Type A Aortic Dissection in Heart Transplantation Recipients in the United States.

BACKGROUND: Type A aortic dissection in heart transplantation recipients is rare and lethal, with limited research beyond case reports. This study aimed to analyze patient characteristics and clinical outcomes of this condition through a US national database. METHODS: The National Inpatient Sample database (2002-2018) was used to identify all type A aortic dissection in heart transplantation recipients aged >18 years. Incidence was quantified annually. Primary outcomes were in-hospital mortality; secondary outcomes were hospital length of stay and complications. RESULTS: We identified 78 cases of type A aortic dissection in heart transplantation recipients. Compared with type A aortic dissection patients without a history of solid organ transplantation (N = 70,715), our patients were younger (55.3 vs 60.7 years), less likely female (18.5% vs 33.5%), and more frequently Black or Hispanic (55% vs 23%). They had a greater prevalence of Marfan syndrome (13% vs 3%), congestive heart failure (46% vs 19%), and chronic kidney disease (19% vs 10%), as well as increased in-hospital mortality (30% vs 18%) and a longer hospital length of stay (29.5 vs 13.7 days). They experienced elevated rates of cardiac (57% vs 31%), respiratory (70. % vs 41%), renal (76% vs 30%), and bleeding complications (37% vs 14%). CONCLUSIONS: Type A aortic dissection in heart transplantation recipients appears to exhibit distinct characteristics and poorer outcomes compared with those in the general population. Heart transplantation recipients with predisposing risk factors warrant heightened attention to help prevent this devastating condition.

Management of penetrating cardiac injury and tricuspid regurgitation with extracorporeal-membrane oxygenation (ECMO): a case report.

BACKGROUND: Gunshot wounds (GSW) to the heart are lethal, and most patients die before they arrive to the hospital. Survival decreases with number of cardiac chambers involved. We report a case of a 17-year-old male who survived a GSW injury involving two cardiac chambers with acute severe tricuspid regurgitation (TR) who subsequently developed cardiogenic shock requiring extracorporeal membrane oxygenation (ECMO) support. CASE PRESENTATION: A 17-year-old male sustained a single gunshot wound to the left chest, resulting in pericardial tamponade and right hemothorax. Emergency sternotomy revealed injury to the right ventricle and inferior cavoatrial junction with the adjacent pericardium contributing to a right hemothorax. The cardiac injuries were repaired primarily. Tricuspid regurgitation was confirmed immediately postoperatively. Five days after presentation, the patient developed cardiogenic shock secondary to TR requiring emergent stabilization with ECMO. He subsequently underwent successful tricuspid valve replacement. CONCLUSIONS: This is the first report to our knowledge of successful ECMO support of severe TR due to gunshot injury to the heart.

Pericardial Adipose Tissue Thrombospondin-1 Associates With Antiangiogenesis in Ischemic Heart Disease.

Accumulation of ectopic pericardial adipose tissue has been associated with cardiovascular complications which, in part, may relate to adipose-derived factors that regulate vascular responses and angiogenesis. We sought to characterize adipose tissue microvascular angiogenic capacity in subjects who underwent elective cardiac surgeries including aortic, valvular, and coronary artery bypass grafting. Pericardial adipose tissue was collected intraoperatively and examined for angiogenic capacity. Capillary sprouting was significantly blunted (twofold, p <0.001) in subjects with coronary artery disease (CAD) (age 60 ± 9 years, body mass index [BMI] 32 ± 4 kg/m2, low-density lipoprotein cholesterol [LDL-C] 95 ± 46 mg/100 ml, n = 29) compared with age-, BMI-, and LDL-C matched subjects without angiographic obstructive CAD (age 59 ± 10 y, BMI 35 ± 9 kg/m2, LDL-C 101 ± 40 mg/100 ml, n = 12). For potential mechanistic insight, we performed mRNA expression analyses using quantitative real-time polymerase chain reaction and observed no significant differences in pericardial fat gene expression of proangiogenic mediators vascular endothelial growth factor-A (VEGF-A), fibroblast growth factor-2 (FGF-2), and angiopoietin-1 (angpt1), or anti-angiogenic factors soluble fms-like tyrosine kinase-1 (sFlt-1) and endostatin. In contrast, mRNA expression of anti-angiogenic thrombospondin-1 (TSP-1) was significantly upregulated (twofold, p = 0.008) in CAD compared with non-CAD subjects, which was confirmed by protein western-immunoblot analysis. TSP-1 gene knockdown using short hairpin RNA lentiviral delivery significantly improved angiogenic deficiency in CAD (p <0.05). In conclusion, pericardial fat in subjects with CAD may be associated with an antiangiogenic profile linked to functional defects in vascularization capacity. Local paracrine actions of TSP-1 in adipose depots surrounding the heart may play a role in mechanisms of ischemic heart disease.

