• 1.

    Ndumele CE, et al.; American Heart Association. Cardiovascular-kidney-metabolic health: A presidential advisory from the American Heart Association. Circulation 2023; 148:16061635. doi: 10.1161/CIR.0000000000001184

    • PubMed
    • Search Google Scholar
    • Export Citation
  • 2.

    Rubel JR, et al. Renal insufficiency and end-stage renal disease in the heart transplant population. J Heart Lung Transplant 2004; 23:289300. doi: 10.1016/S1053-2498(03)00191-8

    • PubMed
    • Search Google Scholar
    • Export Citation
  • 3.

    Conrad N, et al. Temporal trends and patterns in heart failure incidence: A population-based study of 4 million individuals. Lancet 2018; 391:572580. doi: 10.1016/S0140-6736(17)32520-5

    • PubMed
    • Search Google Scholar
    • Export Citation
  • 4.

    Karkouti K, et al. Acute kidney injury after cardiac surgery: Focus on modifiable risk factors. Circulation 2009; 119:495502. doi: 10.1161/CIRCULATIONAHA.108.786913

    • PubMed
    • Search Google Scholar
    • Export Citation
  • 5.

    Bansal N, et al. Mission and 1-year outcomes of a cardiorenal subspecialty consultation service. Kidney360 2022; 3:749751. doi: 10.34067/KID.0000602022

  • 6.

    Patel RB, et al. Kidney function and outcomes in patients hospitalized with heart failure. J Am Coll Cardiol 2021; 78:330343. doi: 10.1016/j.jacc.2021.05.002

  • 7.

    Fonarow GC, et al. Potential impact of optimal implementation of evidence-based heart failure therapies on mortality. Am Heart J 2011; 161:10241030.e3. doi: 10.1016/j.ahj.2011.01.027

    • PubMed
    • Search Google Scholar
    • Export Citation
  • 8.

    GoodRx. Accessed November 8, 2023. https://www.good-rx.com/

Bridging the Heart-Kidney Divide. Nephrocardiology Services and Clinics Aim to Bring Cardiologists and Nephrologists Together to Treat Complex Conditions

Bridget M. Kuehn
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The relationship between heart and kidney health—and sometimes between cardiologists and nephrologists—can be fraught. “The struggle is that there's very complicated pathophysiology happening and it's a little bit like a marriage or a relationship, where if one person's unhappy, the other person tends to be unhappy as well,” explained Jacob Stevens, MD, FASN, an assistant professor of nephrology at Columbia University Irving Medical Center in New York City. However, Stevens and other clinicians across the United States are working to improve the care of patients with heart and kidney diseases and close the gap between specialties by building cardiorenal services or clinics. During the “Nephrocardiology Care Models: From Idea to Implementation” session at Kidney Week 2023, Stevens and three other presenters shared how several institutions provide nephrocardiology (also known as cardiorenal or cardionephrology) care.

The session occurred amidst growing recognition of the need for multidisciplinary care for patients with cardio-renal-metabolic diseases, including a recent presidential advisory from the American Heart Association (AHA) (1), which was co-authored by Janani Rangaswami, MD, section chief of nephrology at the Washington, DC, Veterans Affairs Medical Center and professor of medicine at The George Washington University School of Medicine and Health Sciences, who co-moderated the session at Kidney Week. Session presenter Nisha Bansal, MD, FASN, professor of medicine in nephrology at the University of Washington (UW) in Seattle, noted that there has also been increasing calls from within the nephrology field over the past 5 to 10 years to increase kidney-cardio care specialization.

“Interdisciplinary care models were highlighted [in the AHA advisory] as a critical need to actually achieve the goals of managing cardio-kidney-metabolic disease,” Bansal said. “Given the call from nephrology, as well as now cardiology, I do think the time is now to think about how to move nephrocardiology care forward.”

Patients with complex conditions

Growing incidence of congestive heart failure and improvements in care have led to more patients living longer with advanced heart failure, Stevens noted. Use of mechanical circulatory support, such as extracorporeal membrane oxygenation or intraballoon pumps in intensive care units (ICUs), can provide a bridge to transplant or to receiving a durable mechanical support device like a left ventricular assist device, he explained. More patients are also receiving heart transplants and surviving after the procedures, he said.

