Safety analysis of intermittent hemodialysis in patients with continuous flow left ventricular assist devices

Evaluation and Management of Kidney Dysfunction in Advanced Heart Failure: A Scientific Statement From the American Heart Association

Early identification of kidney dysfunction in patients with advanced heart failure is crucial for timely interventions. In addition to elevations in serum creatinine, kidney dysfunction encompasses inadequate maintenance of sodium and volume homeostasis, retention of uremic solutes, and disrupted endocrine functions. Hemodynamic derangements and maladaptive neurohormonal upregulations contribute to fluctuations in kidney indices and electrolytes that may recover with guideline-directed medical therapy. Quantifying the extent of underlying irreversible intrinsic kidney disease is crucial in predicting whether optimization of congestion and guideline-directed medical therapy can stabilize kidney function. This scientific statement focuses on clinical management of patients experiencing kidney dysfunction through the trajectory of advanced heart failure, with specific focus on (1) the conceptual framework for appropriate evaluation of kidney dysfunction within the context of clinical trajectories in advanced heart failure, including in the consideration of advanced heart failure therapies; (2) preoperative, perioperative, and postoperative approaches to evaluation and management of kidney disease for advanced surgical therapies (durable left ventricular assist device/heart transplantation) and kidney replacement therapies; and (3) the key concepts in palliative care and decision-making processes unique to individuals with concomitant advanced heart failure and kidney disease.

Management of patients with heart failure and chronic kidney disease

Chronic kidney disease (CKD) and heart failure are often co-existing conditions due to a shared pathophysiological process involving neurohormonal activation and hemodynamic maladaptation. A wide range of pharmaceutical and interventional tools are available to patients with CKD, consisting of traditional ones with decades of experience and newer emerging therapies that are rapidly reshaping the landscape of medical care for this population. Management of patients with heart failure and CKD requires a stepwise approach based on renal function and the clinical phenotype of heart failure. This is often challenging due to altered drug pharmacokinetics interactions with various degrees of kidney function and frequent adverse effects from the therapy that lead to poor patient tolerance. Despite a great body of clinical evidence and guidelines that have offered various treatment options for patients with heart failure and CKD, respectively, patients with CKD are still underrepresented in heart failure clinical trials, especially for those with advanced CKD and end-stage renal disease (ESRD). Future studies are needed to better understand the generalizability of these therapeutic options among heart failures with different stages of CKD.

Outcomes of Patients With Left Ventricular Assist Devices Requiring Intermittent Hemodialysis: Single-Center Cohort, Systematic Review, and Individual-Participant Data Meta-Analysis

Patients with left ventricular assist devices (LVADs) who require intermittent hemodialysis (iHD) are considered to have a poor prognosis despite a paucity of supportive evidence, mostly from small single-center cohorts and extrapolations from studies of patients who received continuous renal replacement therapy but no iHD. We conducted a systematic review and individual-participant-data meta-analysis of the literature including our single-center cohort to examine the outcomes of patients initiated on iHD following LVAD implantation. Sixty-four patients from 5 cohorts met selection criteria (age 57.5 [46-64.5] years, 87% HeartMate II, mostly bridge to transplantation). Follow-up after iHD initiation was 87.5 (38.5-269.5) days, although it was considerably longer in our center than in other cohorts (601.5 [93-1559] days vs 65 [26-180] days, P = 0.0007). The estimated median survival was 308 (76-912.5) days and varied significantly among cohorts, ranging from 60 (57-65) to 838 (103-1872) days (P = 0.0096). Twelve (18.8%) patients achieved either heart transplantation (HT) or remission during follow-up. Patients who received HT had an 8-fold longer estimated median survival (1972 [799-1972] days vs 244 [64-838] days, P = 0.0112). Being from a more recent cohort was associated with better 1-year survival. Renal recovery occurred in eight patients (13.1%) at 30 days and its cumulative incidence increased to 73% (27/37 patients with available data) at 1 year. Most patients initiated on iHD after LVAD experienced renal recovery within the first year after implantation. Improved survival was observed for patients who received HT and in those from more recent cohorts. Some patients were able to survive on LVAD and iHD support for several years.

