Antonio Hernandez Conte

Multi-contrast atherosclerosis characterization (MATCH) of carotid plaque with a single 5-min scan: technical development and clinical feasibility

BackgroundMulti-contrast weighted imaging is a commonly used cardiovascular magnetic resonance (CMR) protocol for characterization of carotid plaque composition. However, this approach is limited in several aspects including low slice resolution, long scan time, image mis-registration, and complex image interpretation. In this work, a 3D CMR technique, named Multi-contrast Atherosclerosis Characterization (MATCH), was developed to mitigate the above limitations.MethodsMATCH employs a 3D spoiled segmented fast low angle shot readout to acquire data with three different contrast weightings in an interleaved fashion. The inherently co-registered image sets, hyper T1-weighting, gray blood, and T2-weighting, are used to detect intra-plaque hemorrhage (IPH), calcification (CA), lipid-rich necrotic core (LRNC), and loose-matrix (LM). The MATCH sequence was optimized by computer simulations and testing on four healthy volunteers and then evaluated in a pilot study of six patients with carotid plaque, using the conventional multi-contrast protocol as a reference.ResultsOn MATCH images, the major plaque components were easy to identify. Spatial co-registration between the three image sets with MATCH was particularly helpful for the reviewer to discern co-existent components in an image and appreciate their spatial relation. Based on Cohen’s kappa tests, moderate to excellent agreement in the image-based or artery-based component detection between the two protocols was obtained for LRNC, IPH, CA, and LM, respectively. Compared with the conventional multi-contrast protocol, the MATCH protocol yield significantly higher signal contrast ratio for IPH (3.1 ± 1.3 vs. 0.4 ± 0.3, p < 0.001) and CA (1.6 ± 1.5 vs. 0.7 ± 0.6, p = 0.012) with respect to the vessel wall.ConclusionsTo the best of our knowledge, the proposed MATCH sequence is the first 3D CMR technique that acquires spatially co-registered multi-contrast image sets in a single scan for characterization of carotid plaque composition. Our pilot clinical study suggests that the MATCH-based protocol may outperform the conventional multi-contrast protocol in several respects. With further technical improvements and large-scale clinical validation, MATCH has the potential to become a CMR method for assessing the risk of plaque disruption in a clinical workup.

Assessment of Myocardial Reactivity to Controlled Hypercapnia with Free-breathing T2-prepared Cardiac Blood Oxygen Level–Dependent MR Imaging

PURPOSE To examine whether controlled and tolerable levels of hypercapnia may be an alternative to adenosine, a routinely used coronary vasodilator, in healthy human subjects and animals. MATERIALS AND METHODS Human studies were approved by the institutional review board and were HIPAA compliant. Eighteen subjects had end-tidal partial pressure of carbon dioxide (PetCO2) increased by 10 mm Hg, and myocardial perfusion was monitored with myocardial blood oxygen level-dependent (BOLD) magnetic resonance (MR) imaging. Animal studies were approved by the institutional animal care and use committee. Anesthetized canines with (n = 7) and without (n = 7) induced stenosis of the left anterior descending artery (LAD) underwent vasodilator challenges with hypercapnia and adenosine. LAD coronary blood flow velocity and free-breathing myocardial BOLD MR responses were measured at each intervention. Appropriate statistical tests were performed to evaluate measured quantitative changes in all parameters of interest in response to changes in partial pressure of carbon dioxide. RESULTS Changes in myocardial BOLD MR signal were equivalent to reported changes with adenosine (11.2% ± 10.6 [hypercapnia, 10 mm Hg] vs 12% ± 12.3 [adenosine]; P = .75). In intact canines, there was a sigmoidal relationship between BOLD MR response and PetCO2 with most of the response occurring over a 10 mm Hg span. BOLD MR (17% ± 14 [hypercapnia] vs 14% ± 24 [adenosine]; P = .80) and coronary blood flow velocity (21% ± 16 [hypercapnia] vs 26% ± 27 [adenosine]; P > .99) responses were similar to that of adenosine infusion. BOLD MR signal changes in canines with LAD stenosis during hypercapnia and adenosine infusion were not different (1% ± 4 [hypercapnia] vs 6% ± 4 [adenosine]; P = .12). CONCLUSION Free-breathing T2-prepared myocardial BOLD MR imaging showed that hypercapnia of 10 mm Hg may provide a cardiac hyperemic stimulus similar to adenosine.

Cardiac steatosis and left ventricular dysfunction in HIV-infected patients treated with highly active antiretroviral therapy.