Sex-based outcomes in surgical repair of acute type A aortic dissection: A meta-analysis and meta-regression.

OBJECTIVE: Epidemiologic variation with respect to sex has been established in aortic dissection. However, current literature on sex-based outcomes in patients with aortic dissection is conflicting. In this study we aimed to compare perioperative outcomes according to sex in patients treated surgically for acute type A aortic dissection. METHODS: PubMed/MEDLINE, Embase, and Web of Science were searched for studies that reported sex-based differences in postoperative outcomes among patients with acute type A aortic dissection. The primary outcome was in-hospital/30-day mortality, and secondary outcomes included postoperative stroke, renal failure requiring dialysis, and reoperation for bleeding. Data were aggregated using the random effects model as pooled risk ratio (RR). Meta-regression was applied to identify sources of heterogeneity between studies. RESULTS: Nine of 1022 studies were included for final analysis comprising 3338 female and 5979 male participants. Compared with male sex, female sex was associated with similar in-hospital/30-day mortality (RR, 1.04; 95% CI, 0.85-1.28; P = .67), postoperative stroke risk (RR, 1.07; 95% CI, 0.91-1.25; P = .43), and postoperative risk of acute renal failure requiring dialysis (RR, 0.84; 95% CI, 0.59-1.19; P = .32). A decreased risk of reoperation for bleeding (RR, 0.84; 95% CI, 0.75-0.94; P < .01) was observed in female participants. Meta-regression analysis indicated that differences in preoperative shock were a source of heterogeneity in the sex difference in in-hospital/30-day mortality across studies. CONCLUSIONS: Among patients treated surgically for acute type A aortic dissection, female sex was not associated with increased risk of short-term mortality nor with major postoperative complications. Male sex was associated with a greater risk of postoperative bleeding.

Aortic Dissection During Pregnancy and Puerperium: Contemporary Incidence and Outcomes in the United States.

Background Aortic dissection (AD) during pregnancy and puerperium is a rare catastrophe with devastating consequences for both parent and fetus. Population-level incidence trends and outcomes remain relatively undetermined. Methods and Results We queried a US population-based health care database, the National Inpatient Sample, and identified all patients with a pregnancy-related AD hospitalization from 2002 to 2017. In total, 472 pregnancy-related AD hospitalizations (mean age, 30.9±0.6 years) were identified from 68 514 000 pregnancy-related hospitalizations (0.69 per 100 000 pregnancy-related hospitalizations), with 107 (22.7%) being type A and 365 (77.3%) being type B. The incidence of AD appeared to increase over the 16-year study period but was not statistically significant (P for trend >0.05). Marfan syndrome, primary hypertension, and preeclampsia/eclampsia were found in 21.9%, 14.4%, and 11.5%, respectively. On multivariable logistic regression analysis, Marfan syndrome was associated with the highest risk of developing AD during pregnancy and puerperium (adjusted odds ratio, 3469.36 [95% CI, 1767.84-6831.75]; P<0.001). The in-hospital mortalities of AD, type A AD, and type B AD were 7.3%, 4.3%, and 8.1%, respectively. Length of hospital stay for the AD, type A AD, and type B AD groups were 7.7±0.8, 10.4±1.9, and 6.9±0.9 days, respectively. Conclusions We quantified population-level incidence and in-hospital mortality in the United States and observed an increase in the incidence of pregnancy-related AD. In contrast, its in-hospital mortality appears lower than that of non-pregnancy-related AD.

Association of Intravenous Drug Use and Length of Stay Following Infective Endocarditis.

