Aortic Aneurism Rupture Risk

An abdominal aortic aneurism – a ballooning of the main artery to the lower body – is likely to prove lethal, or at least life-threatening, if it ruptures. One might think that almost any drug that controls high blood pressure would help prevent such a rupture, but a Canadian study has shown that among antihypertensive drugs, only ACE inhibitors (angiotensin converting enzyme inhibitors, such as enalapril, or Vasotec®) can provide some protection.

The records of more than 15,000 patients hospitalized with a ruptured or intact abdominal aortic aneurism over a 10-year period. The medication histories of the patients were analyzed in relation to the risk of rupture. It was found that ACE-inhibitor use was associated with an 18% decreased risk of rupture, even after adjusting for known factors influencing the risk, including advanced age (over 75) and high blood pressure. No protective effect was seen for beta-blockers, calcium channel blockers, alpha-blockers, angiotensin receptor blockers (ARBs), or thiazide diuretics (water pills); in addition, other common medications (antacids, antidepressants, cholesterol-lowering drugs, etc) were without influence.

Because aortic aneurism is largely without any symptoms (until it ruptures), a medication that offers protection against rupture would be most attractive. But an 18% decreased risk is not very much. This finding, therefore, serves to act as an early lead for development of a potentially more effective drug. In this respect, it’s interesting to note that, in 2002, a British group reported that use of ACE inhibitors are associated with decreased stiffness and greater collagen turnover in people with an aneurism.

If you want to know more about abdominal aortic aneurism, there’s a good tutorial for patients at the Medline site.