Heart disease is a major contributor to morbidity and mortality in persons infected with human immunodeficiency virus (HIV), and both HIV and highly active antiretroviral therapy (HAART) may be associated with abnormalities in cardiac function and metabolism [(1)][1]. Ectopic fat deposition in

CARDIAC STEATOSIS AND LEFT VENTRICULAR DYSFUNCTION IS ASSOCIATED WITH EXPOSURE TO HUMAN IMMUNODEFICIENCY VIRUS HIGHLY ACTIVE ANTIRETROVIRAL THERAPY: A 3-TESLA CARDIAC MAGNETIC RESONANCE IMAGING STUDY

Highly-active anti-retroviral therapy (HAART) for Human Immunodeficiency Virus (HIV) infection is associated with metabolic abnormalities including dyslipidemia, hyperglycemia, and increased risk of cardiovascular disease. We hypothesized that HIV patients on HAART would have increased intra-

Transesophageal echocardiographic evaluation of left main coronary artery stent protection during transcatheter aortic valve implantation.

94-year-old man with a history of severe symptomatic aortic stenosis, atrial fibrillation, hyper tension, and left main coronary artery disease presented for transcatheter aortic valve implantation (TAVI) via the transfemoral approach; written consent was obtained from the patient for presentation of this case. Given his age and comorbidities, a left main coronary stent was placed for his proximal left main coronary disease before TAVI. Technical considerations resulted in the stent protruding into the aortic root at the level of the sinotubular junction. Intraoperative transesophageal echocardiography (TEE) was performed using a Philips iE33 ultrasound system with an X7-2t TEE probe (Philips Healthcare, Andover, MA) revealing severe aortic valve (AV) stenosis (valve area 0.6 cm 2 by the continuity equation; mean gradient 44 mm Hg; peak gradient 78 mm Hg) with significant calcific degeneration and minimal motion of all 3 coronary cusps; mild aortic regurgitation was noted. The AV annular and sinotubular junction diameters were 23 mm and 25 mm, respectively. Mild-to-moderate tricuspid regurgitation, no mitral valve regurgitation, no significant left ventricu lar wall motion abnormalities, and left ventricular ejection fraction estimated as 66% were also noted. An echodense structure was visible in the aortic root at the level of the sinotubular junction in the midesophageal (ME) long-axis (LAX) view (Fig. 1 and Video 1, Loop 1, see Supplemental Digital Content 1, http://links.lww.com/AA/A478) and ME short-axis (SAX) view near the left coronary cusp (Video 1, Loop 2, Supplemental Digital Content 1, http://links. lww.com/AA/A478); it was also visible with fluoroscopy and consistent with a left coronary ostial stent protruding approximately 0.5 cm into the aortic root. Two-dimensional color-flow Doppler interrogation demonstrated flow through the stent, and real-time 3-dimensional TEE imaging provided additional confirmation of stent protrusion (Fig. 2A). Because the implanted bioprosthetic AV is deployed within the native AV extending below and above the

Three-dimensional coronary dark-blood interleaved with gray-blood (cDIG) magnetic resonance imaging at 3 tesla.

Three‐dimensional (3D) dark‐blood MRI has shown great potential in coronary artery plaque evaluation. However, substantial variability in quantification could result from superficial calcification because of its low signal. To address this issue, a 3D coronary dark‐blood interleaved with gray‐blood (cDIG) technique was developed.

Comparison of the C-MAC video laryngoscope to a flexible fiberoptic scope for intubation with cervical spine immobilization

STUDY OBJECTIVE To compare the C-MAC video laryngoscope to the standard flexible fiberoptic scope (FFS) with an eye piece (but without a camera or a video screen) for intubation of patients undergoing cervical spine surgery with manual inline stabilization. The primary end point was the time to achieve successful tracheal intubation. Secondary end points included glottic view at intubation and number of intubation attempts. DESIGN Prospective, randomized, single-blinded study. SETTING Cedars Sinai Medical Center in Los Angeles, CA. PATIENTS One hundred forty patients (American Society of Anaesthesiologists physical status I-III), aged 18 to 80years undergoing elective cervical spine surgery. INTERVENTION Patients were prospectively randomized to undergo tracheal intubation using either an FFS (n=70) or the C-MAC video laryngoscope (n=70). MEASUREMENTS After performing a preoperative airway evaluation, patients underwent a standardized induction sequence. The glottic view was assessed at the time of tracheal tube placement using the Cormack-Lehane and percentage of glottic opening scoring systems. In addition, the time required for successful insertion of the tracheal tube, number of intubation attempts to secure the airway, the need for adjuvant airway devices, hemodynamic changes, adverse events, and any airway-related trauma were recorded. MAIN RESULTS The glottic view at the time of intubation did not differ significantly with the 2 devices; however, the C-MAC facilitated more rapid tracheal intubation compared with the FFS (P=.001). The peak heart rate response following insertion of the tracheal tube was also reduced (P=.004) in the C-MAC (vs FFS) group. CONCLUSION The C-MAC may offer an advantage over the FFS with respect to the time required to obtain glottic view and successful placement of the tracheal tube in patients requiring cervical spine immobilization.

