Clinical characteristics and outcomes of patients requiring prolonged inotropes after left ventricular assist device implantation.

Limited data exist regarding patients with continuous-flow left ventricular assist device (LVAD) support who require long-term inotropes. Our primary objective was to evaluate the clinical characteristics and all-cause mortality of LVAD recipients with prolonged inotrope use (PIU). Secondary endpoints were to compare predictors of PIU, mortality, risk of late re-initiation of inotropes, time to gastrointestinal bleed (GIB), infection, and arrhythmias. Retrospective cohort study was conducted on adult patients with primary continuous-flow LVADs implanted from January 2008 to February 2017 and the patients were followed up through February 2018. We defined PIU as ≥14 days of inotrope support. Kaplan-Meier method, competing risk models and Cox proportional hazard models were used. Final analytic sample was 203 patients, 58% required PIU, and 10% were discharged on inotropes. There was no difference in preimplant characteristics. One-year survival rate was 87% if no PIU required, 74% if PIU required, and 72% if discharged on inotropes. PIU was associated with longer length of stay and higher incidence of GIB. We found no association between PIU and late re-initiation of inotropes, infection or arrhythmias. Adjusted hazard risk of death was increased in patients with PIU (HR = 1.66, P = .046), older age (HR = 1.28, P = .031), and higher creatinine levels (HR = 1.60, P = .007). Prolonged inotrope use is frequently encountered following LVAD implantation and is associated with adverse prognosis but remains a therapeutic option. Inability to wean inotropes prior to hospital discharge is a marker of patients at particularly higher risk of mortality following LVAD implantation.

High Right Atrial Pressure and Low Pulse Pressure Predict Gastrointestinal Bleeding in Patients With Left Ventricular Assist Device.

BACKGROUND: Gastrointestinal bleeding (GIB) remains a major morbid event during continuous flow left ventricular assist device (LVAD) support. This study investigated whether a common hemodynamic profile is associated with GIB in patients with LVADs. METHODS AND RESULTS: A single institution analysis reviewed all patients who underwent right heart catheterization (RHC) following LVAD implant between January 1, 2006, and December 31, 2013, with follow-up through June 2015. Kaplan-Meier and multiphase hazard statistical methods were employed. Among 108 patients with 341 RHC, 55 hospitalizations for GIB occurred within 1 year of RHC. Freedom from GIB at 6 months was 92% in patients with pulse pressure ≥35 mmHg, compared with 76% with pulse pressure <35 mmHg. By multivariable analysis, the significant predictors of GIB were: older age at implant, number of prior GIB, lower pulse pressure, lower mean arterial pressure, and higher right atrial pressure (all P < .05). The magnitude of effect is influenced by pulse pressure. CONCLUSIONS: Greater pulsatility and less venous congestion, along with other factors, are associated with a lower risk for GIB. It is reasonable to adjust therapeutic strategies to target this hemodynamic profile in patients with a propensity for GIB.

Acute Hemodynamic Effects of Biventricular Pacing After Left Ventricular Assist Device.

BACKGROUND: Despite cardiac resynchronization therapy (CRT), some patients with heart failure progress and undergo left ventricular assist device (LVAD) implantation. Management of CRT after LVAD implantation has not been well studied. The purpose of this study was to determine whether RV pacing or biventricular pacing measurably affects acute hemodynamics in patients with an LVAD and a CRT device. METHODS AND RESULTS: Seven patients with CRT and LVAD underwent right heart catheterization. Pressures and oximetry were measured and LVAD parameters were recorded during 3 different conditions: RV pacing alone, biventricular pacing, and intrinsic atrioventricular conduction. Paired t tests were used to evaluate changes within subjects. There were no significant changes in right atrial pressure, pulmonary arterial pressures, pulmonary capillary wedge pressure, cardiac index, or any LVAD parameter (P > .05). CONCLUSIONS: Our data suggest that CRT probably has no acute hemodynamic effect in patients with LVADs, but further study is needed.

Infection and rejection risk after cardiac transplantation with induction vs. no induction: a multi-institutional study.

