Remove lines from LineSegmentsGeometry 'A' if already in 'B'?

I’m creating a set of edges (A) like so:

let lineGeom = new THREE.EdgesGeometry( mesh.geometry, params.edgeThreshold );
const thickLineGeom = new LineSegmentsGeometry().fromEdgesGeometry( lineGeom );
const thickLines = new LineSegments2( thickLineGeom, new LineMaterial(...) );

Now I create a different set of edges (B) of the same model, for example with a larger edgeThreshold value.

How can I iterate over set B and remove any edge that is already in A?