Constantino S. Peña

Triage of patients presenting with chest pain to the emergency department: implementation of coronary CT angiography in a large urban health care system.

OBJECTIVE There is growing evidence supporting the use of coronary CT angiography (CTA) to triage patients in the emergency department (ED) with acute chest pain and low risk of acute coronary syndrome (ACS). We hypothesized that coronary CTA can guide early management and safely discharge patients by introducing a dedicated patient management protocol. SUBJECTS AND METHODS We conducted a prospective cohort study in three EDs of a large health care system (> 1300 beds). Five hundred twenty-nine patients (mean age, 52.1 years; 56% women) with chest pain, negative cardiac enzyme results, normal or nondiagnostic ECG findings, and a thrombolysis in myocardial infarction (TIMI) risk score of 2 or less were admitted and underwent CTA. A new dedicated chest pain triage protocol (levels 1-5) was implemented. On the basis of CTA findings, patients were stratified into one of the following four groups: 0, low (negative CTA findings); 1, mild (1-49% stenosis); 2, moderate (50-69% stenosis); or 3, severe (≥ 70% stenosis) risk of ACS. Outcome measures included major adverse cardiac events (MACEs) during the first 30 days after CTA, downstream testing results, and length of stay (LOS). LOS was compared before and after implementation of our chest pain triage protocol. RESULTS Three hundred seventeen patients (59.9%) with negative CTA findings and 151 (28.5%) with mild stenosis were discharged from the ED with a very low downstream testing rate and a very low MACE rate (negative predictive value = 99.8%). Twenty-five patients (4.7%) had moderate stenosis (n = 17 undergoing further testing). Thirty-six patients (6.8%) had stenosis of 70% or greater by CTA (n = 34 positive by invasive angiography or SPECT-myocardial perfusion imaging). The sensitivity of CTA was 94%. The rate of MACEs in patients with stenosis of 70% or greater (8.3%) was significantly higher (p < 0.001) than in patients with negative CTA findings (0%) or those with mild stenosis (0.2%). A 51% decrease in LOS-from 28.8 to 14.0 hours--was noted after implementation of the dedicated chest pain protocol (p < 0.001). CONCLUSION Chest pain patients with negative or mild nonobstructive CTA findings can be safely discharged from the ED without further testing. Implementation of a dedicated chest pain triage protocol is critical for the success of a coronary CTA program.

Evaluation of novel disposable, light-weight radiation protection devices in an interventional radiology setting: a randomized controlled trial

OBJECTIVE Radiation exposure to interventionalists is increasing. The currently available standard radiation protection devices are heavy and do not protect the head of the operator. The aim of this study was to evaluate the effectiveness and comfort of caps and thyroid collars made of a disposable, light-weight, lead-free material (XPF) for occupational radiation protection in a clinical setting. SUBJECTS AND METHODS Up to two interventional operators were randomized to wear a XPF or standard 0.5-mm lead-equivalent thyroid collars in 60 consecutive endovascular procedures requiring fluoroscopy. Simultaneously a XPF cap was worn by all operators. Radiation doses were measured using dosimeters placed outside and underneath the caps and thyroid collars. Wearing comfort was assessed at the end of each procedure on a visual analog scale (0-100 [100 = optimal]). RESULTS Patient and procedure data did not differ between the XPF and standard protection groups. The cumulative radiation dose measured outside the cap was 15,700 μSv and outside the thyroid collars 21,240 μSv. Measured radiation attenuation provided by the XPF caps (n = 70), XPF thyroid collars (n = 40), and standard thyroid collars (n = 38) was 85.4% ± 25.6%, 79.7% ± 25.8% and 71.9% ± 34.2%, respectively (mean difference XPF vs standard thyroid collars, 7.8% [95% CI, -5.9% to 21.6%]; p = 0.258). The median XPF cap weight was 144 g (interquartile range, 128-170 g), and the XPF thyroid collars were 27% lighter than the standard thyroid collars (p < 0.0001). Operators rated the comfort of all devices as high (mean scores for XPF caps and XPF thyroid collars 83.4 ± 12.7 (SD) and 88.5 ± 14.6, respectively; mean scores for standard thyroid collars 89.6 ± 9.9) (p = 0.648). CONCLUSION Light-weight disposable caps and thyroid collars made of XPF were assessed as being comfortable to wear, and they provide radiation protection similar to that of standard 0.5-mm lead-equivalent thyroid collars.