Data from Cardiac Transplant Research Database (CTRD) were analyzed from 1999 to 2006 to examine the effects of different induction strategies at the time of cardiac transplantation. A total of 2090 primary heart transplants were categorized by induction with interleukin-2 receptor blocker (IL-2RB), antithymocyte globulin (ATG), or no induction (NI). Probabilities for rejection and infection were estimated with parametric time-related models. Using these models, hazard was calculated for two theoretical patient profiles, one at lower risk for rejection and higher risk of infection (Profile 1) and higher risk for rejection and lower risk of infection (Profile 2). Of the 2090 transplants, 49.8% (1095) did not receive induction, 27.3% (599) received IL-2RB, and 18.0% (396) received ATG. Profile 1 patients had lower hazard for rejection with IL-2RB compared to ATG and NI (p < 0.01), but at the cost of increased risk of infection (5.0 vs. 1.8 vs. 1.6, respectively, at four wk, p < 0.01). Profile 2 patients experienced a fivefold decreased hazard for rejection when treated with IL-2RB compared with ATG and NI (p < 0.01). In patients at high risk of infection, IL-2RB reduced risk of rejection but at the expense of increased hazard for infection.

Giant-cell myocarditis management using short-term TandemHeart support, MANTA closure device, and combination immunosuppression.

We present the case of a 53-year-old woman who presented to the hospital with palpitations and fatigue. The workup revealed new-onset systolic heart failure secondary to giant cell myocarditis. She developed cardiogenic shock, which was managed with the TandemHeart left ventricular assist device and combination immunosuppression strategy. This article highlights our management approach that avoided the need for an urgent heart transplant.

Narrative review of pharmacotherapy for transthyretin cardiac amyloid.

Treatment of cardiac amyloidosis is determined by the amyloid type and degree of involvement. Two types of amyloid commonly infiltrate the heart: immunoglobulin light-chain amyloid (AL), and transthyretin amyloid (ATTR), that encompasses other two forms, a hereditary form (hATTR), and a sporadic, age-related wild-type (wtATTR). The prevalence is expected to increase with aging population. The natural history of ATTR cardiomyopathy includes progressive heart failure (HF), complicated by arrhythmias and conduction system disease. New therapies options have been approved or are under investigation. We performed a narrative literature review, manually-searched the reference lists of included articles and relevant reviews. Treatment for cardiac ATTR should be directed towards alleviation of HF symptoms and to slow or stop progressive amyloid deposition. Conventional HF medications are poorly tolerated and may not alter the disease progression or symptoms, except perhaps with the administration of diuretics. There are three approaches of therapy for ATTR cardiomyopathy: tetramer stabilizers, inhibition of ATTR protein synthesis and clearance of deposited fibrils. Tafamidis diminishes the progression of cardiomyopathy, functional parameters, improves overall outcome in patients with early disease stages, irrespective of ATTR status and is well tolerated. Diflunisal has shown promising results in early studies, but at the expense of significant side effects. Two new agents, antisense oligonucleotides, patisiran and inotersen are under investigation in cardiac amyloidosis. Patisiran appears to be the most effective treatment for hATTR, although evidence is limited, with a relatively small cardiac subpopulation. Therapies considering clearance of amyloid fibrils from tissue remain experimental. In conclusion, tafamidis is the only approved agent for the treatment of ATTR cardiomyopathy although multiple other agents have shown promising early results and are undergoing clinical trials. Careful consideration of the type of ATTR, comorbidities and disease stage will be key in deciding the optimal therapy for ATTR patients.

Persistent mitral regurgitation after left ventricular assist device: a clinical conundrum.

AIMS: Persistent mitral valve regurgitation (MR) after continuous flow left ventricular assist device implantation (cfLVAD) is associated with pulmonary hypertension and right ventricular failure with variable effects on survival across published studies. The aim of this study is to determine the incidence and predictors of persistent MR at 6-month follow-up after cfLVAD implantation and its impact on survival, haemodynamics, right ventricular function, and morbidity. METHODS AND RESULTS: We performed a retrospective review of all adult cfLVAD recipients from January 2012 to June 2017 at a single tertiary university hospital with follow-up until April 2019. Primary outcome was to compare survival between patients with no-to-mild compared with persistent moderate-to-severe MR at 6 months. Secondary outcomes included right heart failure (RHF), length of stay, re-hospitalizations, and composite of death, transplant, and pump exchange during the length of follow-up. Final analytic sample was 111 patients. The incidence of persistent moderate or severe MR at 6 months was 26%. Significant predictors of persistent MR at 6 months were left atrium dimension and volume. The group with persistent moderate-to-severe MR at 6 months had higher incidence of RHF at 6 months (45% vs. 25%, P = 0.04). There was no difference in survival at 1 year between the groups (no-to-mild MR 85.5%, moderate-to-severe MR 87.9%, Wilcoxon P-value = 0.63). There was no difference in re-hospitalizations, length of stay, composite of death, transplant, or pump exchange during the length of follow-up between the comparison groups. CONCLUSIONS: Persistent moderate-to-severe MR after cfLVAD implantation is present in one fourth of patients and is associated with increased incidence of RHF, higher mean pulmonary pressure, and pulmonary capillary wedge pressure with no effect on 1 year survival. Increased left atrium size was associated with persistent moderate-to-severe MR at 6 months.

