Utility of 64 detector coronary computed tomographic angiography in patients with and without prior equivocal stress tests.

This study sought to compare and the utility of cardiac computed tomographic angiography (CCTA) in patients with and without prior equivocal stress testing, and the subsequent need for invasive angiography and revascularization after CCTA. Evidence for the clinical utility of CCTA in the assessment of low to intermediate risk patients with equivocal stress testing is limited. Consecutive patients referred for outpatient CCTA for evaluation of suspected CAD with and without prior equivocal stress testing were included. CCTA studies were performed on a 64 detector scanner (Toshiba Aquilion). The diagnostic yield of CCTA for coronary stenoses and the subsequent need of the patients for invasive angiography and revascularization was evaluated. Of 228 patients evaluated, 43.9% were male, average age 59.3 ± 10.3. 66.2% (n = 151) had an equivocal stress test prior to CCTA. The prevelance of significant lesions (>50% stenosis) was high at 31% (n = 71), and was similar for those with and without a prior equivocal stress test (29.1 vs. 35.0%, P = NS). During a mean follow up of 1.4 ± 0.4 years, all patients with normal or stenosis by CCTA of <50% remained free from revascularization. Among those with a >50% stenosis by CCTA, the revascularization rate was 33.8%. The rates of angiography and revascularization were similar in those with or without prior stress tests (19 vs. 27%, P = 0.13 and 12 vs. 7.8%, P = 0.34 respectively). Regardless of whether or not patients had prior equivocal stress tests, CCTA detected a substantial number of obstructive CAD lesions and effectively identified the need for subsequent invasive angiography and revascularization. It appears to be a very promising triage test in this population.

Ultrasound-guided gadolinium joint injections for magnetic resonance arthrography.

PURPOSE: To determine the feasibility and accuracy of ultrasound (US) -guided gadolinium injection for MR arthrography of shoulders, wrists, hips, and knee joints as an alternate technique to fluoroscopy. METHODS: One hundred patients referred to our center for an MR arthrogram of shoulders, wrists, hips, and knees were included in the study. There were 53 males and 47 females and ages ranged from 17 to 63 years (mean age, 37). US was used to guide the needle tip into the joint. The intra-articular location of the needle tip was confirmed by fluoroscopic visualization of injected iodinated contrast medium, prior to gadolinium injection. The patients then proceeded for the MRI examination. RESULTS: Ninety-nine of the 100 patients were successfully injected with gadolinium under US guidance. One patient had a vasovagal reaction after local anesthetic injection and the procedure was aborted. CONCLUSION: US is an effective alternate guidance technique for the injection of gadolinium into shoulder, hip, knee, and wrist joints for MR arthrography. Its advantages are cost effectiveness, ease of performance, and lack of radiation.

Randomized trial of aspirin and clopidogrel versus aspirin alone for the prevention of coronary artery bypass graft occlusion: the Preoperative Aspirin and Postoperative Antiplatelets in Coronary Artery Bypass Grafting study.

BACKGROUND: Routine use of postoperative aspirin after coronary artery bypass grafting (CABG) reduces graft failure and cardiovascular events. The efficacy and safety of adding clopidogrel to aspirin for the prevention of graft failure and cardiovascular events after CABG are unknown. We performed a pilot study measuring safety and efficacy outcomes of aspirin and clopidogrel therapy after CABG. METHODS: We randomized 100 patients undergoing CABG to receive placebo or clopidogrel started after surgery and for 30 days. All patients received aspirin 81 mg daily. Graft patency was measured by cardiac computed tomography angiography at 30 days. RESULTS: Clinical follow-up was complete for 99 patients, and 79 (80%) underwent computed tomography angiography. The proportion of patients with ≥1 occluded graft was not significantly different between placebo and clopidogrel groups (9/39 [23.1%] vs 7/40 [17.5%], relative risk 0.95, 95% CI 0.80-1.14, P=.54). Among radial artery grafts, the placebo group had a significantly higher number of occlusions or "string signs" compared with the clopidogrel group (7/16 [43.8%] vs 2/19 [10.5%], relative risk 0.24, 95% CI 0.06-1.00, P=.05). There was no difference between placebo and clopidogrel groups in the safety outcomes of total postoperative bleeding, transfusions, bleeding events, and reexploration and in the efficacy outcomes of nonfatal myocardial infarction, stroke, and death. CONCLUSIONS: This pilot study confirms a high rate of graft occlusion after CABG surgery and suggests that the addition of clopidogrel to aspirin is feasible and safe and may be superior for prevention of graft failure in radial artery grafts.

