Incidence and risk factors for severe renal impairment after first diagnosis of heart failure: A cohort and nested case-control study in UK general practice.

Objective: We aimed to evaluate the incidence, time-course and risk factors for severe renal impairment (SRI) among incident heart failure (HF) patients.

Methods And Results: Patients aged 1-89years from 2000 to 2005 with incident HF and without SRI or cancer (N=18,049) were identified from The Health Improvement Network (a primary care database representative of the UK population). Patients with a first ever record of SRI during follow-up were identified and eligible non-cases used as controls (N=5377; mean age 74years). Cohort and nested case-control analyses were conducted to identify risk factors for SRI. 2818 patients (15.6%, mean age 75years) in the HF cohort developed SRI over a mean of 2.84years with incidence highest in the first year following HF diagnosis. Hazard ratios (HRs) with 95% confidence intervals (CIs) were as follows: diabetes (1.96, 1.80-2.14), hypertension (1.23, 1.14-1.33), peripheral artery disease (1.29, 1.15-1.45), ischemic cerebrovascular disease (1.14, 1.03-1.26), and anemia (1.19, 1.06-1.34). Several cardiovascular medications were associated with SRI in the case-control analysis, odds ratios (95% CIs): 5.07 (3.87-6.64) for all diuretics, 3.22 (2.83-3.66) for potassium-sparing diuretics, 2.40 (1.96-2.93) for thiazide and related diuretics and 3.27 (2.67-4.01) for loop-diuretics.

Conclusion: SRI is a frequent complication in patients with newly diagnosed HF. Comorbidities may contribute to its development and should be adequately treated. Robust clinical trial data on beneficial or possibly deleterious effects of diuretics, especially loop-diuretics and potassium-sparing diuretics, on SRI development in HF patients are warranted.