NEW YORK (Reuters Health) – New research suggests that coronary artery calcium score (CACS) and single-photon emission computed tomography (SPECT) provide complimentary information in predicting a person’s short- and long-term risk of cardiac events.
“Our results support a strategy of adding CACS testing in patients with a normal SPECT result to identify those at high long-term risk for cardiac events,” Dr. John J. Mahmarian, from the Methodist DeBakey Heart and Vascular Center, Houston, and colleagues conclude.
To determine whether combining CACS and SPECT would enhance predictive performance, the researchers analyzed data from 1126 subjects without prior cardiovascular disease who underwent both tests within a median of 56 days. The subjects were then followed for a median of 6.9 years for total cardiac events and all-cause death/MI.
According to their report in the Journal of the American College of Cardiology for November 10, the prevalence of abnormal SPECT findings rose as CACS increased, from <1% when CACS was no more than 10, to 29% when CACS was above 400 (p < 0.001). Risks for total cardiac events and death/MI also climbed with rising CACS and abnormal SPECT findings. CACS was particularly useful in subjects with a normal SPECT result, however. In such patients, a severe CACS (>400) was associated with a 3.55-fold increased risk of any cardiac event compared with a minimal CACS (10 or less).
“Although a normal SPECT result predicts excellent short-term event-free survival, it doesn’t tell us anything about long-term risk, and long-term outcome is significantly worse if the CACS is severe,” Dr. Mahmarian said in a statement. “By integrating these two tests, we can identify patients at high long-term risk for heart problems and may, thereby, have a better shot at preventing further development of obstructive disease and improving outcomes.”
J Am Coll Cardiol 2009;54:1872-1882.