Reliability and Accuracy of Simple Visual Estimation in Assessment of Peripheral Arterial Stenosis

PURPOSE To evaluate reliability, accuracy, and agreement of simple visual estimation (SVE) in determining the degree of peripheral arterial stenosis compared with calibrated measurements. MATERIALS AND METHODS In 2 sessions, 23 interventionists with a wide range of experience and subspecialty training reviewed 42 angiographic images of lower extremity and carotid arteries (21 iliofemoral arteries and 21 carotid arteries). An independent physician measured all lesions using manual calipers. Intrarater and interrater reliability were assessed by intraclass correlation. A ± 5% error was considered the threshold for accuracy, and weighted κ statistics were computed to assess agreement with respect to the degree of stenosis (< 50%, nonsignificant; 50%-80%, significant; > 80%, severe). RESULTS Intrarater reliability of SVE was 0.99, and interrater reliability was 0.83. Accuracy varied from 52.8% for images of severe stenosis to 26.5% and 18.1% for significant and nonsignificant stenosis, respectively (P < .001). Agreement between SVE and caliper with regard to degree of stenosis was good (weighted κ 0.56) overall with correct classification ranging from 92.6% for severe stenosis to 53.4% and 68.2% for significant and nonsignificant stenosis, respectively (P < .001). Misclassification of nonsignificant and significant stenosis was more frequent for carotid arteries than for lower extremities. CONCLUSIONS Despite high reliability, SVE of peripheral arterial stenosis has limited accuracy in determining the exact degree of stenosis. Although severe stenosis is readily identified by SVE, arterial stenosis of < 80% is frequently overestimated, especially for carotid arteries, and should be confirmed by caliper assessment.

Lightweight Bilayer Barium Sulfate–Bismuth Oxide Composite Thyroid Collars for Superior Radiation Protection in Fluoroscopy-guided Interventions: A Prospective Randomized Controlled Trial

PURPOSE To test whether newer bilayer barium sulfate-bismuth oxide composite (XPF) thyroid collars (TCs) provide superior radiation protection and comfort during fluoroscopy-guided interventions compared with standard 0.5-mm lead-equivalent TCs. MATERIALS AND METHODS Institutional review board approval and written informed consent were obtained for this HIPAA-compliant study, and 144 fluoroscopy-guided vascular interventions were included at one center between October 2011 and July 2012, with up to two operators randomly assigned to wear XPF (n = 135) or standard 0.5-mm lead-equivalent (n = 121) TCs. Radiation doses were measured by using dosimeters placed outside and underneath the TCs. Wearing comfort was assessed at the end of each procedure on a visual analog scale (0-100, with 100 indicating optimal comfort). Adjusted differences in comfort and radiation dose reductions were calculated by using a mixed logistic regression model and the common method of inverse variance weighting, respectively. RESULTS Patient (height, weight, and body mass index) and procedure (type and duration of intervention, operator, fluoroscopy time, dose-area product, and air kerma) data did not differ between the XPF and standard groups. Comfort was assessed in all 256 measurements. On average, the XPF TCs were 47.6% lighter than the standard TCs (mean weight ± standard deviation, 133 g ± 14 vs 254 g ± 44; P < .001) and had a significantly higher likelihood of a high level of comfort (visual analog scale >90; odds ratio, 7.6; 95% confidence interval: 3.0, 19.2; P < .001). Radiation dose reduction provided by the TCs was analyzed in 117 data sets (60 in the XPF group, 57 in the standard group). The mean radiation dose reductions (ie, radiation protection) provided by XPF and standard TCs were 90.7% and 72.4%, with an adjusted mean difference of 17.9% (95% confidence interval: 7.7%, 28.1%; P < .001) favoring XPF. CONCLUSION XPF TCs are a lightweight alternative to standard 0.5-mm lead-equivalent TCs and provide superior radiation protection during fluoroscopy-guided interventions.

