The prognostic value of renal dysfunction in patients with chronic heart failure: 12-month follow-up

Abstract

Introduction: Renal function assessment is an important element of management and therapeutic decision-making in patients with chronic heart failure (CHF).

Aim: To evaluate the prognostic value of renal dysfunction in patients with CHF in 12-month follow-up.

Methods: 639 consecutive patients hospitalised in our department from 1 July 2002 to 31 December 2003 with diagnosis of CHF (NYHA II-IV), based on medical records, were initially enrolled in the study. Patients underwent one-year follow-up. Finally, 498 patients, aged 22-98 years (mean age 69+/-12 years) in whom creatinine concentration was measured and creatinine clearance was estimated at admission with the Cockroft-Gault quotation and with long-term follow-up results obtained, were enrolled in the study. Patients were divided into two groups according to the creatinine level: Group I without renal dysfunction (creatinine level <1.4 mg/dl), and Group II--with renal dysfunction (creatinine level >1.4 mg/dl).

Results: Patients with renal dysfunction were significantly older and more likely to be male and in NYHA class III-IV (p <0.001). Analysis of pharmacotherapy for CHF revealed that patients with renal impairment significantly less frequently received beta-blockers (67% vs 81%, p <0.005), angiotensin-converting enzyme inhibitors (68% vs 82%, p <0.005) and combined treatment of beta-blocker and angiotensin-converting enzyme inhibitor (56% vs 71%, p <0.05), whereas loop diuretics were more frequently prescribed in this group (80% vs 70%, p <0.05). In patients with renal dysfunction, there was a significantly higher mortality rate at 30 days (32% vs 14%, p <0.001) as well as at 12 months (45% vs 20%, p <0.001). The incidence of re-hospitalisation for cardiovascular reasons (CHF worsening, myocardial infarction, stroke) was significantly higher in patients with renal dysfunction (70% vs 55%, p <0.005). Multivariate analysis of all factors affecting one-year mortality demonstrated that renal dysfunction is a strong and independent risk factor for death in patients with CHF (RR=2.13, 95% CI: 1.31-3.45; p <0.05) and it increases the risk of re-hospitalisation (RR=1.53, 95% CI: 1.01-2.14; p <0.05).

Conclusions: Renal dysfunction is an independent prognostic factor in patients with CHF, which allows identification of a high-risk group and administration of optimal therapy, which in turn can result in a reduction of mortality.