Myocardial strain assessment using cardiovascular magnetic resonance imaging in recipients of implantable cardioverter defibrillators.

BACKGROUND: Cardiovascular magnetic resonance (CMR) is increasingly used in the evaluation of patients who are potential candidates for implantable cardioverter-defibrillator (ICD) therapy to assess left ventricular (LV) ejection fraction (LVEF), myocardial fibrosis, and etiology of cardiomyopathy. It is unclear whether CMR-derived strain measurements are predictive of appropriate shocks and death among patients who receive an ICD. We evaluated the prognostic value of LV strain parameters on feature-tracking (FT) CMR in patients who underwent subsequent ICD implant for primary or secondary prevention of sudden cardiac death. METHODS: Consecutive patients from 2 Canadian tertiary care hospitals who underwent ICD implant and had a pre-implant CMR scan were included. Using FT-CMR, a single, blinded, reader measured LV global longitudinal (GLS), circumferential (GCS), and radial (GRS) strain. Cox proportional hazards regression was performed to assess the associations between strain measurements and the primary composite endpoint of all-cause death or appropriate ICD shock that was independently ascertained. RESULTS: Of 364 patients (mean 61 years, mean LVEF 32%), 64(17.6%) died and 118(32.4%) reached the primary endpoint over a median follow-up of 62 months. Univariate analyses showed significant associations between GLS, GCS, and GRS and appropriate ICD shocks or death (all p < 0.01). In multivariable Cox models incorporating LVEF, GLS remained an independent predictor of both the primary endpoint (HR 1.05 per 1% higher GLS, 95% CI 1.01-1.09, p = 0.010) and death alone (HR 1.06 per 1% higher GLS, 95% CI 1.02-1.11, p = 0.003). There was no significant interaction between GLS and indication for ICD implant, presence of ischemic heart disease or late gadolinium enhancement (all p > 0.30). CONCLUSIONS: GLS by FT-CMR is an independent predictor of appropriate shocks or mortality in ICD patients, beyond conventional prognosticators including LVEF. Further study is needed to elucidate the role of LV strain analysis to refine risk stratification in routine assessment of ICD treatment benefit.

Delayed dehiscence of modified mechanical Bentall 7 years postsurgery for Takayasu's arteritis.

Following aortic surgery for vasculitis, the incidence and duration of onset of anastomotic breakdown is unclear. A case is presented of a young female patient with Takayasu's arteritis (TA) who was found to have frank dehiscence of a modified Bentall repair 7 years after surgery. The case highlights (i) the lack of normal healing following aortic surgery in TA, and (ii) need to differentiate imaging protocols for patients with defined vasculitis as opposed to degenerative aortic conditions. A recommendation is made for appropriate surveillance imaging modality alternating between computed tomography and magnetic resonance imaging in the often young patient population affected by vasculitis.

Multiple radiologist review of adrenal CT still frequently misses lateralized surgical primary aldosteronism.

Patients with primary aldosteronism (PA) have increased morbidity and mortality compared to those with essential hypertension. Accurate detection of lateralized PA is important so that affected patients can receive potentially curative adrenalectomy. However, around 40% of patients with lateralized PA have "normal" adrenal glands on computed tomography (CT). Additional independent review of imaging has been shown to improve diagnostic accuracy in many areas of imaging. Therefore, the authors sought to establish if multi-reader re-assessment of previously reported normal CT scans would result in increased detection of surgically remediable disease. The authors found that re-assessment of CT imaging by one, two, or three additional radiologists (or a combination thereof) slightly increased the detection of lateralized disease, but these differences were not statistically significant (p > .05). Readers had low inter-observer agreement (kappa = 0.17). If detection of a discrete nodule on CT was made a prerequisite for adrenal vein sampling (AVS), a second read by another reviewer would still result in an excess of missed cases (84.2%, 36.8%, and 65.8%, respectively, for each of the three independent reviewers). Therefore, a "normal" CT does not preclude the possibility of lateralized PA. Adrenal vein sampling should still be strongly considered wherever available and whenever surgery is considered for treatment of PA, irrespective of CT findings.

Subclavian atherectomy and angioplasty for coronary subclavian steal syndrome post CABG.

