Invasive Hemodynamic Monitoring Research Articles

Abstract 13282: Oxygen Uptake and Cardiac Output Exhibit Delayed Recovery After Maximum Incremental Ramp Exercise in Patients With Exercise Pulmonary Hypertension

Introduction: In individuals with dyspnea on exertion (DOE) and suspected exercise pulmonary hypertension (exPH), oxygen uptake (VO 2 ), cardiac output (CO), peripheral oxygen extraction (Ca-vO 2 ), and mean pulmonary artery pressure (mPAP) have been well characterized during incremental exercise but less is known about the kinetics of post-exercise recovery patterns. Hypothesis: Exercise recovery cardiac output kinetics are slowed in patients with exPH. Methods: Upright maximum incremental ramp cycle ergometry cardiopulmonary exercise testing with invasive hemodynamic monitoring and serial blood gas measurements during exercise and recovery was performed in 50 consecutive patients referred for evaluation of DOE of unclear etiology. VO 2 , arterial and venous oxygen content (Ca-vO 2 ), Fick cardiac output, and mPAP were analyzed from rest, peak exercise, and 2 minutes post-exercise. ExPH was defined in a consistent manner with recent consensus statements (ΔmPAP/ΔCO >3.0 mmHg/L/min) from rest to peak exercise. Results: Among 50 patients with DOE, [62% female, Age 61.7±11.8, BMI 30.7±8.2] 2-min post-exercise VO 2 was -56±11%, CO: -22±19%, Ca-vO 2 :-42±15% compared to peak exercise values. The % fall in CO at 2min was significantly lower in the 26 patients with exPH compared to the 24 patients without exPH (Table). The average mPAP remained elevated at 2 min post-exercise (>20mmHg) in exPH despite normal average resting values. Conclusions: Patients with exPH demonstrate slowed CO recovery kinetics in conjunction with persistent PAP elevation 2-min post-exercise. Persistent elevation in blood flow through the pulmonary circuit at a time conducive to non-invasive assessment of PAP (i.e. by echocardiography) may lend itself to non-invasive detection of exercise-PH in patients undergoing evaluation of dyspnea on exertion.

Abstract 14041: The Association of Left Heart Pressures and Survival After Starting Veno-Arterial Extracorporeal Membrane Oxygenation for Cardiogenic Shock

Introduction: Despite the ability to provide full hemodynamic support in patients with refractory cardiogenic shock (CS), a potential limitation is elevated intracardiac filling pressures from increased left ventricular afterload. There is a paucity of data regarding the correlation of left atrial pressures (LAP) with outcomes. Hypothesis: Our objective was to determine association between LAP and survival for patients with refractory CS after 24 hours of VA ECMO support. Methods: Cohort analysis among 10,906 patients ≥18yrs from the Extracorporeal Life Support Organization (ELSO) Registry (2015 - 2020), with refractory CS on VA ECMO. LAP values were defined as pulmonary capillary wedge pressure (PCWP) or pulmonary arterial diastolic pressure (PAD) values if PCWP was missing. The exposure was LAP values at 24 hours on VA ECMO support. Our primary outcome was survival to discharge. We used multivariate regression, adjusted for age, and the following pre-ECMO variables: PaO2/FiO2, pH, mean arterial blood pressure (MAP), and SCAI classification; and the following variables after 24 hours of support: pH, MAP; and year. Results: Median age was 57 [IQR,46; 65] years old and 31% were females. Thirty two percent (n=3,465) presented with acute myocardial infarction, 29% (n=3,112) with acute heart failure and 1% (n=965) with both etiologies. Invasive hemodynamic monitoring was measured in 33% (n=3608) of patients. Median LAP was 18mmHg [IQR,14; 23]. Every 1 mm Hg incremental of LAP on support was associated with lower survival (aOR 0.97 [95% CI 0.95 to 0.98]; p<0.001), and 30% increase in duration of VA-ECMO support (beta-coeff 1.37 [95% CI 0.42 to 2.3]; p=0.005). Conclusions: Reduced LAP may be associated with higher adjusted hospital survival in patients with refractory CS on VA-ECMO. These findings merit further investigation and prospective validation to assess the relationship between hemodynamically tailored management and outcomes in this patient population.

