Timothy S. Lancaster

Improved survival after heart transplant for failed Fontan patients with preserved ventricular function.

BACKGROUND Patients with a failing Fontan continue to have decreased survival after heart transplant (HT), particularly those with preserved ventricular function (PVF) compared with impaired ventricular function (IVF). In this study we evaluated the effect of institutional changes on post-HT outcomes. METHODS Data were retrospectively collected for all Fontan patients who underwent HT. Mode of failure was defined by the last echocardiogram before HT, with mild or no dysfunction considered PVF and moderate or severe considered IVF. Outcomes were compared between early era (EE, 1995 to 2008) and current era (CE, 2009 to 2014). Management changes in the CE included volume load reduction with aortopulmonary collateral (APC) embolization, advanced cardiothoracic imaging, higher goal donor/recipient weight ratio and aggressive monitoring for post-HT vasoplegia. RESULTS A total of 47 patients were included: 27 in the EE (13 PVF, 14 IVF) and 20 in the CE (12 PVF, 8 IVF). Groups were similar pre-HT, except for more PLE in PVF patients. More patients underwent APC embolization in the CE (80% vs 28%, p < 0.01). There was no difference in donor/recipient weight ratio between eras. There was a trend toward higher primary graft failure for PVF in the EE (77% vs 36%, p = 0.05) but not the CE (42% vs 75%, p = 0.20). Overall, 1-year survival improved in the CE (90%) from the EE (63%) (p = 0.05), mainly due to increased survival for PVF (82 vs 38%, p = 0.04). CONCLUSIONS Post-HT survival for failing Fontan patients has improved, particularly for PVF. In the CE, our Fontan patients had a 1-year post-HT survival similar to other indications.

Improved waitlist and transplant outcomes for pediatric lung transplantation after implementation of the lung allocation score

BACKGROUND Although the lung allocation score (LAS) has not been considered valid for lung allocation to children, several additional policy changes for pediatric lung allocation have been adopted since its implementation. We compared changes in waitlist and transplant outcomes for pediatric and adult lung transplant candidates since LAS implementation. METHODS The United Network for Organ Sharing database was reviewed for all lung transplant listings during the period 1995 to June 2014. Outcomes were analyzed based on date of listing (pre-LAS vs post-LAS) and candidate age at listing (adults >18 years, adolescents 12 to 17 years, children 0 to 11 years). RESULTS Of the 39,962 total listings, 2,096 (5%) were for pediatric candidates. Median waiting time decreased after LAS implementation for all age groups (adults: 379 vs 83 days; adolescents: 414 vs 104 days; children: 211 vs 109 days; p < 0.001). The proportion of candidates reaching transplant increased after LAS (adults: 52.6% vs 71.6%, p < 0.001; adolescents: 40.3% vs 61.6%, p < 0.001; children: 42.4% vs 50.9%, p = 0.014), whereas deaths on the waitlist decreased (adults: 28.0% vs 14.4%, p < 0.001; adolescents: 33.1% vs 20.9%, p < 0.001; children: 32.2% vs 25.0%; p = 0.025), despite more critically ill candidates in all groups. Median recipient survival increased after LAS for adults and children (adults: 5.1 vs 5.5 years, p < 0.001; children: 6.5 vs 7.6 years, p = 0.047), but not for adolescents (3.6 vs 4.3 years, p = 0.295). CONCLUSIONS Improvements in waiting time, mortality and post-transplant survival have occurred in children after LAS implementation. Continued refinement of urgency-based allocation to children and broader sharing of pediatric donor lungs may help to maximize these benefits.

Current approaches to device implantation in pediatric and congenital heart disease patients

The pediatric ventricular assist device (VAD) has recently shown substantial improvements in survival as a bridge to heart transplant for patients with end-stage heart failure. Since that time, its use has become much more frequent. With increasing utilization, additional questions have arisen including patient selection, timing of VAD implantation and device selection. These challenges are amplified by the uniqueness of each patient, the recent abundance of literature surrounding VAD use as well as the technological advancements in the devices themselves. Ideal strategies for device placement must be sought, for not only improved patient care, but also for optimal resource utilization. Here, we review the most relevant literature to highlight some of the challenges facing the heart failure specialist, and any physician, who will care for a child with a VAD.

Minimally invasive surgery for atrial fibrillation.

The surgical treatment of atrial fibrillation (AF) has been revolutionized over the past two decades through surgical innovation and improvements in endoscopic imaging, ablation technology, and surgical instrumentation. These advances have prompted the development of the less complex and less morbid Cox-Maze IV procedure, and have allowed its adaptation to a minimally invasive right mini-thoracotomy approach that can be used in stand-alone AF ablation and in patients undergoing concomitant mitral and tricuspid valve surgery. Other minimally invasive ablation techniques have been developed for stand-alone AF ablation, including video-assisted pulmonary vein isolation, extended left atrial lesion sets, and a hybrid approach. This review will discuss the tools, techniques, and outcomes of minimally invasive surgical procedures currently being practiced for AF ablation.

Topographic mapping of left ventricular regional contractile injury in ischemic mitral regurgitation.