Coronary subclavian steal syndrome is an uncommon complication occurring in patients with coronary artery bypass graft (CABG). We describe a case of a 69-year-old male with a remote history of CABG who presented with exertional left arm pain and angina. Computed Tomographic Angiography of the chest demonstrated a severe left proximal subclavian artery stenosis. The case demonstrates successful application of subclavian atherectomy with use of embolic protective device, alleviating the need of stent, for treatment of Coronary subclavian steal syndrome in patient with remote history of CABG.

Multidimensional Analysis of Descending Aortic Growth After Acute Type A Aortic Dissection.

BACKGROUND: After repair of acute type A aortic dissection, typical geometric variables of conventional aortic surveillance focus on maximum diameter and its rate of growth, potentially missing important geometric changes elsewhere. We determined additional information provided by a semiautomated, 3-dimensional (3D), nonlinear growth model of the descending thoracic aorta after repair of type A aortic dissection. METHODS: Computed tomographic angiography data were retrospectively collected after hemiarch repair of type A aortic dissection. The descending aorta was systematically reconstructed to generate a 3D model made up of individual segments. The baseline and follow-up diameters were measured semiautomatically for each segment, and the nonlinear interval growth was determined. RESULTS: The fastest growing segment expanded at a rate of 3.8 mm/y (interquartile range, 2.2 to 5.4 mm/y) vs 0.6 mm/y (interquartile range, -0.3 to 1.7 mm/y) when measured at the original site of maximum diameter (P < .01). The maximum baseline diameter was a poor predictor of location with fastest growth (r = 0.10, P > .1). Using the society recommended growth limits, a greater proportion of patients would be considered "at risk" when assessed by our method vs conventional surveillance measures. CONCLUSIONS: Our model identifies areas of rapid aortic growth after repair of type A dissection that would likely be missed using current surveillance techniques. The increased precision, resolution, and reproducibility provided by our technique may improve on limitations of current surveillance techniques, provide novel geometric data on aortic remodeling, and contribute to the pursuit of a comprehensive patient-specific approach to aortic risk stratification.

The Many Care Models to Treat Thoracic Aortic Disease in Canada: A Nationwide Survey of Cardiac Surgeons, Cardiologists, Interventional Radiologists, and Vascular Surgeons.

BACKGROUND: Several specialties treat thoracic aortic disease, resulting in multiple patient care pathways. This study aimed to characterize these varied care models to guide health policy. METHODS: A 57-question e-survey was sent to staff cardiac surgeons, cardiologists, interventional radiologists, and vascular surgeons at 7 Canadian medical societies. RESULTS: For 914 physicians, the response rate was 76% (86 of 113) for cardiac surgeons, 40% (58 of 146) for vascular surgeons, 24% (34 of 140) for radiologists, and 14% (70 of 515) for cardiologists. Several services admitted type B dissections (vascular 37%, cardiology 31%, cardiac 18%, other 7%), and care was heterogeneous. Ownership of disease management was overestimated relative to the perspective of the other specialties. Type A dissection admissions and treatment were more uniform, but emergent call coverage varied. A 24/7 aortic specialist on-call schedule was present only 4% of the time. "Aortic" case rounds promoted attendance by a broader aortic specialty contingency relative to rounds that were specialty specific. Although 89% of respondents felt an aortic team was best for patient care, only 54% worked at an institution with an aortic team present, and only 28% utilized an aortic clinic. Questions designed to define an aortic team derived 63 different combinations. CONCLUSIONS: Thoracic aortic disease follows a network of undefined and variable care pathways, despite its high-risk population in need of complex treatment considerations. Multidisciplinary aortic teams and clinics exist in low volume, and the "aortic team" remains an obscure construct. A multispecialty initiative to define the aortic team and outline standardized navigation pathways within the health systems hospitals is advocated.