Nephrology Considerations in the Management of Durable and Temporary Mechanical Circulatory Support

Durable and temporary mechanical circulatory support (MCS) use is growing for a range of cardiovascular indications. Kidney dysfunction is common in people evaluated for or receiving durable or temporary MCS and portends worse outcomes. This kidney dysfunction can be due to preexisting kidney chronic kidney disease (CKD), acute kidney injury (AKI) related to acute cardiovascular disease necessitating MCS, AKI due to cardiac procedures, and acute and chronic MCS effects and complications. Durable MCS, with implantable continuous flow pumps, is used for long-term support in advanced heart failure refractory to guideline-directed medical and device therapy, either permanently or as a bridge to heart transplantation. Temporary MCS-encompassing in this review intra-aortic balloon pumps (IABP), axial flow pumps, centrifugal flow pumps, and venoarterial ECMO-is used for diverse situations: high-risk percutaneous coronary interventions (PCI), acute decompensated heart failure, cardiogenic shock, and resuscitation after cardiac arrest. The wide adoption of MCS makes it imperative to improve understanding of the effects of MCS on kidney health/function and of kidney health/function on MCS outcomes. The complex structure and functions of the kidney, and the complex health states of individuals receiving MCS, makes investigations in this area challenging, and current knowledge is limited. Fortunately, the increasing nephrology toolbox of noninvasive kidney health/function assessments may enable development and testing of individualized management strategies and therapeutics in the future. We review technology, epidemiology, pathophysiology, clinical considerations, and future directions in MCS and nephrology.

Peritoneal dialysis improves quality-of-life in a left ventricular assist device destination therapy patient-a case report

BACKGROUND

Progressive renal insufficiency is frequent in heart failure patients with a left ventricular assist device (LVAD). The optimal strategy for long-term dialysis in LVAD patients and its effect on quality-of-life in these patients remain to be determined.

CASE SUMMARY

Our 55-year-old patient with pre-existing renal insufficiency received an LVAD as destination therapy because of advanced ischaemic heart failure. Six years after implantation, he developed end-stage renal disease for which peritoneal dialysis (PD) was initiated. Left ventricular assist device flow alterations during ultrafiltration did not cause clinical or technical problems. The patient's exercise capacity increased and quality-of-life improved. Over 7.5 years after LVAD implantation and 16 months after PD initiation, he died from encephalitis.

DISCUSSION

Despite initial improvement, renal function often gradually decreases after LVAD implantation. Data on long-term renal replacement therapy in LVAD patients are limited. Haemodialysis is most commonly applied. Conceptually, however, PD has advantages over haemodialysis including less bloodstream infections, less haemodynamic shifts, and the comfort of the ambulant setting. This case illustrates that PD in an LVAD patient is feasible and improves quality-of-life. Key factors contributing to successful PD in LVAD patients may be a good right ventricular function and close cardiology-nephrology collaboration.

Ventricular Assist Devices and Chronic Kidney Replacement Therapy: Technology and Outcomes

Heart failure and kidney failure are very common conditions, precipitating and exacerbating each other. Left ventricular assist devices (LVADs) represent a relatively new technology for treatment of advanced heart failure. Kidney dysfunction, if present, makes candidate selection for LVADs challenging and contributes to multiple complications while the patients are on an LVAD support. Although kidney function generally improves after LVAD implantation, some patients develop acute and then chronic kidney disease sometimes requiring kidney replacement therapies (KRTs). Overall, chronic KRT in LVAD recipients is feasible and well tolerated, but routine technique of blood pressure monitoring should be adjusted to the continuous blood flow. Both hemodialysis and peritoneal dialysis can be used. Unique challenges for chronic KRT posed by the presence of LVAD are discussed in this review.

Trends, Outcomes, and Readmissions Among Left Ventricular Assist Device Recipients with Acute Kidney Injury Requiring Hemodialysis

