Stroke after implantation of continuous flow left ventricular assist devices

Sex-Based Differences in Patients With Left Ventricular-Assisted Devices and Strokes

Background

Sex-based differences in clinical outcomes among patients with stroke related to left ventricular assist devices (LVADs) are not well described.

Objectives

In this study, the authors examined differences in clinical characteristics and outcomes in men and women who had a stroke during LVAD hospitalization.

Methods

The National Inpatient Sample from 2010 and 2019 was used to identify patients with stroke during LVAD hospitalization. Outcomes of interest include inpatient mortality and clinical complications among men vs women. Weighted logistic regression was used to determine the association of sex and outcomes. Adjustments were made for age and the Elixhauser comorbidity index.

Results

In total, 35,820 patients underwent LVAD implantation (77% men), and 6.12% (n = 2,192) of patients experienced stroke. Women who had stroke were younger than men who had stroke (mean age in women was 51 years vs men 59 years, P < 0.001). Men with strokes had a higher burden of comorbidities than women. While there were no differences in the odds of ischemic stroke, women had higher odds of hemorrhagic stroke compared to men (OR: 1.49 [95% CI: 1.02-2.18]). Mortality in patients with LVAD who had stroke was significantly higher than in those without stroke. Between 2010 and 2019, stroke rates significantly increased among men, while the trend remained variable among women.

Conclusions

In this national cohort, men had a higher comorbidity burden and had worsening stroke trends over the last decade compared to women. Women had fewer LVAD implants and a higher incidence of hemorrhagic stroke. Understanding the factors that contribute to sex-related outcome disparities among LVAD stroke patients is crucial in addressing these diverging trends.

Interplay between driveline infection, vessel wall inflammation, cerebrovascular events and mortality in patients with left ventricular assist device

In patients with left ventricular assist device (LVAD), infections and thrombotic events represent severe complications. We investigated device-specific local and systemic inflammation and its impact on cerebrovascular events (CVE) and mortality. In 118 LVAD patients referred for 18F-FDG-PET/CT, metabolic activity of LVAD components, thoracic aortic wall, lymphoid and hematopoietic organs, was quantified and correlated with clinical characteristics, laboratory findings, and outcome. Driveline infection was detected in 92/118 (78%) patients by 18F-FDG-PET/CT. Activity at the driveline entry site was associated with increased signals in aortic wall (r = 0.32, p < 0.001), spleen (r = 0.20, p = 0.03) and bone marrow (r = 0.20, p = 0.03), indicating systemic interactions. Multivariable analysis revealed independent associations of aortic wall activity with activity of spleen (β = 0.43, 95% CI 0.18-0.68, p < 0.001) and driveline entry site (β = 0.04, 95% CI 0.01-0.06, p = 0.001). Twenty-two (19%) patients suffered CVE after PET/CT. In a binary logistic regression analysis metabolic activity at the driveline entry site missed the level of significance as an influencing factor for CVE after adjusting for anticoagulation (OR = 1.16, 95% CI 1-1.33, p = 0.05). Metabolic activity of the subcutaneous driveline (OR = 1.13, 95% CI 1.02-1.24, p = 0.016) emerged as independent risk factor for mortality. Molecular imaging revealed systemic inflammatory interplay between thoracic aorta, hematopoietic organs, and infected device components in LVAD patients, the latter predicting CVE and mortality.

Bridge from central extracorporeal life support is a risk factor of cerebrovascular accidents after durable left ventricular assist device implantation

A bridging strategy from extracorporeal life support (ECLS) is effective in salvage and a bridge to recovery or to a durable left ventricular assist device (LVAD) for acute refractory heart failure. However, the correlation of this strategy with adverse events after durable LVAD implantation has not been fully investigated. This study enrolled 158 consecutive patients who had either the HeartMate II or HeartMate 3 and were implanted for bridge-to-transplantation. These devices were implanted as the primary mechanical support device in 115 patients, whereas the remaining 43 underwent LVAD implantation as the bridge from central ECLS. The primary study endpoint was all-cause mortality and cerebrovascular accidents (CVAs) after durable LVAD implantation, and the secondary endpoints were adverse events. Overall survival was not significantly different between the two groups. In contrast, the probability of CVAs was significantly greater in the bridge group than in the primary group (probability of CVAs, P = 0.002; log-rank test). In Cox multivariate logistic regression analysis, a bridge from central ECLS was an independent predictive factor of CVAs (hazard ratio 4.27, 95% confidence interval 1.43-12.8; P = 0.0095). Patients who are bridged from central ECLS are more frequently complicated by CVAs compared with those who undergo primary implantation of a durable LVAD, but survival is not significantly different between the two groups. A bridge from central ECLS is an independent predictive factor of CVAs post-implantation of an LVAD.

