Bottomline: Excellent review paper, which describes how the potent inflammatory compounds, which trigger asthma, also damage arteries, via the leukotrienes generated from the omega-6 fat, arachidonic acid.  Cardiovasc Drugs Ther. 2008 Oct 24. [Epub ahead of print]

Summary: This review paper describes the accumulating body of evidence, demonstrating how leukotrienes, the powerful group of eicosanoids, infamous for damaging lungs and triggering asthma, are also involved in heart disease.  The key stages of arterial damage are described, beginning with irritation of the blood vessels linings, resulting in plaque accumulation and ultimately the potentially deadly rupture of the plaque (as depicted above). 

Fascinating pieces of evidence link the leukotriene-inflammation connection to: sleep apnea, periodontal disease, and chronic obstructive pulmonary disease (COPD); conditions all of which are associated with increased risk for heart disease. Experimental evidence shows that treatment with asthma drugs (leukotriene inhibitors or modifiers) reduces atherosclerosis, summarized in the diagram below:

Comment: A study on patients with a genetic profile causing increased leukotriene formation, had increased atherosclerosis if that ate a high omega-6 fat diet.  (For more details see Heart Disease and Clogged Arteries--Increased Risk with Dietary Omega-6 Fat).  A similar effect was recently demonstrated in breast cancer patients--those with a genetic disposition of generating leukotrienes and eating a high omega-6 fat diet, resulted in increased disease incidence. (For more details see Another New Breast Cancer Study: Omega-6 Fat Increases Risk Two-fold in Large U.S. Study

Credits and Link to Study:
Figures and diagrams are from the paper cited below (under Creative Commons Attribution Noncommercial License)

Bäck M.
Leukotriene Signaling in Atherosclerosis and Ischemia.
Cardiovasc Drugs Ther. 2008 Oct 24. [Epub ahead of print]