INTRODUCTION: Intravenous drug use (IVDU) and associated infective endocarditis (IE) has been on the rise in the US since the beginning of the opioid epidemic. IVDU-IE has high morbidity and mortality, and treatment can be lengthy. We aim to quantify the association between IVDU and length of stay (LOS) in IE patients. METHODS: The National Inpatient Sample database was used to identify IE patients, which was then stratified into IVDU-IE and non-IVDU-IE groups. Weighted values of hospitalizations were used to generate national estimates. Multivariable linear and logistic regression analyses were applied to estimate the effects of IVDU on LOS. RESULTS: We identified 1,114,257 adult IE patients, among which 123,409 (11.1%) were IVDU-IE. Compared to non-IVDU-IE patients, IVDU-IE patients were younger, had fewer comorbidities, and had an overall longer LOS (median [interquartile range]: 10 [5-20] versus 7 [4-13] d, P < 0.001), with a greater percentage of patients with a LOS longer than 30 d (13.7% versus 5.7%, P < 0.001). After adjusting for multiple demographic and clinical factors, IVDU was independently associated with a 1.25-d increase in LOS (beta-coefficient = 1.25, 95% confidence interval [CI]: 0.95-1.54, P < 0.001) and 35% higher odds of being hospitalized for more than 30 d (odds ratio = 1.35, 95% CI: 1.27-1.44, P < 0.001). CONCLUSIONS: Among IE patients, being IVDU has associated with a longer LOS and a higher risk of prolonged hospital stay. Steps toward the prevention of IE in the IVDU population should be taken to avoid an undue burden on the healthcare system.

Changes in treatment patterns of thoracoabdominal aortic aneurysms in the United States.

Background: The introduction of endovascular repair provides an alternative to traditional open repair of thoracoabdominal aortic aneurysms (TAAA). Its utility is not well defined, however. Using a national database, we studied the treatment patterns and outcomes of TAAA to gain insight into its contemporary surgical practice in the United States. Methods: Records of TAAA patients who received endovascular and open repair were retrieved from the 2002 to 2018 National Inpatient Sample database. Each cohort was stratified into 4 age groups: ≤50, 51 to 60, 61 to 70, and >70 years. Patient characteristics and in-hospital outcomes were compared between the 2 repair modalities. Temporal trends were investigated. Results: Endovascular repair use increased steadily, whereas open repair volume remained stable until 2012, before declining by 50% by 2018. This appears to be associated with a declining number of open repairs in patients age >60 years. Patients who underwent endovascular repair were older and had a higher Charlson Comorbidity Index (mean, 2.8 ± 1.7 vs 2.5 ± 1.5; P < .001) but lower in-hospital mortality (mean, 8.9% vs 17.1%; P < .001), shorter length of stay (mean, 10.1 ± 12.2 days vs 17.1 ± 17.4 days; P < .001), and fewer postoperative complications. A difference in mortality between open and endovascular repair was observed for patients age >60 years but not for patients age ≤60 years. Conclusions: There has been a shift in the treatment of TAAA in the United States from open repair-dominant to endovascular repair-dominant. It has increased surgical access for older and more comorbid patients and has led to a decline in the use of open repair while lowering in-hospital mortality.

Surgical outcomes of pulmonary valve infective endocarditis: A US population-based analysis.

BACKGROUND: Pulmonary valve infective endocarditis (PVIE) represents a rare subset of right-sided IE. This study aimed to evaluate the population-level surgical outcomes of PVIE in the United States. METHODS: We performed a retrospective observational study using the 2002-2017 National Inpatient Sample database. We included hospitalizations with both IE and PV interventions. We excluded Tetralogy of Fallot, congenital PV malformation, and those who underwent the Ross procedure. The primary outcome was in-hospital mortality. The secondary outcomes included major complications and length of hospital stay. RESULTS: We identified 677 PVIE hospitalizations that underwent surgical treatment, accounting for 0.06% of all IE hospitalizations. The mean age was 35.2 ± 1.7 years; 60.0% were White, 30.3% were women, and 11.4% were intravenous drug users. Most were treated in large-sized (70.1%) urban teaching (88.8%) hospitals. Close to 30% of patients received at least one concomitant valve procedure. The in-hospital mortality was 5.5% for the entire cohort, and the median length of stay was 16 days. Major complications included complete heart block (8.7%), acute kidney injury (8.1%), and stroke (1.3%). The differences in mortality and complications rate comparing PV repair and replacement were not statistically significant. PV repair was associated with a longer length of hospital stay compared to PV replacement (median: 25 vs. 16 days, p = 0.03). CONCLUSIONS: This study defines the population-level in-hospital outcomes after surgical intervention of PVIE. Surgically treated PVIE patients are associated with relatively low mortality and morbidities. The outcomes between PV replacement and repair are similar.

