Abstract 2416: Use of Multislice Computed Tomograph Angiography in Symptomatic Patients with Suspected Coronary Artery Disease and Negative Stress Testing
Background: Contrast-enhanced 64-slice computed tomograph angiography (CTA) has recently been validated as a reliable noninvasive tool in the assessment of coronary anatomy. However, studies evaluating its applications in clinical practice are still emerging. We aimed to establish if CTA can guide the use of invasive coronary angiography (ICA) in patients with symptoms suggestive of coronary artery disease (CAD) but with negative stress testing.
Methods: From April 2005 to February 2006, all cases referred for CTA to a single-specialty cardiology practice were entered into a prospective database. Inclusion criteria were: 1. no known CAD 2. symptoms of chest pain (CP), dyspnea on exertion (DOE) 3. prior negative stress test. All subjects underwent CTA and if severe stenosis was found, they were sent for ICA. All had four-month follow-up. The main outcome measures were: number of patients sent for invasive coronary angiography, occurrence of revascularization and adverse events (death, myocardial infarction or need for invasive coronary angiography) for medically-managed patients.
Results: 168 patients were included, 88% had CP and 29% DOE. 56% were men, age was 58±13 years. 53% had hypertension; 59% had dyslipidemia and 12% had diabetes. The Framingham risk score (FRS) was 12±9%. Fifty-six percent had undergone nuclear stress testing and 44% stress echocardiography. Duke treadmill score was 8.5±3.7. Adequate images were obtained in 100% of cases, with 5 studies having motion artifact of the right coronary artery. Fourteen (8%) had severe stenoses; 10 (6%) were revascularized, 1 was overestimation and 3 were not amenable to intervention. All stenoses were found in patients with FRS of at least 5% (14/148) versus none in patients with FRS < 5% (0/20). Per-segment agreement between computed tomograph and invasive coronary angiography was 92%. All medically-managed patients completed four-month follow-up without adverse events.
Conclusion: Computed tomograph angiography can be successfully used as the next step in the clinical evaluation of symptomatic patients suspected to have CAD in the setting of negative stress testing, especially in the setting of a Framingham risk score above 5%.