Selection and management considerations to enhance outcomes in patients supported by left ventricular assist devices

PURPOSE OF REVIEW

Left ventricular assist devices (LVADs) are life-saving therapies for patients in end-stage heart failure (HF) with reduced ejection fraction regardless of candidacy for heart transplantation. Multiple clinical trials have demonstrated improved morbidity and mortality with LVADs when compared to medical therapy alone. However, the uptake of LVADs as a therapeutic option in a larger section of end-stage HF patients remains limited, partly due to associated adverse events and re-hospitalization.

RECENT FINDINGS

Accurate assessment and staging of HF patients is crucial to guide appropriate use of LVADs. Innovative methods to risk stratify patients and manage cardiac and noncardiac comorbidities can translate to improved outcomes in LVAD recipients. Inclusion of quality of life metrics and measurements of adverse events can better inform heart failure cardiologists to help identify ideal LVAD candidates. Addition of machine learning algorithms to this process may guide patient selection to improve outcomes.

SUMMARY

Patient selection and assessment of reversible medical comorbidities are critical to the postoperative success of LVAD implantation. Identifying patients most likely to benefit and least likely to experience adverse events should be a priority.

A role for the Reitan catheter pump for percutaneous cardiac circulatory support of patients presenting acute congestive heart failure with low output and renal dysfunction?

Outcomes in acute decompensated heart failure remain poor, in particular when patients present with impaired renal function. Recent results indicate that treatment of acute decompensated heart failure patients with the Reitan catheter pump not only increases cardiac index, but also improves renal function resulting in maintained increase of diuresis. These favorable effects were achieved without significant hemolysis, bleeding or vascular complications suggesting that Reitan catheter pump treatment has the potential to facilitate recovery from acute decompensated heart failure with low output and complicated by renal dysfunction.

Cardiorenal Syndrome: Classification, Pathophysiology, Diagnosis, and Treatment Strategies: A Scientific Statement From the American Heart Association

Cardiorenal syndrome encompasses a spectrum of disorders involving both the heart and kidneys in which acute or chronic dysfunction in 1 organ may induce acute or chronic dysfunction in the other organ. It represents the confluence of heart-kidney interactions across several interfaces. These include the hemodynamic cross-talk between the failing heart and the response of the kidneys and vice versa, as well as alterations in neurohormonal markers and inflammatory molecular signatures characteristic of its clinical phenotypes. The mission of this scientific statement is to describe the epidemiology and pathogenesis of cardiorenal syndrome in the context of the continuously evolving nature of its clinicopathological description over the past decade. It also describes diagnostic and therapeutic strategies applicable to cardiorenal syndrome, summarizes cardiac-kidney interactions in special populations such as patients with diabetes mellitus and kidney transplant recipients, and emphasizes the role of palliative care in patients with cardiorenal syndrome. Finally, it outlines the need for a cardiorenal education track that will guide future cardiorenal trials and integrate the clinical and research needs of this important field in the future.

Hemodynamic Support With a Microaxial Percutaneous Left Ventricular Assist Device (Impella) Protects Against Acute Kidney Injury in Patients Undergoing High-Risk Percutaneous Coronary Intervention

Rationale:

Acute kidney injury (AKI) is common during high-risk percutaneous coronary intervention (PCI), particularly in those with severely reduced left ventricular ejection fraction. The impact of partial hemodynamic support with a microaxial percutaneous left ventricular assist device (pLVAD) on renal function after high-risk PCI remains unknown.

Objective:

We tested the hypothesis that partial hemodynamic support with the Impella 2.5 microaxial pLVAD during high-risk PCI protected against AKI.

Methods and Results:

In this retrospective, single-center study, we analyzed data from 230 patients (115 consecutive pLVAD-supported and 115 unsupported matched-controls) undergoing high-risk PCI with ejection fraction ≤35%. The primary outcome was incidence of in-hospital AKI according to AKI network criteria. Logistic regression analysis determined the predictors of AKI. Overall, 5.2% (6) of pLVAD-supported patients versus 27.8% (32) of unsupported control patients developed AKI ( P <0.001). Similarly, 0.9% (1) versus 6.1% (7) required postprocedural hemodialysis ( P <0.05). Microaxial pLVAD support during high-risk PCI was independently associated with a significant reduction in AKI (adjusted odds ratio, 0.13; 95% confidence intervals, 0.09–0.31; P <0.001). Despite preexisting CKD or a lower ejection fraction, pLVAD support protection against AKI persisted (adjusted odds ratio, 0.63; 95% confidence intervals, 0.25–0.83; P =0.04 and adjusted odds ratio, 0.16; 95% confidence intervals, 0.12–0.28; P <0.001, respectively).

Conclusions:

Impella 2.5 (pLVAD) support protected against AKI during high-risk PCI. This renal protective effect persisted despite the presence of underlying CKD and decreasing ejection fraction.

Implantable left ventricular assist devices and the kidney

The use of left ventricular assist devices (LVADs) in treating patients with advanced heart failure restores cardiac output resulting in improved perfusion to multiple organ systems with important clinical benefits. Renal pathophysiology during LVAD support remains an evolving, poorly understood, and potentially dynamic problem. Changes in renal function after LVAD placement have been investigated in multiple studies with contradictory results. Renal dysfunction is common prior to LVAD placement, which complicates postoperative clinical outcomes. The purpose of this review is to assess the latest information regarding the effects of LVADs on renal function with regard to hemodynamics, physiology, pathology and clinical issues prior to and after placement of the devices. The review should then aid in identifying patients best suited to benefit from this technology and to refine the therapy to reduce associated risks.

A patient with heart failure and worsening kidney function

There is high prevalence of CKD, defined by reduced GFR, in patients with heart failure. Reduced kidney function is associated with increased morbidity and mortality in this patient population. The cardiorenal syndrome (CRS) involves a bidirectional relationship between the heart and kidneys whereby dysfunction in either may exacerbate the function of the other, but this syndrome has been difficult to precisely define because it has many complex physiologic, biochemical, and hormonal abnormalities. The pathophysiology of CRS is not completely understood, but potential mechanisms include reduced kidney perfusion due to decreased forward flow, increased right ventricular and venous pressure, and neurohormonal adaptations. Treatment options include inotropic medications; diuretics; ultrafiltration; and medications, such as β-blockers, inhibitors of the renin-angiotensin-aldosterone system, and more novel treatments that focus on unique aspects of the pathophysiology. Recent observational studies suggest that treatments that result in a decrease in venous pressure and lead to hemoconcentration may be associated with improved outcomes. Patients with CRS that is not responsive to medical interventions should be considered for ventricular assist devices, heart transplantation, or combined heart and kidney transplantation.