Extracardiac findings in cardiac computed tomographic angiography in patients at low to intermediate risk for coronary artery disease.

PURPOSE: To evaluate the prevalence, clinical significance, interobserver agreement, and follow-up of extracardiac findings on coronary computed tomographic angiography (CTA). METHODS: A prospectively recruited cohort of 80 patients at low to intermediate risk of having coronary artery disease underwent CTA with field of view imaging from lung apices to upper abdomen. Two staff radiologists read each scan independently. Scans read by reader no. 1 were read as part of routine clinical practice, and the findings were subsequently reclassified to potentially significant, as defined by requiring clinical or radiologic follow-up, and insignificant by a separate observer, whereas reader no. 2 retrospectively read and autonomously classified the findings as potentially significant or insignificant. RESULTS: Reader no. 1 found 7 potentially significant findings in 7 patients and 33 insignificant findings in 29 patients. Reader no. 2 found 10 potentially significant findings in 10 patients and 59 insignificant findings in 42 patients. Inter-rater agreement was moderate (kappa = 0.49; 95% confidence interval, 0.31-0.67) for the presence vs the absence of extracardiac findings and moderate (kappa = 0.52; 95% confidence interval, 0.15-0.89) for the presence of potentially significant extracardiac findings. The most common potentially significant finding was possibly malignant lung nodule (n = 6 [reader 1], 4 [reader 2]). Four patients with potentially significant findings received follow-up imaging, and 1 patient underwent biopsy, which was complicated by pneumothorax. No diagnoses of malignancy were made. CONCLUSIONS: Extracardiac findings are frequent and moderately reproducible, however, in this study, not associated with clinical benefit. Large prospective studies are required to establish whether reporting of extracardiac findings is associated with improved patient outcomes.

Computed tomographic coronary angiographic assessment of high-risk coronary anatomy in patients with suspected coronary artery disease and intermediate pretest probability.

BACKGROUND: It is unclear if computed tomographic coronary angiography (CTA), an evolving technique for the evaluation of coronary artery disease (CAD), can identify patients with high-risk coronary anatomy. METHODS: Among patients referred for invasive angiography at Hamilton Health Sciences (Hamilton, Ontario, Canada), those with an intermediate pretest probability (25%-60% likelihood of a significant stenosis) were prospectively identified using a multivariate risk score and were studied on a 64-detector Toshiba Aquilion scanner (Toshiba Medical Systems, Tokyo, Japan) before invasive angiography. Patients with high-risk anatomy (left main, 3-vessel CAD, or 2-vessel CAD involving the proximal left anterior descending artery) or at least 1 significant stenosis were identified on CTA and invasive angiography, and the results of these modalities were compared on a per patient basis. RESULTS: Eighty patients were enrolled in the study (mean age 56 +/- 9 years, male-female ratio 43:37). Nondiagnostic scan results were obtained in 5 patients (6%). By CTA, 13 patients had high-risk anatomy and 31 patients had at least 1 significant stenosis. For the per patient detection of high-risk anatomy, CTA had 100% sensitivity (95% CI 69%-100%), 95% specificity (95% CI 86%-95%), a positive likelihood ratio of 18.0 (95% CI 6.4-50.3), and a negative likelihood ratio of 0.05 (95% CI 0-0.072). Revascularization was performed in 100% of patients with high-risk anatomy on CTA, 83% with at least 1 significant stenosis on CTA, and 0% without a significant stenosis on CTA. CONCLUSION: In appropriately selected patients, CTA is a highly sensitive and specific technique for the detection of high-risk anatomy and maybe a valuable method for noninvasive risk stratification.