coronary occlusion vs occlusion

coronary occlusion and occlusion both are nouns.

Word	Noun	Adjective	Verb	Adverb
coronary occlusion	Yes	No	No	No
occlusion	Yes	No	No	No

As nouns, occlusion is a hypernym of coronary occlusion; that is, occlusion is a word with a broader meaning than coronary occlusion:

coronary occlusion: occlusion of a coronary artery caused either by progressive atherosclerosis or by a blood clot
occlusion: closure or blockage (as of a blood vessel)

Other hypernyms of coronary occlusion include coronary heart disease.

coronary occlusion (noun)	occlusion (noun)
occlusion of a coronary artery caused either by progressive atherosclerosis or by a blood clot	the act of blocking
	an obstruction in a pipe or tube
	(dentistry) the normal spatial relation of the teeth when the jaws are closed
	(meteorology) a composite front when colder air surrounds a mass of warm air and forces it aloft
	closure or blockage (as of a blood vessel)