Successful Treatment of Severely Hypotensive Pediatric Patients with Multisystem Inflammatory Syndrome in Children (MIS-C) with the Guidance of Invasive Hemodynamic Monitoring: A Report of Three Cases

Introduction: Since the beginning of the coronavirus disease 2019 (COVID-19) outbreak, it was assumed that infection rate in pediatric patients is lower than in adults and that infection is less severe in children than adult patients. Recently, there have been several reports and case series presenting critically-ill children with COVID-19, but still, severe hypotension is rare in pediatric patients with COVID-19. Case Presentation: We describe three pediatric cases with COVID-19 who presented with multi-system organ failure and severe hypotension treated with the guidance of the parameters of an invasive continuous hemodynamic monitoring device. We also compare their parameters with few articles on pediatric sepsis parameters. Conclusions: Although we usually start the treatment of hypotensive pediatric patients with hydration and epinephrine as an inotrope, in our cases, we required a different treatment plan according to the hemodynamic monitoring parameters, which indicates the value of the utilization of these devices in pediatric intensive care units

Invasive hemodynamic monitoring by Swan-Ganz pulmonary artery catheter: concepts and utility

Since its beginnings in the last century, pulmonary artery catheterization (PAC) has evolved into an invasive hemodynamic evaluation technique that can be performed at the patient's bedside through a Swan-Ganz catheter; this procedure has maintained an intermittent course in terms of its use; however, it has currently demonstrated relevance in specific scenarios. The PAC allows access to the central venous circulation, the right heart and the pulmonary artery; it performs the calculation of hemodynamic variables directly or indirectly by means of established formulas and methods. This makes possible to perform an adequate hemodynamic evaluation and classification, perform specific tests (e.g. vasoreactivity test), which help to define the diagnosis, therapeutic , monitor the response to treatment, evaluation prior to advanced therapies (e.g. cardiac transplantation or mechanical circulatory assistance devices), and prognosis in our patients. In this article we discuss the concepts and usefulness of pulmonary artery catheterization.

Neurosurgical intervention in children with ventricular assist devices: A single-center case series review.

The incidence of neurological complications related to ventricular assist devices (VAD) remains high and includes life-threatening conditions such as intracranial hemorrhage or ischemic stroke. Although no definitive management guidelines exist, operative interventions may be required for major neurological injuries. This case series describes the perioperative management of children at a single center who underwent neurosurgical procedures for major intracranial bleeds or ischemic strokes while on VAD support. A database review identified all pediatric VAD patients who underwent a neurosurgical procedure for an intracranial hemorrhage or ischemic stroke from April 2014 to January 2020. Data regarding patient characteristics, preoperative medical management, intraoperative anesthetic management, and postoperative outcomes were collected using retrospective chart review. Ninety VADs were implanted in 78 patients. Five neurosurgical interventions were performed: four for intracranial hemorrhages and one for an ischemic stroke. All four patients with hemorrhages were receiving anticoagulation at the time of their event and the three patients on warfarin received emergent reversal with prothrombin concentrate complex and vitamin K. Three patients also received pre-procedural platelet transfusions. Two of the five procedures were emergent bedside external ventricular drain placements, and three were surgical operations. All three patients who underwent operative procedures received invasive hemodynamic monitoring and were supported with a combination of inotropes and afterload reduction. One patient required a massive blood product transfusion. The two patients who underwent external ventricular drain placement had no further surgical interventions and died from the severity of their neurological injuries. All three patients who underwent operative procedures survived to transplantation and discharge home. Perioperative concerns for the anesthesiologist include VAD hemodynamic management, bleeding, VAD thrombosis, and prevention of secondary brain injury. A systematic, multidisciplinary approach to management is paramount to attain favorable outcomes.

Invasive Hemodynamic Monitoring in Cardiogenic Shock Is Associated With Lower In-Hospital Mortality.

BackgroundThere is increasing utilization of cardiogenic shock treatment algorithms. The cornerstone of these algorithms is the use of invasive hemodynamic monitoring (IHM). We sought to compare the in‐hospital outcomes in patients who received IHM versus no IHM in a real‐world contemporary database.Methods and ResultsPatients with cardiogenic shock admitted during October 1, 2015 to December 31, 2018, were identified from the National Inpatient Sample. Among this group, we compared the outcomes among patients who received IHM versus no IHM. The primary end point was in‐hospital mortality. Secondary end points included vascular complications, major bleeding, need for renal replacement therapy, length of stay, cost of hospitalization, and rate of utilization of left ventricular assist devices and heart transplantation. Propensity score matching was used for covariate adjustment. A total of 394 635 (IHM=62 565; no IHM=332 070) patients were included. After propensity score matching, 2 well‐matched groups were compared (IHM=62 220; no IHM=62 220). The IHM group had lower in‐hospital mortality (24.1% versus 30.6%, P<0.01), higher percentages of left ventricular assist devices (4.4% versus 1.3%, P<0.01) and heart transplantation (1.3% versus 0.7%, P<0.01) utilization, longer length of hospitalization and higher costs. There was no difference between the 2 groups in terms of vascular complications, major bleeding, and the need for renal replacement therapy.ConclusionsAmong patients with cardiogenic shock, the use of IHM is associated with a reduction in in‐hospital mortality and increased utilization of advanced heart failure therapies. Due to the observational nature of the current study, the results should be considered hypothesis‐generating, and future prospective studies confirming these findings are needed.