CONTEXTE: La prise en charge de la maladie de l'aorte thoracique peut faire appel à plusieurs spécialités, ce qui a pour effet de multiplier les trajectoires de soins des patients. Cette étude visait à caractériser ces différents modèles de soins afin d'éclairer l'élaboration des politiques de santé. MÉTHODOLOGIE: Un sondage électronique de 57 questions a été envoyé aux chirurgiens cardiaques, aux cardiologues, aux radiologistes interventionnels et aux chirurgiens vasculaires membres de 7 associations médicales canadiennes. RÉSULTATS: Sur un total de 914 médecins, le taux de réponse a été de 76 % (86 sur 113) chez les chirurgiens cardiaques, de 40 % (58 sur 146) chez les chirurgiens vasculaires, de 24 % (34 sur 140) chez les radiologistes et de 14 % (70 sur 515) chez les cardiologues. Plusieurs services avaient admis des cas de dissection aortique de type B (chirurgie vasculaire 37 %, cardiologie 31 %, chirurgie cardiaque 18 %, autre 7 %) et les soins étaient hétérogènes. Les spécialistes surestimaient leur responsabilité de la prise en charge des cas par rapport à celle des autres spécialistes. Les admissions de cas de dissection de type A et leur traitement étaient plus uniformes, mais la présence de spécialistes de garde pouvant traiter les cas urgents était variable. La présence continue d'un spécialiste de l'aorte de garde n'était observée que pendant 4 % du temps. Les séances de discussion de cas « aortiques ¼ favorisaient la participation par une gamme plus large de spécialistes de l'aorte que les discussions axées sur une spécialité donnée. Si 89 % des répondants estimaient qu'une équipe « aortique ¼ était la meilleure option pour les soins aux patients, ils n'étaient que 54 % à travailler dans un établissement disposant d'une telle équipe et 28 % à utiliser les services d'une clinique de l'aorte. En réponse aux questions portant sur les éléments constitutifs d'une équipe aortique, 63 combinaisons différentes de spécialités ont été proposées. CONCLUSIONS: La prise en charge de la maladie de l'aorte thoracique emprunte un dédale de trajectoires de soins non définies et variables, alors que sa population à haut risque a besoin de traitements complexes. Les équipes multidisciplinaires et les cliniques spécialisées dans le traitement de l'aorte sont rares, et la notion d' « équipe aortique ¼ demeure un concept obscur. Nous préconisons une initiative réunissant des spécialistes de différents domaines pour définir les éléments constitutifs d'une équipe aortique et établir des trajectoires de navigation normalisées au sein des hôpitaux du système de santé.

Outcome Analysis of Posterolateral Decompression and Spinal Stabilization for Tuberculous Spine.

AIM: This is a prospective study to analyze the clinical, radiological, and functional outcomes of posterolateral decompression and spinal stabilization with pedicle screws and rods done for the thoracolumbar tuberculous spine. MATERIALS AND METHODS: This study was conducted at Gandhi Medical College and Hospital from September 2016 to September 2017 on 30 patients who underwent posterolateral decompression and spinal stabilization using pedicle screw and rod fixation for active spinal tuberculosis. Pain, erythrocyte sedimentation rate (ESR), kyphotic angle correction, and Frankel's grading were taken to study the clinical, radiological, and functional outcome at the end of 1 year. Other parameters taken into consideration were the duration of stay and level of involvement; antituberculous therapy was given to all the patients for 16-18 months until the signs of radiological healing were evident. RESULTS: This study comprised of 30 patients with a mean age of presentation of 39.835 ± 14.75 and M: F ratio of 1:1. The mean duration of stay is 10.67 ± 4.06, and the most common level of involvement is D6-D11. Kyphotic angle was corrected by a mean of 19.08 ± 5.44 at the end of 1 year (P < 0.001). Visual analog score improved from a median of 8 preoperatively to 2 at follow-up (P < 0.001). ESR improved from a mean of 37.08 ± 12.64 mm/h preoperatively to 19.83 ± 13.68 mm/h at follow-up (P = 0.01). There was an improvement in Frankel's grading in most of the patients at the end of 12 months. Radiological healing was evident in the form of the reappearance of trabeculae formation and bony fusion at the end of 12 months. CONCLUSION: Posterolateral approach is a good method for decompression and spinal stabilization because of significant kyphotic correction, improvement in pain, good neurological recovery, less duration of stay, and less morbidity.

Extended-arch repair for acute type-A aortic dissection: perioperative and mid-term results.

