Acute aortic dissection (AAD) - a lethal disease: the epidemiology, pathophysiology and natural history.

Aortic dissection is a life-threatening condition that is often under-recognised. In the first in a series of articles about the condition, the epidemiology, pathology, classification and clinical presentation of aortic dissection are discussed.

Redo aortic valve replacement versus valve-in-valve trans-catheter aortic valve implantation: a UK propensity-matched analysis.

This study sought to compare the morbidity and mortality of redo aortic valve replacement (redo-AVR) versus valve-in-valve trans-catheter aortic valve implantation (valve-in-valve TAVI) for patients with a failing bioprosthetic valve. A multicenter UK retrospective study of redo-AVR or valve-in-valve TAVI for patients referred for redo aortic valve intervention due to a degenerated aortic bioprosthesis. Propensity score matching was performed for confounding factors. From July 2005 to April 2021, 911 patients underwent redo-AVR and 411 patients underwent valve-in-valve TAVI. There were 125 pairs for analysis after propensity score matching. The mean age was 75.2±8.5 years. In-hospital mortality was 7.2% (n=9) for redo-AVR versus 0 for valve-in-valve TAVI, p=0.002. Surgical patients suffered more post-operative complications, including intra-aortic balloon pump support (p=0.02), early re-operation (p<0.001), arrhythmias (p<0.001), respiratory and neurological complications (p=0.02 and p=0.03) and multi-organ failure (p=0.01). The valve-in-valve TAVI group had a shorter intensive care unit and hospital stay (p<0.001 for both). However, moderate aortic regurgitation at discharge and higher post-procedural gradients were more common after valve-in-valve TAVI (p<0.001 for both). Survival probabilities in patients who were successfully discharged from the hospital were similar after valve-in-valve TAVI and redo-AVR over the 6-year follow-up (log-rank p=0.26). In elderly patients with a degenerated aortic bioprosthesis, valve-in-valve TAVI provides better early outcomes as opposed to redo-AVR, although there was no difference in mid-term survival in patients successfully discharged from the hospital.

A human model of bilateral pulmonary vein sampling to assess the effects of one-lung ventilation on neutrophil function.

BACKGROUND: Neutrophil activation drives lung complications after cardiopulmonary bypass (CPB). Evidence suggests the healthy, ventilated lung may beneficially re-condition pro-inflammatory neutrophils. However, evidence in humans is lacking, due to a paucity of good models. CPB with simultaneous central venous and bilateral pulmonary vein sampling provides an opportunity to model effects of one-lung ventilation. The study's primary objectives were to establish a model of intra-operative, bilateral pulmonary vein sampling and to determine whether neutrophil function differed after passing through inflated or deflated lungs. METHODS: Seventeen patients having "on pump" coronary artery bypass grafting (CABG) with one-lung ventilation (in two cohorts with tidal volume 2ml kg-1 and FiO2 0.21, or tidal volume 4 ml kg-1 and FiO2 0.5 respectively) were recruited. Cohort 1 consisted of 9 patients (7 male, median age 62.0 years) and Cohort 2 consisted of 8 male patients (median age 65.5 years). Recruitment was via prospective screening of scheduled elective and non-elective CABG procedures with cardiopulmonary bypass. Each patient had five blood samples taken-central venous blood pre-operatively; central venous blood pre-CPB; central venous blood post-CPB; pulmonary venous blood draining the ventilated lung post-CPB; and pulmonary venous blood draining the deflated lung post-CPB. Neutrophil phagocytosis and priming status were quantified. Plasma cytokines were measured. RESULTS: Phagocytosis and priming were not significantly different in neutrophils returning from the ventilated lung as compared to the non-ventilated lung. Plasma IL-6, IL-8 and IL-10 were significantly elevated by CPB. CONCLUSIONS: The intra-operative, bilateral pulmonary vein sampling model provides unique opportunities to assess biological effects of interventions to one lung, with the other lung acting as an internal control. Single-lung ventilation during CPB had no significant effects on neutrophil function.

Using an Endovascular Strategy in the Open Setting: The Challenges of Hybrid Repair Using Frozen Elephant Trunk in an Extensively Dilated Aorta Associated with Coarctation.

