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Background: The use of low-titer group O whole blood is increasing. To reduce wastage, unused units can be converted to packed red blood cells. Supernatant is currently discarded post-conversion; however, it could be a valuable transfusable product. The aim of this study was to evaluate supernatant prepared from late-storage low-titer group O whole blood being converted to red blood cells, hypothesizing it will have higher hemostatic activity compared to fresh never-frozen liquid plasma., Methods: Low-titer group O whole blood supernatant (n = 12) prepared on storage day 15 was tested on days 15, 21, and 26 and liquid plasma (n = 12) on 3, 15, 21, and 26. Same-day assays included cell counts, rotational thromboelastometry, and thrombin generation. Centrifuged plasma from units was banked for microparticle characterization, conventional coagulation, clot structure, hemoglobin, and additional thrombin generation assays., Results: Low-titer group O whole blood supernatant contained more residual platelets and microparticles compared to liquid plasma. At day 15, low-titer group O whole blood supernatant elicited a faster intrinsic clotting time compared to liquid plasma (257 ± 41 vs. 299 ± 36 s, P = 0.044), and increased clot firmness (49 ± 9 vs. 28 ± 5 mm, P < 0.0001). Low-titer group O whole blood supernatant showed more significant thrombin generation compared to liquid plasma (day 15 endogenous thrombin potential 1,071 ± 315 vs. 285 ± 221 nM·min, P < 0.0001). Flow cytometry demonstrated low-titer group O whole blood supernatant contained significantly more phosphatidylserine and CD41+ microparticles. However, thrombin generation in isolated plasma suggested residual platelets in low-titer group O whole blood supernatant were a greater contributor than microparticles. Additionally, low-titer group O whole blood supernatant and liquid plasma showed no difference in clot structure, despite higher CD61+ microparticle presence., Conclusions: Plasma supernatant produced from late-storage low-titer group O whole blood shows comparable, if not enhanced, in vitro hemostatic efficacy to liquid plasma., (Copyright © 2023 American Society of Anesthesiologists. All Rights Reserved.)

Objective: This study aimed to validate 4-dimensional phase contrast (4D PC) cine magnetic resonance imaging (MRI) as a means of evaluating left ventricular outflow tract (LVOT) obstruction in patients with hypertrophic cardiomyopathy (HCM)., Methods: In this institutional review board-approved prospective study, 23 patients with suspected HCM from October 2012 to September 2013 underwent 4D PC MRI. Postprocessed 4D PC pathline cine data were reviewed by 2 blinded reviewers to determine presence or absence of LVOT obstruction. Sensitivity, specificity, and accuracy in 4D PC qualitative and quantitative assessment of LVOT obstruction were calculated using echo as reference standard., Results: Consensus interpretation of 4D PC showed 100.0% (7/7) sensitivity, 75.0% specificity (12/16), and 82.6% (19/23) accuracy in assessment of LVOT obstruction. The 4D PC quantitative estimates of LVOT gradient have 71.4% (5/7) sensitivity, 93.8% (15/16) specificity, and 87.0% (20/23) accuracy in evaluation of LVOT obstruction compared with echo., Conclusions: The 4D PC MRI can assess for LVOT obstruction in HCM patients.

