blood clot vs cardiovascular disease

blood clot

noun
  • A clot formed from platelets and other elements; that forms in a blood vessel in a living organism, and causes thrombosis or obstruction of the vessel at its point of formation or travel to other areas of the body. 

cardiovascular disease

noun
  • A disease involving the heart or blood vessels, i.e. arteries and veins, such as coronary heart disease. 

How often have the words blood clot and cardiovascular disease occurred in a corpus of books? (source: Google Ngram Viewer )