Contrast-induced nephropathy in urgent coronary interventions

Patients submitted to urgent percutaneous coronary interventions (PCIs) are quite often at high risk for contrast-induced nephropathy (CIN) since they exhibit several predisposing factors such as electrical and haemodynamic instability together with the lack of time to undergo adequate prophylaxis. This was a not blinded, non-randomized study whose aims were (i) to evaluate the incidence of CIN after urgent PCI in a high-volume cardiovascular referral practice (patients with acute myocardial infarction or with acute coronary syndromes enrolled in a single centre), and (ii) to assess the prognostic implications of CIN during hospitalization and at 1-month follow-up.

Between 1 October 2003 and 1 April 2004, 194 consecutive patients undergoing urgent coronary angiography and PCIs at our catheterization laboratory were enrolled in the study: 67 patients (34.5%) received the iso-osmolar contrast medium iodixanol (group A) and 127 patients (65.5%) received the hypo-osmolar contrast medium iopromid (group B).

The overall incidence of CIN was 10.82%. Patients of group A showed a higher incidence of CIN than patients of group B (22.3 vs. 4.7%, P < 0.05). On univariate logistic analysis, age, pre-existing renal insufficiency, intra-aortic balloon pump (an indirect indicator of haemodynamic instability), dyslipidaemia, and postprocedural hypotension were risk indicators for the development of CIN after primary PCI. On multivariate logistic analysis, age and postprocedural hypotension remained significant independent correlates of CIN.

In emergency PCIs, CIN is a frequent complication mainly related to haemodynamic instability and pre-existing renal dysfunction. Since CIN is associated with a high in-hospital mortality rate, our data stress the need for the development and validation of new preventive strategies for renal protection during emergency PCIs.