The emerging role of the cardio-renal physician

Editor’s note: Patients with kidney disease often face a compromised cardiovascular system. Sudden cardiac death is common among patients in the first 90 days of dialysis. Such risks suggest the value of a specialists in both cardiac care and nephrology. We asked Peter McCullough, MD, MPH, FACC, FACP, FCCP, FAHA, FCRS and Savas Petrides, MD, FACP, FCRS, of the Cardio Renal Society of America, about the role of this new specialist. -by Mark Neumann

NN&I: Explain the connection between the heart and the kidney. At what stage of chronic kidney disease do the two organs intersect?

McCullough: The heart and kidney are integrally connected. The heart is the pump that drives the kidney and the kidney is the regulator of volume and metabolic balance that allows the heart to work efficiently. These organs intersect at all stages of CKD, depending on the etiology of the disease. Chronic and acute cardiac events lead to decreased renal function and vice versa. You cannot draw a line at any particular stage of CKD and say you now have cardio-renal syndrome. That is why we have divided CRS into types depending on the presumed primary etiology of the dual organ dysfunction.

NN&I: Sudden cardiac death is common for patients in the first 90 days of dialysis. Expound on the data and help us understand why these patients are so vulnerable

Petrides: Dialysis can be a shock to the system, with dramatic changes in blood potassium and other electrolytes. The long process of renal failure before the onset of dialysis causes thickening of the heart muscle, calcium deposits in blood vessels, and higher blood pressure and volume. This is the environment where sudden death can occur.

NN&I: Explain the role of the cardio-renal physician. Is this someone with previous training in cardiology who now learns about kidney function? Or the other way around?

McCullough: The cardio-renal physician is able to integrate knowledge and evidence-based care for both organ systems and provide optimal care to patients. This can be a cardiologist/nephrologist or even an internal medicine physician who has specific training and experience with the physiology and pharmacology of CRS. What we see is the nephrologist managing the primary renal patient with cardiac decompensation and cardiology primarily managing the cardiac patient with secondary renal dysfunction. When we merge the two, the patient receives highly coordinated care with improved quality of life and fewer hospitalizations.

NN&I: Is this position more focused on AKI or on maintenance hemodialysis? Do I need a cardio-renal physician if I have been on peritoneal dialysis for two years? What kind of patient would benefit most?

Petrides: CRS has many subpopulations. AKI is one group but it can be divided into two subpopulations:

AKI resulting in cardiac decompensation

Cardiac patients who develop AKI due to an acute cardiac event.

These acute patients need a particular plan of care different from the chronic renal failure patient. The advanced CKD and ESRD population have significant cardiovascular mortality and it is the leading cause of death in this group. So, a PD patient needs a physician who understands the cardiovascular risk and provides appropriate screening and monitoring for cardiac issues.

The two populations that will benefit most are the chronic heart failure patients who can avoid frequent decompensation and hospitalization by closer renal management of volume and electrolyte status. The other is the CKD/ESRD population discussed above. These patients have high rates of both systolic and diastolic cardiac dysfunction, ischemic heart disease, and valvular calcifications. Routine screening and optimization of cardiac status will improve their outcomes.

NN&I: What about education and training (certification)? How would you go about creating this hybrid physician?

McCullough: I think we are a long way from a dual certification program or new stand-alone specialty, but our focus is to develop integrated care models to improve the quality of specialized care to the patient while decreasing cost to the health care system.

NN&I: Any reaction to date from the cardio or kidney world? Tell us about the goals of the society.

McCullough: The individual specialties have embraced this duality of care and are very supportive. We also see health care delivery systems anxious to incorporate this type of multi-specialty care into their clinical networks and service lines to improve quality and efficiency in their organizations.

CRSA is a multifaceted group. It continues to expand its academic efforts, building consensus groups and publishing peer-reviewed articles in cardio-renal medicine. Additionally, in partnership with the National Kidney Foundation of Arizona, CRSA is involved in national Path to Wellness population screenings in underserved and high risk communities throughout the nations (see sidebar). This is an important population we want to reach in the early stages of kidney disease.

NN&I: What is the next step for CRSA?

Petrides: In addition to continuing the efforts above, the CRSA is developing a training course with the support of Fresenius Medical Care. CardioRenal University will start educating fellows on integrating evidence-based care from both specialties.

The Cardio-Renal Society of America

CRSA is a 501(c)3 charitable organization founded in 2011 by a group of physicians concerned about the lack of protocols for patients facing cardiorenal syndrome: the complex interactions between kidney disease, heart disease, and metabolic disorders. A founding member and clinical nephrologist notes, “By the time I see a patient, I’m no longer treating the kidney. I’m treating the heart.” The interactions between these comorbid conditions, coupled with the lack of comprehensive treatment protocols, leads to higher mortality, longer hospital stays, more frequent readmissions and significantly increased cost. CRSA is working to improve outcomes for cardio-renal patients through medical education, community outreach, and research.

CRSA programs

Path to Wellness, a community outreach program developed in partnership with the National Kidney Foundation of Arizona

The Cardiorenal Metabolic Conference, CRSA’s annual multi-disciplinary meeting

Cardiorenal Grand Rounds, a medical education program for small groups that targets specific issues

Plus, symposia held at large medical conferences, and this year, introducing Cardiorenal University, cross training in cardiology and nephrology designed to affect a paradigm shift in the care of CKD, CVD and HF patients.

The Path to Wellness is an important outreach project for CRSA. It is a comprehensive community outreach program and IRB approved research project developed in partnership with the National Kidney Foundation of Arizona and with funding from local charitable and health care organizations. It was designed to identify the prevalence of cardiorenal syndrome and its co-morbid conditions in at-risk, underserved, underinsured populations.

CRSA recently took PTW nationwide with funding from Sanofi, and most recently, from Astra Zeneca. The free comprehensive screening employs point-of-care testing devices, a chronic disease education station with pre and post testing, and an on-site physician consult. Attendees are given an opportunity to sign up for free chronic disease self-management courses, connect with a medical home, and consult with an insurance navigator. Follow-up protocols are being developed to study the impact of PTW as a vehicle for behavioral change that can lead to improved outcomes. The data collected will facilitate research that may help develop future prevention models and intervention strategies.

For more information on CRSA, visit www.cardiorenalsociety.org