Primary cardiac lymphoma.

OBJECTIVE: This study aimed to understand the population-level treatment modalities and to evaluate the survival benefits of surgical resection in primary cardiac lymphoma. METHODS: We queried the Surveillance, Epidemiology, and End Results Program database, which covers 35% of the US population. Patients with a histologic diagnosis of primary cardiac lymphoma from 1973 to 2015 were included. Multivariable accelerated failure time regression was performed to evaluate the associations between clinical factors and overall survival. RESULTS: A total of 184 patients were identified. The median age was 68 years, 80% were White, and 46% were women. Diffuse large B-cell lymphoma (80%) was the most common histology, and the majority (65%) was low-stage lymphoma (Ann Arbor stage I or II). Median survival was 2.2 years. Seventy-three percent of patients received chemotherapy. Only 10% of patients received local resection or debulking. Multivariable analysis demonstrated that local resection or debulking was not independently associated with overall survival (adjusted hazard ratio, 0.67; 95% confidence interval, 0.30-1.48; P = .32). Instead, chemotherapy (adjusted hazard ratio, 0.4; 95% confidence interval, 0.23-0.69; P < .001) was independently associated with improved survival, whereas increasing age (adjusted hazard ratio of 5-year increment, 1.13; 95% confidence interval, 1.04-1.22; P <.001) and advanced stage (adjusted hazard ratio, 2.18; 95% confidence interval, 1.33-3.56; P < .001) were independently associated with worse survival. CONCLUSIONS: Surgical resection was not independently associated with survival in patients with primary cardiac lymphoma. Chemotherapy was the predominant treatment option and associated with improved survival, whereas increasing age and advanced stage were independently associated with worse outcomes.

Primary Pericardial Mesothelioma: A Population-Based Propensity Score-Matched Analysis.

Primary pericardial mesothelioma is a rare malignancy of the mesothelial lining of the pericardium. This study aimed to evaluate the clinical characteristics and survival outcomes of these patients using a United States population-based cancer database. We queried the Surveillance, Epidemiology, and End Results program (1973-2015). Primary pericardial mesothelioma patients with complete follow-up data were included, and primary pleural mesothelioma patients were identified as controls. Propensity-score matching was used to balance individual characteristics. Kaplan-Meier analysis and log-rank tests were performed to compare overall survival. Forty-one primary pericardial mesothelioma and 15,970 primary pleural mesothelioma patients were identified. Before matching, when compared to the pleural mesothelioma counterparts, primary pericardial mesothelioma patients were younger (median 57 vs 73 years, P < 0.001), more likely to be female (46.3% vs 20.2%, P < 0.001), more likely to be nonwhite (24.4% vs 8.4%, P = 0.001), and less likely to have been diagnosed in the most recent study decade (2006-2015, 34.1% vs 43.5%, P = 0.002). The overall 1- and 2-year survival rates were 22.0% and 12.2%, with a median survival of 2 months (IQR: 1-6). After 1:2 nearest neighbor propensity-score matching, 38 pericardial mesothelioma and 76 matched pleural mesothelioma cases were identified. The 2 matched groups had comparable baseline characteristics, including age, sex, race, year of diagnosis, histological type, and cancer history. Compared to their pleural mesothelioma counterparts, primary pericardial mesothelioma patients were less likely to receive chemotherapy (23.7% vs 50.0%, P = 0.01) and had worse overall survival (median survival: 2 vs 10 months, log-rank P = 0.006). Primary pericardial mesothelioma has worse survival outcomes than pleural mesothelioma, with a median survival of only 2 months. These patients should seek care from experienced multidisciplinary teams at tertiary care centers that handle high volumes of mesothelioma patients.

Liver Dysfunction Associated With In-Hospital Mortality in Adult Extracorporeal Membrane Oxygenation Support.

