Luke had just been spending some time meditating out in nature, just as he'd gotten used to doing quite often back on Yavin IV. He hadn't expected the man to materialize like this close by.
He could feel spikes of pain through the Force, and it was obvious the man was in distress.
"Try and relax...I'm going to try and see something." he said after going to the newcomer's side. He reached out carefully with the Force, confirming to himself that it was indeed a heart attack. He was no healer, though he knew of a few possible techniques to try. He also pulled out his phone, quickly calling the hospital for help.
He did try visualizing through the Force, focusing on the blocked area and trying to thin it, to open a pathway for the blood without causing damage while still keeping the man alive until those who could help further got there.