Peri-operative assessment of right heart function: role of echocardiography.

The right heart contributes significantly to overall cardiac function. Right ventricular (RV) haemodynamics and function have been defined to be physiologically different from the left ventricle, and yet independently associated with outcomes in a spectrum of conditions. In particular, RV function has been shown to influence prognosis of patients undergoing surgery. The assessment of right heart function during the intra-operative and immediate postoperative periods plays an important role in the clinical management of patients having surgery. While a number of techniques are available for the assessment of the right heart intra-operatively, echocardiography remains the prime choice being least invasive, relatively safe, readily accessible and cost-effective. Advancements in the field of echocardiographic have improved ability to assess right heart function. This review examines the role echocardiography and advances in this imaging modality in the assessment of right heart function within the peri-operative setting.

Implantation of short-term biventricular assist device (BiVAD) using the CentriMag™ system: the Manchester technique.

Biventricular assist devices (BiVADs) using the CentriMag™ system are being used increasingly as a form of short-term mechanical circulatory support for the treatment of acute cardiogenic shock from any aetiology. They can be used as a bridge to decision, recovery or transplantation. BiVADs are associated with better clinical outcomes when compared to veno-arterial (VA) extracorporeal membrane oxygenator (ECMO) systems. In this paper, we describe a safe and reproducible method of BiVAD implantation using the CentriMag™ system at our institution.

A national pilot of donation after circulatory death (DCD) heart transplantation within the United Kingdom.

BACKGROUND: The United Kingdom (UK) was one of the first countries to pioneer heart transplantation from donation after circulatory death (DCD) donors. To facilitate equity of access to DCD hearts by all UK heart transplant centers and expand the retrieval zone nationwide, a Joint Innovation Fund (JIF) pilot was provided by NHS Blood and Transplant (NHSBT) and NHS England (NHSE). The activity and outcomes of this national DCD heart pilot program are reported. METHODS: This is a national multi-center, retrospective cohort study examining early outcomes of DCD heart transplants performed across 7 heart transplant centers, adult and pediatric, throughout the UK. Hearts were retrieved using the direct procurement and perfusion (DPP) technique by 3 specialist retrieval teams trained in ex-situ normothermic machine perfusion. Outcomes were compared against DCD heart transplants before the national pilot era and against contemporaneous donation after brain death (DBD) heart transplants, and analyzed using Kaplan-Meier analysis, chi-square test, and Wilcoxon's rank-sum. RESULTS: From September 7, 2020 to February 28, 2022, 215 potential DCD hearts were offered of which 98 (46%) were accepted and attended. There were 77 potential donors (36%) which proceeded to death within 2 hours, with 57 (27%) donor hearts successfully retrieved and perfused ex situ and 50 (23%) DCD hearts going on to be transplanted. During this same period, 179 DBD hearts were transplanted. Overall, there was no difference in the 30-day survival rate between DCD and DBD (94% vs 93%) or 90 day survival (90% vs 90%) respectively. There was a higher rate of ECMO use post-DCD heart transplants compared to DBD (40% vs 16%, p = 0.0006), and DCD hearts in the pre pilot era, (17%, p = 0.002). There was no difference in length of ICU stay (9 DCD vs 8 days DBD, p = 0.13) nor hospital stay (28 DCD vs 27 DBD days, p = 0.46). CONCLUSION: During this pilot study, 3 specialist retrieval teams were able to retrieve DCD hearts nationally for all 7 UK heart transplant centers. DCD donors increased overall heart transplantation in the UK by 28% with equivalent early posttransplant survival compared with DBD donors.

Traversing the Learning Curve Associated with a New Minimal Access Aortic Valve Replacement Service.

