In a large observational study of patients receiving home kidney dialysis, home hemodialysis was associated with improvements in key cardiovascular outcomes compared with peritoneal dialysis; however, experts noted a variety of important caveats.
"We found that patients on incident home hemodialysis had a lower adjusted risk of cardiovascular events, cardiovascular death, and all-cause death," reported the authors in the study, published this month in Kidney360, an open access journal of the American Society of Nephrology.
In the study of more than 68,000 patients who initiated home dialysis between January 1, 2005, and December 31, 2018, and had a mean follow-up of 1.8 years, those who were treated with home hemodialysis had a slightly lower adjusted risk for cardiovascular events than those treated with peritoneal dialysis (hazard ratio [HR], 0.92).
The risk for stroke was significantly lower with home hemodialysis (at 42%) than with peritoneal dialysis (HR, 0.58), and the adjusted risk for acute coronary syndrome was 17% lower (HR, 0.83).
Home hemodialysis was further associated with a 22% lower risk for cardiovascular death (HR, 0.78) and an 8% lower risk for all-cause death (HR, 0.92) than peritoneal dialysis, after the multivariate adjustment.
While patients on home hemodialysis were older and had more diabetes than those on peritoneal dialysis, "after adjustment with these covariates, patients on home dialysis had lower hazards of cardiovascular events than those on peritoneal dialysis," the authors noted.
Cardiovascular Death Risk 20 Times Higher Among Those Receiving Dialysis
As many as half of the patients undergoing dialysis are reported to have cardiovascular disease, and those patients have a 20 times higher risk for cardiovascular death than the general population, with cardiovascular disease representing the leading cause of death among those patients, the authors reported.
Studies show a cardiovascular benefit of more frequent hemodialysis compared with conventional three times per week hemodialysis, and home hemodialysis, which allows for more convenience in the more frequent sessions, is encouraged in policies, including the Advancing American Kidney Health Initiative.
However, the costs of home hemodialysis, which requires an artificial kidney machine, can be a significant barrier, and training and skill are necessary to administer the dialysis, which requires needle access.
Peritoneal dialysis, which provides continuous dialysis through the abdomen and does not involve needles, can provide more mobility and lower cost but has its own disadvantages, such as not having days off and involving a catheter that may affect body image.
Currently in the United States, the prevalence of home dialysis use among the population with end-stage kidney disease (ESKD) is 13.7%, with just 2.1% undergoing home hemodialysis and 11.6% doing peritoneal dialysis, the authors reported.
Previous studies have shown reduced rates of cardiovascular hospitalizations in patients receiving home hemodialysis vs peritoneal dialysis; however, data on the differences in cardiovascular outcomes is lacking and complicated by limitations such as small sample sizes.
To address those issues in the new study, the authors evaluated data from the United States Renal Data System with linked Medicare claims, identifying specifically 68,645 patients, who had a mean age of 64 and of whom 42.3% were women.
All patients had initiated home dialysis within 6 months of the first ESKD service date. Patients with less than 3 months of continuous home dialysis, not including breaks of less than 1 month, were excluded, as were those receiving care in a facility, with more than 90% of patients residing in a skilled nursing facility.
Among those enrolled, 66.5% were non-Hispanic White patients, 18.1% were non-Hispanic Black patients, 9.8% were Hispanic patients, 3.8% were Asian patients, and 0.9% were Native American patients.
The majority of patients (87.6%) had a history of hypertension and 38.3% had a history of cardiovascular disease. Diabetes was the most common attributed cause of kidney failure among patients on dialysis, occurring in 44%, followed by hypertension (30.1%).
The reductions in cardiovascular events, death, and other factors were observed after adjustment for factors such as demographics, nursing home residency, socioeconomic characteristics, and other clinical characteristics.
Of note, no significant differences were observed in the risk for heart failure with home hemodialysis compared with peritoneal dialysis (HR, 1.05).
In a press statement, first author Silvi Shah, MD, associate professor in the University of Cincinnati College of Medicine, Cincinnati, speculated that the improved cardiovascular health outcomes with home hemodialysis could be the result of that option representing a more intensive approach.
"I think there may be better fluid management with home hemodialysis," Shah said.
"So, with more intensive dialysis, there is better solute clearance in blood and better control of bone and mineral metabolism parameters," she said.
In addition, "there is better reduction in ventricular volumes and regression of left ventricular mass, which is thought to help with blood pressure."
Caveats Include Underlying Risk Factors
Commenting on the study, Alan S. Kliger, MD, a clinical professor of medicine at Yale School of Medicine, in New Haven, Connecticut, noted that, while studies have shown that more intensive hemodialysis has been shown to reduce some cardiovascular risk, "there has been less attention paid to any possible differences between dialysis modalities and these outcomes."
"Therefore, this 13-year observational study examining cardiovascular outcomes in home hemodialysis and peritoneal dialysis is an important contribution," he told Medscape Medical News.
While the study adjusted for multiple possible confounders, a key caveat is that the adjustment "does not include all of the underlying risk factor differences between these two groups of patients," Kliger noted.
"For example, in dialysis training facilities that offer both modalities, patients often see the challenge of learning and safely performing home hemodialysis as more demanding than peritoneal dialysis."
In addition, "those choosing home hemodialysis may have better home support, better dexterity, or less frailty," he added. "These may or may not be true, but such differences in the population may be key factors determining cardiovascular outcomes rather than the dialysis modality chosen."
Another caveat is the study's lack of data on the residual kidney function of the patients, which is important because "residual kidney function has been shown to be a powerful force in the mortality of dialysis patients."
In an editorial published with the study, author Jeffrey Perl, MD, of the Division of Nephrology, St. Michael's Hospital, Unity Health, University of Toronto, Toronto, Ontario, Canada, and colleagues, added that the study's exclusion of patients with less than 3 months of home dialysis treatment is another important limitation for various reasons, including that home peritoneal dialysis is usually a first dialysis modality for patients, whereas home hemodialysis is often commenced after some time on in-center hemodialysis, including with training.
"This could also have contributed to the poorer cardiovascular outcomes found in peritoneal dialysis compared with home hemodialysis," the editorial authors wrote.
The editorial argues that, with modifiable factors such as smoking and poverty being much more strongly associated with cardiovascular risk in home dialysis patients, "strategies that address disparities in care are needed independent of dialysis modality to prevent cardiovascular events in this high-risk population."
"As we try to individualize dialysis treatment to each patient's goals and preferences, this small difference seen across home dialysis modalities in the present study should not be the primary driver of home dialysis modality choices," they wrote.
Kliger added that many dialysis centers are not equipped to offer home dialysis choices, and patients by default are sent to in-center treatment, without being provided a choice.
"Patients should be informed early in their exploration of treatment choice for kidney failure that they have choices to consider — kidney transplant, hemodialysis in center or at home, peritoneal dialysis, and the choice to receive supportive care and not receive dialysis or transplant," he said.
The study and editorial authors' disclosures are detailed in the published study. Kliger had no disclosures to report.