Extracorporeal membrane oxygenator support is a powerful clinical tool that is currently enjoying a resurgence in popularity. Wider use of extracorporeal membrane oxygenator support is limited by its significant risk profile and extreme consumption of resources. This study examines the role of markers of liver dysfunction in predicting outcomes of adult patients requiring extracorporeal membrane oxygenator support. DESIGN: Retrospective review. SETTING: Large extracorporeal membrane oxygenator center, Chicago, IL. PATIENTS: This study reports a single institution experience examining all adult patients for whom extracorporeal membrane oxygenator support was used over an 8-year period. Data were collected regarding patient demographics, details of extracorporeal membrane oxygenator support provided, laboratory data, and outcomes. Trends in liver function were examined for their ability to predict survival. INTERVENTION: Extracorporeal membrane oxygenator support, critical care. MEASUREMENTS AND MAIN RESULTS: Mean age was 50 years (range, 19-82 yr). There were 86 male patients (56.6%) and 66 female patients (43.4%). Indications for initiation of extracorporeal membrane oxygenator support included cardiac 76 patients (50.0%), respiratory 48 patients (31.6%), extracorporeal cardiopulmonary resuscitation 21 patients (13.3%), and combined cardiac/respiratory seven patients (4.6%). Mean duration of extracorporeal membrane oxygenator support was 17 days (range 1-223 d) or median 8 days (interquartile range, 4-17 d). Overall, in-hospital mortality was 56% (86/152). Forty-five percent of adult patients (68/152) surpassed at least one of the following established liver dysfunction thresholds: total bilirubin greater than 15 mg/dL, aspartate aminotransferase greater than 20× upper limit of normal, and alanine aminotransferase greater than 20× upper limit of normal. The multivariable logistic analysis yielded three significant findings associated with in-hospital mortality: highest total bilirubin greater than 15 (adjusted odds ratio = 4.40; 95% CI, 1.19-21.87; p = 0.04), age (adjusted odds ratio = 1.03; 95% CI, 1.00-1.05; p = 0.04), and highest lactate (adjusted odds ratio = 1.15; 95% CI, 1.06-1.26; p = 0.002). CONCLUSIONS: Increases in age, highest total bilirubin, and lactate all correlated with in-hospital mortality in multivariable analysis of patients requiring extracorporeal membrane oxygenator support.

Traumatic thoracic rib cage and chest wall hernias: A review and discussion of management principles.

Traumatic thoracic or chest wall hernias are relatively uncommon but highly challenging injuries that can be seen after a variety of injury mechanisms. Despite their description throughout history there remains scant literature on this topic that is primarily limited to case reports or series. Until recently, there also has been no effort to create a reliable grading system that can assess severity, predict outcomes, and guide the choice of surgical repair. The purpose of this article is to review the reported literature on this topic and to analyze the history, common injury mechanisms, likely presentations, and optimal management strategies to guide clinicians who are faced with these challenging cases. We also report a modified and updated version of our previously developed grading system for traumatic chest wall hernias that can be utilized to guide surgical management techniques and approaches.

Extracorporeal membrane oxygenation in the management of granulomatosis with polyangiitis.

Granulomatosis with polyangiitis (GPA, also known as Wegener's granulomatosis) is a type of systematic vasculitis that primarily involves the lung and kidney. Diffuse alveolar hemorrhage (DAH) and associated acute respiratory failure are uncommon but devastating complications of GPA. Experience in using extracorporeal membrane oxygenation (ECMO) to manage DAH caused by GPA is limited. We report two GPA patients with DAH that were successfully managed using ECMO support. Examining 13 cases identified in the literature and two of our own, we observed that most patients experienced rapid deterioration in respiratory function in conjunction with a precedent respiratory infection. All 15 patients received veno-venous ECMO support. The median duration of ECMO support was 11 days (interquartile range: 7.5-20.75 days). Bleeding was the most common complication, seen in four (26.7%) cases. All patients were successfully weaned off ECMO after a median length of hospital stay of 42 days (interquartile range: 30-78 days). We demonstrated that the use of ECMO is a reasonable and effective support option in the management of GPA patients with DAH. The risk of bleeding is high but maybe reduced using a lower anticoagulation goal.

Aortoventricular Dissociation and Refractory Fungal Endocarditis Caused by a Rare Pathogen Lichtheimia: A Surgical and Medical Management Strategy.

