Patent foramen ovale in carcinoid heart disease: The potential role for and risks of percutaneous closure prior to cardiothoracic surgery.

Neuroendocrine tumours (NETs) are rare but once metastasised, can lead to the release of vasoactive substances into the systemic circulation, and the classical features of carcinoid syndrome (CS) such as flushing and diarrhoea. A consequence of CS is carcinoid heart disease (CHD) which primarily affects the right-sided heart valves and can eventually lead to right heart failure. In this cohort, tricuspid and/or pulmonary valve replacement provides symptomatic relief. A patent foramen ovale (PFO) in patients with CHD can lead to the shunting of oxygen deficient blood to the systemic circulation causing hypoxaemia and reduced exercise tolerance. Additionally, the haemodynamic changes caused by regurgitant right-sided heart valves can increase the patency of a PFO allowing the passage of vasoactive substances to the systemic circulation thereby affecting the left-sided heart valves. We present data on the incidence of PFO in patients referred for surgery at our centre, in which the standard approach is to close the defect at time of cardiothoracic surgery. In addition, we present a series of four cases that highlight how the option of percutaneous PFO closure prior to open valve surgery may reduce haemodynamic instability and open a window of opportunity to enhance preoperative status. Percutaneous PFO closure then acts as a bridge to definitive cardiothoracic surgery, although there are risks in such an approach.

The Role of Transthoracic Echocardiography for Assessment of Mortality in Patients with Carcinoid Heart Disease Undergoing Valve Replacement.

Patients with carcinoid heart disease (CHD) are referred for valve replacement if they have severe symptomatic disease or evidence of right ventricular (RV) failure and an anticipated survival of at least 12 months. Data are lacking, however, on the role of transthoracic echocardiography in predicting outcomes. We carried out a retrospective, single-centre cohort study of patients with a biopsy-confirmed neuroendocrine tumour (NET) and CHD undergoing valve replacement for severe valve disease and symptoms of right heart failure. The aim was to identify factors associated with postoperative mortality, both within one year of surgery and during long-term follow-up. Of 88 patients with NET, 49 were treated surgically (mean age: 64.4 ± 7.6 years; 55% male), of whom 48 had a bioprosthetic tricuspid valve replacement for severe tricuspid regurgitation; 39 patients had a pulmonary valve replacement. Over a median potential follow-up of 96 months (interquartile range: 56-125), there were 37 deaths, with 30-day and one-year mortality of 14% (n = 7) and 39% (n = 19), respectively. A significant relationship between RV size and one-year mortality was observed, with 57% of those with severe RV dilatation dying within a year of surgery, compared to 33% in those with normal RV size (p = 0.039). This difference remained significant in the time-to-event analysis of long-term survival (p = 0.008). RV size was found to reduce significantly with surgery (p < 0.001). Those with persisting RV dilatation (p = 0.007) or worse RV function (p = 0.001) on postoperative echocardiography had significantly shorter long-term survival. In this single-centre retrospective study of patients undergoing surgery for CHD, increasingly severe RV dilatation on preoperative echocardiography predicted adverse outcomes, yielding a doubling of the one-year mortality rate relative to normal RV size. These data support the possibility that early surgery might deliver greater long-term benefits in this patient cohort.

Surgical Correction of Carcinoid Heart Disease Improves Liver Function and 5-Hydroxyindoleacetic Acid Levels.

Introduction: Carcinoid heart disease (CHD) is a consequence of neuroendocrine tumors releasing 5-hydroxytryptamine (5-HT) into the systemic circulation, affecting right heart valves, causing fibrosis, and eventually right heart failure. The aim of this study was to determine the effect of valve-replacement on kidney function, liver function, and 5-hydroxyindoleacetic acid (5-HIAA) levels. Methods: A Retrospective study of 17 patients with CHD who had undergone heart-valve replacement surgery between 2010 and 2019, from the Queen Elizabeth Hospital Birmingham. 5-HIAA levels, liver, and kidney function were measured in addition to hepatic inferior vena cava (IVC) diameter and its relationship to carcinoid symptoms. Results: Eleven patients were male and six were female. At time of surgery, average age was 66.6 ± 8.1 years and average BMI was 25.8 ± 5.5 Kg/cm2. Three out of 17 patients had one valve replaced, 13/17 had two replaced (tricuspid and pulmonary), and 1/17 had three replaced (tricuspid, pulmonary and aortic). There was a 31% average decline in 5-HIAA [799.8 (343.6-1078.0) to 555.3 (275.8-817.9), p = 0.011], a 35% decline in bilirubin [20 (16-29) to 13 (10-19), p = < 0.001], and a 15% reduction in the short and long axes of the IVC after valve-replacement surgery [20.0 (18.0-25.0) and 36.5 (29.0-39.8) to 17.0 (14.5-19.3) and 31.0 (26.5-34.3) respectively, p = < 0.001 and 0.002 respectively]. Conclusion: Valve replacement surgery improves 5-HIAA levels alongside improved liver function and hepatic IVC diameter. These findings are consistent with resolution of congestive hepatopathy, and therefore enhanced clearance of 5-HIAA. This suggests that valve-replacement surgery can indirectly have beneficial outcomes on hepatic function and is also associated with a drop in the circulating levels of tumor derived serotonin.

Assembly Line ICU: what the Long Shops taught us about managing surge capacity for COVID-19.

