Cardiovascular Effects of Home Dialysis Therapies: A Scientific Statement From the American Heart Association

Coronary and Systemic Vasodilator Responsiveness of Patients Receiving Conventional Intermittent or Nocturnal Hemodialysis

BACKGROUND

Nocturnal hemodialysis (nHD) restores the attenuated brachial artery vasodilator responsiveness of patients receiving conventional intermittent hemodialysis (iHD). Its impact on coronary vasodilatation is unknown.

METHODS

We evaluated 25 patients on hemodialysis who fulfilled transplant criteria: 15 on iHD (4-hour sessions, 3 d/wk) and 10 on nHD (≈40 h/wk over 8-10-hour sessions) plus 6 control participants. Following diagnostic angiography, left anterior descending (LAD) coronary flow reserve and mean luminal diameter were quantified at baseline and during sequential intracoronary administration of adenosine (infusion and bolus), nitroglycerin (bolus), acetylcholine (infusion), acetylcholine coinfused with vitamin C, and, finally, sublingual nitroglycerin.

RESULTS

Coronary flow reserve in those receiving nHD was augmented relative to iHD (3.28±0.26 versus 2.17±0.12 [mean±SEM]; P<0.03) but attenuated, relative to controls (4.80±0.63; P=0.011). Luminal dilatations induced by intracoronary adenosine and nitroglycerin were similar in nHD and controls but blunted in the iHD cohort (P<0.05 versus both). ACh elicited vasodilatation in controls but constriction in both dialysis groups (both P<0.05, versus control); vitamin C coinfusion had no effect. Sublingual nitroglycerin increased mid-left anterior descending diameter and reduced mean arterial pressure in controls (+15.2±2.68%; -16.00±1.60%) and in nHD recipients (+14.78±5.46%; -15.82±1.32%); iHD responses were markedly attenuated (+1.9±0.86%; -5.89±1.41%; P<0.05, all comparisons).

CONCLUSIONS

Coronary and systemic vasodilator responsiveness to both adenosine and nitroglycerin is augmented in patients receiving nHD relative to those receiving iHD, whereas vasoconstrictor responsiveness to acetylcholine does not differ. By improving coronary conduit and microvascular function, nHD may reduce the cardiovascular risk of patients on dialysis.

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.

Strategies for the Management of Cardiorenal Syndrome in the Acute Hospital Setting

Cardiorenal syndrome (CRS) is a life-threatening disorder that involves a complex interplay between the two organs. Managing this multifaceted syndrome is challenging in the hospital and requires a multidisciplinary approach to tackle the many manifestations and complications. There is no universally accepted algorithm to treat patients, and therapeutic options vary from one patient to another. The mainstays of therapy involve the stabilization of hemodynamics, decongestion using diuretics or renal replacement therapy, improvement of cardiac output with inotropes, and goal-directed medical treatment with renin–angiotensin–aldosterone system inhibitors, beta-blockers, and other medications. Mechanical circulatory support is another viable option in the armamentarium of agents that improve symptoms in select patients.

[Which dialysis method for whom? In-center dialysis vs home dialysis]

There are various dialysis methods available to treat patients with chronic kidney failure. Generally, a distinction is made between peritoneal dialysis and hemodialysis, as well as between home dialysis methods and center-based dialysis methods. To be able to advise patients optimally, it is important to understand the opportunities and limitations of the different method variants. This article provides an overview of the therapy options and describes their strengths and weaknesses.

Knowledge, attitudes, and practices toward cardiovascular complications among end-stage renal disease patients undergoing maintenance hemodialysis

BACKGROUND

This study aimed to investigate the knowledge, attitudes, and practices (KAP) toward cardiovascular complications among end-stage renal disease patients undergoing maintenance hemodialysis.

METHODS

This web-based cross-sectional study was conducted at Guangdong Provincial People's Hospital between December 2022, and May 2023.