Although renal function may improve after left ventricular assist devices (LVAD) implantation, acute kidney injury (AKI) requiring hemodialysis (HD) therapy can occur postoperatively. We used data from the National Readmissions Database to calculate annual rates of in-hospital outcomes and readmissions among patients who underwent implantation and developed acute kidney injury (AKI) requiring hemodialysis (HD) for years 2012-2015. We identified 178 (weighted 469) patients with AKI requiring HD after LVAD implantation. In-hospital mortality was significantly higher among LVAD recipients who required HD for AKI compared with those who did not (42.38% vs. 8.38%, p < 0.001). Rates of in-hospital mortality (from 52.1% in 2012 to 33.9% in 2014, p = 0.046) and length of stay (from 60.3 days in 2012 to 47.1 days in 2014, p = 0.003) decreased significantly, whereas there was a trend toward reduced hospital cost (from $320,414 in 2012 to $267,285 in 2014, p = 0.076) during the study period. However, postoperative bleeding increased significantly (p = 0.01). Acute kidney injury requiring HD after implantation was not associated with significantly higher rates of readmissions compared with LVAD recipients without AKI on HD, after adjustment for clinical and hospital characteristics (41.4% vs. 30.5%; odds ratio 1.28; 95% confidence interval [CI]: 0.85-1.95; P = 0.239). However, 5.42% of these patients required maintenance hemodialysis in readmissions. In-hospital mortality and length of stay are decreasing but remain unacceptably high in patients requiring HD for AKI after LVAD implantation but remain higher than LVAD recipients without AKI on HD. A minority of these patients who survive hospital discharge require maintenance hemodialysis.

Outcomes Among Patients With Left Ventricular Assist Devices Receiving Maintenance Outpatient Hemodialysis: A Case Series

RATIONALE & OBJECTIVE

The incidence of left ventricular assist device (LVAD) implantation as destination therapy for heart failure is increasing and kidney failure requiring maintenance hemodialysis is a common complication. Because little is known about the safety or efficacy of outpatient hemodialysis among patients with LVADs, this study sought to describe their clinical course.

STUDY DESIGN

Case series of patients with an LVAD undergoing maintenance outpatient hemodialysis whose clinical data were obtained from an electronic medical record.

SETTING & PARTICIPANTS

Adults who received an LVAD, survived to hospital discharge, and were subsequently treated with maintenance hemodialysis by a not-for-profit dialysis provider between 2011 and 2019.

RESULTS

11 patients were included. 6 had a known history of chronic kidney disease. Patients underwent outpatient hemodialysis for a mean duration of 165.2 (range, 31-542) days, during which they were treated with 544 total dialysis sessions. 6 of these sessions were stopped early due to dialysis-related adverse events (1.1%). More than 80% of follow-up time was spent out of the hospital; however, 55% of patients were rehospitalized within 1 month of starting outpatient hemodialysis. The most common reason for hospitalization was infection (32%), followed by hypervolemia (14%), and cerebrovascular accident or transient ischemic attack (11%). 4 patients recovered kidney function, 1 underwent combined heart and kidney transplantation, 2 continued treatment, 2 died, and 2 were lost to follow-up.

LIMITATIONS

Retrospective design, small number of cases, and lack of complete follow-up data.

CONCLUSIONS

Approximately half the patients with complete follow-up either recovered kidney function or underwent combined heart and kidney transplantation. This case series demonstrates that outpatient hemodialysis centers, in partnership with LVAD treatment teams, can successfully provide hemodialysis to patients on LVAD support.

Heart failure management in dialysis patients: Many treatment options with no clear evidence

Heart failure with reduced ejection fraction (HFrEF) impacts approximately 20% of dialysis patients and is associated with high mortality rates. Key issues discussed in this review of HFrEF management in dialysis include dialysis modality choice, vascular access, dialysate composition, pharmacological therapies, and strategies to reduce sudden cardiac death, including the use of cardiac devices. Peritoneal dialysis and more frequent or longer duration of hemodialysis may be better tolerated due to slower ultrafiltration rates, leading to less intradialytic hypotension and better volume control; dialysate cooling and higher dialysate calcium may also have benefits. While high-quality evidence exists for many drug classes in the non-dialysis population, dialysis patients were excluded from major trials, and only limited data exist for many medications in kidney failure patients. Despite limited evidence, beta blocker and angiotensin-converting enzyme inhibitor or angiotensin receptor blocker use is common in dialysis. Similarly, devices such as implantable cardiac defibrillators (ICDs) and cardiac resynchronization therapy that have proven benefits in non-dialysis HFrEF patients have not consistently been beneficial in the limited dialysis studies. The use of leadless pacemakers and subcutaneous ICDs can mitigate future hemodialysis access limitations. Additional research is critical to address knowledge gaps in treating maintenance dialysis patients with HFrEF.

Predictors and Outcomes of Renal Replacement Therapy After Left Ventricular Assist Device Implantation

OBJECTIVE

To examine the frequency and outcomes of patients requiring renal replacement therapy (RRT) early after left ventricular assist device (LVAD) implantation.