With both stenosis and aneurysm, repairing a severely tortuous and coarcted aorta can present certain difficulties. The advent of hybrid arch frozen elephant trunk techniques, as well as other endovascular solutions, has produced safer surgical repair methods for such cases. We present the reconstruction and repair of a Type-1 thoracoabdominal aortic aneurysm using a staged approach in less-than-optimal anatomy. Interventions included hybrid frozen elephant trunk, balloon dilation, and thoracic endovascular repair.

Surgical aortic valve replacement in the era of transcatheter aortic valve implantation: a review of the UK national database.

OBJECTIVES: To date the reported outcomes of surgical aortic valve replacement (SAVR) are mainly in the settings of trials comparing it with evolving transcatheter aortic valve implantation. We set out to examine characteristics and outcomes in people who underwent SAVR reflecting a national cohort and therefore 'real-world' practice. DESIGN: Retrospective analysis of prospectively collected data of consecutive people who underwent SAVR with or without coronary artery bypass graft (CABG) surgery between April 2013 and March 2018 in the UK. This included elective, urgent and emergency operations. Participants' demographics, preoperative risk factors, operative data, in-hospital mortality, postoperative complications and effect of the addition of CABG to SAVR were analysed. SETTING: 27 (90%) tertiary cardiac surgical centres in the UK submitted their data for analysis. PARTICIPANTS: 31 277 people with AVR were identified. 19 670 (62.9%) had only SAVR and 11 607 (37.1%) had AVR+CABG. RESULTS: In-hospital mortality for isolated SAVR was 1.9% (95% CI 1.6% to 2.1%) and was 2.4% for AVR+CABG. Mortality by age category for SAVR only were: <60 years=2.0%, 60-75 years=1.5%, >75 years=2.2%. For SAVR+CABG these were; 2.2%, 1.8% and 3.1%. For different categories of EuroSCORE, mortality for SAVR in low risk people was 1.3%, in intermediate risk 1% and for high risk 3.9%. 74.3% of the operations were elective, 24% urgent and 1.7% emergency/salvage. The incidences of resternotomy for bleeding and stroke were 3.9% and 1.1%, respectively. Multivariable analyses provided no evidence that concomitant CABG influenced outcome. However, urgency of the operation, poor ventricular function, higher EuroSCORE and longer cross clamp and cardiopulmonary bypass times adversely affected outcomes. CONCLUSIONS: Surgical SAVR±CABG has low mortality risk and a low level of complications in the UK in people of all ages and risk factors. These results should inform consideration of treatment options in people with aortic valve disease.

Dissecting the Management and Outcomes of Thoracic Aortovascular Disease During the COVID-19 Pandemic.

OBJECTIVE: The COVID-19 pandemic has forced the cancellation of planned surgery and led to significant surgical service reductions. Early intervention in aortovascular disease is often critical and cannot be deferred despite these reductions. There is urgent need to evaluate the provision and outcomes of thoracic aortovascular intervention during the peak of the pandemic. METHODS: Prospective data was collected for patients receiving open and endovascular thoracic aortovascular intervention over two-time points; January-May 2020 and January-May 2019 at three tertiary cardiovascular centres. Baseline demographics, cardiovascular risk and COVID-19 screening results were noted. Primary outcomes were median length of intensive care unit and hospital stay, intra-operative mortality, 30-day mortality, post-operative stroke, and spinal cord injury. RESULTS: Patients operated in 2020 (41) had significantly higher median EuroSCORE II than 2019 (53) (7.44 vs. 5.86, P = 0.032) and rates of previous cardiac (19.5% vs. 3.8%, P = 0.019), aortic (14.6% vs. 1.9%, P = 0.041), and endovascular (22.0% vs. 3.8%, P = 0.009) intervention. There was an increase in proportion of urgent cases in 2020 (31.7% vs. 18.9%). There were no intra-operative deaths in 2020 and 1 in 2019 (P = 1.00). There were no significant differences (P ≥ 0.05) in 30-day mortality (4.9% vs. 13.2%), median intensive care unit length of stay (72 vs. 70 hr), median hospital length of stay (8 vs. 9 days), post-operative stroke (3 vs. 6), or spinal cord injury (2 vs. 1) between 2020 and 2019 respectively. CONCLUSIONS: Despite the increased mortality risk of patients and urgency of cases during COVID-19, complicated by the introduction of cohorting and screening regimens, thoracic aortovascular intervention remained safe with comparable in outcomes to pre-COVID-19.

