- Persistent proteinuria defined as urinary protein excretion ? 1g/24h in two distinct 24-h urine collections at least 1 week apart within 3 months prior to study entry (baseline, Month 0 visit) without evidence of urinary tract infection or overt heart failure (NYHA class III or more); OR creatinine clearance ? 60 mL/min in two distinct measures at least 1 week apart within 3 months prior to study entry (baseline, Month 0 visit).