The Influence of Statin Therapy on Restenosis in Patients Who Underwent Nitinol Stent Implantation for de Novo Femoropopliteal Artery Disease: Two-Year Follow-up at a Single Center

PURPOSE To determine whether statin therapy is associated with reduced restenosis following nitinol stent implantation for de novo femoropopliteal artery disease. MATERIALS AND METHODS A total of 135 limbs in 135 patients (mean age, 72 y) implanted with nitinol stents in femoropopliteal occlusions were analyzed (statin arm, n = 91; nonstatin arm, n = 44). The patients were treated with one type of nitinol stent. RESULTS At baseline, lesions and procedural characteristics were comparable between groups, except that the statin group had more hypertension, coronary artery disease, and hyperlipidemia. There were significant differences in the incidence of binary restenosis between groups at 1 year (45.5% for nonstatin group vs 28.6% for statin group; P = .05) and 2 years (56.8% for nonstatin group vs 38.5% for statin group; P = .04). Primary patency rates at 1 year were 50.5% in the nonstatin group and 72.5% in the statin group (P = .01). Two-year target lesion revascularization rates were 54.5% in the nonstatin group and 35.2% in the statin group (P = .03). On univariate analysis, statin therapy was associated with decreased relative risk of binary restenosis at 1 year (odds ratio [OR], 0.480; 95% confidence interval [CI], 0.227-1.014; P = .050). On multivariate analysis, statin therapy did not significantly affect the odds of binary restenosis (OR, 0.415; 95% CI, 0.071-2.437; P = .330). CONCLUSIONS The incidence of binary restenosis was significantly lower in the statin group than in the nonstatin group following nitinol stent implantation for de novo femoropopliteal artery disease.

Volumetric Single-Beat Coronary Computed Tomography Angiography: Relationship of Image Quality, Heart Rate, and Body Mass Index. Initial Patient Experience With a New Computed Tomography Scanner.

Background Cardiac computed tomography (CT) image quality (IQ) is very important for accurate diagnosis. We propose to evaluate IQ expressed as Likert scale, signal-to-noise ratio (SNR), and contrast-to-noise ratio (CNR) from coronary CT angiography images acquired with a new volumetric single-beat CT scanner on consecutive patients and assess the IQ dependence on heart rate (HR) and body mass index (BMI). Methods We retrospectively analyzed the data of the first 439 consecutive patients (mean age, 55.13 [SD, 12.1] years; 51.47% male), who underwent noninvasive coronary CT angiography in a new single-beat volumetric CT scanner (Revolution CT) to evaluate chest pain at West Kendall Baptist Hospital. Based on patient BMI (mean, 29.43 [SD, 5.81] kg/m2), the kVp (kilovolt potential) value and tube current were adjusted within a range of 80 to 140 kVp and 122 to 720 mA, respectively. Each scan was performed in a single-beat acquisition within 1 cardiac cycle, regardless of the HR. Motion correction software (SnapShot Freeze) was used for correcting motion artifacts in patients with higher HRs. Autogating was used to automatically acquire systolic and diastolic phases for higher HRs with electrocardiographic milliampere dose modulation. Image quality was assessed qualitatively by Likert scale and quantitatively by SNR and CNR for the 4 major vessels right coronary, left main, left anterior descending, and left circumflex arteries on axial and multiplanar reformatted images. Values for Likert scale were as follows: 1, nondiagnostic; 2, poor; 3, good; 4, very good; and 5, excellent. Signal-to-noise ratio and CNR were calculated from the average 2 CT attenuation values within regions of interest placed in the proximal left main and proximal right coronary artery. For contrast comparison, a region of interest was selected from left ventricular wall at midcavity level using a dedicated workstation. We divided patients in 2 groups related to the HR: less than or equal to 70 beats/min (bpm) and greater than 70 bpm and also analyzed them in 2 BMI groupings: BMI less than or equal to 30 kg/m2 and BMI greater than 30 kg/m2. Results Mean SNR was 8.7 (SD, 3.1) (n = 349) for group with HR 70 bpm or less and 7.7 (SD, 2.4) (n = 78) for group with HR greater than 70 bpm (P = 0.008). Mean CNR was 6.9 (SD, 2.7) (n = 349) for group with HR 70 bpm or less and 5.9 (SD, 2.2) (n = 78) for group with HR 70 bpm or greater (P = 0.002). Mean SNR was 8.8 (SD, 3.2) (n = 249) for group with BMI 30 kg/m2 or less and 8.1 (SD, 2.6) (n = 176) for group with BMI greater than 30 kg/m2 (P = 0.008). Mean CNR was 7.0 (SD, 2.8) (n = 249) for group with BMI 30 kg/m2 or less and 6.4 (SD, 2.4) (n = 176) for group with BMI greater than 30 kg/m2 (P = 0.002). The results for mean Likert scale values were statistically different, reflecting difference in IQ between people with HR 70 bpm or less and greater than 70 bpm, BMI 30 kg/m2 or less, and BMI greater than 30 kg/m2.

