Renal function is an underappreciated prognostic factor in heart failure (HF), and renal insufficiency is commonly viewed as a relative contraindication for some proven efficacious therapies. It is unclear whether ACE inhibitors, aldosterone antagonists and beta-blockers exert similar benefits in patients with kidney disease as these patients are infrequently enrolled in HF trials.
We analyzed data from a prospective cohort of heart failure patients followed in a specialty clinic. Renal insufficiency was defined as creatinine clearance <60 mL /min using the Cockcroft-Gault equation. Our hypothesis was that renal insufficiency was an independent predictor of outcome as measured by hospitalizations.
In our database of 167 outpatients, 71 (42%) had creatinine clearances calculated at > 60 mL/min (Group 1; mean creatinine clearance of 81.6 mL/min); 96 (58%) had creatinine clearances calculated < 60 mL/min (Group 2; mean creatinine clearance of 39.7 mL/min). There was no difference in the presence of co-morbidities including hypertension, diabetes, and hyperlipidemia. Group 2 patients were older (71±17 versus 60±9 years) and had more atrial fibrillation (32% vs. 18%; p=0.043). The log of pro-brain natriuretic peptide (pro-BNP) level was higher in Group 2 (7.6 + 1.5 vs. 6.7 + 1.5; p<0.0001). The two Groups were similar regarding the etiology of heart failure (52% ischemic in Group 1; 57% in Group 2; p=NS), and advanced heart failure NYHA III/IV (61% in Group 1; 62% in Group 2; p=NS). Patients in both groups received identical therapy, except statin therapy (61% in Group 1; 41% in Group 2; p=0.011). All cause hospitalization rate for Group 2 was greater compared to Group 1 patients (1.6 vs. 1.2 admissions per patient; p<0.05).
Despite similarities in therapies, co-morbidities, NYHA functional class and etiology of heart failure, patients with renal dysfunction with systolic heart failure had a greater all cause hospitalization rate than patients with preserved renal function.
Abnormal renal function is prevalent in patients with systolic heart failure and is an independent prognostic factor for hospitalization.
Jun Chiong, None.