he incidence of hypertension (HT) and of diabetes mellitus (DM) has been continuously increasing with the aging of society and changes in lifestyle. HT and DM can be factors in cardiac and vascular disorders, and chronic renal insufficiency (CRI), so the probability of encountering coronary artery disease in a patient with CRI is relatively high. Contrast-induced nephropathy (CIN) is defined as acute renal dysfunction manifesting as temporary elevated serum creatinine level (Scr) because of the use of a contrast agent, with no other causes, and is reversible with sufficient fluid infusion in most cases. However, there may be an irreversible disturbance. The elevation of Scr in CIN is 0.3-1.0 mg/dl or more, or by 20-50% from the previous level. 1 Recently it has become clear that renal function is an independent prognostic factor of cardiovascular diseases. 2,3 The efficacy of hemofiltration (HF) after using a contrast agent has also been indicated. However, it has been reported that hemodialysis (HD) after the administration of a contrast agent does not completely prevent complications such as CIN,5 and that CIN could not be prevented even when the area under curve of the level of contrast agent concentration decreased. 6 Contrast nephrotoxicity is believed to b temporary and furthermore, the effect on renal function over the long term is unknown. Therefore, the
Circulation Journal Vol.72, March 2008effect of a contrast agent on long-term renal function was studied.
Methods
Study PatientsIn CIN, acute renal failure tends to occur first, and thereafter some renal insufficiency may remain. Therefore, to investigate the effect of a contrast agent on renal function in the acute phase, Scr values before the use of a contrast agent, immediately after the use of a contrast agent (max. Scr within 2 weeks after use of a contrast agent), and after use of a contrast agent in the recovery phase (within 2 months after use of a contrast agent) were recorded. Among the patients who had been administered a contrast agent from July 1997 to April 2004, those with a Scr of less than 1.2 mg/dl before the administration of a contrast agent were classified as Group N (20 patients), and those having a Scr of at least 1.2 mg/dl but less than 2.0 mg/dl before administration of a contrast agent were categorized into the following 2 groups: Group D1: 10 patients without hemodiafiltration (HDF) after use of a contrast agent, and Group D2: 15 patients with HDF after use of a contrast agent.The subjects in groups N, D1, and D2 were selected randomly. All patients gave informed consent individually before enrolling. This study was approved by the Review Committee for Clinical Research of Yamaguchi University Hospital.The background of the patients is shown in Table 1. Glomerular filtration rate (GFR) was calculated using the Modification of Diet in Renal Disease Study (MDRD) method. 7 Scr was 0.85±0.18 mg/dl, 1.45±0.14 mg/dl, and 1.59±0.26mg/dl for Groups N, D1 and D2, respectively, and the respective GFR were 71.0±15.0ml/min, 36.8±4.1ml/min,...