“Not only is the volume of patients that we are seeing increasing, but they are increasingly complex,” Stevens said. “They are living longer and have a lot higher rate of comorbid illnesses, which is good because it means cardiologists are doing a good job of keeping them alive.”

Heart transplant recipients often have pre-existing comorbid conditions that may have contributed to the development of heart failure, and they may also experience acute kidney injury (AKI) during transplant or other procedures and ongoing kidney stress from immunosuppressants and other medications, Stevens said. These factors may contribute to persistent kidney injury in patients who have limited kidney reserve, which leads to AKI transforming into chronic kidney disease (CKD) or end stage kidney disease (ESKD) at much higher rates in this population. One year post-heart transplant, 15% of patients have a 50% reduction in their estimated glomerular filtration rate (eGFR), and by 10 years post-transplant, 15% have ESKD and are either treated with dialysis or have received a kidney transplant (2). Additionally, nearly one-quarter of patients with advanced heart failure have CKD (3).

Patients undergoing other types of heart surgery also have increased AKI risk (4), with many progressing to CKD, Stevens noted. He also noted that there are special considerations for patients with ESKD or CKD who are undergoing cardiac procedures and for patients who need dialysis after heart surgery. “Caring for these patients requires a special knowledge set,” Stevens said.

Yet, despite the need for integrated heart and kidney care, Bansal noted that traditional care pathways can create barriers to appropriate care for patients with concurrent heart and kidney diseases. Prior to launching a nephrocardiology service at UW, Bansal noted that care protocols were not standardized and often varied depending on who was attending. Transitioning patients from inpatient to outpatient settings was also complicated by numerous subspecialists and limited communication among them. “These patients were in the hospital with multiple consultants, multiple revolving attendings, and we found that communication was often disjointed, and there wasn't a high level of trust between subspecialists.”

Nephrocardiology service?

Stevens proposed a checklist of questions for hospitals considering whether to create a nephrocardiology program to meet these growing needs. Chief among them was whether an institution had enough patient volume to support the service. At Columbia University, which has over 7000 ICU admissions each year and more than 2200 heart procedures performed each year, Stevens and his colleagues, who perform the nephrocardiology services, have an average patient census of 18 to 22 patients. Twelve of Columbia's 33 nephrologists attend the service, and there is a fellow and sometimes medical students, residents, or anesthesia or critical care fellows participating.

“It's really important to work with the electronic health records team at your institution to start pulling some numbers,” Stevens said. He suggested looking at the numbers of nephrology consults requested by cardiology and cardiothoracic surgery or the number of consults for patients admitted or discharged with kidney diseases and a heart condition.

Bansal noted that UW underwent this process and decided it did have the volume of patients with medically complex conditions to support it. She explained that UW serves a five-state region, including Alaska, Idaho, Montana, Washington, and Wyoming. The analysis revealed that 65% of patients admitted for heart failure also had AKI, and 40% of patients who had mechanical circulatory support during hospitalization needed dialysis (5). Patients with heart failure and AKI had longer lengths of stay, higher inpatient death rates, and higher readmission rates.

“We saw a clear need and an opportunity to improve outcomes,” she said. The consultation service was launched in August 2020 amidst the COVID-19 pandemic. Initially staffed by herself and two other nephrologists, they take turns rotating and seeing patients of the cardiology or cardiothoracic surgery team. Their average patient census is approximately 15 but can range as high as 27 patients, she said.

Liam Plant, MBChB, clinical professor in renal medicine at Cork University Hospital, Ireland, offered an international perspective from a national health care system. In his presentation, he noted that in some countries or provinces, there may be fewer nephrologists than are included in the nephrocardiology teams at Columbia University or UW, and they may be serving a much smaller number of patients. In such cases, the volume may not justify a dedicated service, and patients may be better served by improving care in existing care pathways. “We probably need to broaden and deepen the integration of our current care pathways and perhaps also add a new subspecialty, which we might call cardiorenal,” Plant said. “We need to be careful that in addressing complexity, we don't invent a complex solution that leaves us with the rest of things undone.”