Device related infections: are we making progress?

Infection was identified early in development of mechanical circulatory support devices (MCSDs) as an important cause of morbidity and mortality. Sepsis, infection of implanted pump components, and infections of percutaneous drivelines continue to limit survival and decrease quality of life for patients with a MCSD. This review examines five questions related to whether there has been progress in preventing or managing infection complications in patients with MCSDs. Have changes in patient selection, device design, and surgical implant techniques decreased the incidence of infection? Do smaller implanted blood pumps have a lower risk for infection than larger implanted blood pumps? Will fully implanted circulatory support systems have fewer infection complications than tethered MCSDs? Can optimal design of a driveline together with improvements in surgical techniques and care of the percutaneous driveline diminish the rate and consequences of driveline infections? Have improvements in the preoperative, intraoperative, and immediate postoperative management of patients with MCSDs decreased the risk of sepsis? Although infection remains an important problem for patients with MCSDs, there is evidence that we are making progress as described in this review. It is crucial that we continue.

Management of reproductive health in patients with pulmonary hypertension.

Pulmonary hypertension is characterized by elevated pulmonary artery pressure caused by several clinical conditions that affect pulmonary vasculature. Morbidity and death in this condition are related to the development of right ventricular failure. Normal physiologic changes that occur in pregnancy to support the growing fetus can pose hemodynamic challenges to the pregnant patient with pulmonary hypertension that results in increased morbidity and mortality rates. Current guidelines recommend that patients with known pulmonary hypertension be counseled against pregnancy. This review aims to provide clinicians with guidelines for preconception counseling, medication management, and delivery planning.

Invasive monitoring in patients with heart failure.

The syndrome of heart failure is characterized by symptoms that are relatively insensitive and nonspecific. Physical diagnosis may be unreliable even in the hands of experienced clinicians, despite the presence of significantly elevated filling pressures or a significantly depressed cardiac output. Instrumentation and devices such as the insertion of a pulmonary artery catheter and the implantable hemodynamic monitor have a major role in the diagnosis and management of cardiovascular disease. They provide a means of measuring intracardiac pressures for point-in-time measurements (cardiac catheterization), short term in an acute situation (insertion of a pulmonary arterial catheter), and, more recently, a long-term assessment increasing our understanding of the nuances of the hemodynamic derangements associated with heart failure and other conditions. With improved ability to accurately assess and monitor filling pressures, clinicians can more precisely adjust therapy with the goal of improving patient symptoms and possibly outcomes.

Implantable hemodynamic monitors.

The evaluation and management of volume status in patients with heart failure is a challenge for most clinicians. In addition, such an evaluation is possible only during a personal clinician-patient interface. The ability to acquire hemodynamic data continuously with the help of implanted devices with remote monitoring capability can provide early warning of heart failure decompensation and thus may aid in preventing hospitalizations for heart failure. The data obtained also may improve the understanding of the disease process. It is important for the clinician treating patients who have heart failure to become acquainted with this type of technology and learn to interpret and use these data appropriately. This article reviews the implantable hemodynamics monitors currently available.

Performance of Noninvasive Assessment in the Diagnosis of Right Heart Failure After Left Ventricular Assist Device.

Right heart failure (RHF) after left ventricular assist device (LVAD) is associated with poor outcomes. Interagency Registry for Mechanically Assisted Circulatory Support (Intermacs) defines RHF as elevated right atrial pressure (RAP) plus venous congestion. The purpose of this study was to examine the diagnostic performance of the noninvasive Intermacs criteria using RAP as the gold standard. We analyzed 108 patients with LVAD who underwent 341 right heart catheterizations (RHC) between January 1, 2006, and December 31, 2013. Physical exam, echocardiography, and laboratory data at the time of RHC were collected. Conventional two-by-two tables were used and missing data were excluded. The noninvasive Intermacs definition of RHF is 32% sensitive (95% cardiac index (CI), 0.21-0.44) and 97% specific (95% CI, 0.95-0.99) for identifying elevated RAP. Clinical assessment failed to identify two-thirds of LVAD patients with RAP > 16 mm Hg. More than half of patients with elevated RAP did not have venous congestion, which may represent a physiologic opportunity to mitigate the progression of disease before end-organ damage occurs. One-quarter of patients who met the noninvasive definition of RHF did not actually have elevated RAP, potentially exposing patients to unnecessary therapies. In practice, if any component of the Intermacs definition is present or equivocal, our data suggest RHC is warranted to establish the diagnosis.