Stroke in Patients with Left Ventricular Assist Devices

BACKGROUND

Left ventricular assist devices (LVADs) are artificial pumps used in end-stage heart failure to support the circulatory system. These cardiac assist devices work in parallel to the heart, diverting blood from the left ventricle through an outflow graft and into the ascending aorta. LVADs have allowed patients with end-stage heart failure to live longer and with improved quality of life compared to best medical therapy alone. However, they are associated with significant risks related to both thrombosis and bleeding in this medically complex patient population. As LVADs continue to be used more widely, stroke neurologists need to become familiar with the unique physical exam and vascular imaging findings associated with this population.

SUMMARY

Reported rates of LVAD-associated stroke at 2 years post-implantation range from 10 to 30%, which is significantly higher than in age-matched controls. There are approximately equal rates of ischemic and hemorrhagic strokes, and rates are highest during the peri-implantation period and in the first year of therapy. Risk factors associated with ischemic and hemorrhagic stroke in this cohort can be grouped into treatment-related factors, including specific devices and antithrombotic/anticoagulation strategy, and patient-related factors. Evidence for reperfusion therapy for acute stroke in this population is limited. Intravenous tissue plasminogen activator (IV-tPA) is often contraindicated as events may occur in the perioperative setting, or in the context of therapeutic anticoagulation. Endovascular therapy with successful recanalization is reported, but there is little experience documented in the published literature. Key messages: LVAD use is increasingly common. Given the high associated risks of stroke, neurologists will need to become increasingly familiar with an approach to assessment and therapy for LVAD patients with cerebrovascular issues.

Pharmacotherapy for durable left ventricular assist devices

Left ventricular assist devices (LVADs) have revolutionized the care of patients with advanced heart failure, yet still require concomitant medications in order to achieve the best possible clinical outcomes. Since the outset of routine placement of durable, continuous-flow LVADs, much of the medication management of these patients to date has been based on International Society of Heart and Lung Transplantation (ISHLT) guidance, most recently published in 2013. Since 2013, numerous multidisciplinary pharmacotherapy publications have increased the LVAD community's understanding of best practices with respect to medications. We identified the major domains of LVAD medication management and conducted a comprehensive search of US National Library of Medicine MEDLINE^® database using keywords chosen to identify medication-related publications of significance dated 2013 or later. Trials pertaining to the HeartMate II™ and the HeartMate™ 3 LVADs (Abbott, Chicago, IL) and the HeartWare™ HVAD™ System (Medtronic, Minneapolis, MN) were chosen for inclusion. Highest priority for inclusion was given to prospective, randomized, controlled studies. Absent these, controlled trials (retrospective or prospective observational) were given next-highest consideration, followed by retrospective uncontrolled studies, and finally case series. Reference lists of qualified publications were reviewed to find any other publications of interest that were not discovered on initial search. Case reports were generally excluded, except where the insight gained was deemed to be uniquely pertinent. This document serves to provide a comprehensive review of the current understanding of optimal medication management in patients with durable, continuous-flow LVADs.

The influence of left ventricular assist device inflow cannula position on thrombosis risk

The use of left ventricular assist devices (LVADs) as a treatment method for heart failure patients has been steadily increasing; however, pathological studies showed presence of thrombi around the HeartWare ventricular assist device inflow cannula (IC) in more than 95% of patients after device explantation. Flow fields around the IC might trigger thrombus formation and require further investigation. In this study flow dynamics parameters were evaluated for different patient geometries using computational fluid dynamics (CFD) simulations. Left ventricular (LV) models of two LVAD patients were obtained from CT scans. The LV volumes of Patient 1 (P1) and Patient 2 (P2) were 264 and 114 cm3 with an IC angle of 20° and 9° from the mitral-IC tip axis at the coronal plane. The IC insertion site at the apex was central for P1, whereas it was lateral for P2. Transient CFD simulations were performed over 9 cardiac cycles. The wedge area was defined from the cannula tip to the wall of the LV apex. Mean velocity magnitude and blood stagnation region (volume with mean velocity <5 mm/s) as well as the wall shear stress (WSS) at the IC surface were calculated. Cardiac support resulted in a flow mainly crossing the ventricle from the mitral valve to the LVAD cannula for P2, while the main inflow jet deviated toward the septal wall in P1. Lower WSS at the IC surface and consequently larger stagnation volumes were observed for P2 (P1: 0.17, P2: 0.77 cm3 ). Flow fields around an LVAD cannula can be influenced by many parameters such as LV size, IC angle, and implantation site. Careful consideration of influencing parameters is essential to get reliable evaluations of the apical flow field and its connection to apical thrombus formation. Higher blood washout and lower stagnation were observed for a central implantation of the IC at the apex.