PATIENTS AND METHODS

We examined use of in-hospital RRT and outcomes in consecutive adults who underwent continuous-flow LVAD implantation from February 15, 2007, through August 8, 2017. Logistic regression was used to examine predictors of RRT. The associations of RRT with outcomes were examined using Cox proportional hazards regression.

RESULTS

Of 354 patients who underwent LVAD implantation, 54 (15%) required in-hospital RRT. Patients receiving RRT had higher preoperative Charlson Comorbidity Index values (median, 5 vs 4; P=.03), Model for End-Stage Liver Disease scores (mean, 19.0 vs 14.5; P<.001), right atrial pressure (mean, 19.1 vs 13.4 mm Hg; P<.001), and estimated 24-hour urine protein levels (median, 357 vs 174 mg; P<.001) and lower preoperative estimated glomerular filtration rate (eGFR) (median, 43 vs 57 mL/min; P<.001) and measured GFR using ¹²⁵I-iothalamate clearance (median, 33 vs 51 mL/min; P=.001) than those who did not require RRT. Approximately 40% of patients with eGFR less than 45 mL/min/1.73 m² and 24-hour urine protein level greater than 400 mg required RRT vs 6% with eGFR greater than45 mL/min/1.73 m² and without significant proteinuria. Lower preoperative eGFR, higher estimated 24-hour urine protein level, higher right atrial pressure, and longer cardiopulmonary bypass time were independent predictors of RRT after LVAD implantation. Of patients requiring in-hospital RRT, 18 (33%) had renal recovery, 18 (33%) required outpatient hemodialysis, and 18 (33%) died before hospital discharge. After median (Q1, Q3) follow-up of 24.3 (8.9, 49.6) months, RRT was associated with increased risk of death (adjusted hazard ratio [HR], 2.86; 95% CI, 1.90-4.33; P<.001) and gastrointestinal bleeding (adjusted HR, 4.47; 95% CI, 2.57-7.75; P<.001).

CONCLUSION

In-hospital RRT is associated with poor prognosis after LVAD. A detailed preoperative assessment of renal function before LVAD may be helpful in risk stratification and patient selection.

Advanced Heart Failure Therapies and Cardiorenal Syndrome

Heart failure (HF) is extremely prevalent and for those with end-stage (stage D) disease, 1-year survival is only 25-50%. Several studies have captured the mortality impact of kidney disease on patients with HF, and measures of kidney function are a component of many HF risk stratification scores. The management of advanced HF complicated by cardiorenal syndrome (CRS) is challenging, and irreversible kidney failure often limits patient candidacy for advanced HF therapies, such as transplant or left ventricular assist device therapy. Thus, prompt institution of aggressive therapy is warranted in stage D HF patients with CRS to prevent irreversible kidney failure. In this chapter, we discuss the assessment and management of patients with CRS with end-stage HF. In addition to discussing medical therapy aimed at decongestion and increased cardiac inotropy, we provide a summary of temporary circulatory support devices that can be considered for those whom hospice is not desired. In all circumstances, a close collaboration between the advanced HF specialist and nephrologist is needed to achieve the best patient outcomes.

Implantable Ventricular Assist Device Use and Outcomes in People With End-Stage Renal Disease

Background

People with end‐stage renal disease (ESRD) are at risk for advanced heart failure, but little is known about use and outcomes of durable mechanical circulatory support in this setting. We examined use and outcomes of implantable ventricular assist devices (VADs) in a national ESRD cohort.

Methods and Results

We performed a retrospective cohort study of Medicare beneficiaries with ESRD who underwent implantable VAD placement from 2006 to 2014. We examined in‐hospital and 1‐year mortality, all‐cause and cause‐specific hospitalizations, and heart/kidney transplantation outcomes. We investigated as predictors demographic factors, time‐period of VAD implantation, primary or post‐cardiotomy implantation, and duration of ESRD before VAD implantation. We identified 96 people with ESRD who underwent implantable VAD placement. At time of VAD implantation, 74 (77.1%) were receiving hemodialysis, 10 (10.4%) were receiving peritoneal dialysis and 12 (12.5%) had renal transplant. Time from incident ESRD to VAD implantation was median 4.0 (interquartile range 1.1, 8.2) years. Mortality during the implantation hospitalization was 40.6%. Within 1 year of implantation 61.5% of people had died. On multivariable analysis, males had half the mortality risk of females. Lower mortality risk was also seen with VAD implantation in a primary setting, and with more recent year of implantation, but these results did not reach statistical significance.

