The correlation between aortic sclerosis and higher risk for myocardial infarction and death that has been found in some recent studies may be due to inflammation as the common underlying condition, according to an article in the January 21st issue of the Journal of the American College of Cardiology.

"The study is important from 2 standpoints. First, it helps us understand a little bit more why aortic sclerosis increases the risk of future cardiac events. It also suggests that systemic inflammation probably plays an important role both in thickening of the aortic valve and also in coronary artery disease," said William W. O'Neill, MD, the study’s lead author.

Aortic sclerosis is common in older people, and, unlike aortic stenosis, it does not appear to directly impair heart function. Thus, the apparent link to adverse cardiovascular events and cardiac mortality seen in some studies has perplexed researchers. The current study offers a possible explanation.

"The reason is that those patients have higher levels of systemic inflammation; and so the same thing that's causing their aortic sclerosis is also causing progression of coronary artery disease. So the patient's risk is not really from the valve problem itself as much as the fact that they are developing coronary artery disease," according to O'Neill.

The American research group analyzed cardiac ultrasound and blood test results for 425 patients (average age 68 ± 15 years, 54 percent men) who presented at a single emergency room with chest pain. Investigators studied the relationship among aortic sclerosis, coronary artery disease, serologic markers of inflammation (including C-reactive protein), and cardiovascular outcomes (including myocardial infarction and death within 1 year).

O'Neill said that although the results indicate aortic sclerosis does not cause other heart problems, it is a warning sign. He suggested that patients with aortic sclerosis should be tested for C-reactive protein and other indications of inflammation or coronary disease risk.

"Also, studies need to be done prospectively to try to alter the prognosis of the patients by doing things such as aggressive cholesterol lowering in patients who have aortic sclerosis to try to prevent the disease from progressing," O'Neill said.

In an editorial in the journal, Catherine M. Otto, MD, who did some of the earlier research linking aortic sclerosis and cardiac risk, wrote that despite the current findings pointing toward inflammation as the underlying cause, the explanation for the link is not yet clear. She pointed out several alternatives.

"This paper is not definitive. Calcific aortic valve disease (such as aortic sclerosis) likely is a multifactorial process. Other underlying factors, such as hyperlipidemia, genetic factors, and factors leading to tissue calcification may be more important than inflammation. It is possible that aortic sclerosis and coronary diseases are related only in that they both are manifestations of an as yet unknown underlying disease process," Otto said.