November 2007

Early Detection of Heart Disease

Gautham P. Reddy, M.D., M.P.H.
Chief of Cardiac and Pulmonary Imaging
UCSF Heart and Vascular Center

Coronary computed tomographic angiography (CTA), also known as the 64-slice CT scan, is a new and advanced non-invasive test to detect early coronary artery disease (CAD) and assess coronary artery obstruction. In about five seconds, the 64-detector CT scanner provides direct visualization of the arteries and heart. Recent studies have shown high accuracy of CTA for detection of coronary stenosis or occlusion, with a negative predictive value of 93 percent to 100 percent (aggregate of 97 percent).

Compared to a traditional CT scan, the 64-slice scan can acquire clear images of the heart and its blood vessels in multiple slices in rapid sequence without the blurring effects of cardiac motion. Using advanced technology, the information is reconstructed into 3-D views of the heart and its blood vessels, revealing not only stenotic areas of the blood vessels, but also early disease in the vessel walls that may not be narrowed.

Non-invasive Procedure

During the test, patients receive an IV injection of a contrast agent. They are asked to hold their breath for five seconds during the scan. The entire procedure takes about an hour. The test is only available at select leading heart and vascular centers in the United States, including the UCSF Heart and Vascular Center.

Patients with suspected CAD typically undergo an exercise stress test, stress perfusion scintigraphy or stress echocardiography, but these exams don't provide a direct look at the coronary arteries. Definitive diagnosis is based on catheter-based, X-ray angiography, but this study is invasive and relatively expensive, and about 40 percent of diagnostic angiograms are normal.

Better Treatment

CTA can eliminate the need for a catheter-based X-ray angiography in a substantial proportion of patients, particularly those who are at low to moderate risk for CAD. Indications include a history of atypical chest pain or a history of chest pain without EKG changes or elevated serum levels of cardiac enzymes. Other indications include evaluation of coronary bypass grafts, assessment of coronary anomalies and early detection of coronary artery disease in the asymptomatic patient with multiple coronary risk factors, such as smoking, male gender, age over 40 years, elevated serum cholesterol and family history of coronary disease.

CAD is the leading cause of morbidity and mortality in the United States and other industrialized countries. Patients can present with chest pain, but sudden death is the initial presenting symptom in up to 50 percent of patients. By accurately and quickly detecting heart disease, CTA greatly reduces the risk of life-threatening problems related to CAD and means better treatment, a faster recovery time and increased comfort and convenience for patients at risk for CAD.

For more information, contact the Physician Referral Service at UCSF Medical Center:

Phone (888) 689-UCSF or (888) 689-8273

Other Resources

UCSF Heart and Vascular Center
UCSF Department of Radiology


1. Raff GL, Gallagher MJ, O'Neill WW, Goldstein JA. J Am Coll Cardiol. 2005 Aug 2;46(3):552-7. Diagnostic accuracy of noninvasive coronary angiography using 64-slice spiral computed tomography.

2. Leschka S, Alkadhi H, Plass A, Desbiolles L, Grunenfelder J, Marincek B, Wildermuth S. Accuracy of MSCT coronary angiography with 64-slice technology: first experience. Eur Heart J. 2005 Aug;26(15):1482-7. Epub 2005 Apr 19.

3. Herzog C, Zwerner PL, Doll JR, Nielsen CD, Nguyen SA, Savino G, Vogl TJ, Costello P, Schoepf UJ. Radiology. 2007 Jul;244(1):112-20. Significant coronary artery stenosis: comparison on per-patient and per-vessel or per-segment basis at 64-section CT angiography.