RESULTS

A total of 545 valid questionnaires were collected, with an average age of 57.72 ± 13.47 years. The mean knowledge, attitudes and practices scores were 8.17 ± 2.9 (possible range: 0-24), 37.63 ± 3.80 (possible range: 10-50), 33.07 ± 6.10 (possible range: 10-50) respectively. Multivariate logistic regression analysis showed that patients from non-urban area had lower knowledge compared to those from urban area (odds ratio (OR) = 0.411, 95% CI: 0.262-0.644, P < 0.001). Furthermore, higher levels of education were associated with better knowledge, as indicated by OR for college and above (OR = 4.858, 95% CI: 2.483-9.504), high school/vocational school (OR = 3.457, 95% CI: 1.930-6.192), junior high school (OR = 3.300, 95% CI: 1.945-5.598), with primary school and below as reference group (all P < 0.001). Besides, better knowledge (OR = 1.220, 95% CI: 1.132-1.316, P < 0.001) and higher educational levels were independently associated with positive attitudes. Specifically, individuals with a college degree and above (OR = 2.986, 95% CI: 1.411-6.321, P = 0.004) and those with high school/vocational school education (OR = 2.418, 95% CI: 1.314-4.451, P = 0.005) have more positive attitude, with primary school and below as reference group. Next, better attitude (OR = 1.174, 95% CI: 1.107-1.246, P < 0.001) and higher education were independently associated with proactive practices. Those with college and above (OR = 2.870, 95% CI: 1.359-6.059, P = 0.006), and those with high school/vocational school education (OR = 1.886, 95% CI: 1.032-3.447, P = 0.039) had more proactive practices, with primary school and below as reference group.

CONCLUSIONS

End-stage renal disease patients undergoing maintenance hemodialysis demonstrated insufficient knowledge, positive attitudes, and moderate practices regarding cardiovascular complications. Targeted interventions should prioritize improving knowledge and attitudes, particularly among patients with lower educational levels and income, to enhance the management of cardiovascular complications in end-stage renal disease.

Integrated home dialysis model: facilitating home-to-home transition

Peritoneal dialysis (PD) and home hemodialysis (HHD) are the two home dialysis modalities offered to patients. They promote patient autonomy, enhance independence, and are generally associated with better quality of life compared to facility hemodialysis. PD offers some advantages (enhanced flexibility, ability to travel, preservation of residual kidney function, and vascular access sites) but few patients remain on PD indefinitely due to peritonitis and other complications. By contrast, HHD incurs longer and more intensive training combined with increased upfront health costs compared to PD, but is easier to sustain in the long term. As a result, the integrated home dialysis model was proposed to combine the advantages of both home-based dialysis modalities. In this paradigm, patients are encouraged to initiate dialysis on PD and transfer to HHD after PD termination. Available evidence demonstrates the feasibility and safety of this approach and some observational studies have shown that patients who undergo the PD-to-HHD transition have clinical outcomes comparable to patients who initiate dialysis directly on HHD. Nevertheless, the prevalence of PD-to-HHD transfers remains low, reflecting the multiple barriers that prevent the full uptake of home-to-home transitions, notably a lack of awareness about the model, home-care "burnout," clinical inertia after a transfer to facility HD, suboptimal integration of PD and HHD centers, and insufficient funding for home dialysis programs. In this review, we will examine the conceptual advantages and disadvantages of integrated home dialysis, present the evidence that underlies it, identify challenges that prevent its success and finally, propose solutions to increase its adoption.

Patient-Centered Home Hemodialysis: Approaches and Prescription

Writing a home hemodialysis (HD) prescription is a complex, multifactorial process that requires the incorporation of patient values, preferences, and lifestyle. Knowledge of the different options available for home HD modality (conventional, nocturnal, short daily, and alternate nightly) is also important when customizing a prescription. Finally, an understanding of the different home HD machines currently approved for use at home and their different attributes and limitations helps guide providers when formulating their prescriptions. In this review article, we set out to address these different aspects to help guide providers in providing a patient-centered home HD approach.

Home Dialysis in Patients with Cardiovascular Diseases

Kidney failure with replacement therapy and cardiovascular disease are frequently comorbid. In patients with kidney failure with replacement therapy, cardiovascular disease is a major contributor to morbidity and mortality. Conventional thrice-weekly in-center dialysis confers risk factors for cardiovascular disease, including acute hemodynamic fluctuations and rapid shifts in volume and solute concentration. Home hemodialysis and peritoneal dialysis (PD) may offer benefits in attenuation of cardiovascular disease risk factors primarily through improved volume and BP control, reduction (or slowing progression) of left ventricular mass, decreased myocardial stunning, and improved bone and mineral metabolism. Importantly, although trial data are available for several of these risk factors for home hemodialysis, evidence for PD is limited. Among patients with prevalent cardiovascular disease, home hemodialysis and PD may also have potential benefits. PD may offer particular advantages in heart failure given it removes volume directly from the splanchnic circulation, thus offering an efficient method of relieving intravascular congestion. PD also avoids the risk of blood stream infections in patients with cardiac devices or venous wires. We recognize that both home hemodialysis and PD are also associated with potential risks, and these are described in more detail. We conclude with a discussion of barriers to home dialysis and the critical importance of interdisciplinary care models as one component of advancing health equity with respect to home dialysis.