Heart transplantation in the UK during the first wave of the SARS-CoV-2 pandemic.

BACKGROUND: We aim to evaluate practice and understand the impact of the first wave of the SARS-CoV-2 pandemic on heart transplantation in the UK. METHODS: A retrospective review of the UK Transplant Registry (UKTR) and a national survey of UK heart transplant centers have been performed. The early pandemic period is defined here as 1 March to 31 May 2020. RESULTS: There was geographic variation in the prevalence of COVID-19 across the UK. All centers reported adaptations to maintain the safety of their staff, candidate, and recipient populations. The number of donors fell by 31% during the early pandemic period. Heart utilization increased to 35%, compared to 26% during the same period of 2019. The number of heart transplants was well maintained, across all centers, with 38 performed, compared to 41 during the same period of 2019, with no change in 30-day survival. Twenty-seven heart transplant recipients with confirmed COVID-19 infection were reported during the study period. CONCLUSION: All UK heart transplant centers have successfully adapted their programs to overcome the challenges of staff redeployment and ICU and hospital resource limitation, associated with the pandemic, whilst continuing heart transplant activity. On-going evaluation of practice changes, with sharing of lessons learned, is required as the pandemic continues.

The impact of the SARS-CoV-2 pandemic and COVID-19 on lung transplantation in the UK: Lessons learned from the first wave.

BACKGROUND: Lung transplantation is particularly susceptible to the impact of the severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) pandemic, and evaluation of changes to practice is required to inform future decision-making. METHODS: A retrospective review of the UK Transplant Registry (UKTR) and national survey of UK lung transplant centers has been performed. RESULTS: There was geographic variation in the prevalence of COVID-19 infection across the UK. The number of donors fell by 48% during the early pandemic period. Lung utilization fell to 10% (compared with 24% for the same period of 2019). The number of lung transplants performed fell by 77% from 53, March to May 2019, to 12. Seven (58%) of these were performed in a single-center, designated "COVID-light." The number of patients who died on the lung transplant waiting list increased, compared to the same period of 2019 (p = .0118). Twenty-six lung transplant recipients with confirmed COVID-19 infection were reported during the study period. CONCLUSION: As the pandemic continues, reviewing practice and implementing the lessons learned during this period, including the use of robust donor testing strategies and the provision of "COVID-light" hospitals, are vital in ensuring the safe continuation of our lung transplant program.

Type A aortic dissection: Why there is still a role for echocardiography when every second counts.

Aortic dissection is often regarded as a catastrophic aortic syndrome with high rates of mortality. The sensitivity and specificity of transthoracic echocardiography when diagnosing acute type A aortic dissection has been reported as high as 97% and 100%, respectively, in patients with optimal imaging quality when compared to computed tomography. In this article, we discuss the benefit of transthoracic echocardiography in a patient with type A aortic dissection extending from ascending aorta to iliac arteries.

Neutrophil to Lymphocyte Ratio Is Related to Thrombotic Complications and Survival in Continuous Flow Left Ventricular Assist Devices.

Left ventricular assist devices (LVADs) have become an established treatment for advanced heart failure, although with long-term support these patients are potentially exposed to serious complications. Our purpose was to assess the role of the neutrophil to lymphocyte ratio (NLR) in LVAD complications and to evaluate if higher values of NLR after 4-6 months on LVAD support (NLR 4_6m) are associated with worse prognosis. All consecutive patients who received a HeartWare LVAD (N = 188, age 50 ± 13 years), as bridge to transplant from December 2009 to January 2018 were included. Neutrophil to lymphocyte ratio was recorded pre-LVAD, post-LVAD, after 4-6 months on support and in case of a first adverse event to occur after the 4-6 months NLR was recorded. Median NLR values were pre-LVAD 4.26 (interquartile range [IQR], 3.1-6.9), at 1 day postoperative 11.6 (IQR, 8.3-16.6), and NLR 4_6m 4.4 (IQR, 3.0-6.4) (p < 0.001). Neutrophil to lymphocyte ratio increased significantly when patients had an infection, stroke, or pump thrombosis, as compared with the NLR 4_6m (all p < 0.05). Patients with NLR 4_6m ≥ median had higher rates of stroke and mortality. Survival time was shorter among patients with NLR 4_6m ≥ 4.4 (log-rank test p = 0.006). Neutrophil to lymphocyte ratio 4_6m was found to be predictive of increased mortality (area under the curve of 0.62, p = 0.007). After multivariate analysis, NLR 4_6m remained independently associated with increased mortality (hazard ratio [HR] 1.67; 95% confidence interval [CI], 1.03-2.7; p = 0.037). Neutrophil to lymphocyte ratio 4_6m values significantly increase in association with adverse events on LVAD support and are independently associated with mortality. This association suggests presence of inflammation adversely affects LVAD outcomes.

