Department of Research & Evaluation News

Research by physicians at the Kaiser Permanente Los Angeles Medical Center is helping patients with heart failure to transition more smoothly and safely to dialysis if they develop chronic kidney disease.

“We wanted to look at whether patients with heart failure have any differences in how they transition to dialysis compared to those patients without heart failure,” said Mitchell Flagg, MD, a resident at the Los Angeles Medical Center, and lead author on the study. “We found there was a big difference over a 10-year-period. Many of these heart failure patients started their dialysis with a ‘crash start’ in the hospital, without the kind of planning we ideally want to do for all patients with chronic kidney disease.”

Planning for dialysis is important for health

People who have chronic kidney disease, or CKD, have kidneys that can’t remove waste from their blood and excess fluids from their body. Dialysis is a treatment that removes the body’s waste and excess fluid when the kidneys are no longer functioning properly.

Typically, there are 2 ways that people without fully functioning kidneys can be connected to a dialysis machine that cleans their blood. One is a fistula, which is a surgically created connection between an artery and a vein, usually in the arm. This allows for easy access to a large blood flow needed to perform dialysis by enabling needles to be inserted into the enlarged vein created by the joined artery and vein. Essentially, it’s a modified blood vessel that provides a reliable access point for dialysis treatment. (A graft, which is a similar surgical procedure, uses a synthetic tube to the artery and vein.)

The other way to do dialysis is with a catheter, which is a flexible tube that’s inserted into a vein in the neck, chest, or groin to access a patient’s blood for dialysis treatment. The catheter has 2 tubes that carry blood to and from the dialysis machine.

A fistula is generally considered the better option because there is significantly lower risk of infection and better blood flow, and it lasts much longer than a catheter. However, a fistula requires planning as it is several months after the surgery and before the fistula is usable. A catheter is usually only used when there isn’t the time to do a fistula or graft.

How collaboration led to discovery

“There was a knowledge gap or ‘black hole’ in what we knew about dialysis initiation and transition among heart failure patients and CKD,” said the study’s senior author, John J. Sim, MD, a nephrologist at the Los Angeles Medical Center and a clinical researcher at the Kaiser Permanente Southern California Department of Research & Evaluation. He is also the director of Graduate Medical Education and Research, where he met Dr. Flagg, a second-year Internal Medicine resident planning to specialize in cardiology.

“Dr. Flagg reached out to me the first week he started residency at LAMC,” Dr. Sim recalled. “He said he wanted to study information on a large level, identify problems, and help solve clinical issues that can affect many patients at once.”

They discussed a previous study Dr. Sim had worked on that found that patients with higher levels of kidney function at start of dialysis had a much higher risk of death. When they evaluated who those patients were, many of them were patients with heart failure.

“Given that some of my earlier research showed the early transition period to dialysis was the most vulnerable period, we wanted to see how heart failure patients with CKD transitioned to dialysis compared to non-heart failure CKD patients,” Dr. Sim said. “And look at ways to see if we can make a change to help transition smoother and optimize outcomes. With Mitchell’s mind and initiative, he jumped on the project right away.”

What the study found

Their study looked at the electronic health records of more than 6,800 Kaiser Permanente Southern California patients with and without heart failure who began dialysis between 2007 and 2018.

Their research found:

• Chronic kidney disease patients with heart failure start dialysis in the hospital nearly 2 times more often than patients without heart failure.
• The patients with heart failure started dialysis with higher levels of kidney function, or estimated glomerular filtration rate (eGFR), which is a blood test that measures how well a person’s kidneys are filtering waste products from their blood. This could mean that eGFR may not be the best indicator of dialysis need among heart failure patients with CKD, and that these patients may present with different clinical indications for dialysis compared to other chronic kidney patients.
• The heart failure patients with CKD frequently required dialysis catheters to be placed for dialysis, rather than having a fistula or graft placed.
• Race and ethnicity had no significant association with the placement of catheters or fistulas for dialysis within Kaiser Permanente’s integrated health system, where patients have similar access to care.

How research became practice

The findings were initially shared at the American Society of Nephrology annual conference in November 2023.

“Our findings were compelling enough for us to implement a new practice guidance for our chronic kidney disease providers within Kaiser Permanente Southern California,” Dr. Sim said. “Using a population care management approach, we identified CKD patients with heart failure and prioritized them for outreach so as to start preparation for dialysis earlier than we were previously doing.”

The process to improve dialysis preparation and transition for heart failure patients was rolled out in February 2024 by the Kaiser Permanente Southern California CKD Committee and the Kaiser Permanente Southern California Renal Business Group. It included more frequent outreach and follow-up for CKD patients with heart failure.

The research was published Feb. 18, 2025 in Mayo Clinic Proceedings.

Better patient outcomes

“The more frequent outreach with these heart failure patients will hopefully lead to more patients transitioning to dialysis in a more smooth and stable manner, rather than as a crisis in the hospital,” Dr. Sim said. “This will also equate to better clinical outcomes for the patients and less resource utilization down the line for any health system.”

The researchers said that their next step is more research.

“We still have so much to learn about in terms of heart failure medical management specific to CKD patients, the most successful type of dialysis AV access such as fistula versus a graft, and ultimately the ideal timing of transition to dialysis,” Dr. Sim said. “But the immediate goal is to study the impact of our new implementation to determine if it lowers hospitalizations, catheter use, and improves clinical outcomes for our CKD patients with heart failure.”

A personal milestone

For Dr. Flagg, this is a major personal milestone as well. While he has been involved in numerous research projects throughout his training, this is his first publication as first author.

“Being able to answer clinical questions like this in a real-world setting with such a large and diverse population is one of the many wonderful things about being at Kaiser Permanente,” Dr. Flagg said. “The research opportunities here are incredible, and I look forward to continuing work on projects like this in the future.”

“The most important part, though, is seeing this already affecting clinical practice and knowing that our work is already helping patients.”

Co-authors on this research included Simran K. Bhandari, MD, of the Kaiser Permanente Downey Medical Center; Katherine J. Pak, MS, Hui Zhou, PhD, Sally F. Shaw, DrPH, MPH, Jiaxiao M. Shi, PhD, and Dr. Benjamin I. Broder MD, PhD, of the Kaiser Permanente Southern California Department of Research & Evaluation; and Connie M. Rhee MD, MSc, of the University of California Los Angeles Medical Center. Dr. Sim, Dr. Zhou, and Dr. Bhandari also are affiliated with the Kaiser Permanente Bernard J Tyson School of Medicine.

Dr. Sim also said he wanted to give special thanks to David Selevan, PMP, Paul Saario MBA, Gbemisola Adenuga, MD, the CKD Committee, and the Renal Business Group. The study was funded by the Department of Research & Evaluation and supported by Benjamin Broder, MD, PhD, the interim senior director of Research.