Evaluation of coronary in-stent restenosis by 64-slice computed tomography in patients with optimal heart rate control by systematic administration of beta-blocker drugs.

BACKGROUND: Imaging artifacts due to metallic stent struts can reduce the diagnostic accuracy of multislice computed tomography (MSCT) in the evaluation of in-stent restenosis (ISR). Our aim was to determine the accuracy of binary ISR exclusion using a 64-slice MSCT scanner and a systematic administration of beta-blockers having an aggressive heart rate (HR) control. METHODS: We performed 64-slice MSCT in 218 consecutive patients revascularized by stenting. All patients were treated with oral/intravenous beta-blocker drugs in order to obtain a HR less than 65 beats/min in the prescan phase. Coronary stents were evaluated by two experienced observers in order to rule out the presence of significant (>50%) ISR. Quantitative conventional coronary angiography (CCA) served as a standard for reference. RESULTS: Five patients (2.3%) were excluded from the analysis; mean HR was 59 +/- 3 beats/min in the prescan phase and 62 +/- 5 beats/min during acquisition. In the 321 stented coronary segments, CCA found 27 significant ISRs. MSCT correctly diagnosed 26 significant ISRs, with two false-positive and one false-negative case. In a per-segment analysis, the sensitivity was 96%, specificity 99%, positive predictive value (PPV) 92.8%, and negative predictive value (NPV) 99%. In a per-patient analysis, the sensitivity was 100%, specificity 98.9%, PPV 92.8%, and NPV 100%. CONCLUSION: In our study, the evaluation of significant ISR by MSCT showed an excellent diagnostic accuracy with a PPV of 92.8% and a NPV of 99%. Selection criteria and radiation exposure can be considered a limitation of the method.

Revascularization strategy in patients with multivessel disease and a major vessel chronically occluded; data from the CABRI trial.

OBJECTIVE: In patients with multivessel coronary artery disease and total occlusion of major epicardial vessel, completeness of revascularization has not been investigated in specific trials comparing the surgical and the percutaneous revascularization strategy. Analyzing the database of the CABRI study, which randomized a substantial number of these patients, we investigated the long-term effects of a successful or unsuccessful revascularization of the occluded vessel and completeness of the revascularization. METHODS AND RESULTS: The CABRI study randomized 1054 patients with multivessel coronary disease to coronary bypass or to coronary angioplasty. From the database of this trial, we selected patients with a major vessel chronically occluded (103 in the bypass group and 120 in the angioplasty group). At a median follow-up of 30 months, the incidence of death or Q-wave myocardial infarction (combined end point) was significantly lower in the bypass group than in the angioplasty group (6.8% vs 17.5%, respectively; hazard ratio [HR], 0.42 [95% CI 0.17-0.98]; p=0.047). On univariate analysis, age, proximal occlusion, complete revascularization, revascularization of the occluded vessel and revascularization procedure were identified as significant predictors of combined end points. On multivariate analysis, independent predictors of combined end points resulted in completeness of revascularization (HR 0.26; 95% CI 0.09-0.76; p=0.01) and age (HR 1.07; 95% CI 1.02-1.12; p<0.01). CONCLUSION: In patients with multivessel coronary disease and chronic occlusion of a major epicardial vessel, achieving of a complete revascularization by reopening or bypassing the occluded vessel is associated with a significantly better long-term prognosis.

In-stent restenosis and multislice computed tomography: is the method ready to start?

We present two patients revascularized by coronary stents and evaluated by multislice computed tomography (CT). In first patient, angio-CT (16 slices/rotation scanner) detected a high-grade restenosis on the distal part of a drug-eluting stent; conventional coronary angiography confirmed the diagnosis. In second patient, angio-CT (64 slices/rotation) showed a tissue proliferation, non-flow-limiting, in the proximal part of a bare metal stent; conventional angiography confirmed the diagnosis. Blooming effects and partial volume averaging still limit the widespread application of this method. New scanners and the use of a special convolution kernel are likely to improve the accuracy of CT angiography in patients with stents.

Accuracy of thin-slice computed tomography in the detection of coronary stenoses.

AIM: Our aim was to investigate the accuracy of multislice spiral computed tomography (MSCT) in the detection of significant (>50%) coronary stenosis using a scanner equipped for 16 x 0.625 mm collimation. METHODS: In 64 patients (59 male, mean age 58 +/- 5 years) with suspected coronary artery disease, MSCT (GE Light Speed-16, collimation: 16 x 0.625 mm) was performed 20 +/- 5 days before coronary angiography (CAG). Only angiographic segments >1.5 mm were considered for analysis. RESULTS: In all patients, MSCT was carried out without complications. Three patients were excluded from the analysis. Of 729 angiographic segments, 613 (84%) were judged evaluable by MSCT. Considering only the segments judged evaluable, the sensitivity was 89%, specificity 98%, positive predictive value 90%, and negative predictive value 98%. Including all segments in the analysis (evaluable and nonevaluable), sensitivity was 78%. CONCLUSIONS: Using a scanner with a collimation of 16 x 0.625 mm, our study confirms the potential role of MSCT in the detection of significant coronary stenosis with a sensitivity of 89% and a very high specificity (98%). Exclusion criteria and less than full evaluability of the coronary arteries must still be considered limitations of the method.

Limitations of four-slice multirow detector computed tomography in the detection of coronary stenosis.

BACKGROUND: Our aim was to compare 4-slice spiral computed tomography with conventional coronary angiography in the detection of significant (> 50%) coronary stenosis. METHODS: Sixty-two patients (41 males, 21 females, mean age 60 +/- 8 years) with suspected coronary artery disease were submitted to coronary angiography and then to multislice spiral computed tomography (GE Light Speed 4 slice) performed 12 +/- 5 days later. RESULTS: We excluded 25% of the patients from analysis because of a heart rate > 70 b/min or because of frequent ectopic beats. We also excluded from analysis 23% of all the angiographic segments judged not evaluable at multislice spiral computed tomography. Within these limits, the sensitivity was 65%, the specificity 98%, the positive predictive value 88%, and the negative predictive value 92%. CONCLUSIONS: By considering the intrinsic limitations such as its low temporal and spatial resolution, 4-slice spiral computed tomography has a limited applicability and has to be used with caution in the evaluation of native coronary arteries.