Initial conservative management strategy of HeartWare left ventricular assist device thrombosis with intravenous heparin or bivalirudin.

INTRODUCTION AND OBJECTIVES: Pump thrombosis is a serious left ventricular assist device complication, though there are no guidelines regarding its treatment. The main aim of this study was to describe a strategy of intravenous anticoagulation as the initial treatment in these patients and then to compare intravenous heparin with bivalirudin. METHODS: All consecutive patients who received a HeartWare left ventricular assist device from July 2009 to March 2019 were retrospectively analysed. Patients developing a pump thrombosis were selected, and treatment, outcomes and complications were recorded. RESULTS: During this period of time (116 months), 220 patients underwent HeartWare left ventricular assist device implantation and 57 developed pump thrombosis, with an incidence rate of first pump thrombosis of 0.17 events per patient-year of support (incidence rate of all episodes of pump thrombosis: 0.30 events per patient-year of support). All the patients were initially treated medically, predominantly with either intravenous heparin (n = 26) or bivalirudin (n = 16). Patients treated with bivalirudin during the first pump thrombosis episode had less subsequent re-thrombosis episodes (18.7% vs 57.7%, p < 0.05). In addition, percentage time in therapeutic range was greater for bivalirudin compared with heparin (68.5% ± 16.9% vs 37.4% ± 31.0%, p < 0.01). During the first pump thrombosis episode, 26.3% of the patients needed surgery (left ventricular assist device exchange (n = 8), transplant (n = 6) or decommissioning (n = 1)). The overall survival at 1 year was 61.4%, and there was no significant difference in survival. CONCLUSION: Left ventricular assist device thrombosis is a serious life-threatening complication; hence, we propose an initial conservative management of pump thrombosis with enhanced intravenous anticoagulation with either intravenous heparin or bivalirudin, with surgery reserved for refractory cases.

Impact of donor variables on heart transplantation outcomes in mechanically bridged versus standard recipients†.

OBJECTIVES: This study aimed to quantify the impact of donor variables on post-heart transplantation mortality and morbidity in recipients with and without a pretransplant left ventricular assist device (LVAD). METHODS: This is a prospective cohort study of the ISHLT Transplant Registry that includes all primary heart transplants in adult recipients (January 2005-June 2013, n = 15 532). All recipients were divided into patients with a durable continuous-flow LVAD (LVAD recipient, n = 3315) and without mechanical support (standard recipient, n = 12 217). Donors were classified as high risk (n = 3751) and low risk (n = 11 781). Transplants were categorized into low-risk donor/standard recipient (n = 9214), high-risk donor/standard recipient (n = 3003), low-risk donor/LVAD recipient (n = 2567) and high-risk donor/LVAD recipient (n = 748). Outcomes prior to discharge, survival at 5 years and freedom from complications were computed for each group. RESULTS: LVAD recipients experienced more episodes of infection, stroke and acute rejection with both low- (P < 0.001, P < 0.001, P < 0.001) and high-risk donors (P < 0.001, P = 0.008, P = 0.028) prior to transplant discharge. Within standard recipients, a higher rate of primary graft failure (P = 0.035), infection (P = 0.001), dialysis (P = 0.012), acute rejection (P = 0.037) and less freedom from cardiac allograft vasculopathy (P < 0.001) and malignancy (P = 0.004) was observed with high-risk donors. Within LVAD recipients, no differences in complications prior to discharge or long-term morbidity were detected between low- and high-risk donors. When compared to standard recipient/low-risk donors, all the 3 remaining categories had an increased probability of death or graft failure within 90 days: LVAD recipient/low-risk donor [hazard ratio (HR) 1.26, confidence interval (CI) 1.05-1.51; P = 0.012], standard recipient/high-risk donor (HR 1.47, CI 1.27-1.71; P < 0.001) and LVAD recipient/high-risk donor (HR 1.72, CI 1.32-2.24; P < 0.001). Between 90 days and 5 years, only standard recipient/high-risk donor had an increased probability of death or graft failure (HR 1.140, CI 1.020-1.274; P = 0.021) when compared to standard recipient/low-risk donor. CONCLUSIONS: LVAD recipients, whether with high- or low-risk donors, have worse early (but not late) survival and more early complications than those of standard recipients. We found that adverse donor characteristics are less predictive for determining the outcome of LVAD-bridged recipients than standard recipients.

