Contrast nephropathy in high-risk patients undergoing coronary angiography and intervention.

OBJECTIVE: To determine the incidence of contrast nephropathy in high-risk patients undergoing coronary angiography and percutaneous coronary intervention (PCI), and to define the characteristics of this cohort.

DESIGN: Discriptive study.

PLACE AND DURATION OF STUDY: The Aga Khan University Hospital, Karachi from January to December 2002.

PATIENTS AND METHODS: One hundred and fifteen patients with serum creatinine greater than 1.4mg/dl who underwent coronary angiography or PCI were included. All patients received non-ionic contrast dye. Acute contrast nephropathy was defined as rise in serum creatinine of 0.5mg/dl within 48 hours following the index procedure. Means and standard deviations were calculated for continuous variables and frequencies for categorical variables.

RESULTS: Mean age of patients was 62.3 years +/- 8.83. Mean pre-contrast creatinine was 1.9 +/- 0.9 mg/dl. Eleven (9.65%) patients developed contrast nephropathy. 4.4% of patients with serum creatinine < 2.0 developed contrast nephropathy compared to 42.9% of patients with creatinine > 4.0(p-value 0.001). 11.9% diabetic patients developed nephropathy compared to 6.3% of non-diabetics(p-value 0.355). 11.4% of hypertensive and 3.7% of non-hypertensive patients developed contrast-nephropathy (p-value 0.454). 12.9% of low dose group(<100 ml) and 5.7% of high dose group (>100 ml) developed nephropathy (p-value 0.188). Mean serum creatinine in low dose group was higher (3.0 mg/dl vs. 1.7 mg/dl).

CONCLUSION: The incidence of contrast nephropathy in this study was similar to that reported in literature. Risk of CIN was found to be significantly proportional to the severity of baseline renal disease. Trends towards higher risk of CIN were seen in patients with diabetes and hypertension. Higher incidence of CIN in patients receiving low-dose contrast was confounded by higher baseline serum creatinine in that group.