covered stent will be inserted through the atriotomy into the left pulmonary artery and balloon dilated to stabilize the device. The target shunt diameter will be 3.5-4 mm to minimize LAA stasis.

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Composite of device safety and performance	At three months feasibility will be met if there is no: Device related complicationsBleeding attributable to device implantationReintervention (surgical or percutaneous) on the shuntResting systemic saturations <92%Documented Qp:Qs <0.8; Device related performance a. Shunt patency at 3 months as assessed by TEE	3 months

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Device related performance - maintaining patency	Shunt patency as assessed by TEE	1 year
Systemic embolization	Systemic embolization - includes stroke, TIA, MI or peripheral embolization attributable to either LAA thrombus or paradoxical embolization as clinically diagnosed by treating physician	1 year
Systemic saturations	Resting saturations <92% - threshold	1 year
Need for intervention to close the shunt	Need for intervention to close the shunt either surgically or percutaneously to	1 year

Collaborators and Investigators

• Sponsor: Ottawa Heart Institute Research Corporation

Study record dates

Study Major Dates

• Study Start (Actual): March 19, 2021
• Primary Completion (Actual): December 15, 2021
• Study Completion (Actual): December 15, 2021

Study Registration Dates

• First Submitted: November 2, 2020
• First Submitted That Met QC Criteria: January 7, 2021
• First Posted (Actual): January 12, 2021

Study Record Updates

• Last Update Posted (Actual): October 12, 2022
• Last Update Submitted That Met QC Criteria: October 7, 2022
• Last Verified: October 1, 2022

More Information

Terms related to this study

• Keywords: shunting
• Additional Relevant MeSH Terms: Cardiovascular Diseases; Vascular Diseases; Embolism and Thrombosis; Thrombosis
• Other Study ID Numbers: 20200646-01H

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: No

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: No
• product manufactured in and exported from the U.S.: No