OBJECTIVES: To safely expand and adapt the normal workings of a large critical care unit in response to the COVID-19 pandemic. METHODS: In April 2020, UK health systems were challenged to expand critical care capacity rapidly during the first wave of the COVID-19 pandemic so that they could accommodate patients with respiratory and multiple organ failure. Here, we describe the preparation and adaptive responses of a large critical care unit to the oncoming burden of disease. Our changes were similar to the revolution in manufacturing brought about by 'Long Shops' of 1853 when Richard Garrett and Sons of Leiston started mass manufacture of traction engines. This innovation broke the whole process into smaller parts and increased productivity. When applied to COVID-19 preparations, an assembly line approach had the advantage that our ICU became easily scalable to manage an influx of additional staff as well as the increase in admissions. Healthcare professionals could be replaced in case of absence and training focused on a smaller number of tasks. RESULTS: Compared with the equivalent period in 2019, the ICU provided 30.9% more patient days (2599 to 3402), 1845 of which were ventilated days (compared with 694 in 2019, 165.8% increase) while time from first referral to ICU admission reduced from 193.8±123.8 min (±SD) to 110.7±76.75 min (±SD). Throughout, ICU maintained adequate capacity and also accepted patients from neighbouring hospitals. This was done by managing an additional 205 doctors (70% increase), 168 nurses who had previously worked in ICU and another 261 nurses deployed from other parts of the hospital (82% increase).Our large tertiary hospital ensured a dedicated non-COVID ICU was staffed and equipped to take regional emergency referrals so that those patients requiring specialist surgery and treatment were treated throughout the COVID-19 pandemic. CONCLUSIONS: We report how the challenge of managing a huge influx of patients and redeployed staff was met by deconstructing ICU care into its constituent parts. Although reported from the largest colocated ICU in the UK, we believe that this offers solutions to ICUs of all sizes and may provide a generalisable model for critical care pandemic surge planning.

Multidisciplinary team management of carcinoid heart disease.

Carcinoid heart disease (CHD) is a consequence of valvular fibrosis triggered by vasoactive substances released from neuroendocrine tumours, classically in those with metastatic disease and resulting in tricuspid and pulmonary valve failure. CHD affects one in five patients who have carcinoid syndrome (CS). Valve leaflets become thickened, retracted and immobile, resulting most often in regurgitation that causes right ventricular dilatation and ultimately, right heart failure. The development of CHD heralds a significantly worse prognosis than those patients with CS who do not develop valvular disease. Diagnosis requires a low threshold of suspicion in all patients with CS, since symptoms occur late in the disease process and clinical signs are difficult to elicit. As a result, routine screening is recommended using the biomarker, N-terminal pro-natriuretic peptide, and regular echocardiography is then required for diagnosis and follow-up. There is no direct medical therapy for CHD, but the focus of non-surgical care is to control CS symptoms, reduce tumour load and decrease hormone levels. Valve surgery improves long-term outcome for those with severe disease compared to medical management, although peri-operative mortality remains at between 10 and 20% in experienced centres. Therefore, care needs to be multidisciplinary at all stages, with clear discussion with the patient and between teams to ensure optimum outcome for these often-complex patients.

Multicentre double-blind randomized controlled trial of perhexiline as a metabolic modulator to augment myocardial protection in patients with left ventricular hypertrophy undergoing cardiac surgery.

OBJECTIVES: Patients undergoing cardiac surgery require adequate myocardial protection. Manipulating myocardial metabolism may improve the extent of myocardial protection. Perhexiline has been shown to be an effective anti-anginal agent due to its metabolic modulation properties by inhibiting the uptake of free fatty acids into the mitochondrion, and thereby promoting a more efficient carbohydrate-driven myocardial metabolism. Metabolic modulation may augment myocardial protection, particularly in patients with left ventricular hypertrophy (LVH) known to have a deranged metabolic state and are at risk of poor postoperative outcomes. This study aimed to evaluate the role of perhexiline as an adjunct in myocardial protection in patients with LVH secondary to aortic stenosis (AS), undergoing an aortic valve replacement (AVR). METHODS: In a multicentre double-blind randomized controlled trial of patients with AS undergoing AVR ± coronary artery bypass graft surgery, patients were randomized to preoperative oral therapy with either perhexiline or placebo. The primary end point was incidence of inotrope use to improve haemodynamic performance due to a low cardiac output state during the first 6 h of reperfusion, judged by a blinded end points committee. Secondary outcome measures included haemodynamic measurements, electrocardiographic and biochemical markers of new myocardial injury and clinical safety outcome measures. RESULTS: The trial was halted early on the advice of the Data Safety and Monitoring Board. Sixty-two patients were randomized to perhexiline and 65 to placebo. Of these, 112 (54 perhexiline and 48 placebo) patients received the intervention, remained in the trial at the time of the operation and were analysed. Of 110 patients who achieved the primary end point, 30 patients (16 perhexiline and 14 placebo) had inotropes started appropriately; there was no difference in the incidence of inotrope usage OR of 1.65 [confidence interval (CI): 0.67-4.06] P = 0.28. There was no difference in myocardial injury as evidenced by electrocardiogram odds ratio (OR) of 0.36 (CI: 0.07-1.97) P = 0.24 or postoperative troponin release. Gross secondary outcome measures were comparable between the groups. CONCLUSIONS: Perhexiline as a metabolic modulator to enhance standard myocardial protection does not provide an additional benefit in haemodynamic performance or attenuate myocardial injury in the hypertrophied heart secondary to AS. The role of perhexiline in cardiac surgery is limited.

Recommendations for haemodynamic and neurological monitoring in repair of acute type a aortic dissection.

During treatment of acute type A aortic dissection there is potential for both pre- and intra-operative malperfusion. There are a number of monitoring strategies that may allow for earlier detection of potentially catastrophic malperfusion (particularly cerebral malperfusion) phenomena available for the anaesthetist and surgeon. This review article sets out to discuss the benefits of the current standard monitoring techniques available as well as desirable/experimental techniques which may serve as adjuncts in the monitoring of these complex patients.