Influence of Statin Therapy on Aneurysm Sac Regression after Endovascular Aortic Repair

PURPOSE To determine whether statin therapy is associated with abdominal aortic aneurysm (AAA) sac regression after endovascular aneurysm repair (EVAR). MATERIALS AND METHODS A total of 109 patients treated with EVAR were retrospectively analyzed (no-statin group, n = 45; statin group, n = 64). The primary endpoint was the incidence of AAA sac regression. To investigate independent predictors of AAA sac regression, regression analysis was performed. The mean age was 74 years (range, 55-90 y), and 87.2% of patients were men. RESULTS The no-statin group had higher rates of AAA sac regression than the statin group at 1 year (no-statin group, 66.7%; statin group, 45.3%; P = .028). The incidence of AAA sac regression increased over time in the statin group, and no statistical difference was seen between the two groups at 2 years (no-statin group, 66.7%; statin group, 57.8%; P = .350). The difference between the changes in maximum AAA diameter was significant between groups at 1 year (no-statin group vs statin group, -4.9 mm ± 5.9; P = .041), but the difference did not reach statistical significance at 2 years (no-statin group, -10.0 mm ± 10.1; statin group, -8.0 mm ± 9.6; P = .306). Statin therapy was not associated with AAA sac regression on univariate (odds ratio [OR], 0.685; 95% confidence interval [CI], 0.310-1.516; P = .351) and multivariate analyses (OR, 0.617; 95% CI, 0.215-1.772; P = .369). CONCLUSIONS Statin therapy had no effect on AAA sac regression at 2 years. There is insufficient evidence to recommend statin therapy for AAA sac regression.

Spindle cell sarcoma of the common femoral vein as a possible differential for deep venous thrombosis on ultrasound

We present a case of a spindle cell tumor, initially diagnosed as deep venous thrombosis (DVT), in a previously healthy 50-year-old man presenting with acute onset shortness of breath. The patient had no known risk factors for development of thromboembolic disease. However, multiple bilateral pulmonary emboli were detected on spiral computed tomography (CT) of the chest. Duplex study demonstrated a non-compressible right common femoral vein with minimal flow that was read as an acute DVT (Panel A). The patient did not complain of any leg pain at this time and there were no palpable masses on physical exam. The patient was started on anticoagulation with intravenous heparin and subsequently bridged to warfarin and discharged. Despite adequate anticoagulation, the patient complained of progressively worsening symptoms of tenderness and edema of the right lower extremity. Two months after initial presentation, a repeat duplex study revealed enlargement of the right common femoral vein with minimal vascularity appreciable on ultrasound (Panel B). Given the interval growth, a contrast-enhanced CT was ordered, which revealed an enhancing 4.6 × 2.3 cm soft tissue mass intrinsic to the right common femoral vein (Panel C). Images in vascular medicine

Step-by-Step Approach to Management of Type II Endoleaks

Seventy-five percent of abdominal aortic aneurysms are now treated by endovascular aneurysm repair (EVAR) rather than open repair, given the decreased periprocedural mortality, complications, and length of hospital stay for EVAR compared to the surgical counterpart. An endoleak is a potential complication after EVAR, characterized by continued perfusion of the aneurysm sac after stent graft placement. Type II endoleak is the most common endoleak, and often has a benign course with spontaneous resolution, occurring in the first 6 months after repair. However, these type II endoleaks may result in pressurization of the aneurysm sac and potentially sac rupture. They occur from retrograde collateral blood flow into the aneurysm sac, typically from a lumbar artery or the inferior mesenteric artery. Alternative sources include accessory renal, gonadal, median sacral arteries, and the internal iliac artery. We will discuss our protocol for post-EVAR imaging surveillance and potential type II endoleak treatment strategies, including transarterial, translumbar, transcaval, and perigraft approaches, as well as open surgery.

Fenestrated Endovascular Abdominal Aortic Aneurysm Repair

In order to offer more patients a durable endovascular abdominal aortic aneurysm repair parallel, branched, and fenestrated grafts have been utilized. These treatments aim at increasing the quality of the proximal aortic graft landing zone by incorporating the healthy aortic neck at the renal and visceral arteries. Fenestrated endovascular aneurysm repair has provided a standardized and approved treatment option for patients who may otherwise not be candidates for endovascular repair. We discuss the technique of fenestrated endovascular aneurysm repair and the challenges involved in selecting the appropriate patients.