Cardiovascular Outcomes in Patients on Home Hemodialysis and Peritoneal Dialysis

Key Points

Background

Cardiovascular disease is the leading cause of morbidity and mortality in patients with ESKD. Little is known about differences in cardiovascular outcomes between home hemodialysis (HHD) and peritoneal dialysis (PD).

Methods

We evaluated 68,645 patients who initiated home dialysis between January 1, 2005, and December 31, 2018, using the United States Renal Data System with linked Medicare claims. Rates for incident cardiovascular events of acute coronary syndrome, heart failure, and stroke hospitalizations were determined. Using adjusted time-to-event models, the associations of type of home dialysis modality with the outcomes of incident cardiovascular events, cardiovascular death, and all-cause death were examined.

Results

Mean age of patients in the study cohort was 64±15 years, and 42.3% were women. The mean time of follow-up was 1.8±1.6 years. The unadjusted cardiovascular event rate was 95.1 per thousand person-years (PTPY) (95% confidence interval [CI], 93.6 to 96.8), with a higher rate in patients on HHD than on PD (127.8 PTPY; 95% CI, 118.9 to 137.2 versus 93.3 PTPY; 95% CI, 91.5 to 95.1). However, HHD was associated with a slightly lower adjusted risk of cardiovascular events than PD (hazard ratio [HR], 0.92; 95% CI, 0.85 to 0.997). Compared with patients on PD, patients on HHD had 42% lower adjusted risk of stroke (HR, 0.58; 95% CI, 0.48 to 0.71), 17% lower adjusted risk of acute coronary syndrome (HR, 0.83; 95% CI, 0.72 to 0.95), and no difference in risk of heart failure (HR, 1.05; 95% CI, 0.94 to 1.16). HHD was associated with 22% lower adjusted risk of cardiovascular death (HR, 0.78; 95% CI, 0.71 to 0.86) and 8% lower adjusted risk of all-cause death (HR, 0.92; 95% CI, 0.87 to 0.97) as compared with PD.

Conclusions

Relative to PD, HHD is associated with decreased risk of stroke, acute coronary syndrome, cardiovascular death, and all-cause death. Further studies are needed to better understand the factors associated with differences in cardiovascular outcomes by type of home dialysis modality in patients with kidney failure.

Home-Based Dialysis: A Primer for the Internist

Home-based dialysis modalities offer both clinical and practical advantages to patients. The use of the home-based modalities, peritoneal dialysis and home hemodialysis, has been increasing over the past decade after a long period of decline. Given the increasing frequency of use of these types of dialysis, it is important for clinicians to be familiar with how these types of dialysis are performed and key clinical aspects of care related to their use in patients with end-stage kidney disease.

A Synopsis of the Evidence for the Science and Clinical Management of Cardiovascular-Kidney-Metabolic (CKM) Syndrome: A Scientific Statement From the American Heart Association

A growing appreciation of the pathophysiological interrelatedness of metabolic risk factors such as obesity and diabetes, chronic kidney disease, and cardiovascular disease has led to the conceptualization of cardiovascular-kidney-metabolic syndrome. The confluence of metabolic risk factors and chronic kidney disease within cardiovascular-kidney-metabolic syndrome is strongly linked to risk for adverse cardiovascular and kidney outcomes. In addition, there are unique management considerations for individuals with established cardiovascular disease and coexisting metabolic risk factors, chronic kidney disease, or both. An extensive body of literature supports our scientific understanding of, and approach to, prevention and management for individuals with cardiovascular-kidney-metabolic syndrome. However, there are critical gaps in knowledge related to cardiovascular-kidney-metabolic syndrome in terms of mechanisms of disease development, heterogeneity within clinical phenotypes, interplay between social determinants of health and biological risk factors, and accurate assessments of disease incidence in the context of competing risks. There are also key limitations in the data supporting the clinical care for cardiovascular-kidney-metabolic syndrome, particularly in terms of early-life prevention, screening for risk factors, interdisciplinary care models, optimal strategies for supporting lifestyle modification and weight loss, targeting of emerging cardioprotective and kidney-protective therapies, management of patients with both cardiovascular disease and chronic kidney disease, and the impact of systematically assessing and addressing social determinants of health. This scientific statement uses a crosswalk of major guidelines, in addition to a review of the scientific literature, to summarize the evidence and fundamental gaps related to the science, screening, prevention, and management of cardiovascular-kidney-metabolic syndrome.