OBJECTIVE: Isolated aortic valve replacement is a safe and frequently performed cardiac surgical procedure. Although minimal access approaches including right anterior thoracotomy and partial sternotomy have been adopted by some surgeons in recent years, concerns about additional procedural morbidity and mortality during the early phase of the learning curve persist. The aim of this study was to assess the impact of the learning curve on outcomes for a single surgeon implementing a new minimal access aortic valve replacement service. METHODS: Ninety-three patients undergoing minimal access aortic valve replacement performed by a single surgeon in our institution between October 2014 and March 2019 were analysed. Patients were divided into tertiles according to procedure order. Endpoints included peri-operative mortality and post-operative complications, and these were compared across tertiles to assess the impact of the learning curve on procedural outcomes. RESULTS: Overall in-hospital mortality was 2.15% (n=2). Despite significantly longer cardiopulmonary bypass and cross-clamp duration in the early tertile, there was no significant difference in the rate of post-operative complications, post-operative length of stay or in-hospital mortality between tertiles. CONCLUSIONS: Although our results have demonstrated a significant learning curve effect associated with the introduction of this minimally invasive approach to aortic valve replacement, as demonstrated by the significant reduction in cardiopulmonary bypass and cross-clamp duration over time, our findings suggest that a minimal access aortic valve replacement service can be safely commenced by an experienced surgeon without concerns about the learning curve significantly affecting post-operative morbidity and mortality.

Financial implications of using extracorporeal membrane oxygenation following heart transplantation.

OBJECTIVES: Primary graft dysfunction after heart transplant is associated with high morbidity and mortality. Extracorporeal membrane oxygenation (ECMO) can be used to wean patients from cardiopulmonary bypass. This study retrospectively reviews a single-centre experience of post-transplant ECMO in regard to outcomes and associated costs. METHODS: Between May 2006 and May 2019, a total of 267 adult heart transplants were performed. We compared donor and recipient variables, ECMO duration and the incidence of renal failure, bleeding, infection and cost analysis between ECMO and non-ECMO groups. RESULTS: ECMO support was required postoperatively to manage primary graft dysfunction in 72 (27%) patients. The mean duration of ECMO support was 6 ± 3.2 days. Mean ischaemic times were similar between the groups. There was a significantly higher proportion of ventricular assist device explant to transplant in the ECMO group versus non-ECMO (38.2% vs 14.1%; P < 0.0001). ECMO patients had a longer duration of stay in the intensive care unit (P < 0.0001) and total hospital stay (P < 0.0001). Greater mortality was observed in the ECMO group (P < 0.0001). The median cost of providing ECMO was £18 000 [interquartile range (IQR): £12 750-£24 000] per patient with an additional median £35 225 (IQR: £21 487.25-£51 780.75) for ITU stay whilst on ECMO. The total median cost per patient inclusive of hospital stay, ECMO and dialysis costs was £65 737.50 (IQR: £52 566.50-£95 221.75) in the non-ECMO group compared to £145 415.71 (IQR: £102 523.21-£200 618.96) per patient in the ECMO group (P < 0.0001). CONCLUSIONS: Patients with primary graft dysfunction following heart transplantation who require ECMO are frequently bridged to a recovery; however, the medium and longer-term survival for these patients is poorer than for patients who do not require ECMO.

Outcome of CentriMag™ extracorporeal mechanical circulatory support use in critical cardiogenic shock (INTERMACS 1) patients.