Анестезіологічний менеджмент феохромоцитом в умовах спеціалізованого ендокринологічного центру

Мета роботи: упровадження сучасного анестезіологічного менеджменту пацієнтів із фео­хромоцитомою в умовах спеціалізованого ендокринологічного центру із застосуванням алгоритму етапного періопераційного гемодинамічного контролю.Матеріали й методи. Проведена імплементація анестезіологічного менеджменту в 33 жінок із фео­хромоцитомою надниркових залоз при її хірургічному видаленні шляхом відеоасистованої лапароскопічної адреналектомії. Усім пацієнткам застосовувався алгоритм етапного періопераційного гемодинамічного менедженту (ЕПОГМ): передопераційна таблетована гіпотензивна терапія до надходження в стаціонар, передопераційна інфузійна керована гіпотензивна терапія урапідилом та корекція гіповолемії збалансованими кристалоїдними розчинами та 10% розчином гідроксіетилкрохмалю (ГЕК) (200/0,5) на другому етапі, інтраопераційна інфузійна керована гіпотензивна терапія урапідилом на третьому етапі під контролем інвазивного та неінвазівного моніторингу гемодинаміки і профілактика надниркової недостатності та корекція гіповолемії на четвертому етапі.Результати та обговорення. У всіх хворих був відмічений вірогідно (p &lt; 0,001) підвищений рівень метанефринів добової сечі до 1831,6 ± 337,9 мкг/24 год (контроль 169,3 ± 12,7 мкг/24 год). Згідно з розробленим алгоритмом ЕПОГМ на першому етапі застосовували доксазозин 10,0 ± 1,0 мг або урапідил 144,0 ± 11,2 мг у 2 прийоми. На другому етапі виконували гемодилюцію 10% розчином ГЕК (200/0,5) та інфузійну керовану гіпотензивну терапію урапідилом із середньою швидкістю 9,7 ± 1,9 мг/год. На третьому етапі інтраопераційно швидкість інфузії урапідилу становила 1,25 ± 0,08 мг/хв (додатково при хірургічному видаленні надниркової залози з феохромоцитомою болюсно вводився урапідил 25–50 мг в/в при виявленні навіть мінімального підвищення артеріального тиску). На четвертому етапі здійснювалась профілактика надниркової недостатності та гіповолемії.Висновки. Упровадження анестезіологічного менеджменту пацієнтів із феохромоцитомами в спеціалізованому ендокринологічному центрі забезпечило високу ефективність та безпеку при лапароскопічних адреналектоміях під час загальної анестезії та відсутність випадків із летальним кинцем. ЕПОГМ при підготовці до операції та під час хірургічного втручання є ефективним, легко керованим та безпечним методом стабілізації показників гемодинаміки у пацієнтів із феохромоцитомами під час адреналектомії.

Metoprolol in Critically Ill Patients With COVID-19

BackgroundSevere coronavirus disease-2019 (COVID-19) can progress to an acute respiratory distress syndrome (ARDS), which involves alveolar infiltration by activated neutrophils. The beta-blocker metoprolol has been shown to ameliorate exacerbated inflammation in the myocardial infarction setting. ObjectivesThe purpose of this study was to evaluate the effects of metoprolol on alveolar inflammation and on respiratory function in patients with COVID-19–associated ARDS. MethodsA total of 20 COVID-19 patients with ARDS on invasive mechanical ventilation were randomized to metoprolol (15 mg daily for 3 days) or control (no treatment). All patients underwent bronchoalveolar lavage (BAL) before and after metoprolol/control. The safety of metoprolol administration was evaluated by invasive hemodynamic and electrocardiogram monitoring and echocardiography. ResultsMetoprolol administration was without side effects. At baseline, neutrophil content in BAL did not differ between groups. Conversely, patients randomized to metoprolol had significantly fewer neutrophils in BAL on day 4 (median: 14.3 neutrophils/µl [Q1, Q3: 4.63, 265 neutrophils/µl] vs median: 397 neutrophils/µl [Q1, Q3: 222, 1,346 neutrophils/µl] in the metoprolol and control groups, respectively; P = 0.016). Metoprolol also reduced neutrophil extracellular traps content and other markers of lung inflammation. Oxygenation (PaO2:FiO2) significantly improved after 3 days of metoprolol treatment (median: 130 [Q1, Q3: 110, 162] vs median: 267 [Q1, Q3: 199, 298] at baseline and day 4, respectively; P = 0.003), whereas it remained unchanged in control subjects. Metoprolol-treated patients spent fewer days on invasive mechanical ventilation than those in the control group (15.5 ± 7.6 vs 21.9 ± 12.6 days; P = 0.17). ConclusionsIn this pilot trial, intravenous metoprolol administration to patients with COVID-19–associated ARDS was safe, reduced exacerbated lung inflammation, and improved oxygenation. Repurposing metoprolol for COVID-19–associated ARDS appears to be a safe and inexpensive strategy that can alleviate the burden of the COVID-19 pandemic.