Evaluation of flow-modulation approaches in ventricular assist devices using an in-vitro endothelial cell culture model.

BACKGROUND: Continuous-flow ventricular assist devices (CF-VADs) produce non-physiologic flow with diminished pulsatility, which is a major risk factor for development of adverse events, including gastrointestinal (GI) bleeding and arteriovenous malformations (AVMs). Introduction of artificial pulsatility by modulating CF-VAD flow has been suggested as a potential solution. However, the levels of pulsatility and frequency of CF-VAD modulation necessary to prevent adverse events are currently unknown and need to be evaluated. METHODS: The purpose of this study was to use human aortic endothelial cells (HAECs) cultured within an endothelial cell culture model (ECCM) to: (i) identify and validate biomarkers to determine the effects of pulsatility; and (ii) conclude whether introduction of artificial pulsatility using flow-modulation approaches can mitigate changes in endothelial cells seen with diminished pulsatile flow. Nuclear factor erythroid 2-related factor 2 (Nrf-2)-regulated anti-oxidant genes and proteins and the endothelial nitric oxide synthase/endothelin-1 (eNOS/ET-1) signaling pathway are known to be differentially regulated in response to changes in pulsatility. RESULTS: Comparison of HAECs cultured within the ECCM (normal pulsatile vs CF-VAD) with aortic wall samples from patients (normal pulsatile [n = 5] vs CF-VADs [n = 5]) confirmed that both the Nrf-2-activated anti-oxidant response and eNOS/ET-1 signaling pathways were differentially regulated in response to diminished pulsatility. Evaluation of 2 specific CF-VAD flow-modulation protocols to introduce artificial pulsatility, synchronous (SYN, 80 cycles/min, pulse pressure 20 mm Hg) and asynchronous (ASYN, 40 cycles/min, pulse pressure 45 mm Hg), suggested that both increased expression of Nrf-2-regulated anti-oxidant genes and proteins along with changes in levels of eNOS and ET-1 can potentially be minimized with ASYN and, to a lesser extent, with SYN. CONCLUSIONS: HAECs cultured within the ECCM can be used as an accurate model of large vessels in patients to identify biomarkers and select appropriate flow-modulation protocols. Pressure amplitude may have a greater effect in normalizing anti-oxidant response compared with frequency of modulation.

Treprostinil-based therapy in the treatment of moderate-to-severe pulmonary arterial hypertension: long-term efficacy and combination with bosentan.

BACKGROUND: Treprostinil, a long-acting prostacyclin analog, diminished the symptoms of pulmonary arterial hypertension (PAH) in controlled 12-week clinical efficacy studies. This retrospective, single-center, open-label study was designed to assess the efficacy of long-term, subcutaneously administered, treprostinil-based therapy alone or in combination with bosentan for the treatment of moderate-to-severe PAH. METHODS: Thirty-eight patients with pulmonary hypertension treated with subcutaneous treprostinil were followed up for a mean (+/-SD) duration of 984+/-468 days (range, 165 to 1,847 days). Oral bosentan was added to the treprostinil regimen if patients remained in New York Heart Association (NYHA) functional class III or II with intolerable prostacyclin side effects that limited therapy. Hemodynamic studies, Borg dyspnea score evaluations, 6-min walk (6MW) tests, and NYHA functional class determinations were performed at approximately 6-month intervals. RESULTS: Mean pulmonary artery pressure decreased from 59.7 to 50.5 mm Hg (p<0.001). Significant and sustained improvement in 6MW distance (p=0.022) and Borg dyspnea score (p=0.023) were observed. At the final observation, the mean dose of treprostinil was 37.8 ng/kg/min (range, 7.5 to 115 ng/kg/min). At baseline, 5% of patients were in NYHA functional class 2 or lower vs 58% at the last follow-up. Bosentan was added to the regimens of 19 patients. In those patients, significant additional improvement occurred in the pulmonary arterial pressure (p<0.001), 6MW distance (p=0.001), and Borg dyspnea scale (p=0.020) compared to baseline. CONCLUSIONS: Long-term treatment with subcutaneous treprostinil-based therapy improved functional parameters and hemodynamics in patients with moderate-to-severe PAH. In patients requiring combination therapy, the addition of oral bosentan to treprostinil-based therapy was safe, well-tolerated, and associated with further clinical improvements.