OBJECTIVES: Extended-arch techniques offer the potential to comprehensively treat acute type-A aortic dissection (ATAAD), but add surgical complexity compared to the standard hemiarch technique. This study describes both perioperative and mid-term outcomes following the introduction of an extended-arch technique for ATAAD. METHODS: Ours is a retrospective single-centre observational study of 95 consecutive patients with ATAAD from 2011 to 2016. The decision to perform extended-arch or hemiarch repair was individualized based on clinical and radiological features. Extended-arch repair was defined as replacement of the ascending aorta and arch with reimplantation of head vessels with or without distal endovascular extension. Clinical follow-up was 100% complete. Cross-sectional double-oblique measurements were performed for aortic remodelling analysis. RESULTS: Extended-arch (n = 28) and hemiarch (n = 67) repair resulted in a in-hospital mortality of 10% (n = 3) and 10%, (n = 7), and permanent neurological deficit rate of 7% and 12%, respectively. At a mean imaging follow-up duration of 2.7 ± 1.5 years, false lumen thrombosis was achieved in 57% and 9% of patients undergoing extended-arch and hemiarch repair, respectively. Rate of growth in the proximal descending aorta was 0.7 ± 2.3 mm/year in the extended-arch group vs 2.7 ± 3.9 mm/year in the hemiarch group. At a mean clinical follow-up time of 3.0 ± 1.6 years, open surgical aortic reoperation was 0% in the extended-arch group and 22% in the hemiarch group. CONCLUSIONS: Extended-arch repair of ATAAD can be introduced in the acute setting without increase in perioperative mortality or morbidity. At mid-term follow-up, extended-arch for ATAAD improves aortic remodelling and reduces the need for open surgical reoperation.

Serial Measurements of Left Ventricular Systolic and Diastolic Function by Cardiac Magnetic Resonance Imaging in Patients with Early Stage Breast Cancer on Trastuzumab.

Our aim was to evaluate the temporal changes in left ventricular (LV) diastolic filling in relation to other LV parameters using cardiac MRI (CMR) in patients with HER2 positive breast cancer receiving trastuzumab therapy. Fourty-one women with early stage HER2+ breast cancer underwent serial CMR (baseline, 6, 12, and 18 months) after initiation of trastuzumab therapy. A single, blinded observer measured LV parameters on de-identified CMRs in random order. Linear mixed models were used to investigate temporal changes. Compared to baseline, there were significant decreases in systolic function as measured by both left ventricular ejection fraction (LVEF) (p <0.001 at 6 and 12 months) and peak ejection rate corrected for end-diastolic volume (PER/LVEDV) (p = 0.008 at 6 months, p = 0.01 at 12 months). However, these differences were no longer significant at 18 months. In contrast, significant reductions in diastolic function as measured by LV peak filling rate corrected for end-diastolic volume (PFR/LVEDV) were observed at 6 months (p = 0.012), 12 months (p = 0.031), and up to 18 months (p = 0.034). There were no significant temporal changes in the time to peak filling rate corrected for cardiac cycle (TPF/RR). The reduction in PFR/LVEDV at 18 months was no longer significant when corrected for heart rate. In conclusion, there were significant subclinical deleterious effects on both LV systolic and diastolic function among patients receiving trastuzumab. While there was recovery in LV systolic function after therapy cessation at 18 months, reduction in PFR/LVEDV appeared to persist. Thus, diastolic dysfunction may serve as a marker of trastuzumab-induced cardiotoxicity that needs to be confirmed in a larger study.

Hybrid Arch for Acute Type A Aortic Dissection: When to Deploy the Endograft? Debate: Frozen versus Staged?

Advances in open and endovascular techniques have resulted in novel approaches to repair of acute Type A aortic dissection. Hybrid arch procedures involve open arch resection and stent grafting of the descending aorta with stent graft insertion in one of two ways: Frozen or Staged. In this article, pros and cons of the two different paradigms of emerging hybrid arch techniques for acute Type A aortic dissections are discussed.

Cardiac MRI and radionuclide ventriculography for measurement of left ventricular ejection fraction in ICD candidates.