B-PO05-170 CATHETER ABLATION OF VENTRICULAR TACHYCARDIA IN PATIENTS WITH CARDIOGENIC SHOCK IN THE UNITED STATES: INCIDENCE, PREDICTORS, AND OUTCOMES

Ventricular tachycardia (VT) is common in patients presenting with cardiogenic shock (CS). However, the role of catheter ablation (CA) in this vulnerable population remains unclear. To evaluate the in-hospital mortality and complications of CA in CS patients with VT. The Nationwide Inpatient Sample database was queried from 10/2015 to 12/2018 for adult patients who presented with CS and developed VT (International Classification of Diseases, Tenth Edition, Clinical Modification [ICD-10-CM] code I47.2). The primary outcome was in-hospital all-cause mortality. Propensity-score matching (1:3 CA:control utilizing 18 variables) was used to evaluate in-hospital outcomes, and multivariate logistic regression was performed to identify predictors of in-hospital mortality. Of 363,570 CS patients, 65,540 (18.0%) had VT and 1,385 (2.1%) underwent CA. Ischemic cardiomyopathy was the most common co-morbidity among patients who underwent CA (45.8%). Invasive hemodynamic monitoring was utilized in 32.9% of CA group (vs 22.6% in the control; p<0.01), and 36.8% (vs 30.3% control; p<0.01) received mechanical circulatory support (MCS). In comparison with the matched control group, CA was associated with a significantly reduced all-cause mortality (25.1% vs 33.2%; p=0.01) and cardiac arrest (7.4% vs 13.4%; p<0.01). However, CA was associated with increased costs (median 333,305 vs 172,880 USD; p<0.01) and length-of-stay (median 13.0 vs 9.0 days; p<0.01). The utilization of MCS was the sole predictor of reduced mortality in those who underwent CA (odds ratio=0.38; 95% confidence interval=0.29-0.50; p<0.01). In-hospital complications included 11.4% pericardial (5.5% tamponade) and 3.3% vascular injuries in the CA group. Among patients with CS and VT, CA was associated with significantly reduced in-hospital mortality, but with increased costs and length of stay. MCS might provide favorable outcomes in patients with CS and VT undergoing CA.

Recurrent pulmonary thromboembolism during radical cystectomy: A case report

Intraoperative incidences of pulmonary embolism (PE) have been reported in orthopedic and neurosurgeries. Here, we present the case of a 69-year-old man who presented with complaints of abdominal pain and hematuria for 2 months. He underwent radical cystectomy for urinary bladder cancer when he suddenly developed severe shock , hypoxia and decrease in lung compliance. We managed hypotension with vasopressors and inotropes guided by cardiac output monitoring. Post-operative CT pulmonary angiography revealed partially occluding thrombi in the left lower lobar pulmonary artery in segmental branches. The patient was started on therapeutic anticoagulation and he recovered subsequently. We commonly encounter thromboembolism in the post-operative period, and clinical presentation of massive occlusive embolus is well recognized. In this case, the presentation was intraoperative and the thrombus was non-massive, causing only partial obstruction of the pulmonary artery. This atypical presentation of intraoperative non-massive pulmonary thromboembolism needs to be recognized promptly. The use of invasive hemodynamic monitoring and point-of-care echocardiography is vital in the management of intraoperative pulmonary embolism.

Perioperative management of post-COVID-19 surgical patients: Indian Society of Anaesthesiologists (ISA National) Advisory and Position Statement.

Perioperative management of post-COVID-19 surgical patients: Indian Society of Anaesthesiologists (ISA National) Advisory and Position Statement.

Feasibility of non-invasive measurement of central blood pressure and arterial stiffness in shock.