Donor and recipient risk factor analysis of inferior postheart transplantation outcome in the era of durable mechanical assist devices.

The study objective is to quantify the impact of donor and recipient variables on heart transplant survival in recipients with a significant proportion of implanted continuous-flow left ventricular assist devices (LVADs). This is a prospective cohort study of International Society for Heart and Lung Transplantation (ISHLT) Registry that includes all primary heart-alone transplants in adult recipients (January 2005 and June 2013, N = 15 532, 27% LVADs). Donor and recipient characteristics were assessed for association with death or graft failure within 90 days and between 90 days and 5 years after transplantation. On Cox proportional hazard model donor cause of death other than head trauma (hazard ratio [HR] 1.985, P < 0.0001), recipient congenital (HR 2.7555, P < 0.0001) and ischemic (HR 1.165, P = 0.0383) vs dilated etiology and female donor heart transplanted into male recipient (HR 1.207, P = 0.0354) were predictors of death or graft failure within 90 days. Between 90 days and 5 years, donor cigarette use (HR 1.232, P = 0.0001), recipient cigarette use (HR 1.193, P = 0.0003), diabetes (HR 1.159, P = 0.0050), arterial hypertension (HR 1.129, P = 0.0115), and ischemic vs dilative cardiomyopathy had an increased probability of death or graft failure.

Training cardiothoracic surgeons of the future: The UK experience.

OBJECTIVE: The study aimed to assess targeted simulation courses, including live animal operating, as complementary training tools with regard to 2 key surgical skills in early cardiothoracic surgeon training. METHODS: Twenty UK surgical trainees (equivalent to cardiothoracic surgery resident physicians in the United States) in their first year of residency training were evaluated. Assessment of skills in pulmonary wedge resection and cardiopulmonary bypass were undertaken before and after 2 boot camp-style courses, including live animal operating (boot camp 1 and boot camp 2). Resident performance was evaluated by surgical trainers using objective structured assessment of technical skills matrices. Trainers completed a survey on skill development and trainer confidence in the trainee precourse and postcourse. RESULTS: Trainee assessment scores pre- and postcourses were analyzed using a 2-tailed Wilcoxon signed-rank test demonstrating a significant improvement in trainee performance in boot camp 1 in performing cardiopulmonary bypass (median score, 21 precourse and 28 postcourse; P = .001) and pulmonary wedge resection (median score, 25 precourse and 32 postcourse; P = .012), and in boot camp 2, in performing cardiopulmonary bypass (median score, 28 precourse and 30.5 postcourse; P = .018) and pulmonary wedge resection (median score, 31.5 precourse and 37 postcourse; P = .018). Trainers reported increased confidence and decision-making competency of residents and increased confidence of trainers to allow more participation in management. It was found that 83.3% of trainers would support trainee attendance in subsequent years. CONCLUSIONS: Live animal operating as a component of targeted cardiothoracic surgery skill training courses significantly improves technical skills, builds confidence of surgical trainers in resident physicians' practice, and should be supported by the surgery community.

Novel Management of Atrial Septal Defect at Time of Lung Transplantation.

We present a case of a young female patient with end-stage lung failure because of pulmonary arterial hypertension who was failing maximal medical therapy and was listed for a single sequential lung transplantation. The challenge of the case was a concomitant presence of a large atrial septal defect. The novelty of our approach was a device closure of atrial septal defect before performing transplantation with the use of intraoperative venoarterial extracorporeal membrane oxygenation.

Descending aortic aneurysm in Wiskott-Aldrich syndrome: options for repair.

We report open surgical repair of a previously stented descending thoracic aneurysm in a patient with Wiskott-Aldrich syndrome and a platelet count <10 × 109·L-1. The same patient was described previously in a report of the first endovascular stent in this form of vasculitis. We describe the pre- and intraoperative management, and suggest a change in strategy in this setting.