Determination of the Best Parameter for Defining the Hemodynamic Significance of an Iliac Artery Stenosis Detected on Computed Tomography Angiography.

PURPOSE: The purpose of this study was to determine the best parameter, derived from computed tomography angiography (CTA) for accurate prediction of a hemodynamically significant stenosis of the common or external iliac artery. METHODS: A retrospective keyword search was performed on the Radiology Information System at our tertiary academic medical centre. Reports from January 2008 to September 2013 were searched using the keywords iliac, stenosis, and pressure. Patients who had both and CTA and a pelvic angiogram with pressure measurements obtained across a potential stenosis were selected. Using 3D postprocessing software (TeraRecon, Foster City, CA), the CTAs were analysed for the following parameters of each lesion: minimum diameter of stenosis, minimum cross-sectional area of stenosis, percent narrowing of vessel diameter, and percent reduction in vessel area. The percent stenosis was calculated in reference to the outer diameter at the point of maximal narrowing and also in reference to a normal segment of vessel more distal to the stenosis. These parameters were then compared with the measured pressure gradient using receiver-operating characteristic analysis and the Mann-Whitney U test to determine which best predicted a significant stenosis, defined as a greater than 10% drop in systolic pressure across a lesion. RESULTS: One hundred and two stenoses in 83 patients (26 women, 57 men; 47-88 years old) were identified. Mean diameter of the stenosis was 2.8 mm for significant stenosis compared to 3.8 mm in nonsignificant stenoses (P = .005). Mean minimum area for significant stenoses was 11.8 mm(2) compared to 17.22 mm(2) for nonsignificant stenoses (P = .032) No other variables showed a significant difference between significant and nonsignificant stenoses. A minimum diameter of ≤4.0 mm at the level of a stenosis is 92% sensitive and 48% specific for predicting a hemodynamically significant iliac artery stenosis, with a positive predictive value of 88%. CONCLUSIONS: A simple measurement of the minimum diameter of an iliac artery at the level of stenosis is the best predictor of the hemodynamic significance of a stenosis in the common or external iliac artery.

Peri-Infarct Quantification by Cardiac Magnetic Resonance to Predict Outcomes in Ischemic Cardiomyopathy: Prognostic Systematic Review and Meta-Analysis.

BACKGROUND: In ischemic cardiomyopathy, cardiac magnetic resonance assessment of the peri-infarct zone, a potential substrate for arrhythmogenesis, may serve as a novel prognosticator and guide the optimal use of implantable cardioverter-defibrillators. We undertook a systematic review and meta-analysis assessing the prognostic value of the peri-infarct zone on late gadolinium enhancement cardiac magnetic resonance in ischemic cardiomyopathy. METHODS: We searched MEDLINE (Medical Literature Analysis and Retrieval System Online), EMBASE (Medical Literature Analysis and Retrieval System Online), and CENTRAL (Medical Literature Analysis and Retrieval System Online) from inception to January 2019 for prognostic studies relating peri-infarct size with clinical outcomes in ischemic cardiomyopathy. Two authors independently performed study selection and data extraction. Pooled effect estimates were calculated with random effects models, risk of bias and strength of evidence were assessed by the Quality in Prognostic Studies tool and Grading of Recommendations Assessment, Development, and Education, respectively. RESULTS: Twenty studies were eligible, representing 14 cohort studies (n=1518) with mean follow-up of 3.6 years and 6 cross-sectional studies (n=189). The extent of the peri-infarct zone was significantly predictive of all-cause mortality (3 studies; n=539; hazard ratio, 1.34/10 g [95% CI, 1.13-1.59]; I2=0%; high-quality evidence), appropriate implantable cardioverter-defibrillator therapy (5 studies; n=361; hazard ratio, 1.31/10 g [95% CI, 1.17-1.47]; I2=0%; high-quality evidence), and inducibility of ventricular tachycardia on electrophysiological study (5 studies; n=167; OR, 2.63/g [95% CI, 1.39-4.96]; I2=14%; low-quality evidence). After adjusting for age and left ventricular ejection fraction, the peri-infarct zone, as a percentage of total infarct size, remained an independent predictor of all-cause mortality (2 studies; n=445; hazard ratio, 1.29/10% [95% CI, 1.15-1.44]; I2=0%; high-quality evidence). CONCLUSIONS: There is limited but consistent evidence that quantification of the peri-infarct zone predicts long-term mortality and appropriate implantable cardioverter-defibrillator therapy in ischemic cardiomyopathy. Future studies should confirm whether late gadolinium enhancement-cardiac magnetic resonance assessment may improve implantable cardioverter-defibrillator treatment decisions. CLINICAL TRIAL REGISTRATION: URL: https://www.crd.york.ac.uk/prospero/. Unique identifier: CRD42017077337.