Experience and Outcomes of a Dedicated Cardio-Nephrology Service: A Step Towards Integrated Cardiovascular-Kidney-Metabolic Syndrome Care.

BACKGROUND: The cardiovascular-kidney-metabolic (CKM) syndrome, estimated to affect up to 90% of U.S. adults, is increasingly recognized as a disease spectrum that requires an interdisciplinary approach. The purpose of this descriptive study was to characterize the patients and the clinical outcomes of a specialized cardio-nephrology inpatient service. These data were compared to data from comparable patients prior to the service's launch. METHODS: This was a retrospective observational study of a specialized Kidney-Heart service that was launched at the University of Washington in 2020 to serve as the nephrology service for patients hospitalized with primary cardiac disease. Chart review was pursued to obtain patient demographics, reason for consult and hospital outcomes in the first 2.5 years of the service. We also obtained data from a historical cohort of patients with a cardiology diagnosis seen by the general nephrology consult service as a comparator. Descriptive analyses were performed to characterize demographics, consult categories, and primary reasons for hospitalization in patients seen on the Kidney-Heart Service versus the historical cohort. RESULTS: The mean age for the patients seen on the Kidney-Heart Service was 63 (SD 15) vs. 60 (SD 15) years in the comparator cohort (p<0.001). For the Kidney-Heart Service, AKI was the most common reason for consult (57.7%), followed by CKD G5D (30.9%), diuretic management (8.9%) and electrolyte abnormalities (7.8%). Patients seen by the Kidney-Heart Service were most commonly hospitalized for decompensated heart failure and cardiogenic shock (46.9%). Use of mechanical circulatory support was common (22%), and 48.2% of those patients required dialysis. AKI dialysis (36.7 vs 42%, p=0.05) and mortality rates (16.5% vs. 25%, p<0.01) were lower in the Kidney-Heart service cohort vs. the comparator cohort, although mean lengths of stay were longer (14 vs 11 days, p<0.001.) Follow- up in nephrology clinic within the University of Washington system was low for AKI patients at 1.7%. CONCLUSIONS: Our single-center experience demonstrates a model by which a specialized cardio-nephrology service can be implemented and provide care for complex patients. Further implementation clinical trials are needed to determine whether integrated care models can improve CKM outcomes.