Objective: Restrictive leaflet tethering resulting from regional left ventricular (LV) contractile injury causes ischemic mitral regurgitation (MR). We hypothesized that 3‐dimensional LV topographic mapping by MRI‐based multiparametric strain analysis could characterize the regional contractile injury patterns that differentiate ischemic coronary artery disease patients who have ischemic MR from those who do not. Methods: Magnetic resonance imaging‐based multiparametric strain data were calculated for 15,300 LV grid points in 100 normal volunteers. Strain parameters from ischemic MR (n = 10) and ischemic no‐MR (n = 36) patients were then normalized to this normal human strain database with z score quantification of standard deviation from the normal mean. Mean multiparametric strain z scores were calculated for 18 LV subregions (basilar/mid/apical levels; 6 LV regions). Mean strain z scores for papillary muscle‐related (basilar/mid levels of anterolateral, posterolateral, and posterior) and nonpapillary muscle‐related (all other) subregions were compared between ischemic MR and ischemic no‐MR groups. Results: Across all patients, contractile injury was greater in the papillary muscle‐related regions compared with the nonpapillary regions (P = .007). In the papillary regions, contractile injury was greater in the ischemic MR group compared with the no‐MR group (z scores, 1.91 ± 1.13 vs 1.20 ± 1.01, respectively; P < .001). Strain values in the nonpapillary muscle‐related subregions were not different between the 2 groups (1.31 ± 1.04 vs 1.20 ± 1.03; P = .301). Conclusions: Multiparametric strain analysis demonstrated severe normalized contractile injury in the papillary muscle‐related LV subregions in patients with ischemic MR. The mean degree of normalized injury approached 2 standard deviations and was significantly worse than the levels seen in ischemic no‐MR patients.

Postoperative atrial fibrillation following cardiac surgery: a persistent complication

Abstract Postoperative atrial fibrillation (POAF) is a common, expensive and potentially morbid complication following cardiac surgery. POAF occurs in around 35% of cardiac surgery cases and has a peak incidence on postoperative day 2. Patients who develop POAF incur on average

The Hemodynamic and Atrial Electrophysiologic Consequences of Chronic Left Atrial Volume Overload in a Controllable Canine Model

10 000‐

Tracheal Resection With Carinal Reconstruction for Squamous Cell Carcinoma

20 000 in additional hospital treatment costs, 12‐24 h of prolonged ICU time, and an additional 2 to 5 days in the hospital. POAF has been identified as an independent predictor of numerous adverse outcomes, including a 2‐ to 4‐fold increased risk of stroke, reoperation for bleeding, infection, renal or respiratory failure, cardiac arrest, cerebral complications, need for permanent pacemaker placement, and a 2‐fold increase in all‐cause 30‐day and 6‐month mortality. The pathogenesis of POAF is incompletely understood but likely involves interplay between pre‐existing physiological components and local and systemic inflammation. POAF is associated with numerous risk factors including advanced age, pre‐existing conditions that cause cardiac remodelling and certain non‐cardiovascular conditions. Clinical management of POAF includes both prophylactic and therapeutic measures, although the efficacy of many interventions remains in question. This review provides a comprehensive and up‐to‐date summary of the pathogenesis of POAF, outlines current clinical guidelines for POAF prophylaxis and management, and discusses new avenues for further investigation.

Outcomes and Trends of Ventricular Assist Device Selection in Children with End-Stage Heart Failure.

Objective The purpose of this study was to determine the effects of chronic left atrial volume overload on atrial anatomy, hemodynamics, and electrophysiology using a titratable left ventriculoatrial shunt in a canine model. Methods Canines (n = 16) underwent implantation of a shunt between the left ventricle and the left atrium. Sham animals (n = 8) underwent a median sternotomy without a shunt. Atrial activation times and effective refractory periods were determined using 250‐bipolar epicardial electrodes. Biatrial pressures, systemic pressures, left atrial and left ventricle diameters and volumes, atrial fibrillation inducibility, and durations were recorded at the initial and at 6‐month terminal study. Results Baseline shunt fraction was 46% ± 8%. The left atrial pressure increased from 9.7 ± 3.5 mm Hg to 13.8 ± 4 mm Hg (P < .001). At the terminal study, the left atrial diameter increased from a baseline of 2.9 ± 0.05 cm to 4.1 ± 0.6 cm (P < .001) and left ventricular ejection fraction decreased from 64% ± 1.5% to 54% ± 2.7% (P < .001). Induced atrial fibrillation duration (median, range) was 95 seconds (0‐7200) compared with 0 seconds (0‐40) in the sham group (P = .02). The total activation time was longer in the shunt group compared with the sham group (72 ± 11 ms vs 62 ± 3 ms, P = .003). The right atrial and not left atrial effective refractory periods were shorter in the shunt compared with the sham group (right atrial effective refractory period: 156 ± 11 ms vs 141 ± 11 ms, P = .005; left atrial effective refractory period: 142 ± 23 ms vs 133 ± 11 ms, P = .35). Conclusions This canine model of mitral regurgitation reproduced the mechanical and electrical remodeling seen in clinical mitral regurgitation. Left atrial size increased, with a corresponding decrease in left ventricle systolic function, and an increased atrial activation times, lower effective refractory periods, and increased atrial fibrillation inducibility. This model provides a means to understand the remodeling by which mitral regurgitation causes atrial fibrillation.

Pulmonary Valve Replacement With Small Intestine Submucosa-Extracellular Matrix in a Porcine Model

Surgical resection is the treatment of choice for primary malignancies of the trachea. We present here the rare case of a lifelong nonsmoker with primary squamous cell carcinoma of the trachea, requiring tracheal resection and anterior carinal reconstruction. Patient preparation, surgical technique, and considerations to avoid airway anastomotic complications are discussed.