Acute Right Ventricular Failure in the Setting of Acute Pulmonary Embolism or Chronic Pulmonary Hypertension: A Detailed Review of the Pathophysiology, Diagnosis, and Management

The right ventricle (RV) is integral to normal cardiac function, but receives little attention in the medical literature. The etiologic causes of acute RV failure often differ from those encountered in left ventricular dysfunction. Thus, RV failure frequently requires diagnostic procedures and management strategies that differ from those routinely used in the management of intrinsic left ventricular dysfunction. In this summary, the structure and function of the RV will be reviewed, concentrating on the pathophysiologic mechanisms behind the development of RV dysfunction. We will then focus on two distinct populations of patients who are at risk for acute RV failure: those with chronic pulmonary arterial hypertension (PAH) and those with acute pulmonary embolism. In chronic PAH, we will examine clinical circumstances common to hospitalized patients that may provoke acute RV decompensation, as well as pharmacologic therapies that are unique to RV failure management in PAH. Individuals with acute RV failure in the setting of pulmonary embolism represent a group with particularly high mortality, and the specific diagnostic and management strategies that are important for improved survival will be discussed

Adverse Interaction Between a Left Ventricular Assist Device and an Implantable Cardioverter Defibrillator

Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/73346/1/j.1540-8167.2007.00805.x.pd

Sarcoidosis: Hiding in Plain Sight

Introduction: Sarcoidosis is a systemic disease that can masquerade as many conditions. Due to its often patchy distribution, myocardial biopsy is only ∼30% sensitive. Herein we present a case of sarcoidosis diagnosed from an extra-cardiac biopsy years after the onset of cardiomyopathy. Case Report: A 54 year old man initially presented with dyspnea and fatigue due to new onset HFrEF of 20%. He had a significant family history of SCD. His workup revealed non-obstructive CAD, a myxomatous mitral valve with bileaflet prolapse and moderate regurgitation, and a cystic structure attached to the tricuspid valve. Given his frequent ventricular ectopy, he was discharged on guideline therapy for HFrEF and a wearable cardioverter defibrillator. Genetic testing for dilated cardiomyopathies revealed EYA4 and TTN variants of unknown significance. A cardiac MRI a few months later demonstrated no abnormal late gadolinium enhancement and persistent systolic dysfunction, so he underwent AICD implant. His course was further complicated by recurrent admissions for supraventricular and ventricular tachyarrhythmias. A cardiopulmonary exercise stress test demonstrated low-risk results. Further evaluation noted prolonged AV conduction. A RHC revealed mild post-capillary pulmonary hypertension and a mildly decreased cardiac index at 2.01 L/min/m2. Months later, he underwent CRT-D upgrade. He started improving functionally until he developed left eyelid swelling, initially thought to be lymphoma. An orbital biopsy revealed non-caseating granulomas. A PET/CT demonstrated FDG uptake within subcarinal lymph nodes but no cardiac uptake. Initially he declined immunomodulatory therapy, but as his symptoms worsened, he started corticosteroids and transitioned to mycophenolate mofetil due to intolerance of methotrexate. Due to disease progression on repeat FDG-PET, he was switched to infliximab. The diagnosis of sarcoidosis can be difficult due to its variable presentation, including heart block, heart failure, ventricular arrhythmias and sudden cardiac death. Cardiac involvement occurs in 25% of cases. Our case was complicated by a cMRI that was negative for cardiac involvement, which emphasizes the importance of complimentary inflammatory imaging with FDG-PET. A multidisciplinary approach is needed that engages sarcoid specialists for earlier diagnosis to ensure rapid initiation of therapy to reduce end-organ dysfunction

From Benchtop to Beside: Patient-specific Outcomes Explained by Invitro Experiment

