Assessment by Coronary Computed Tomographic Angiography of Individuals Undergoing Invasive Coronary Angiography - ACCURACY

Nov 10, 2008
Font Size
A
A
A
Author/Summarized by Author:
Anthony A. Bavry, MD, MPH, FACC
Summary Reviewer:
Deepak L. Bhatt, MD, MPH, MBA, FACC
Trial Sponsor:
General Electric Healthcare
Date Published:
01/01/2008
Date Updated:
11/10/2008
Original Posted Date:
11/10/2008
References

Description:

The goal of the trial was to evaluate the diagnostic accuracy of 64-multidetector row computed tomography (CT) in the evaluation of coronary artery stenosis among patients with chest pain.

Hypothesis:

64-multidetector row CT would produce similar diagnostic results as invasive coronary angiography.

Study Design

  • Blinded

Patients Screened: 245
Patients Enrolled: 230
Mean Patient Age: 57 years
Female: 41%

Patient Populations:

  • Patients with chest pain who were referred for non-emergent invasive coronary angiography

Exclusions:

  • Less than 18 years of age
  • Known coronary artery disease
  • Allergy to contrast dye
  • Renal insufficiency (creatinine ≥1.7 mg/dl)
  • Irregular cardiac rhythm or resting heart rate >100 bpm
  • Systolic blood pressure <100 mm Hg
  • Contraindication to beta-blockers, calcium channel blockers, or nitroglycerin
  • Pregnancy
  • There was no exclusion based on coronary artery calcium score or body mass index

Primary Endpoints:

  • Sensitivity and specificity of multidetector row CT
  • Primary predictive value and negative predictive value of multidetector row CT to detect ≥50% or ≥70% stenosis

Drug/Procedures Used:

Patients with chest pain and intermediate likelihood of coronary artery disease who were referred for invasive coronary angiography were prospectively evaluated by 64-multidetector row CT (n = 230).

Concomitant Medications:

Patients received 80 cc of iodixanol iodinated contrast during acquisition. Patients with resting heart rate >65 bpm received oral beta-blockers; however, intravenous metoprolol (5 mg to a total of 25 mg) could also be administered to achieve satisfactory heart rate.

Principal Findings:

Overall, 230 patients were enrolled. The mean age was 57 years, 59% of participants were men, 24% had diabetes, mean body mass index was 31.4 kg/m2, and mean coronary artery calcium score was 284. There was one iatrogenic dissection of the right coronary artery with invasive coronary angiography. There were no adverse events related to multi-detector row CT.

For detection of stenoses greater than 50%, the sensitivity and specificity of 64-multidetector row CT were 95% and 83%, and for stenoses greater than 70%, sensitivity and specificity were 94% and 83%, respectively. The positive and negative predictive values for detecting a 50% stenosis were 64% and 99%, and for detecting 70% stenoses they were 48% and 99%, respectively.

The sensitivity for detecting stenoses greater than 50% for patients with calcium score ≤400, 400-600, and >600 was 95.8%, 93.6%, and 96.9%, respectively (p = 0.37). The sensitivity for detecting stenoses greater than 50% for nonobese versus obese patients (body mass index >30 kg/m2) was 94.4% vs. 94.7%, respectively (p = 0.96). The sensitivity for detecting stenoses greater than 50% for patients with slow heart rate versus patients with elevated heart rate (>65 bpm) was 92.9% versus 100%, respectively (p > 0.35).

Interpretation:

Among patients with chest pain and intermediate likelihood for coronary artery disease, 64-multidetector row CT produces high sensitivity and specificity for detecting stenoses greater than 50% and 70%. The positive predictive value for detecting a 70% stenosis was only 48%; however, the negative predictive values for detecting 50% and 70% stenoses were 99% and 100%, respectively. The sensitivity was the same regardless of calcium score, body mass index, or resting heart rate. This technology represents a significant improvement in diagnostic accuracy compared with 16-multidetector row CT.

Perhaps one of the most important utilities of 64-multidetector row CT will be in ruling out the presence of obstructive coronary stenoses among patients with low to intermediate probability of coronary artery disease. The use of multidetector row CT in higher risk patients remains uncertain. As this technology becomes incorporated more into clinical practice, the additional radiation that some patients would receive from both CT and invasive coronary angiography studies will need to be considered.

References:

Budoff MJ, Dowe D, Jollis JG, et al. Diagnostic performance of 64-multidetector row coronary computed tomographic angiography for evaluation of coronary artery stenosis in individuals without known coronary artery disease: results from the prospective multicenter ACCURACY (Assessment by Coronary Computed Tomographic Angiography of Individuals Undergoing Invasive Coronary Angiography) Trial. J Am Coll Cardiol 2008;52:1724-32.

Keywords: Coronary Artery Disease, Body Mass Index, Coronary Stenosis, Coronary Angiography, Sensitivity and Specificity, Multidetector Computed Tomography, Constriction, Pathologic, Heart Rate, Diabetes Mellitus


< Back to Listings