[Risk factors and prognosis of contrast-induced nephropathy with renal dysfunction]

To investigate the risk factors, clinical characteristics, and prognosis of contrast-induced nephropathy (CIN) in patients with renal dysfunction.

We retrospectively analyzed 44 patients with renal dysfunction who received coronary angiography in our hospital. CIN was found in 23 patients, after angiography. We compared the clinical characteristics, medication during angiography day, volume of contrast-medium, as well as renal function changes before and after angiography in patients with (23 cases) and without (21 cases) CIN. The CIN patients were further divided into two groups according to their serum creatinine (Scr) levels: renal function recovery group (12 cases) and renal function non-recovery group (11 cases), and difference between these two groups was analyzed.

CIN incidence was 52.3% (23/44) in all 44 patients with renal dysfunction. CIN incidence was 42% (8/19) in patients whose Scr was between 132.6 - 168 micromol/L, was 60% (15/25) in those whose Scr was more than 176.8 micromol/L. In all 23 CIN patients, the average volume of contrast-medium was (144.79 +/- 71.8) ml, while 43.5% of the CIN patients whose dosage was over the maximum threshold of contrast-medium; the average risk factors were 5.14 +/- 1.3. Compared with the group without CIN, the difference was statistically significant (P < 0.05). Multiple stepwise regression analysis showed the volume of radio-contrast-medium was correlated with CIN in patients with renal dysfunction (F=10.4, P=0.003). Patients in the CIN group showed a significant rise of Scr level 24, 48, and 72 hours after angiography. However, the urine volume had no change before and after angiography. Renal function was improved in 12 of 23 patients (52.2%), and deteriorated in 11 patients (47.8%). Four patients (17.4%) received dialysis. Compared with the non-reavery group, Scr levels [(194.5 +/- 70.7) micromol/L, (443.8 +/- 282.9) micromol/L, respectively] of pre-angiography in renal function recovery group and the patients whose dosage was over maximum threshold of contrast-medium (2/12, 8/11) had significant difference (P < 0.05).

Higher volume of contrast-medium is a risk factor of CIN in patients with renal dysfunction. Pre-angiography Scr level and the contrast-medium volume are correlated with the prognosis of CIN in such patients.