Study: Recent analyses show that females have higher early postoperative (PO) mortality and right ventricular failure (RVF) than males after left ventricular assist device (LVAD) implantation; and that this association is partially mediated by smaller LV size in females. Benchtop experiments allow us to investigate patient-specific (PS) characteristics in a reproducible way given the fact that the PS anatomy and physiology is mimicked accurately. With multiple heart models of varying LV size, we can directly study the individual effects of titrating the LVAD speed and the resulting bi-ventricular volumes, shedding light on the interplay between LV and RV as well as resulting inter-ventricular septum (IVS) positions, which may cause the different outcomes pertaining to sex. Methods: In vitro, we studied the impact of the heart size to IVS position using two smaller and two larger sized PS silicone heart phantoms derived from clinical CT images (Fig. 1A). With ultrasound crystals that were integrated on a placeholder inflow cannula, the IVS position was measured during LV and RV volume changes (dV) mimicking varying ventricular loading states (Fig. 1B). Figure 1 A Two small (blue) and two large PS heart phantoms (orange) on B benchtop. C Median septum curvature results. LVEDD/LVV/RVV: LV enddiastolic diameter/LV and RV volume. Results: Going from small to large dV, at zero curvature, the septum starts to shift towards the left; for smaller hearts at dV = -40 mL and for larger hearts at dV = -50 mL (Fig. 1C). This result indicates that smaller hearts are more prone to an IVS shift to the left than larger hearts. We conclude that smaller LV size may therefore mediate increased early PO LVAD mortality and RVF observed in females compared to males. Novel 3D silicone printing technology enables us to study accurate, PS heart models across a heterogeneous patient population. PS relationships can be studied simultaneously to clinical assessments and support the decision-making prior to LVAD implantation

Right Ventricular Failure Following Left Ventricular Assist Device Implant: An Intermacs Analysis

Purpose: Right heart failure (RHF) management following LVAD include inotropes, right ventricular mechanical support and heart transplant. We analyzed the outcomes of severe RHF following implant of a fully magnetically levitated or hybrid magnetic centrifugal durable LVAD. Methods: In this INTERMACS analysis we identified patients who developed severe RHF following LVAD from 2013 until 2020 as bridge to recovery or transplant. Patients were categorized in three groups based on RHF treatment strategy: inotrope support (group 1), temporary mechanical support (group 2), and durable centrifugal RVAD (group 3). Kaplan Meier and Cox-regression survival analysis between groups was undertaken. Logistic regression analysis for new onset dialysis was conducted. Results: 2509 patients developed severe RHF after LVAD. 2199 (87.6%) patients were managed with inotropes (group 1), 233 (9.3%) with temporary RVAD (group 2) and 77 (3.1%) with durable RVAD (group 3). Group 1 had fewer patients with INTERMACS profile 1 and 2 (21.6%, p\u3c0.001). One year survival was 84.6%, 59.3%, and 63.8% in groups 1,2, and 3 (mortality HR=2.4 and 3.3 for groups 2 and 3 vs. group 1, p\u3c0.05). One year survival to transplant was 27%, 36.5%, and 53.6% in groups 1, 2, and 3, respectively (p\u3c0.05). Group 2 had higher incidence of new onset dialysis (42.6%, p=0.049). Conclusion: Survival with RHF following LVAD implant varies based on treatment strategy; inotrope support is associated with increased survival. Patients with durable RVAD are more likely to survive to transplant. Patient selection studies for durable RVAD with contraindications for transplant are necessary

Hemodynamic and Echocardiographic Assessment of Left Ventricle Recovery with Left Ventricular Assist Devices: Do We Explant?

Introduction: Explantation of left ventricular assist devices (LVAD) after left ventricular (LV) recovery is estimated to occur in 1-2% of cases. Herein, we present a case of hemodynamic and echocardiographic assessment of LV recovery during outflow graft balloon occlusion leading to LVAD explantation. Case Report: A 56-year-old female with medical history of systolic heart failure due to non-ischemic cardiomyopathy with LVEF 25%. She underwent an urgent HeartMate 3 LVAD implant after an admission for cardiogenic shock. Post LVAD course was complicated by driveline infection. History was notable for admissions due to low-flow alarms in the setting of dehydration. On echocardiogram, progressive LVEF improvement was noted although with suboptimal images. CT angiography did not demonstrate any occlusion of the cannulas. Right heart catheterization showed stable cardiac index despite minimal flow on LVAD. Cardiopulmonary testing was favorable. After multi-disciplinary discussion, patient underwent LVAD wean study in the cath lab under hemodynamic and transesophageal echo (TEE) guidance with therapeutic anticoagulation. LVAD was turned off for 10 minutes with outflow graft occluded by Armada 14 mm x 20 cm peripheral balloon. Wiring of the outflow graft from aorta and balloon occlusion were visualized by TEE (Figure). The left and right ventricular function were similar to baseline with no change in mitral regurgitation. Cardiac index was normal (Figure). Patient subsequently underwent successful LVAD explant. She is doing well with NYHA class I symptoms and LVEF 45-50% noted upon 3-months follow-up LVAD explantation is a feasible option in LV recovery after appropriate hemodynamic and echocardiographic assessment. TEE is an essential tool, especially in patients with suboptimal windows. Outflow graft balloon occlusion can be used if there is concern about falsely poor results related to backflow or ongoing LVAD support at low speed leading to falsely improved results

