23 Serum ngal identifies contrast nephropathy early in patients with diabetes mellitus and chronic kidney disease undergoing coronary angiography and angioplasty

Abstract

<h3>Background</h3> The incidence of contrast nephropathy (CIN) following coronary angiography or percutaneous coronary intervention (PCI) in patients with diabetes mellitus (DM) may be up to 30% and is associated with increased long term morbidity and mortality. <h3>Methods</h3> We recruited 208 consecutive patients undergoing elective or urgent coronary angiography or PCI with known DM and chronic kidney disease (CKD) (defined as eGFR &lt;60 ml/min). CIN was defined as a post procedure rise in creatinine at day 3 of &gt;25% from baseline or an absolute rise of 44.5 μmol/l. Severity of coronary disease was assessed using the SYNTAX Score and risk of CIN using the Mehran risk score. We evaluated serum and urine neutrophil gelatinase-associated lipocalin (NGAL) and albuminuria for additional information about CIN risk. N-acetylcysteine and intravenous hydration were given to all patients with eGFR &lt;50 ml in accordance with local guidelines. <h3>Results</h3> Baseline characteristics are summarised in table 1. 116 patients underwent coronary angiography and 92 underwent PCI. 39 patients (18.8%) developed CIN. Contrast dose was similar in the CIN and non-CIN group (p=0.249). The Mehran risk score was strongly predictive of CIN development (p&lt;0.001). The SYNTAX score did not differ between those who did or did not develop CIN (p=0.188). A significant rise in serum NGAL was seen as early as 2 h post procedure in the CIN arm (p=0.03) and this persisted at 4 h (p=0.007) and 12–24 h (p=0.0015). Urine NGAL levels did not change significantly during the first 24 h. Neither albumin:creatinine ratio (p=0.149) or protein:creatinine ratio (p=0.635) predicted development of CIN. <h3>Conclusions</h3> The current gold standard for measuring CIN is a rise in serum creatinine but this is of limited value as it does not increase until 48–72 h post renal injury. Neither the SYNTAX score, nor urinary albuminuria or proteinuria are predictive of CIN development. A rise in serum NGAL levels within the first 12 h following coronary angiography or PCI appears to be a very promising marker in the early diagnosis of CIN.