Patients in haemodynamic shock are in need for an intensive care treatment. Invasive haemodynamic monitoring is state of the art for these patients. However, evolved, non-invasive blood pressure monitoring devices offer advanced functions like the assessment of central blood pressure and arterial stiffness. We analysed the feasibility of two oscillometric blood pressure devices in patients with shock. We performed a monocentre prospective study, enrolling 57 patients admitted to the intensive care unit (ICU), due to septic and/or cardiogenic shock. We assessed invasive and non-invasive peripheral and central blood pressure <24hours and 48hours after admission on the ICU. Additional haemodynamic parameters such as pulse wave velocity (PWV), augmentation pressure and augmentation index were obtained through Mobil-o-Graph PWA (IEM) and SphygmoCor XCEL (AtCor Medical). A complete haemodynamic assessment was successful in all patients (48) with the Mobil-o-Graph 24hours PWA and in 29 patients with the SphygmoCor XCEL (P=.001), when cases of death or device malfunction were excluded. Reasons for failure were severe peripheral artery disease, haemodynamic instability, oedema and agitation. Invasive blood pressure showed a sufficient correlation with both devices; however, large differences between invasive and non-invasive techniques were recorded in Bland-Altmann analysis (P<.05 for all parameters). PWV differed between the two devices. Non-invasive peripheral blood pressure measurement remains a rescue technique. However, non-invasive assessment of arterial stiffness and central blood pressure is possible in patients with septic or cardiogenic shock. Further studies are required to assess their clinical significance for patients in shock.

Association of obesity-related inflammatory pathways with lung function and exercise capacity

BackgroundObesity has multifactorial effects on lung function and exercise capacity. The contributions of obesity-related inflammatory pathways to alterations in lung function remain unclear.Research Question:To examine the association of obesity-related inflammatory pathways with pulmonary function, exercise capacity, and pulmonary-specific contributors to exercise intolerance. MethodWe examined 695 patients who underwent cardiopulmonary exercise testing (CPET) with invasive hemodynamic monitoring at Massachusetts General Hospital between December 2006–June 2017. We investigated the association of adiponectin, leptin, resistin, IL-6, CRP, and insulin resistance (HOMA-IR) with pulmonary function and exercise parameters using multivariable linear regression. ResultsObesity-related inflammatory pathways were associated with worse lung function. Specifically, higher CRP, IL-6, and HOMA-IR were associated with lower percent predicted FEV1 and FVC with a preserved FEV1/FVC ratio suggesting a restrictive physiology pattern (P ≤ 0.001 for all). For example, a 1-SD higher natural-logged CRP level was associated with a nearly 5% lower percent predicted FEV1 and FVC (beta −4.8, s.e. 0.9 for FEV1; beta −4.9, s.e. 0.8 for FVC; P < 0.0001 for both). Obesity-related inflammatory pathways were associated with worse pulmonary vascular distensibility (adiponectin, IL-6, and CRP, P < 0.05 for all), as well as lower pulmonary artery compliance (IL-6 and CRP, P ≤ 0.01 for both). InterpretationOur findings highlight the importance of obesity-related inflammatory pathways including inflammation and insulin resistance on pulmonary spirometry and pulmonary vascular function. Specifically, systemic inflammation as ascertained by CRP, IL-6 and insulin resistance are associated with restrictive pulmonary physiology independent of BMI. In addition, inflammatory markers were associated with lower exercise capacity and pulmonary vascular dysfunction.

Alternative methods to assess cardiac index: different parameters for physicians when swan-ganz catheter is not available