Purpose: Prognosis of patients presenting with INTERMACS 1 critical cardiogenic shock is generally poor. The aim of our study was to investigate the results of CentriMag™ extracorporeal short-term mechanical circulatory support as a bridge to decision in patients presenting with critical cardiogenic shock in our unit. Methods: We retrospectively analysed 63 consecutive patients from January 2005 to June 2017, who were treated with a CentriMag™ device at our institution as a bridge to decision. Patients requiring extracorporeal support for post-cardiotomy shock and for primary graft dysfunction after heart transplantation were excluded. Results: Patients' median age was 44 years (IQR 31-52, range 15.4-62.0) and 42 (67%) were male. Primary diagnosis at presentation was ischaemic cardiomyopathy (n = 24; 38.1%), viral myocarditis (n = 19; 30.2%), idiopathic dilated cardiomyopathy (n = 8; 12.7%), and others (n = 12; 19%). The median duration of support was 25 (IQR 9.5-56) days. A total of 7 (11%) patients were supported with peripheral veno-arterial (VA) extra corporeal membrane oxygenation (ECMO), 6 (9%) with central VA ECMO, 8 (13%) with left ventricular assist device (LVAD), 17 (27%) with biventricular assist device (BiVAD), and 25 (40%) with ECMO and then converted to BiVAD. Overall, 22 (34.9%) patients died while on CentriMag™ mechanical circulatory support. Complications included bleeding requiring reoperation/intervention in 24 (38%), renal failure requiring dialysis in 29 (46%), bacterial infections in 23 (37%), fungal infections in 15 (24%), critical limb ischaemia in 6 (10%), and stroke in 8 (13%). The overall survival to successful explant from CentriMag™ was 65.1% (n = 41) and survival to hospital discharge was 58.7% (n = 37). Of these, 10 (16%) had cardiac recovery and were successfully explanted, 20 (32%) were bridged to heart transplantation, 11 (17%) were bridged to long-term left ventricular assist device, 3 (4.7%) were later on transplanted, and 1 (1.6%) recovered to decommissioning. The 1-, 5-, and 10-year survival rates were 55%, 46%, and 23% respectively. Conclusion: Our results demonstrate an excellent outcome with the use of the CentriMag™ device in this seriously ill population. Despite requiring multiple procedures, over 58% of patients were discharged from hospital with 5-year survival of 46%.

Establishing a heart transplant programme using donation after circulatory-determined death donors: a United Kingdom based single-centre experience.

OBJECTIVES: Demand for heart transplant donors worldwide continues to outstrip supply. Transplanting hearts following donation after circulatory-determined death (DCD) is increasingly recognized as a safe and effective alternative. As the fourth centre worldwide to have established such a programme, our goal was to present our initial experience. METHODS: This was a single-centre retrospective observational study. All DCD hearts were retrieved using direct procurement and perfusion. Continuous normothermic perfusion of the procured heart was then established on the TransMedics® Organ Care System. The primary outcome of this study was the 30-day survival rate. RESULTS: Between May 2017 and December 2018, 8 DCD hearts were procured and 7 were subsequently implanted, including in 2 patients who had left ventricular assist devices explanted. During the same time period, 30 patients received donation after brainstem death heart transplants. Therefore, the DCD heart transplant programme led to a 23% increase in transplant activity. The median donation warm ischaemic time was 34 min [interquartile range (IQR) 31-39 min]. The median functional warm ischaemic time was 28 min (IQR 25-30 min). The median time spent by the organ on the Organ Care System was 263 min (IQR 242-296 min). The overall 30-day survival rate was 100% and the 90-day survival rate was 86%. Postoperative extracorporeal membrane oxygenation was required in 3/7 (43%). CONCLUSIONS: DCD heart transplants can lead to a 23% increase in heart transplant activity and should be adopted by more institutions across the world. Already established transplant programmes with good early outcomes can start such a programme safely.

Traversing the Learning Curve Associated with a New Minimal Access Aortic Valve Replacement Service