Novel Noninvasive Assessment of Pulmonary Arterial Stiffness Using Velocity Transfer Function.

Background Pulmonary artery ( PA ) stiffness is associated with increased pulmonary vascular resistance ( PVR ). PA stiffness is accurately described by invasive PA impedance because it considers pulsatile blood flow through elastic PA s. We hypothesized that PA stiffness and impedance could be evaluated noninvasively by PA velocity transfer function ( VTF ), calculated as a ratio of the frequency spectra of output/input mean velocity profiles in PA s. Methods and Results In 20 participants (55±19 years, 14 women) undergoing clinically indicated right-sided heart catheterization, comprehensive phase-contrast and cine-cardiac magnetic resonance imaging was performed to calculate PA VTF , along with right ventricular mass and function. PA impedance was measured as a ratio of frequency spectra of invasive PA pressure and echocardiographically derived PA flow waveforms. Mean PA pressure was 29.5±13.6 mm Hg, and PVR was 3.5±2.8 Wood units. A mixed-effects model showed VTF was significantly associated with PA impedance independent of elevation in pulmonary capillary wedge pressure ( P=0.005). The mean of higher frequency moduli of VTF correlated with PVR (ρ=0.63; P=0.003) and discriminated subjects with low (n=10) versus elevated PVR (≥2.5 Wood units, n=10), with an area under the curve of 0.95, similar to discrimination by impedance (area under the curve=0.93). VTF had a strong inverse association with right ventricular ejection fraction (ρ=-0.73; P<0.001) and a significant positive correlation with right ventricular mass index (ρ=0.51; P=0.02). Conclusions VTF , a novel right ventricular- PA axis coupling parameter, is a surrogate for PA impedance with the potential to assess PA stiffness and elevation in PVR noninvasively and reliably using cardiac magnetic resonance imaging.

Xenograft calcification in Reiter's syndrome.

Reiter's syndrome is characterized by multiple joint arthropathy, and can affect the heart. One manifestation of cardiac involvement is aortic insufficiency that may require valve replacement. Herein is reported a case with rapidly progressive and severe calcification of a bovine pericardial prosthesis seven years after implantation, in the setting of Reiter's syndrome. Based on this experience, it is suggested that echocardiographic evaluations be scheduled more frequently than usual if a bioprosthetic rather than mechanical valve is chosen for a patient with Reiter's syndrome.

INTERMACS Analysis of Stroke During Support With Continuous-Flow Left Ventricular Assist Devices: Risk Factors and Outcomes.

OBJECTIVES: This study sought to evaluate predictors of stroke during left ventricular assist device (LVAD) support from data available prior to implantation, and quantify stroke-related morbidity and mortality. BACKGROUND: Stroke is a major complication after LVAD. Pre-implant factors that influence stroke are not well understood. METHODS: We evaluated all patients in INTERMACS (Interagency Registry for Mechanically Assisted Circulatory Support) who were implanted with continuous flow LVADs from May 1, 2012, to March 31, 2015. Pre-operative risk factors for stroke and stroke incidence, morbidity, and mortality were analyzed. RESULTS: During the study period, 7,112 patients underwent continuous flow LVAD placement. Median follow-up was 9.79 months (range 0.02 to 34.96 months). Of all patients, 752 (10.57%) had at least 1 stroke, with an incidence rate of 0.123 strokes per patient-year. A total of 447 (51.38%) strokes were ischemic and 423 (48.62%) were hemorrhagic. Patients with hemorrhagic stroke had worse survival than those with ischemic strokes (30-day survival: 45.3% vs. 80.7%; p < 0.001). Of patients with a first stroke, 13% had a second stroke. Pre-implant predictors of stroke were female sex (hazard ratio [HR]: 1.51; 95% confidence interval [CI]: 1.25 to 1.82; p < 0.001), pre-implant systolic blood pressure (HR: 1.01; 95% CI: 1.00 to 1.01; p = 0.002), heparin-induced thrombocytopenia (HR: 3.68; 95% CI: 1.60 to 8.47; p = 0.002), intra-aortic balloon pump (HR: 1.21; 95% CI: 1.01 to 1.46; p = 0.043), and primary cardiac diagnosis (ischemic/other/unknown) (p = 0.040). CONCLUSIONS: Despite improvements in LVAD technology, stroke-related morbidity and mortality is substantial. Further investigation is necessary to decrease the risk of this devastating complication.