Mechanical circulatory support in acute myocardial infarction and cardiogenic shock: Challenges and importance of randomized control trials

BACKGROUND: Acute myocardial infarction (AMI) complicated by cardiogenic shock (CS) is associated with significant morbidity and mortality. METHODS: We provide an overview of previously conducted studies on the use of mechanical circulatory support (MCS) devices in the treatment of AMI-CS and difficulties which may be encountered in conducting such trials in the United States. RESULTS: Well powered randomized control trials are difficult to conduct in a critically ill patient population due to physician preferences, perceived lack of equipoise and challenges obtaining informed consent. CONCLUSIONS: With growth in utilization of MCS devices in patients with AMI-CS, efforts to perform well-powered, randomized control trials must be undertaken

What If the Destination Is Transplant? Outcomes of Destination Therapy Patients Who Were Transplanted

We sought to characterize patients who underwent heart transplant (HTx) following destination therapy (DT) implant in the combined ENDURANCE/ENDURANCE Supplemental Trials (DT/DT2). A post hoc analysis of the DT/DT2 trials was performed. Baseline characteristics and adverse events between the HTx and no-HTx cohorts were analyzed. Reasons for transplant were examined. Time to HTx was compared with contemporaneous HVAD BTT trial patients. Of the 604 DT/DT2 HVAD patients, 80 (13%) underwent HTx. The HTx cohort was younger (53.6 ± 11.1 vs. 65.2 ± 10.8, P \u3c 0.0001) with fewer Caucasians (60.0% vs. 76.5%, P = 0.002), less ischemic cardiomyopathy (42.5% vs. 58.8%, P = 0.01), and atrial fibrillation (38.8% vs. 54.4%, P = 0.01). The HTx cohort had longer 6-minute walk distances (183.6 vs. 38.0 m, P = 0.02). Most HTx in DT/DT2 were categorized as elective (n = 63, 79%) and, of these, 70% were due to modification of behavioral issues and weight loss. Adverse events were the main indication for urgent HTx (n = 17, 21%). Median times to HTx were longer in DT/DT2 (550.0 days) versus BTT/lateral (285.2 days). In this post hoc analysis of the DT/DT2 trials, over 1 in 10 underwent heart transplantation within 3 years of HVAD support. In DT therapy patients, consideration for transplant following DT VAD implant may be feasible

Characterizing Outflow Graft Narrowing over Time

Purpose: Cases of pump dysfunction due to outflow graft (OG) anastomosis obstruction related to serous fluid accumulation have been reported but the rate of occlusion and actual frequency of asymptomatic OG diminution is not known. Methods: This was a multicenter retrospective analysis of patients on HeartMate II (HMII) or HeartMate 3 (HM3) support surviving at least 180 days with at least one chest computed tomography (CT) scan at 6 months, 1, 2, and/or 3 years postoperative. Patients with OG obstruction due to torsion were excluded. The outflow graft (OG) diameter was measured at its narrowest region; region was categorized as external outflow graft (EOG), mid-graft, or within 2 cm of the aortic anastomosis. Mixed models with repeated measure linear regression was used to assess OG diameter change over time, with 14 mm as reference. Using the narrowest measure, OG diameter was modelled for freedom from death, admission for HF and low flow alarms with hazard ratio [95% CI presented]. Results: Of 71 patients included herein, 25% and 75% were on HMII and HM3 support for a median [25th, 75th] 1230 [703,1592] days. The median CT count was 2 [1,2] per patient. At follow-up, small (1-3 mm, table), but statistically significant reductions in OG diameter were noted (Figure). The median OG narrowing was 7% [0%, 20%]. Time from device implant was the most significant contributing factor (p\u3c0.001) while wrapping of the outflow was nonsignificantly correlated with OG narrowing (p=0.071). Device model was not correlative (p=0.16). OG diameter was not correlated with survival (HR 1.04 [0.81-1.3]), stroke (HR 0.94 [0.78-1.1]) or admissions for heart failure (HR 1.06 [0.88-1.3]), or VAD alarms (HR 0.93 [0.79-1.1]). Conclusion: Minor narrowing of the OG was noted over time, irrespective of LVAD model. The observed degrees of non-twist related-OG narrowing herein did not lead to increase mortality or events. OG wrapping may be associated with OG narrowing over time. Larger sample analyses aim to define degrees of narrowing that elicit device dysfunction