Conclusions

Medicare beneficiaries with ESRD are undergoing durable VAD implantation, often several years after incident ESRD, although in low numbers. Mortality is high among these patients, highlighting the need for investigations to improve treatment selection and management.

Left Ventricular Assist Devices and the Kidney

Left ventricular assist devices (LVADs) are common and implantation carries risk of AKI. LVADs are used as a bridge to heart transplantation or as destination therapy. Patients with refractory heart failure that develop chronic cardiorenal syndrome and CKD often improve after LVAD placement. Nevertheless, reversibility of CKD is hard to predict. After LVAD placement, significant GFR increases may be followed by a late return to near baseline GFR levels, and in some patients, a decline in GFR. In this review, we discuss changes in GFR after LVAD placement, the incidence of AKI and associated mortality after LVAD placement, the management of AKI requiring RRT, and lastly, we review salient features about cardiorenal syndrome learned from the LVAD experience. In light of the growing number of patients using LVADs as a destination therapy, it is important to understand the effect of these devices on the kidney. Additional research and long-term data are required to better understand the relationship between the LVAD and the kidney.

Renal dysfunction and chronic mechanical circulatory support: from patient selection to long-term management and prognosis

PURPOSE OF REVIEW

The purpose of this review is to describe the effects of mechanical circulatory support (MCS) on changes in kidney function and their relationship with mortality, with an additional focus on the evaluation and management of both preimplant and post-MCS renal dysfunction.

RECENT FINDINGS

Renal dysfunction is highly prevalent in patients referred for MCS and is associated with significantly increased mortality and postoperative acute kidney injury. Most patients, including those with renal dysfunction, experience marked early improvement in renal function with MCS, likely secondary to correction of the cardiogenic shock, volume overload, and neurohormonal activation characteristic of advanced heart failure. Currently, there are no diagnostic tests to definitively distinguish reversible forms of renal dysfunction likely to improve with MCS from irreversible renal dysfunction. Furthermore, the characteristic improvements in renal function observed in the early months of MCS are often transient, with subsequent recurrence of renal dysfunction with longer durations of support. Venous congestion, right ventricular dysfunction, and reduced pulsatility are potential mechanisms involved in resurgence of renal dysfunction following MCS.

SUMMARY

With the exponential growth of MCS, research endeavors to both improve understanding of the mechanisms behind observed changes in renal function and elucidate the device-related effects on the kidney are imperative.

Successful Hemodialysis Arteriovenous Fistula Creation in a Patient With Continuous-Flow Left Ventricular Assist Device Support

Heart failure necessitating left ventricular assist device (LVAD) support can lead to kidney failure requiring dialysis. Some of these patients may require long-term hemodialysis (HD). Optimal vascular access for a patient on long-term HD therapy with an LVAD remains a complex issue. The majority of LVADs are of the continuous-flow type, and it has been theorized that native arteriovenous fistula maturation may be impaired in a setting of decreased pulsatile arterial flow. We describe a case of successful creation and use of an arteriovenous fistula in an HD-dependent patient with a continuous-flow LVAD.

Left ventricular assist devices: a kidney's perspective

The left ventricular assist device (LVAD) has become an established treatment option for patients with refractory heart failure. Many of these patients experience chronic kidney disease (CKD) due to chronic cardiorenal syndrome type II, which is often alleviated quickly following LVAD implantation. Nevertheless, reversibility of CKD remains difficult to predict. Interestingly, initial recovery of GFR appears to be transient, being followed by gradual but significant late decline. Nevertheless, GFR often remains elevated compared to preimplant status. Larger GFR increases are followed by a proportionally larger late decline. Several explanations for this gradual decline in renal function after LVAD therapy have been proposed, yet a definitive answer remains elusive. Mortality predictors of LVAD implantation are the occurrence of either postimplantation acute kidney injury (AKI) or preimplant CKD. However, patient outcomes continue to improve as LVAD therapy becomes more widespread, and adverse events including AKI appear to decline. In light of a growing destination therapy population, it is important to understand the cumulative effects of long-term LVAD support on kidney function. Additional research and passage of time are required to further unravel the intricate relationships between the LVAD and the kidney.