Whether one considers the being of beings (the entia, in St. Thomas’s Latin, or the Heideggerian ontic) or the very being of beings (St. Thomas’s esse) Heidegger wants to figure out something else, namely the condition of the possibility of ens/esse. Seen from this angle, Heidegger has ground to critique the Thomistic claim that the condition for the possibility of ens or esse is ipsum esse subsistens, for he appears to ask a more fundamental question that is simply not addressed by speaking of God as the cause of ens/esse.
It's somewhat interesting that Aquinas and the neo-Aristotelians were considered blasphemous by many catholic scholars when they first appeared--my limited understanding of the scholastics leads me to believe that the earlier clerics were not completely supportive of the..empirical /mechanical aspects of Aristotle---then, is Aquinas Aristotelian? Not exactly--IMHE. Aristotle does not really affirm transcendence AFAICT, yet his system is not "naturalist" in modern terms (or is he)--the Metaphysics of substance seems rather...like Hinduism.