Individualized prediction of the effect of angiotensin receptor blockade on renal and cardiovascular outcomes in patients with diabetic nephropathy

AIMS: To predict individualized treatment effects of angiotensin receptor blockers (ARBs) on cardiovascular and renal complications in order to help clinicians and patients assess the benefit of treatment (or adherence) and estimate remaining disease risk. MATERIALS AND METHODS: In patients with diabetic nephropathy, the 3-year treatment effect of ARBs was predicted in terms of absolute risk reduction (ARR) for end-stage renal disease (ESRD) and cardiovascular disease (CVD; i.e. myocardial infarction, stroke, hospitalization for heart failure) and all-cause mortality. Competing-risk-adjusted proportional hazard models were developed based on the Irbesartan Diabetic Nephropathy Trial (IDNT) and externally validated in the Reduction of Endpoints NIDDM with Angiotensin II Antagonist Losartan (RENAAL) trial. RESULTS: Predictors included in the model were age, sex, smoking sex, systolic blood pressure, urinary albumin/creatinine ratio, estimated glomerular filtration rate, albumin and phosphorus. The median predicted 3-year risk without treatment was 6.0% for ESRD and 28.0% for CVD and mortality. The median [interquartile range (IQR)] predicted 3-year ARR was 1.2 (0.4-3.1)% for ESRD and 2.2 (1.8-2.6)% for CVD and mortality, resulting in a combined ARR of 3.4 (2.4-5.5)%. The remaining disease risk was 4.7 (IQR 1.7-12.8)% for ESRD and 25.8% (IQR 20.3-31.9)% for CVD and mortality. CONCLUSIONS: The combined effects of ARBs on ESRD and CVD and mortality in patients with diabetic nephropathy vary considerably between patients. A substantial proportion of patients remain at high risk for both outcomes despite ARB treatment.