Plant suggested leveraging primary care clinicians to help identify patients with chronic diseases, like kidney diseases, which Ireland's health system pays primary care clinicians to do. He suggested that, in addition to finding patients with comorbid heart and kidney diseases, primary care clinicians may be able to execute more structured treatment regimens and provide CKD education. He noted that the rollout of a growing number of cardio-renal-metabolic medications has contributed to enhance education among clinicians about treating this subset of patients.

At Cork University Hospital, nephrologists and cardiologists already closely collaborate. He said that the nephrologists perform approximately 2100 consults each year with approximately 42% involving patients with heart disease, and they typically have approximately 12 patients with cardiorenal dysfunction in the hospital at a time. “We don't have a separate [dedicated] cardionephrology team,” Plant explained. “It is implicit and it's embedded.”

Stevens said it is important to assess the interest of other departments in using a nephrocardiology service. He noted comments from colleagues at Columbia—which has had a nephrocardiology service for 16 years—highlighting the ability to improve processes and working toward shared care goals across disciplines. “It can really benefit not only patients but also clinicians in the hospital,” Stevens said. “It allows for differentiation and professional development of your faculty. It's been a win for everybody.”

Bansal agreed that the need for unique expertise and multidisciplinary training is creating new opportunities for the field of nephrology. Bansal said that UW's service was built with goals of improving care, training the next generation of clinicians, and bolstering research in this subspecialty, including quality improvement studies. “I truly believe it's a way to innovate our field and move forward,” she said.

All three of these speakers emphasized the need to update nephrology training curricula to include nephrocardiology care.

Improved outcomes

Since the Kidney Heart Service at UW launched, Bansal and her colleagues have seen 550 patients with unique conditions. They have observed approximately a 2.3-day reduction in length of stay for patients with co-occurring heart and kidney diseases compared with before the service launched, as well as a 5% reduction in readmissions, a small reduction in patients requiring dialysis, and a trend toward reduced inpatient deaths (5). They have also seen some intangible benefits, Bansal said. She noted that she and her colleagues on the service join cardiology colleagues on rounds and discuss mutual patients. “We’ve developed more streamlined communication,” she said. “We’ve developed a high level of trust.”

That trust has allowed them to work together with their cardiology colleagues to develop standardized approaches to care. They also share resources and new information either through informal bedside discussions or formal joint conferences. “What I’ve really enjoyed being on this service is the bidirectional learning,” she said. She and her colleagues have developed expertise on mechanical circulatory support; trained in point-of-care ultrasound; and developed new protocols for diuretics and when to add adjunctive therapies, like sodium-glucose cotransporter-2 (SGLT2) inhibitors or spironolactone, with the cardiology team. Both cardiology and nephrology fellows have joined the service, and internal medicine residents and some medical students are also participating.

Bansal and her colleagues are also using their experience to identify research questions and build multidisciplinary research teams. So far, they have received two National Institutes of Health grants to study patients with kidney-cardio conditions. One grant is to investigate kidney injury biomarkers that can guide inpatient and outpatient diuretic and heart failure; another is to study bioethical issues in the care of patients with kidney-cardio conditions and patient preferences. “We continue to think about what's next for our group,” she said. The team also recently welcomed a fourth nephrologist and is analyzing ways to incorporate nutritionists, social workers, and other health professionals.

Outpatient options

Conrad Macon, MD, an advanced heart failure and transplant cardiologist at the Oregon Health and Science University in Portland, co-directs the outpatient Cardiorenal Clinic at the institution. The clinic was launched to help improve the use of medications in patients with cardiorenal disease. “We know that people who have renal dysfunction plus heart failure do worse, yet the people that need medications and therapies most are least given it,” he said during his presentation.