Abstract Funding Acknowledgements Type of funding sources: Private hospital(s). Main funding source(s): Sanatorium Mitre Introduction invasive hemodynamic monitoring with Swan-Ganz catheter (SGC) has been the gold standard to determine the cardiac index. However, in many centres is not always available, and the Fick method is also validated for that purpose, but without the same accuracy. There are other used laboratory parameters; nonetheless there is lack of evidence about its association with the cardiac index. We aim to describe the association between these parameters and the patient"s hemodynamic condition. Objectives to assess the association between hemodynamic parameters obtained by SGC and data obtained with a jugular central venous catheter, in critically ill cardiac patients hospitalised in the Intensive Care Unit. Methods prospective, double-blind, observational study, conducted from September 2019 to November 2020. A total of 45 patients with SGC were enrolled. We measured cardiac output and cardiac index (by thermodilution method and Fick estimated method), other hemodynamic parameters, lactic acid, central venous oxygen saturation (CVO2) and venous-to-arterial carbon dioxide difference (VACO2). The variables were analysed with t-test, Wilcoxon and chi2, as appropriate. Statistical significance was assumed when p was less than .05. Results we analysed 45 patients (mean age 58 years; 87% men; 23% postoperative cardiac surgery subjects; mean ejection fraction 30%). We registered a 6% in-hospital mortality and the mean in-hospital stay was 19 days (IQR 25-75: 8-25). We observed a significative correlation between impaired cardiac index (≤2.2 L/min/m2) obtained by SGC and Fick method (r 0.43; p= .0041). Elevated lactic acid and reduced CVO2 were not well correlated with impaired cardiac index (r 0.51, CI 95%: 0.32-0.71; r 0.30, CI 95%: 0.13-0.48; respectively). Among patients with impaired cardiac index, all of them had a VACO2 over 7 mmHg. The c-statistic to predict impaired cardiac index using VACO2 over 7 mmHg was 0.66 (CI 95%: 0.48-0.84), correlation not observed for the CVO2 values. Elevated lactic acid (≤1.9 mmol/L) was only associated with noradrenaline infusion over 0.7 g/kg/min (c-statistic 0.55; p= .0002). Conclusions when invasive hemodynamic monitoring with SGC is not available, the VACO2 value over 7 mmHg (obtained with a central venous catheter) appeared to be a better predictor of impaired cardiac index than the determination of CVO2. The Fick method was an acceptable replacement of the invasive monitoring. Also, noradrenaline infusion over 0.7 g/kg/min, but not cardiac index or other laboratory parameters, showed a better correlation with elevated lactic acid.

Clinical features and outcomes in patients with cardiogenic shock complicating acute myocardial infarction: early vs recent experience with impella

To compare clinical features and outcomes in patients with acute myocardial infarction complicated by cardiogenic shock (AMICS) treated in the early experience with Impella percutaneous ventricular assist device and patients treated recently. Since pre-market approval (PMA) of Impella device as treatment for AMICS, use of the device has grown considerably. We retrospectively analyzed 649 AMICS patients treated with perioperative Impella, with 291 patients treated from 2008 to 2014 comprising the early experience cohort and 358 patients treated from 2017 to 2019 comprising the recent experience cohort. The primary end point was risk adjusted in-hospital mortality. Mean age and gender distribution of patients was similar in the two cohorts. The recent cohort had more invasive hemodynamic monitoring (64% vs 46%; P < .001) and less use of an intra-aortic balloon pump prior to Impella (15% vs 41%; P < .001). Recently treated patients were significantly more likely to receive Impella support prior to PCI (58% vs 44%; P = .005). In-hospital mortality was lower in the recent cohort (48% vs 56%; P = .043). This difference was however no longer significant after risk adjustment (adjusted OR 0.89, 95% CI 0.59-1.34, P = .59). Rates of acute kidney injury, major bleeding, and vascular complications requiring surgery were also significantly lower in the recent cohort. Use of Impella for AMICS during recent years is associated with lower unadjusted in-hospital mortality, which may reflect better patient selection, earlier device implantation, and improved management algorithms. In-depth understanding of these factors may inform the development of future treatment protocols.

Oxygen Pathway Limitations in Patients With Chronic Thromboembolic Pulmonary Hypertension.

Exertional intolerance is a limiting and often crippling symptom in patients with chronic thromboembolic pulmonary hypertension (CTEPH). Traditionally the pathogenesis has been attributed to central factors, including ventilation/perfusion mismatch, increased pulmonary vascular resistance, and right heart dysfunction and uncoupling. Pulmonary endarterectomy and balloon pulmonary angioplasty provide substantial improvement of functional status and hemodynamics. However, despite normalization of pulmonary hemodynamics, exercise capacity often does not return to age-predicted levels. By systematically evaluating the oxygen pathway, we aimed to elucidate the causes of functional limitations in patients with CTEPH before and after pulmonary vascular intervention. Using exercise cardiac magnetic resonance imaging with simultaneous invasive hemodynamic monitoring, we sought to quantify the steps of the O2 transport cascade from the mouth to the mitochondria in patients with CTEPH (n=20) as compared with healthy participants (n=10). Furthermore, we evaluated the effect of pulmonary vascular intervention (pulmonary endarterectomy or balloon angioplasty) on the individual components of the cascade (n=10). Peak Vo2 (oxygen uptake) was significantly reduced in patients with CTEPH relative to controls (56±17 versus 112±20% of predicted; P<0.0001). The difference was attributable to impairments in multiple steps of the O2 cascade, including O2 delivery (product of cardiac output and arterial O2 content), skeletal muscle diffusion capacity, and pulmonary diffusion. The total O2 extracted in the periphery (ie, ΔAVo2 [arteriovenous O2 content difference]) was not different. After pulmonary vascular intervention, peak Vo2 increased significantly (from 12.5±4.0 to 17.8±7.5 mL/[kg·min]; P=0.036) but remained below age-predicted levels (70±11%). The O2 delivery was improved owing to an increase in peak cardiac output and lung diffusion capacity. However, peak exercise ΔAVo2 was unchanged, as was skeletal muscle diffusion capacity. We demonstrated that patients with CTEPH have significant impairment of all steps in the O2 use cascade, resulting in markedly impaired exercise capacity. Pulmonary vascular intervention increased peak Vo2 by partly correcting O2 delivery but had no effect on abnormalities in peripheral O2 extraction. This suggests that current interventions only partially address patients' limitations and that additional therapies may improve functional capacity.