OBJECTIVE: Current guidelines provide left ventricular ejection fraction (LVEF) criterion for use of implantable cardioverter defibrillators (ICD) but do not specify which modality to use for measurement. We compared LVEF measurements by radionuclide ventriculography (RNV) vs cardiac MRI (CMR) in ICD candidates to assess impact on clinical decision making. METHODS: This single-centre study included 124 consecutive patients referred for assessment of ICD implantation who underwent RNV and CMR within 30 days for LVEF measurement. RNV and CMR were interpreted independently by experienced readers. RESULTS: Among 124 patients (age 64 ±â€¯11 years, 77% male), median interval between CMR and RNV was 1 day; mean LVEF was 32 ±â€¯12% by CMR and 33 ±â€¯11% by RNV (p = 0.60). LVEF by CMR and RNV showed good correlation, but Bland-Altman analysis showed relatively wide limits of agreement (-12.1 to 11.4). CMR LVEF reclassified 26 (21%) patients compared to RNV LVEF (kappa = 0.58). LVEF by both modalities showed good interobserver reproducibility (ICC 0.96 and 0.94, respectively) (limits of agreement -7.27 to 5.75 and -8.63 to 6.34, respectively). CONCLUSION: Although LVEF measurements by CMR and RNV show moderate agreement, there is frequent reclassification of patients for ICD placement based on LVEF between these modalities. Future studies should determine if a particular imaging modality for LVEF measurement may enhance ICD decision making and treatment benefit.

Zone 2 Arch Replacement and Staged Thoracic Endovascular Aortic Repair for Acute Type A Aortic Dissection.

Potential benefits of extending the distal extent of repair for acute type A aortic dissection beyond hemiarch has prompted the exploration of various total arch repair approaches. A zone 2 arch is advocated by some surgeons but the nomenclature and technique have not been described.

Early Results of the PETTICOAT Technique for the Management of Acute Type A Aortic Dissection.

Conventional surgical techniques for acute Type A aortic dissection (ATAAD) generally fail to address residual dissection in the descending aorta. The persistence of a false lumen is associated with visceral malperfusion in the acute setting and adverse aortic remodeling in the chronic setting. Hybrid aortic arch repair techniques may improve perioperative and long-term mortality by expanding the true lumen and obliterating the false lumen. However, there is a limit to the extent of aortic coverage due to the concomitant risk of spinal cord ischemia. In Type B dissection, the PETTICOAT (Provisional Extension To Induce Complete Attachment) technique, which entails stent graft coverage of the primary intimal tear followed by bare metal stent placement distally, may improve true lumen caliber and promote false lumen thrombosis without increasing the risk of spinal cord ischemia, as intercostal branches remain perfused through the bare metal stents. The technique of hybrid arch with surgical creation of a Dacron landing zone covering a stent graft in the proximal descending aorta and bare metal stents in the thoraco-abdominal aorta is a promising concept in the treatment of ATAAD.

Ventricular pacing site separation by cardiac computed tomography: validation for the prediction of clinical response to cardiac resynchronization therapy.

Cardiac Resynchronization Therapy (CRT) fails to provide benefit in up to one-third of patients. Maximizing the geographic separation of right and left ventricular pacing lead sites has been suggested as one way to improve response. Cardiac CT provides an opportunity to explore 3-dimensional inter-lead distance (ILD) measures for the prediction of CRT response. The objective of this study was to investigate associations between standardized measures of ILD by cardiac CT and echocardiographic response to CRT. Forty-two consecutive patients undergoing CRT had serial clinical and echocardiographic evaluations performed in addition to a post-procedural cardiac-gated CT with blinded measurement of direct and circumferential (via the myocardium) ILD measures. Clinical response to CRT, the primary clinical outcome, was defined as a ≥15% reduction in LVESV using echocardiography at 6-months. The mean age and ejection fraction was 63.6 ± 8.9 years and 25.2 ± 7.8%, respectively. The primary outcome occurred in 35 of 42 patients (83%). Both direct and circumferential CT-based ILD measures were associated with the primary outcome by univariate analysis. Receiver Operator Characteristic analysis identified Circumferential ILD to have the strongest predictive accuracy (AUC 0.78). Inter- and intra-observer reproducibility of CT-derived ILD measures was excellent. Circumferential ILD measures on cardiac CT are predictive of clinical response to CRT. Incorporation of these measures into the selection of optimal pacing targets, particularly from pre-procedural CT coronary vein imaging may be of therapeutic benefit and warrants further investigation.