We report a rare case of prosthetic valve fungal endocarditis caused by Lichtheimia, a subspecies of the order Mucorales. The patient experienced complicated prosthetic valve endocarditis less than 2 months after uneventful coronary artery bypass grafting (CABG) and 2 aortic valve replacements. Ultimately surgical management required aortic root replacement and lifelong antimicrobial agents. We believe this is the first case of fungal endocarditis caused by Lichtheimia.

Acuity adaptable patient care unit system shortens length of stay and improves outcomes in adult cardiac surgery: University of Wisconsin experience.

OBJECTIVES: The Acuity Adaptable Patient Care (AAC) unit system allows all beds within a nursing unit to negate the need for transfer with changes in patient status. The unit is specialty specific to all levels of patient care. This system was implemented in March 2006 for cardiothoracic surgery at our institution. The purpose of this study was to evaluate the impact of the AAC system on the outcomes after adult cardiac surgery. METHODS: We retrospectively reviewed 2930 consecutive patients who underwent major adult cardiac procedures between January 2003 and December 2010. The cohorts were divided into the pre-AAC group (January 2003 to February 2006, n = 1029) and the AAC group (March 2006 to December 2010, n = 1901). Patient demographics and postoperative outcomes were assessed. RESULTS: The proportion of coronary artery bypass grafting was significantly lower (pre-AAC vs AAC: 43 vs 35%, P < 0.01), while those of aortic procedure (4 vs 11%, P < 0.01) and mechanical assist device insertion (3 vs 5%, P = 0.02) were higher in the AAC group. After the implementation of the AAC system, the incidence of all complications defined by the Society of Thoracic Surgeons (STS) database (49 vs 34%, P < 0.01), the median length of intensive care unit (ICU) stay (49 [interquartile range (IQR), 27-99] vs 26 [19-45] h, P < 0.01), that of hospital stay (6 [4-10] vs 5 [4-7] days, P < 0.01) and the readmission rate of ICU (5 vs 2% P < 0.01) were significantly decreased. Significant reductions in hospital mortality and the rate of hospital readmission <30 days were not observed. CONCLUSIONS: The implementation of the AAC system has improved the outcomes after major cardiac procedures. The incidence of postoperative complications and length of stay have all decreased significantly without increasing readmission rate. AAC creates a system of fluid care with specialty-trained nursing and other ancillary support that expedites discharge and improves overall patient outcomes.

Patient preferences for coronary artery bypass graft surgery or percutaneous intervention in multivessel coronary artery disease.

OBJECTIVES: Determine if patients prefer multivessel percutaneous coronary intervention (mv-PCI) over coronary artery bypass graft surgery (CABG) for treatment of symptomatic multivessel coronary artery disease (mv-CAD) despite high 1-year risk. BACKGROUND: Patient risk perception and preference for CABG or mv-PCI to treat medically refractory mv-CAD are poorly understood. We hypothesize that patients prefer mv-PCI instead of CABG even when quoted high mv-PCI risk. METHODS: 585 patients and 31 physicians were presented standardized questionnaires with a hypothetical scenario describing chest pain and medically refractory mv-CAD. CABG or mv-PCI was presented as treatment options. Risk scenarios included variable 1-year risks of death, stroke, and repeat procedures for mv-PCI and fixed risks for CABG. Participants indicated their preference of revascularization method based on the presented risks. We calculated the odds that patients or physicians would favor mv-PCI over CABG across a range of quoted risks of death, stroke, and repeat procedures. RESULTS: For nearly all quoted risks, patients preferred mv-PCI over CABG, even when the risk of death was double the risk with CABG or the risk of repeat procedures was more than three times that for CABG (P < 0.0001). Compared to patients, physicians chose mv-PCI less often than CABG as the risk of death and repeat procedures increased (P < 0.001 and P = 0.004, respectively). CONCLUSION: Patients favor mv-PCI over CABG to treat mv-CAD, even if 1-year risks of death and repeat procedures far exceed risk with CABG. Physicians are more influenced by actual risk and prefer mv-PCI less than patients despite similarly quoted 1-year risks.

Delayed selective cerebral hypothermia decreases infarct volume after reperfused stroke in baboons.

