Coronary CT angiography versus intravascular ultrasound for estimation of coronary stenosis and atherosclerotic plaque burden: a meta-analysis.

BACKGROUND: Numerous studies have compared coronary CT angiography (CTA) with quantitative coronary angiography. However, the ability of coronary CTA to identify atherosclerosis and to accurately measure plaque and coronary area and volume measurements as compared with intravascular ultrasound (IVUS) has not been fully defined. OBJECTIVE: We sought to assess the ability of coronary CTA to quantify coronary and plaque measurements commonly performed with IVUS. METHODS: We searched multiple databases for diagnostic studies that directly compared coronary CTA and IVUS for coronary plaque detection, vessel luminal area, percentage of area stenosis, plaque area, and plaque volume. We used a bivariate mixed-effects binomial regression model to pool test sensitivity and specificity for detection of any coronary plaque. RESULTS: Forty-two studies that evaluated 1360 patients (75% men; mean age, 59 years) were identified. No significant difference was found between coronary CTA and IVUS measurements of vessel lumen cross-sectional area, plaque area, percentage of area stenosis, or plaque volume within the overall cohort and no difference for the measurement of cross-sectional area (n = 5 studies) and plaque volume (n = 8 studies) among a subgroup that used automated or semiautomated measurement techniques. Sensitivity and specificity of coronary CTA to detect any plaque compared with IVUS were 93% and 92%, respectively, with an area under the receiver-operating curve of 0.97. CONCLUSIONS: Compared with IVUS, coronary CTA appears to be highly accurate for estimation of luminal area, percentage of area stenosis, plaque volume, and plaque area and for detection of plaque. The use of automated vessel and stenosis measurements appears promising in limited studies to date.

Coronary atherosclerosis imaging by coronary CT angiography: current status, correlation with intravascular interrogation and meta-analysis.

Coronary computed tomography angiography (CTA) allows coronary artery visualization and the detection of coronary stenoses. In addition; it has been suggested as a novel, noninvasive modality for coronary atherosclerotic plaque detection, characterization, and quantification. Emerging data show that coronary CTA-based semiquantitative plaque characterization and quantification are sufficiently reproducible for clinical purposes, and fully quantitative approaches may be appropriate for use in clinical trials. Furthermore, several lines of investigation have validated plaque imaging by coronary CTA against other imaging modalities such as intravascular ultrasound/"virtual histology" and optical coherence tomography, and there are emerging data using biochemical modalities such as near-infrared spectroscopy. Finally, clinical validation in patients with acute coronary syndrome and in the outpatient setting has shown incremental value of CTA-based plaque characterization for the prediction of major cardiovascular events. With recent developments in image acquisition and reconstruction technologies, coronary CTA can be performed with relatively low radiation exposure. With further technological innovation and clinical research, coronary CTA may become an important tool in the quest to identify vulnerable plaques and the at-risk patient.

Poor outcomes associated with neutropenia after kidney transplantation: analysis of United States Renal Data System.

BACKGROUND: Posttransplant neutropenia (PTN) is relatively common after kidney transplantation, and may result in a reduction of immunosuppression, which may precipitate acute rejection. Granulocyte colony-stimulating factors (GCSF) have been used to treat PTN, although outcomes associated with use of this medication in this population are unknown. METHODS: In a retrospective cohort of 41,705 adult Medicare primary patients transplanted from January 2001 to June 2006, we assessed Medicare claims for neutropenia, leukopenia, and GCSF use, respectively. Outcomes included allograft loss and death. RESULTS: There were 6043 (14.5%) patients with claims for PTN. Factors associated with PTN included female gender, Caucasian ethnicity, ischemic heart disease, donor cytomegalovirus positive, deceased donor, expanded donor criteria, delayed graft function, elevated panel reactive antibody, higher human leukocyte antigen mismatch, and later year of transplant. Thymoglobulin induction, tacrolimus, and mycophenolate mofetil were also associated. PTN was less frequent among patients with congestive heart failure, recipient cytomegalovirus positive, and interleukin-2 induction. PTN was associated with increased risk of allograft loss (adjusted hazard ratio, 1.59; 95% confidence interval, 1.43-1.76; P<0.001) and death (adjusted hazard ratio, 1.74; 95% confidence interval, 1.59-1.90; P<0.001). Of the 6043 patients with PTN, 740 (12.2%) received GCSF. Patients who received GCSF had a lower risk of death on unadjusted analysis, but this only trended towards significance after adjustment. CONCLUSIONS: Neutropenia after renal transplantation is common and is associated with an increased risk of allograft loss and death. GCSF was used in 12% of cases and did not increase risk of allograft loss. Strategies to avoid PTN and greater use of GCSF may be indicated to prevent graft loss and death.