Abstract Objective: Isolated aortic valve replacement is a safe and frequently performed cardiac surgical procedure. Although minimal access approaches including right anterior thoracotomy and partial sternotomy have been adopted by some surgeons in recent years, concerns about additional procedural morbidity and mortality during the early phase of the learning curve persist. The aim of this study was to assess the impact of the learning curve on outcomes for a single surgeon implementing a new minimal access aortic valve replacement service. Methods: Ninety-three patients undergoing minimal access aortic valve replacement performed by a single surgeon in our institution between October 2014 and March 2019 were analysed. Patients were divided into tertiles according to procedure order. Endpoints included peri-operative mortality and post-operative complications, and these were compared across tertiles to assess the impact of the learning curve on procedural outcomes. Results: Overall in-hospital mortality was 2.15% (n=2). Despite significantly longer cardiopulmonary bypass and cross-clamp duration in the early tertile, there was no significant difference in the rate of post-operative complications, post-operative length of stay or in-hospital mortality between tertiles. Conclusions: Although our results have demonstrated a significant learning curve effect associated with the introduction of this minimally invasive approach to aortic valve replacement, as demonstrated by the significant reduction in cardiopulmonary bypass and cross-clamp duration over time, our findings suggest that a minimal access aortic valve replacement service can be safely commenced by an experienced surgeon without concerns about the learning curve significantly affecting post-operative morbidity and mortality.

Three-Dimensional Field Optimization Method: Clinical Validation of a Novel Color Doppler Method for Quantifying Mitral Regurgitation.

BACKGROUND: Assessment of mitral regurgitation (MR) severity by echocardiography is important for clinical decision making, but MR severity can be challenging to quantitate accurately and reproducibly. The accuracy of effective regurgitant orifice area (EROA) and regurgitant volume (RVol) calculated using two-dimensional (2D) proximal isovelocity surface area is limited by the geometric assumptions of proximal isovelocity surface area shape, and both variables demonstrate interobserver variability. The aim of this study was to compare a novel automated three-dimensional (3D) echocardiographic method for calculating MR regurgitant flow using standard 2D techniques. METHODS: A sheep model of ischemic MR and patients with MR were prospectively examined. Patients with a range of severity of MR were examined. EROA and RVol were calculated from 3D color Doppler acquisitions using a novel computer-automated algorithm based on the field optimization method to measure EROA and RVol. For an independent comparison group, the 3D field optimization method was compared with 2D methods for grading MR in an experimental ovine model of MR. RESULTS: Fifteen 3D data sets from nine sheep (open-chest transthoracic echocardiographic data sets) and 33 transesophageal data sets from patients with MR were prospectively examined. For sheep data sets, mean 2D EROA was 0.16 ± 0.05 cm2, and mean 2D RVol was 21.84 ± 8.03 mL. Mean 3D EROA was 0.09 ± 0.04 cm2, and mean 3D RVol was 14.40 ± 5.79 cm3. There was good correlation between 2D and 3D EROA (R = 0.70) and RVol (R = 0.80). For patient data sets, mean 2D EROA was 0.35 ± 0.35 cm2, and mean 2D RVol was 58.9 ± 52.9 mL. Mean 3D EROA was 0.34 ± 0.29 cm2, and mean 3D RVol was 54.6 ± 36.5 mL. There was excellent correlation between 2D and 3D EROA (R = 0.94) and RVol (R = 0.84). Bland-Altman analysis revealed greater interobserver variability for 2D RVol measurements compared with 3D RVol using the 3D field optimization method measurements, but variability was statistically significant only for RVol. CONCLUSIONS: Direct automated measurement of proximal isovelocity surface area region for EROA calculation using real-time 3D color Doppler echocardiography is feasible, with a high correlation to current 2D EROA methods but less variability. This novel automated method provides an accurate and highly reproducible method for calculating EROA.

Study of arrhythmia prevalence in NUVANT Mobile Cardiac Telemetry system patients.

The Corventis NUVANT™ Mobile Cardiac Telemetry system is an innovative solution in the field of continuous monitoring of symptomatic and asymptomatic cardiac abnormalities to help physicians diagnose and treat non-lethal cardiac arrhythmias. As an FDA cleared product on the market for more than 2 years, the collected body of patient data represents a unique and powerful source of clinical information. Analysis of a sample of 951 NUVANT patients has revealed interesting statistics on the prevalence of various cardiac arrhythmias in the patient population. The population is non-randomized and largely consists of US patients where a traditional Holter Monitor study was negative. The analysis here is focused on classifying the detected arrhythmias using potential therapy solutions as a classifier. Across the total population, 2.2% of patients presented arrhythmias indicating assessment for clinically significant tachycardia, 19% indications of potential bradycardia, 20% had indications of atrial fibrillation, 1% indicating arrhythmias requiring other conditional treatment, and 58% presenting arrhythmias likely not requiring treatment.

