Made this design today. Sculpted the heart in Zbrush and made a depth map of it, which was imported into Inkscape to add the text.
I discovered that Inkscape does in fact have a mesh gradient tool so I used that to add a little dimension to the text. This link shows how to activate it using keyboard shortcuts. http://goinkscape.com/how-to-unlock-the-gradient-mesh-tool-in-inkscape/
Here’s the SVG file and a PNG image to show how the artwork should appear. The SVG is Inkscape native so it may not appear correctly in other viewers because of the mesh gradients.