Transesophageal Echocardiogram-Guided Percutaneous AngioVac Extraction of a Right Atrial Embolus.

March 2016 • Volume 122 • Number 3 www.anesthesia-analgesia.org 651 A 68-year-old man with decompensated nonischemic cardiomyopathy was transferred to our institution for evaluation of heart transplantation or mechanical circulatory support candidacy. He was stabilized in the intensive care unit with intubation, diuresis, and inotropic support. Transthoracic echocardiogram revealed severely depressed right ventricular (RV) and left ventricular function (left ventricular ejection fraction, 10%), severe mitral regurgitation, as well as a mildly dilated right atrium (RA) with a large, mobile mass consistent with thrombus/ embolus. Emergent percutaneous atrial thrombectomy by cardiac surgery with transesophageal echocardiography (TEE) guidance was planned, given the patient’s high operative risk and likelihood of mortality if distal embolization to the pulmonary artery (PA) occurred. Intraoperative TEE confirmed the presence of a large, free-floating, worm-like, mobile thromboembolus within the RA with reduced RV function (Figure 1; Supplemental Digital Content 1, Video 1, http://links.lww.com/AA/ B286). No embolic material was visualized in the RV or PA, and McConnell sign was not present. Cannulation for venovenous extracorporeal bypass was established through right and left femoral veins for use with the AngioVacTM (Angiodynamics, Vortex Medical Inc., New York, NY) venous drainage cannula. The venous cannula was sequentially advanced over a wire (Fig. 2A) until visualized at the inferior vena cava (IVC)–RA junction, and bypass circulation was initiated. The cannula was advanced from the IVC, through the RA (Figure 2B and 2C; Supplemental Digital Content 2, Video 2, http://links.lww.com/AA/B287) and into superior vena cava (SVC) to remove all visible thrombus in the RA (Figure 2D; Supplemental Digital Content 3, Video 3, http://links.lww.com/AA/B288). The patient remained hemodynamically stable receiving dobutamine and dopamine throughout the procedure. Unfortunately, he was not deemed suitable for heart transplant or mechanical circulatory support because of multiple medical comorbidities and he died 14 days after the procedure. Written consent for publication was unable to be obtained because of the patient’s death, and no family member was available to provide consent. IRB approval for publication of this case was obtained.

Successful Orthotopic Heart Transplantation and Immunosuppressive Management in 2 Human Immunodeficiency Virus-Seropositive Patients.

Few orthotopic heart transplantations have been performed in patients infected with the human immunodeficiency virus since the first such case was reported in 2001. Since that time, advances in highly active antiretroviral therapy have resulted in potent and durable suppression of the causative human immunodeficiency virus-accompanied by robust immune reconstitution, reversal of previous immunodeficiency, a marked decrease in opportunistic and other infections, and near-normal long-term survival. Although human immunodeficiency virus infection is not an absolute contraindication, few centers in the United States and Canada have performed heart transplantations in this patient population; these patients have been de facto excluded from this procedure in North America. Re-evaluation of the reasons for excluding these patients from cardiac transplantation is warranted in light of such significant advances in antiretroviral therapy. This case report documents successful orthotopic heart transplantation in 2 patients infected with human immunodeficiency virus, and we describe their antiretroviral therapy and immunosuppressive management challenges. Both patients were doing well without sequelae 43 and 38 months after transplantation.

Iterative Reconstruction Results in Larger Computed Tomography Measurements of Iliofemoral Artery Diameter in Patients Referred for Transcatheter Aortic Valve Replacement.

Objectives We hypothesized that improved iterative reconstruction increases image quality and reduces artifacts for iliofemoral artery computed tomography imaging in patients referred for transcatheter aortic valve replacement (TAVR). Methods We examined 56 consecutive patients undergoing computed tomography for possible TAVR and compared image quality and iliofemoral artery size between adaptive statistical iterative reconstructions (ASIRs) and improved model-based iterative reconstructions (MBIRs). Results Model-based iterative reconstruction (vs ASIR) was associated with improved (P < 0.001 for each) image quality (3.4 ± 0.8 vs 2.8 ± 1.0), beam hardening (3.5 ± 0.8 vs 3.0 ± 1.1), and wall definition (3.6 ± 0.6 vs 3.1 ± 0.8). Image signal-to-noise ratios (20.4 ± 10.1 vs 13.7 ± 6.6, P < 0.001) were also increased with MBIR as compared with ASIR. Mean iliofemoral artery size was larger using MBIR compared with ASIR (left, 7.7 ± 1.5 vs 7.4 ± 1.7 mm, P < 0.001; right, 7.8 ± 1.2 vs 7.4 ± 1.5 mm, P = 0.008). Conclusions In patients referred for TAVR, improved MBIR resulted in higher image quality, reduced artifacts, and larger iliofemoral artery diameters compared with standard iterative reconstructions.