Complications at the Proximal Landing Zone of Endovascular Stent Grafts Deployed in Surgically Replaced Ascending Aorta.

BACKGROUND: The ascending aorta, with its hostile angulations and forces, is the next frontier in the evolution of endovascular surgery. Type II hybrid arch repair, involving surgical replacement of the ascending aorta, arch debranching, and stent graft deployment in the ascending aortic graft, offers an opportunity to study the behavior of an endovascular prosthesis in the ascending aorta. We report complications seen at the proximal landing zone after type II hybrid arch repair. METHODS: A dedicated imaging protocol was used to monitor 20 consecutive patients who underwent type II hybrid arch repair at a single center from June 2009 to July 2014. RESULTS: Mean age was 66 years (range, 47 to 82 years). Mean imaging follow-up was 34 months (range, 12 to 64 months). There was 1 operative death (5%). Bird beaking (>5 mm of nonapposition) of the stent graft at the proximal landing zone occurred in 12 patients, and >20 mm of bird beaking occurred in 7 patients. Proximal landing zone complications occurred in 4 patients (20%), comprising 2 type Ia endoleaks, 1 graft migration, and 1 graft infolding detected on postoperative days 4, 11, 5, and 755, respectively. Three patients underwent endovascular reintervention for proximal landing zone complications. There were no late deaths. CONCLUSIONS: Thoracic aortic stent grafts may be prone to proximal landing zone complications when deployed in the ascending aorta. Bird beaking is common when endografts are deployed in the Dacron (DuPont, Wilmington, DE) ascending aorta. Angulation issues will likely need to be overcome by stent graft refinement to enable future closed chest approaches to the ascending aorta.

Relationship between different blood pressure measurements and left ventricular mass by cardiac magnetic resonance imaging in end-stage renal disease.

Hypertension is prevalent in patients with end-stage renal disease and is strongly associated with left ventricular hypertrophy (LVH), an independent predictor of cardiovascular mortality. Blood pressure (BP) monitoring in hemodialysis patients may be unreliable because of its lability and variability. We compared different methods of BP measurement and their relationship with LVH on cardiac magnetic resonance imaging. Sixty patients undergoing chronic hemodialysis at a single dialysis center had BP recorded at each dialysis session over 12 weeks: pre-dialysis, initial dialysis, nadir during dialysis, and post-dialysis. Forty-five of these patients also underwent 44-hour inter-dialytic ambulatory BP monitoring. Left ventricular mass index (LVMI) was measured using cardiac magnetic resonance imaging and the presence of LVH was ascertained. Receiver operator characteristic curves were generated for each BP measurement for predicting LVH. The mean LVMI was 68 g/m(2) (SD = 15 g/m(2)); 13/60 patients (22%) had LVH. Mean arterial pressure measured shortly after initiation of dialysis session was most strongly correlated with LVMI (Pearson correlation coefficient r = 0.59, P < .0001). LVH was best predicted by post-dialysis systolic BP (area under the curve, 0.83; 95% confidence interval, 0.72-0.94) and initial dialysis systolic BP (area under the curve, 0.81; 95% confidence interval, 0.70-0.92). Forty-four-hour ambulatory BP and BP variability did not significantly predict LVH. Initial dialysis mean arterial pressure and systolic BP and post-dialysis systolic BP are the strongest predictors of LVH, and may represent the potentially best treatment targets in hemodialysis patients to prevent end-organ damage. Further studies are needed to confirm whether treatment targeting these BP measurements can optimize cardiovascular outcomes.

Congenital gluteus maximus contracture syndrome--a case report with review of imaging findings.

Although the clinical features of gluteus maximus contracture syndrome have been frequently described, imaging features have been seldom described. Most commonly reported cases are those following intramuscular injection in the gluteal region although congenital contracture is an uncommon but important occurrence. This condition has most often been reported in children of school going age. These patients often present with difficulty in squatting, limitation of hip motion or specific deformities and often require surgical correction. We describe the plain radiography, ultrasonography (USG) and magnetic resonance imaging (MRI) features of this condition in a patient with no previous known history of intramuscular injections.