For example, he cited data that showed only 45% of patients with an eGFR from 30 to 45 mL/min/1.73 m2 were getting renin-angiotensin system (RAS) inhibitors, and only 24% of those with eGFRs below 30 mL/min/1.73 m2 were getting them (6). Only 15% of patients were receiving triple therapy with a RAS inhibitor, β-blocker, and mineralocorticoid receptor antagonist (MRA). Macon also cited data showing that quadruple therapy may reduce patient mortality from 35% to 9.5% with a number needed to treat of approximately 4 (7). Macon explained that most clinicians are comfortable prescribing β-blockers for patients with renal dysfunction, which can reduce patient mortality from 35% to 23%, but patients are missing out on additional benefits from added therapies. “We’re missing a potential 41% reduction in mortality in this population,” he said. “It's pretty remarkable.”

Macon blamed difficulties treating patients with medications after discharge and medication myths for driving undertreatment. For example, he said that many physicians believe medications that have shown to be beneficial in heart failure, like angiotensin-converting enzyme inhibitors, angiotensin receptor blockers, or SGLT2 inhibitors, are nephrotoxic. However, he said that clinical trials for the drugs demonstrate benefits. “We know these things improve outcomes in heart failure,” he said. “They improve outcomes in renal dysfunction.” He explained that an initial dip in an eGFR on some medications or the “dreaded creatinine bump,” which resolves over time, may contribute to the myths. “We’ve all experienced this moment of panic; did I do this?” Macon said. “This is something you should expect and treat through.” But he noted that for other drugs, like MRAs, the data are more convoluted, suggesting that they improve mortality in patients with heart failure while their renal effects are more questionable.

Drug costs are another deterrent to their use, Macon said. He cited GoodRx data from Portland that show SGLT2 inhibitor prescriptions cost more than $500, while finerenone costs more than $650, and the potassium binder patiromer costs more than $1300 (8). They also can be time and labor intensive to titrate and require frequent visits. But that is what he and his colleagues’ day-to-day work at the clinic entails. They also use remote hemodynamic monitoring, which helps with medication adjustments.

Having a multidisciplinary team at a clinic, including a nephrologist, a clinical pharmacist, and heart failure nurses, is effective. He explained that the clinical pharmacist helps patients obtain medications at an affordable cost, handles prior authorizations, and performs titration visits every 2 weeks. The heart failure nurses answer patients’ frequent electronic medical record questions, follow up on lab results, and manage the remote hemodynamic monitoring. “It really takes a village to [operate] a cardiorenal clinic,” he said.

References

  • 1.

    Ndumele CE, et al.; American Heart Association. Cardiovascular-kidney-metabolic health: A presidential advisory from the American Heart Association. Circulation 2023; 148:16061635. doi: 10.1161/CIR.0000000000001184

    • PubMed
    • Search Google Scholar
    • Export Citation
  • 2.

    Rubel JR, et al. Renal insufficiency and end-stage renal disease in the heart transplant population. J Heart Lung Transplant 2004; 23:289300. doi: 10.1016/S1053-2498(03)00191-8

    • PubMed
    • Search Google Scholar
    • Export Citation
  • 3.

    Conrad N, et al. Temporal trends and patterns in heart failure incidence: A population-based study of 4 million individuals. Lancet 2018; 391:572580. doi: 10.1016/S0140-6736(17)32520-5

    • PubMed
    • Search Google Scholar
    • Export Citation
  • 4.

    Karkouti K, et al. Acute kidney injury after cardiac surgery: Focus on modifiable risk factors. Circulation 2009; 119:495502. doi: 10.1161/CIRCULATIONAHA.108.786913

    • PubMed
    • Search Google Scholar
    • Export Citation
  • 5.

    Bansal N, et al. Mission and 1-year outcomes of a cardiorenal subspecialty consultation service. Kidney360 2022; 3:749751. doi: 10.34067/KID.0000602022

  • 6.

    Patel RB, et al. Kidney function and outcomes in patients hospitalized with heart failure. J Am Coll Cardiol 2021; 78:330343. doi: 10.1016/j.jacc.2021.05.002

  • 7.

    Fonarow GC, et al. Potential impact of optimal implementation of evidence-based heart failure therapies on mortality. Am Heart J 2011; 161:10241030.e3. doi: 10.1016/j.ahj.2011.01.027

    • PubMed
    • Search Google Scholar
    • Export Citation
  • 8.

    GoodRx. Accessed November 8, 2023. https://www.good-rx.com/

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