Mitral Valve Calcification Increases Risk of Cardiovascular Disease and Death

The presence of mitral annular calcification (MAC) independently predicts cardiovascular morbidity and mortality and all-cause mortality in a graded fashion, according to findings from the Framingham Heart Study reported Monday in a rapid access issue of Circulation: Journal of the American Heart Association.

“Clinically, MAC may be thought of as a subclinical marker of CVD,” lead author Dr. Caroline S. Fox, of the National Heart, Lung, and Blood Institute in Bethesda, Maryland, told Reuters Health.

The investigators measured MAC in 445 men and 752 women who had routine echocardiograms between 1979 and 1981 as part of the Framingham study. During 16 years of follow up, there were 307 new cases of CVD and 621 deaths, 213 of which were attributed to CVD.

MAC was “relatively common,” Dr. Fox said, affecting 14% of the study population.

In analyses adjusted for traditional CVD risk factors, individuals with MAC were 50% more likely to have developed CVD during follow-up and 60% more likely to have died of CVD than individuals with no evidence of MAC. For each 1-millimeter increase in MAC, the risk of incident CVD and death from all-causes increased by roughly 10%.

“The reason for this increased risk is not known, but likely stems from shared risk factors between the development of MAC and the development of CVD,” Dr. Fox said.

“Based on our data, it is too early to recommend performing a screening echo to assess for the presence of MAC,” she emphasized. “Furthermore, our data do not indicate whether control of cardiovascular risk factors will reduce the prevalence of MAC.”

Circulation 2003;107:000-000.