Stratification for noninvasive coronary angiography: patient preselection considering atypical angina pectoris, conventional cardiovascular risk assessment, and calcium scoring.

BACKGROUND: Noninvasive coronary angiography (NCA) is recommended to be applied as a filter before invasive coronary angiography in patients with intermediate cardiovascular risk. DESIGN: In this prospective single-center study, we validated multislice computed tomography (MSCT) and magnetic resonance imaging (MRI)-based NCA by primarily selecting patients with atypical angina pectoris (AAP). METHODS: In 68 patients (63.6+/-11.4 years) with AAP, the Prospective Cardiovascular Muenster Study score and the Agatston score equivalent (ASE; calcium score) were initially determined for cardiovascular risk assessment. Subsequently, MSCT and MRI-based NCA were performed followed by quantitative invasive coronary angiography for validation. All tests were finally analyzed. RESULTS: CAD (prevalence 38.2%) was diagnosed in 67.7% of patients at high, 61.5% at intermediate, and 37.8% at low cardiovascular risk according to the Prospective Cardiovascular Muenster Study. CAD was diagnosed in 88.2% of patients with an ASE >or=75th percentile and in 90.9% with an ASE >or=90th percentile. With regard to NCA, patient-based analysis resulted in a sensitivity of 96.2% for MSCT versus 69.2% for MRI, in a specificity of 95.2 versus 64.3%, in a positive predictive value of 97.6 versus 77.1%, in a negative predictive value of 92.6 versus 54.5%, and a diagnostic accuracy of 95.6 versus 66.2% (P<0.05). CONCLUSION: In a patient group with a heterogeneous cardiovascular risk, primarily considering AAP allows for effective patient preselection for NCA. This may be optimized by precluding patients with an ASE >or=75th percentile. MSCT rather than MRI may then effectively be involved.

Noninvasive coronary angiography focusing on calcification: multislice computed tomography compared with magnetic resonance imaging.

OBJECTIVE: Calcification is a principal problem in noninvasive coronary angiography (CA) performed with multislice computed tomography (MSCT). Magnetic resonance imaging (MRI) supposedly neglects calcium. We compared both modalities. METHODS: Sixty-eight patients admitted for CA underwent MSCT- and MRI-based noninvasive CA the day before. Stenosis detection (>or=50%) was visually performed and validated by quantitative CA. RESULTS: The patient-based overall sensitivity, specificity, positive predictive value, and negative predictive value were 96.2%, 95.2%, 92.6%, and 97.6% for MSCT versus 69.2%, 64.3, 54.5%, 64.3%, and 77.1% for MRI, respectively. The segment-based overall results were 74.7%, 97.8%, 75.7%, and 97.6% for MSCT versus 40%, 93.8%, 37.5%, and 94.4% for MRI, respectively. Investigating the impact of coronary calcifications in the patient group with a volume score of 300 microL or greater resulted in 100%, 80%, 92.3%, and 100% for MSCT versus 70.8%, 86.7%, 89.5%, and 65% for MRI, respectively. The segment group with considerable hardening artifacts resulted in 85.3%, 83.9%, 76.3%, and 90.4% for MSCT versus 52.9%, 92.9%, 81.8%, and 76.5% for MRI, respectively. CONCLUSIONS: There are no major advantages of MRI in cases of advanced coronary calcification.

Non-invasive coronary angiography: the clinical value of multi-slice computed tomography in the assessment of patients with prior coronary bypass surgery. Evaluating grafts and native vessels.

BACKGROUND: Contrast enhanced multi-slice computed tomography (MSCT) is the leading modality in non-invasive coronary angiography (CTA) today. We investigated MSCT based assessment of coronary artery bypass grafts (CABG) by analyzing assets and drawbacks of CTA in order to define demands on latest technology. METHODS: In a clinical setting 39 CABG patients (69.2 +/- 1.4 years; male n = 36) underwent CTA (collimation 16 x 0.75 mm, contrast medium 100 ml; 320 mAs, 120 KV). Ninety-seven CABG (61 venous, 36 arterial grafts) were evaluated. A subgroup of 18 patients underwent additional invasive coronary angiography (CA). RESULTS: CTA for CABG assessment resulted in an overall sensitivity (sens.) of 100%, specificity (spec.) of 92.4% and positive and negative predictive values (PPV, NPV) of 60% and 100%, respectively. CABG anastomoses showed slightly inferior diagnostic accuracy than other CABG segments. Limitations in imaging quality caused 21% unevaluable segments of the CABG anastomoses. Evaluation of native vessel segments proximal and distal to the anastomoses resulted in a sens, spec, PPV and NPV of 57.5, 94.6, 92 and 67.3%, respectively. With 28.5% unevaluable segments, the native vessel segments showed serious limitations in imaging quality. Radiation exposure was 9.88 +/- 3.20 mSv (9.69 +/- 3.25 mSv male; 12.08 +/- 1.35 mSv female). CONCLUSION: 16-slice MSCT based CABG assessment offers sufficient diagnostic accuracy. However, focussing on the bypass anastomoses and the native revascularized coronary arteries, clinical value is limited.