Evolving Cardiac Electrical Therapies for Advanced Heart Failure Patients.

Symptomatic heart failure (HF) patients despite optimal medical therapy and advances such as invasive hemodynamic monitoring remain challenging to manage. While cardiac resynchronization therapy remains a highly effective therapy for a subset of HF patients with wide QRS, a majority of symptomatic HF patients are poor candidates for such. Recently, cardiac contractility modulation, neuromodulation based on carotid baroreceptor stimulation, and phrenic nerve stimulation have been approved by the US Food and Drug Administration and are emerging as therapeutic options for symptomatic HF patients. This state-of-the-art review examines the role of these evolving electrical therapies in advanced HF.

Right Ventricular Response to Exercise in LVAD-Supported Patients vs. Heart Failure and Normal Subjects

<h3>Purpose</h3> Knowledge of right ventricular (RV) responses to exercise in LVAD-supported patients is limited. RV reserve might be impaired in LVAD patients. We sought to determine RV reserve during exercise in LVAD patients vs. HF and control subjects. <h3>Methods</h3> In 2016-20, 25 LVAD patients underwent upright ergometer CPET with first-pass radionuclide imaging (n=20), with (n=13) or without (n=12) invasive hemodynamic monitoring. LVAD patients were compared to HFrEF (EF < 40%, n=31), HFpEF (EF ≥ 50%, rest mean PAP ≥ 25, PAWP ≥ 15 mmHg, n=54) and normal subjects (EF ≥ 50%, rest mean PAP ≤ 20, PAWP < 15 mmHg, n=41). Values are expressed as median (25^th-75^th interquartile range). P < 0.05 was considered significant comparison across all groups. <h3>Results</h3> Median RVEF was 41% (LVAD), 40% (HFrEF), 47% (HFpEF), 51% (normal) (p<0.01). On exercise, normal subjects augmented RVEF but LVAD and HF groups did not. Peak VO₂ was 11 (LVAD), 11.9 (HFrEF), 14.2 (HFpEF), 22.7 mL/kg/min (normal) (p<0.01). Peak filling pressures were similar in LVAD and normal subjects. Peak cardiac output (CO) was 9.9 (LVAD), 7.1 (HFrEF), 9.9 (HFpEF), 13.9 L/min (normal) (p<0.01). MeanPAP/CO slope was highest in HFrEF (5.8 mmHg/L/min [3.2-7]), intermediate in LVAD (2.6 [2-4.9]) and HFpEF (3.7 [2.7-4.8]), and lowest in normal (1.8 [1.4-2.1]) (p<0.01). Peak PVR was highest in HFrEF (2.1 Wood units [1.7-3.2], intermediate in LVAD (1.4 [1-1.8]) and HFpEF (1.5 [1.1-2]), and lowest in normal (1 [0.7-1.3]) (p<0.01). Peak RV stroke work index (RVSWI) was lowest in LVAD (0.7 mmHg.L/m² [0.5-0.9]) vs. normal (1.1 [1-1.3]), HFrEF (1.2 [1.1-1.4]) and HFpEF (1.2 [1-1.6]) (p<0.01). Peak RAP/PAWP ratio was highest in LVAD (0.6 [0.5-0.9]) vs. normal (0.5 [0.4-0.6]), HFrEF (0.4 [0.3-0.5]) and HFpEF (0.4 [0.3-0.6]) (p=0.02) (Fig. 1). <h3>Conclusion</h3> At peak upright exercise, LVAD patients had poorer RV reserve than HF and normal subjects (lower RVSWI, higher RAP/PAWP ratio). Research aimed at RV optimization is needed to improve exercise tolerance in LVAD patients.