Purpose: X-ray angiography is currently the standard test for the assessment of coronary artery disease. A substantial minority of patients referred for coronary angiography have no significant coronary artery disease. The purpose of this work was the evaluation of the accuracy of a three-dimensional (3D) breathhold coronary magnetic resonance angiography (MRA) technique in detecting hemodynamically significant coronary artery stenoses in a patient population with x-ray angiographic correlation., Materials and Methods: Sequential subjects (n = 33, M/F = 22/11, average age = 57) who were referred for conventional coronary angiography were enrolled in the study. The study protocol was approved by our institutional review board. Each subject gave written informed consent. Volume-targeted 3D breathhold coronary artery scans with ECG-triggered, segmented True Fast Imaging with Steady-state Precession (TrueFISP) were acquired for the left main (LM), left anterior descending (LAD), and right coronary arteries (RCAs). Coronary MRA was evaluated with conventional angiography as the gold standard., Results: The overall sensitivity, specificity, accuracy, positive predictive value (PPV), and negative predictive value (NPV) for diagnosing any hemodynamically significant coronary artery disease (> or =50% diameter reduction) with coronary MRA was 87%, 57%, 72%, 68%, and 80%, respectively. The sensitivity of the technique in the LM, LAD, and RCA was 100%, 83%, and 100%, respectively. The NPV of the technique in the LM, LAD, and RCA was 100%, 82%, and 100%, respectively., Conclusions: Three-dimensional breathhold True Fast Imaging with Steady-state Precession is a promising technique for coronary artery imaging. It has a relatively high sensitivity and NPV. Results of this study warrant further technical improvements and clinical evaluation of the technique.

Objectives: Coronary artery x-ray angiography (XRA) is currently the gold standard for the assessment of coronary artery disease. A substantial minority of patients referred for coronary angiography have no significant coronary artery disease. The purpose of this study is to evaluate magnetization-prepared contrast-enhanced breath-hold volume-targeted imaging (MPCE-VCATS), a new 3-dimensional breath-hold coronary magnetic resonance angiography (MRA) technique, in detecting hemodynamically significant coronary artery stenoses in a patient population, with XRA correlation., Materials and Methods: A total of 19 subjects who were referred for conventional coronary angiography were enrolled in the study. ECG-triggered MPCE-VCATS coronary artery scans were acquired for the left main coronary artery (LCA), left anterior descending (LAD), and right coronary artery (RCA). Coronary MRA and XRA results were compared., Results: The overall sensitivity, accuracy, and negative predictive value for diagnosing any hemodynamically significant coronary artery disease (> or =50% diameter reduction) was 91%, 80%, and 90%, respectively. The sensitivity of the technique in the LCA, LAD, and RCA was 100%, 100% and 78%, respectively. The negative predictive value of the technique was 100%, 100%, and 71%, respectively., Discussion: MPCE-VCATS is a promising technique for coronary artery imaging. It has a relatively high sensitivity as well as a high NPV. The results of the study may indicate a future role for the technique in obviating the need for some patients to undergo XRA.

Background: The decision to perform coronary revascularization procedures may hinge on assessment of myocardial perfusion reserve. Blood oxygen level-dependent (BOLD) MRI is a potential method to detect the effects of regional variations in myocardial blood flow during vasodilation., Methods and Results: We imaged dogs (n=13) on a 1.5-T whole-body MRI scanner using a new T(2)-prepared steady-state free-precession (SSFP) MRI pulse sequence sensitive to BOLD contrast. Images (in-plane resolution approximately 1 mm(2)) of 5 short-axis and 2 long-axis slices of the heart were acquired during graded levels of adenosine infusion via a surgically placed left circumflex (LCx) catheter (n=11) or via a right atrial catheter in animals with an LCx occluder (n=2). Relative myocardial perfusion was measured with the use of fluorescent microspheres. Signal intensity changes in myocardium subtended by the left anterior descending coronary artery were compared with those in the LCx region. Unprocessed T(2)-weighted images revealed changes in signal intensity corresponding to areas of regional vasodilation or reduced myocardial perfusion reserve during systemic vasodilation. At maximal vasodilation, the signal intensity ratio in the LCx versus left anterior descending territories increased by 33+/-4% compared with baseline, corresponding to a 3.8+/-0.3-fold increase in relative perfusion (P<0.01). MR intensity at progressive levels of vasodilation demonstrated good agreement with microsphere flow (R=0.80, P<0.01)., Conclusions: T(2)-prepared SSFP BOLD imaging is a promising method to determine an index of myocardial perfusion reserve in this animal model.