Prevalence and Clinical Features of Patients with the Cardiorenal Syndrome Admitted to an Internal Medicine Ward

Background: Many patients admitted to a Department of Internal Medicine have different degrees of heart and kidney dysfunction. Mortality, morbidity and cost of care greatly increase when cardiac and renal diseases coexist. Methods: A retrospective cohort study was conducted on 1,087 patients admitted from December 2009 to December 2012 to evaluate the prevalence of the cardiorenal syndrome (CRS) and clinical features. Results: Out of 1,087 patients discharged from our unit during the study period, 190 (17.5%) were diagnosed as having CRS and classified into five types. CRS was more common in males (68.9%). CRS type 1 was associated with higher age (79.9 ± 8.9 years) and accounted for 61.5% of all deaths (p < 0.001), representing a risk factor for mortality (OR 4.23, 95% CI 1.8-10). Congestive heart failure was significantly different among the five CRS types (p < 0.0001) with a greater frequency in type 1 patients. Infectious diseases were more frequent in CRS types 1, 3 and 5 (p < 0.05). Pneumonia presented a statistically higher frequency in CRS types 1 and 5 compared to other classes (p < 0.01), and community-acquired infections were statistically more frequent in CRS types 1 and 5 (p < 0.05). The distribution of community-acquired pneumonia was different among the classes (p < 0.01) with a higher frequency in CRS types 1, 3 and 5. Conclusion: CRS is a condition that is more frequently observed in the clinical practice. The identification of predisposing trigger factors, such as infectious diseases, particularly in the elderly, plays a key role in reducing morbidity and mortality. An early recognition can be useful to optimize therapy, encourage a multidisciplinary approach and prevent complications.