The Acetylcysteine for Contrast-Induced Nephropathy Trial

Inclusion Criteria: At least one of the following criteria: * Aged more than 70 years-old * Chronic renal failure (defined as serum creatinine higher than 1.5mg/dL within the last 3 months) * Diabetes mellitus * Congestive heart failure or ventricular disfunction (left ventricular ejection fraction less than 0.45) * Shock or intra-aortic balloon pump use * Urgency or emergency procedures Exclusion Criteria: * Pregnant women, breastfeeding or aged below 45 years-old and with no efficacious contraceptive methods. * Patients in dialysis * Previous inclusion in this trial * Patient refusal to informed consent * Pacientes com Infarto Agudo do Miocárdio com supradesnivelamento do segmento S-T nos quais não seja possível administrar o protocolo de hidratação pré e pós-procedimento.