ABSTRACT
Serum Creatinine [SCr], widely used for renal function assessment is not an accurate measurement. SCr can be within normal range even when there is substantial nephropathy. The objective was to observe the incidence of contrast induced nephropathy [CIN] with normal SCr and low glomerular filtration rate [GFR]. This was a cross-sectional, observational study involving patients undergoing coronary angioplasty. During a period of 6 months, 64 patients having SCr ? 1.4mg/dl and a GFR of < 80ml/min were selected who underwent elective coronary angioplasty. SCr was measured again after 48 hours of the procedure. CIN was defined as a > 25% increase in SCr from the preprocedure level. For statistical analysis, SPSS version 10 was used to calculate one way Anova was used for comparing variables between CIN and No-CIN groups, while paired t-test was applied for comparison between pre and post procedure SCr. Out of 64 patients, CIN was seen in 14 patients [21.8%]. After the procedure, significant difference was seen in the mean creatinine levels [p < 0.001]. The before and after experiment creatinine values also showed a significant difference [p < 0.05]. SCr along with calculated GFR should be used to assess patients for underlying renal insufficiency undergoing contrast procedures like coronary angioplasty. Patients with low GFR and normal SCr have a significant risk of developing CIN. Identifying such patients before hand can help us decrease the overall incidence of CIN by administering timely prophylactic measures
ABSTRACT
To determine the frequency of patients with underlying renal insufficiency having normal serum creatinine level proceeding for coronary angiography. A total of 693 patients from September 2009 to February 2010 undergoing diagnostic coronary angiography at the National Institute of Cardiovascular Diseases [NICVD] with normal serum creatinine = 1.5mg/dI were selected. Glomerular filtration rate [GFR] was calculated for each patient using the Cockcroft-Gault [C-G] equation and a GFR < 80ml/min was labeled as renal insufficiency. The mean age of males was 51.86 +/- 10.19 years and 51.52 +/- 9.80 years for females. Almost one-third [n=236, 34.1%] of patients had GFR <80ml/min; comparison between male [n=168, 31.2%] and female [n=68, 43.9%] was significant [p-value 0.003]. Age group breakdown showed majority of patients [n=196; 83.05%] with GFR <80 ml/min ranged between 40-69 years [p-value 0.001]. This study has shown that most of the patients with normal serum creatinine have abnormal GFR. Serum creatinine, which is considered to be an important screening test in patients with renal impairment, might remain in the normal range despite the renal function being significantly impaired. Therefore, GFR should be considered as an estimate of renal insufficiency, regardless of serum creatinine levels being in normal range