BACKGROUND: Hypothermia is known to provide neuroprotection from focal ischemia. However, lethal cardiovascular complications resulting from total body cooling have greatly restricted hypothermia as a therapy for stroke. This study determined whether selective cerebral cooling induced after reversible cerebral artery occlusion would decrease the infarct volume. METHODS: Under general anesthesia, 8 baboons were subjected to 1-hour simultaneous occlusion of the left internal carotid artery and anterior cerebral arteries by transorbital surgical approach. Four animals were treated with selective cerebral hypothermia to 25°C, initiated 2.5 hours after placement of cerebral artery clips. Selective cerebral hypothermia was achieved, after heparinization, by continuous withdrawal of femoral arterial blood into an extracorporeal closed-circuit pump system, cooling by water bath and perfusion into the right internal carotid artery. Pump flow was adjusted to maintain right internal carotid artery pressure near systemic blood pressure. Cerebral cortical temperature was maintained below 27°C for 12 hours, whereas systemic temperature was preserved near normal by convective air mattresses and warm water blankets. Four control animals were maintained at 36°C. Blood pressure, pH, and blood gases were maintained at normal values for both groups. Forty-eight to 72 hours after cerebral artery occlusion, magnetic resonance imaging brain scans were obtained and infarct volume measured. RESULTS: Normothermic baboons had infarction of 35.4±4.4% (mean±SD) of the left cerebral hemisphere compared with 0.5±1% for baboons treated with cerebral hypothermia (P<0.01). In brain-cooled animals, esophageal temperature was maintained greater than 34°C, despite cerebral temperature less than 27°C. CONCLUSION: Selective brain cooling initiated 2.5 hours after onset of focal ischemia resulted in marked reduction in infarct volume, without cardiovascular derangement.

Transapical mitral valved stent implantation: a survival series in swine.

OBJECTIVE: To assess short-term survival after transcatheter mitral valve replacement using a unique mitral valved stent design and anchoring system. METHODS: The new nitinol self-expandable valved stent houses a trileaflet glutaraldehyde-preserved bioprosthesis and contains atrial and ventricular fixation systems. Eight pigs underwent transesophageal echocardiogram-guided transapical mitral valved stent implantation through a lower mini-sternotomy. Intracardiac pressure gradients were estimated by transesophageal echocardiogram. RESULTS: The mean mitral annulus size was 24.6 +/- 1.4 mm, and the valved stent size was 26.0 +/- 2.6 mm. The average mean transvalvular gradient across the valved stent immediately after deployment, at 6 hours, and after 1 week remained low. The gradient across the neighboring left ventricular outflow tract was not affected. Average animal survival was 7.3 days (8 hours to 29 days). Animals that died before 1 week (n = 4) were found at necropsy to have valved stent malpositioning. Animals that survived 1 week or more had accurate deployment and only trace post-deployment paravalvular leak. The causes of death in this latter group were endocarditis (n = 1), failure of atrial fixation (n = 2), and failure of ventricular fixation (n = 1). There was no valved stent embolization in any of the animals. CONCLUSION: Adequate function and effective anchoring of the new mitral valved stent allowed for short-term animal survival after transapical mitral valved stent implantation.

The potential of cardiac allografts from donors after cardiac death at the University of Wisconsin Organ Procurement Organization.

OBJECTIVE: The purpose of this study is to investigate the potential availability of hearts from adult donation after cardiac death (DCD) donors within an acceptable hypoxic period. METHODS: We retrospectively reviewed a donor database from the University of Wisconsin Organ Procurement Organization Donor Tracking System between 2004 and 2006. The DCD population (n=78) was screened using our inclusion criteria for DCD cardiac donor suitability, including warm ischaemic time (WIT) limit of 30 min. In the same period, 70 hearts were donated from brain-dead donors. RESULTS: Of 78 DCD donors, 12 (15%) met our proposed DCD cardiac donor criteria. The mean WIT of these 12 DCD donors was 21 min (range 14-29 min). When inclusion criteria are further narrowed to (1) age <30 years, (2) WIT <20 min and (3) male gender, only two out of 12 met the criteria. CONCLUSIONS: Based on our proposed DCD cardiac donor criteria, the potential application of DCD cardiac donors would represent an increase in cardiac donation of 17% (12/70) during the 3-year period. When the criteria were narrowed to the initial 'ideal' case, only two donors met such criteria, suggesting that such 'ideal' DCD donors are rare but they do exist.