Management and Outcome of Left Ventricular Assist Device Infections in Patients Undergoing Cardiac Transplantation

Special Considerations for Advanced Heart Failure Surgeries: Durable Left Ventricular Devices and Heart Transplantation

Heart transplantation and durable left ventricular assist devices (LVADs) represent two definitive therapies for end-stage heart failure in the modern era. Despite technological advances, both treatment modalities continue to experience unique risks that impact surgical and perioperative decision-making. Here, we review special populations and factors that impact risk in LVAD and heart transplant surgery and examine critical decisions in the management of these patients. As both heart transplantation and the use of durable LVADs as destination therapy continue to increase, these considerations will be of increasing relevance in managing advanced heart failure and improving outcomes.

Neutrophil Structural and Functional Alterations After High Mechanical Shear Stress Exposure

Patients on mechanical circulatory support are prone to infections, increasing morbidity and mortality. These circulatory support devices generate high mechanical shear stress (HMSS) that can causes trauma to blood. When leukocytes become damaged, their immune response function may be impaired or weakened, leading to increased infection vulnerability. This study examined neutrophil structural and functional alterations after exposure to 75, 125, and 175 Pa HMSS for 1 second. Human blood was exposed to three levels of HMSS using a blood shearing device. Neutrophil morphological alteration was characterized by examining blood smears. Flow cytometry assays were used to analyze expression levels of CD62L and CD162 receptors, activation level (CD11b), and aggregation (platelet-neutrophil aggregates). Neutrophil phagocytosis and rolling were examined via functional assays. The results show neutrophil structure (morphology and surface receptors) and function (activation, aggregation, phagocytosis, rolling) were significantly altered after HMSS exposure. These alterations include cell membrane damage, loss of surface receptors (CD62L and CD162), initiation of activation and aggregation, upregulation of phagocytic ability and increased rolling speed. The alterations were the most severe after 175 Pa exposure. HMSS caused damage and activation of neutrophils, potentially impairing normal neutrophil function, leading to weakened immune defense and increasing a patient's vulnerability to infections.

Continuous-flow left ventricular assist device systems infections: current outcomes and management strategies

Left ventricular assisted devices (LVADs) are increasingly used for management of patients with advanced heart failure. However, infection remains one of the most commonly reported complications. Diagnosis, as well as treatment of LVAD infections is challenging. There are multiple diagnostic modalities that have been used to assist with accurate diagnosis of LVAD infections. Treatment of the infection can be especially challenging in these patients, given the presence of the implantable device that cannot be easily replaced or removed. There are no clinical trials assessing the best approach to diagnosis, treatment or long-term management of LVAD infections. In this article we review the most recent diagnostic modalities and treatment approaches, as well as offer our guidance on diagnosis and treatment of LVAD infections.

Management of Bloodstream Infections in Left Ventricular Assist Device Recipients: To Suppress, or Not to Suppress?

Background

Ascertaining involvement of left ventricular assist device (LVAD) in a patient presenting with bloodstream infection (BSI) can be challenging, frequently leading to use of chronic antimicrobial suppressive (CAS) therapy. We aimed to assess the efficacy of CAS therapy to prevent relapse of BSI from LVAD and non-LVAD sources.

Methods

We retrospectively screened adults receiving LVAD support from 2010 through 2018, to identify cases of BSI. Bloodstream infection events were classified into LVAD-related, LVAD-associated, and non-LVAD BSIs.

Results

A total of 121 episodes of BSI were identified in 80 patients. Of these, 35 cases in the LVAD-related, 14 in the LVAD-associated, and 46 in the non-LVAD BSI groups completed the recommended initial course of therapy and were evaluated for CAS therapy. Chronic antimicrobial suppressive therapy was prescribed in most of the LVAD-related BSI cases (32 of 35, 91.4%) and 12 (37.5%) experienced relapse. Chronic antimicrobial suppressive therapy was not prescribed in a majority of non-LVAD BSI cases (33, 58.9%), and most (31, 93.9%) did not experience relapse. Chronic antimicrobial suppressive therapy was prescribed in 9 of 14 (64.2%) cases of LVAD-associated BSI and none experienced relapse. Of the 5 cases in this group that were managed without CAS, 2 had relapse.

Conclusions

Patients presenting with LVAD-related BSI are at high risk of relapse. Consequently, CAS therapy may be a reasonable approach in the management of these cases. In contrast, routine use of CAS therapy may be unnecessary for non-LVAD BSIs.