Lack of Arterial Calcium Linked to Low Cardiovascular Risk
Low coronary artery calcification lowers risk in both symptomatic and asymptomatic patients
THURSDAY, June 11 (HealthDay News) -- The absence of coronary artery calcification (CAC) is strongly associated with low risk of cardiovascular events in both symptomatic and asymptomatic patients, according to two studies in the June Journal of the American College of Cardiology: Cardiovascular Imaging.
In one study, Ammar Sarwar, M.D., of Massachusetts General Hospital in Boston, and colleagues reviewed the medical literature between 1990 and 2008 on CAC and cardiovascular risk. The researchers analyzed 49 studies, covering more than 85,000 patients. In one group of 18 studies covering 10,355 patients, the pooled sensitivity and negative predictive value of CAC for coronary artery disease were 98 and 93 percent respectively.
In another study, Michael Blaha, M.D., of the Johns Hopkins Ciccarone Center for the Prevention of Heart Disease in Baltimore, and colleagues followed up 44,052 asymptomatic patients screened for CAC for a mean 5.6 years and assessed mortality. Of that cohort, 19,898 patients had no CAC, 5,388 had low levels of CAC (CAC index 1 to 10), and 18,766 had high levels of CAC (CAC index greater than 10). In the follow-up, there were 104 deaths in those with no CAC, 58 deaths in those with low CAC, and 739 deaths in those with high CAC. The hazard ratio for all-cause mortality among those with high CAC versus low CAC was 1.99.
"Although the strong prognostic utility of the calcium score is unquestionable, further studies are needed to elucidate the subject populations in which this test provides incremental prognostic utility over clinical risk assessment and serum biomarkers," write the authors of an accompanying editorial.