Cardiovascular-Kidney-Metabolic Health: A Presidential Advisory From the American Heart Association

Cardiovascular-kidney-metabolic health reflects the interplay among metabolic risk factors, chronic kidney disease, and the cardiovascular system and has profound impacts on morbidity and mortality. There are multisystem consequences of poor cardiovascular-kidney-metabolic health, with the most significant clinical impact being the high associated incidence of cardiovascular disease events and cardiovascular mortality. There is a high prevalence of poor cardiovascular-kidney-metabolic health in the population, with a disproportionate burden seen among those with adverse social determinants of health. However, there is also a growing number of therapeutic options that favorably affect metabolic risk factors, kidney function, or both that also have cardioprotective effects. To improve cardiovascular-kidney-metabolic health and related outcomes in the population, there is a critical need for (1) more clarity on the definition of cardiovascular-kidney-metabolic syndrome; (2) an approach to cardiovascular-kidney-metabolic staging that promotes prevention across the life course; (3) prediction algorithms that include the exposures and outcomes most relevant to cardiovascular-kidney-metabolic health; and (4) strategies for the prevention and management of cardiovascular disease in relation to cardiovascular-kidney-metabolic health that reflect harmonization across major subspecialty guidelines and emerging scientific evidence. It is also critical to incorporate considerations of social determinants of health into care models for cardiovascular-kidney-metabolic syndrome and to reduce care fragmentation by facilitating approaches for patient-centered interdisciplinary care. This presidential advisory provides guidance on the definition, staging, prediction paradigms, and holistic approaches to care for patients with cardiovascular-kidney-metabolic syndrome and details a multicomponent vision for effectively and equitably enhancing cardiovascular-kidney-metabolic health in the population.

Valvular heart disease in patients on kidney replacement therapy: "opening Pandora's box"

Valvular heart disease (VHD) is highly prevalent among dialysis patients, affecting up to 30%-40% of the population. Aortic and mitral valves are the most frequently affected and commonly lead to valvular stenosis and regurgitation. Although it is well established that VHD is associated with a high morbimortality burden, the optimal management strategy remains unclear, and treatment options are limited due to the high risk of complications and mortality after surgical and transcatheter interventions. In this issue of Clinical Kidney Journal, Elewa et al. provide new evidence in this field by reporting the prevalence and associated outcomes of VHD in patients with kidney failure on renal replacement therapy.

Cardiorenal Syndrome in the Hospital

The cardiorenal syndrome refers to a group of complex, bidirectional pathophysiological pathways involving dysfunction in both the heart and kidney. Upward of 60% of patients admitted for acute decompensated heart failure have CKD, as defined by an eGFR of <60 ml/min per 1.73 m 2 . CKD, in turn, is one of the strongest risk factors for mortality and cardiovascular events in acute decompensated heart failure. Although not well understood, the mechanisms in the cardiorenal syndrome include venous congestion, arterial underfilling, neurohormonal activation, inflammation, and endothelial dysfunction. Arterial underfilling may lead to activation of the renin-angiotensin-aldosterone system and sympathetic nervous system, leading to sodium reabsorption and vasoconstriction. Venous congestion likely also mediates and perpetuates these maladaptive pathways. To rule out intrinsic kidney disease that is distinct from the cardiorenal syndrome, one should obtain a careful history, review longitudinal eGFR trends, assess albuminuria and proteinuria, and review the urine sediment and kidney imaging. The hallmark of the cardiorenal syndrome is intense sodium avidity and diuretic resistance, often requiring a combination of diuretics with varying pharmacological targets, and monitoring of urinary response to guide escalations in therapy. Invasive means of decongestion may be required including ultrafiltration or KRT such as peritoneal dialysis, which is often better tolerated from a hemodynamic perspective than intermittent hemodialysis. Strategies for increasing forward perfusion in states of low cardiac output and cardiogenic shock may include afterload reduction and inotropes and, in the most severe cases, mechanical circulatory support devices, many of which have kidney-specific considerations.