Association of Multidisciplinary Heart Failure Team with Outcomes in Patients Requiring Extracorporeal Membrane Oxygenation

<h3>Purpose</h3> Veno-arterial (VA) ECMO plays a central role in patients with refractory cardiogenic shock. Whether involvement of a multidisciplinary heart failure team (HF-MDT) at time of VA-ECMO initiation would be associated with differences in downstream management and outcomes is unknown. <h3>Methods</h3> Patients who received VA-ECMO (12/16 to 09/20) at a quaternary care center in the Middle East were retrospectively identified. Patients were grouped according to HF- MDT involvement—defined as providing input on VA-ECMO initiation/ weaning in addition to active management of vasoactive medications. Baseline characteristics, subsequent management and clinical outcomes were compared between patient who received VA-ECMO with and without HF-MDT involvement. <h3>Results</h3> A total of 47 unique patients (median age 49 years, 78.7% males) were identified. Most common indications for ECMO initiation was post-cardiotomy (34%), followed by cardiogenic shock secondary to advanced heart failure (25.5%). HF-MDT was involved in ECMO initiation in 48.9% (23/47) patients. Patients where HF-MDT was involved were younger (41.1 ± 13.9 vs 57.9 ± 14.6; P<0.05) with more advanced ventricular systolic dysfunction (LVEF of 22.9% ± 14.7 vs. 39% ± 22.1; P<0.05). Invasive hemodynamic monitoring (65% vs 33.3%; OR 3.7, 95% CI [1.02-13.5]) and inotrope support (82.6% vs. 50%; OR 4.8, 95% CI [1.24-18.19]) were more commonly used in ECMO patients under HF-MDT guidance. However, no differences in ECMO outcomes or risk of in-hospital complications were found with HF-MDT involvement. <h3>Conclusion</h3> HF-MDT involvement in VA-ECMO initiation provides unique input on decision-making, including selection for advanced therapies and hemodynamics-directed use of vasoactive medications. Establishing multidisciplinary teams for cardiogenic shock management helps standardize treatment of this subset of complex patients. The impact of such teams on resource use and clinical outcomes needs to be evaluated in larger studies.

Low Peak VO2 and Pulse Pressure Augmentation on Exercise in LVAD Patients with Recovery and Pump Explant

<h3>Purpose</h3> Recovered LVAD patients have normal EF and hemodynamics, but knowledge of their exercise response is scarce. We compared exercise responses in LVAD vs. HF and normal subjects. <h3>Methods</h3> In 2016-20, 25 LVAD patients had upright ergometer CPET with first-pass radionuclide imaging (n=20), with (n=13) or without (n=12) invasive hemodynamic monitoring. Five had pump explant for recovery after exercising at low pump speeds. LVAD patients were compared to HFrEF (EF < 40%, n=31) vs. normal subjects (EF ≥ 50%, rest mean PAP ≤ 20, PAWP < 15 mmHg, n=41). Values are expressed as median (25^th-75^th interquartile range). P < 0.05 was considered significant comparison across all groups. <h3>Results</h3> Median EF was 55% (explant), 19% (no-explant), 23% (HFrEF), and 63% (normal) (p<0.01). On exercise, LVAD patients did not augment EF as other groups. Peak VO₂ was 14 (explant), 10.1 (no-explant), 11.9 (HFrEF), and 22.7 mL/kg/min (normal) (p<0.01). Max-predicted heart rate (HR) was 90% (explant), 69% (no-explant), 68% (HFrEF), and 89% (normal) (p<0.01). Explant patients did not widen radial artery pulse pressure as normal subjects (Δ pulse pressure 18 vs. 32 mmHg, p<0.01) (Fig 1A). At rest, from supine to upright position, filling pressures dropped in HF and normal subjects but were unchanged in LVAD patients. Peak CO was similar between explant and normal (13.9 L/min [9.9-14.6] vs. 13.9 [11.9-17.1]), but low in no-explant and HF groups (6.9 [6.3-10.5] vs. 7.1 [5.8-9.1]). PAWP/CO slope was lowest in explant and normal (1.4 mmHg/L/min [0.8-2.2] vs. 1.1 [0.9-1.6]), but high in no-explant and HFrEF groups (3.2 [2.2-4.5] vs. 4.2 [2.3-5.4]) (Fig 1B). <h3>Conclusion</h3> Explant patients had higher peak CO, peak HR and lower PAWP/CO slope than no-explant group. Despite normal EF and hemodynamics, explant patients did not completely normalize peak VO₂ or pulse pressure augmentation on exercise. Efforts aimed at improving CO (e.g. pump speed modulation) and reducing chronotropic incompetence may help improve exercise tolerance for LVAD patients.