Sudden cardiac death under anesthesia in pediatric patient with Williams syndrome: a case report and review of literature.

Williams syndrome is a complex syndrome characterized by developmental abnormalities, craniofacial dysmorphic features, and cardiac anomalies. Sudden death has been described as a very common complication associated with anesthesia, surgery, and procedures in this population. Anatomical abnormalities associated with the heart pre-dispose these individuals to sudden death. In addition to a sudden and rapid downhill course, lack of response to resuscitation is another significant feature seen in these patients. The authors report a five-year-old male with Williams syndrome, hypothyroidism, and attention deficit hyperactivity disorder. He suffered an anaphylactic reaction during CT imaging with contrast. Resuscitation was unsuccessful. Previous reports regarding the anesthetic management of patients with Williams are reviewed and the potential for sudden death or peri-procedure related cardiac arrest discussed in this report. The authors also review reasons for refractoriness to defined resuscitation guidelines in this patient population.

Preliminary experience with a combination of dexmedetomidine and propofol infusions for diagnostic cardiac catheterization in children.

No specific regimen has been universally accepted as ideal for procedural sedation during cardiac catheterization in infants and children. In this paper, we retrospectively describe our preliminary experience with a continuous infusion of dexmedetomidine and propofol for sedation during cardiac catheterization in children with congenital heart disease. The short-half life of these two drugs creates a potential for easier titration, quicker recovery and less prolonged sedation-related adverse effects. This combination was not only able to limit the dose of either drugs, but was also very stable from cardio-respiratory standpoint. There were no adverse effects noted in our two patients. This initial experience showed that the combination of propofol and dexmedetomidine as a continuous infusion may be a suitable alternative for sedation in spontaneously breathing children undergoing cardiac catheterization.

Anesthesia for the elderly: selected topics.

PURPOSE OF REVIEW: With the graying of the Western population, there is a continuous increase in the proportion of elderly patients undergoing surgical procedures. Geriatric anesthesia is emerging from a 'subspecialty' to the mainstream of today's anesthesia and perioperative care. Much has been written on anesthesia for the elderly, but this review will concentrate on selected topics related to elderly care that represent current unresolved and pertinent issues for the care of the elderly surgical patient. RECENT FINDINGS: Postoperative cognitive dysfunction, cardiac diastolic dysfunction and prophylactic perioperative beta-blockade in the process of major noncardiac surgery are three main topics that have recently attracted great interest in clinical practice and research, and have therefore been chosen as the selected topics for this current review. SUMMARY: Although age is a clear risk factor for postoperative cognitive dysfunction, the association of general anesthesia with cognitive dysfunction is less clear, as is the effect of anesthesia per se or surgery on long-term cognitive dysfunction. Cardiac diastolic dysfunction is a relatively new and evolving concept in anesthesia and perioperative medicine, yet clearly diastolic dysfunction even with a normal ejection fraction may have a significant effect on the perioperative outcome and management of elderly patients. Small, but powerful studies have shown significant outcome benefit with prophylactic perioperative beta-blockade in high-risk patients undergoing major noncardiac surgery. Data from other studies, however, are still conflicting and the final verdict awaits larger scale outcome studies.

Video-assisted thoracic surgery for hemothorax following coronary artery bypass.

A 56-year-old man complained of dyspnea and cough 9 days after coronary artery bypass grafting. Chest radiography showed opacity and left lung collapse. Following removal of clots from the pleural cavity by videothoracoscopy, he recovered without further incident. Video-assisted thoracic surgery is a feasible and safe option in the management of early hemothorax.