Predictors of contrast induced nephropathy and the applicability of the Mehran risk score in high risk patients undergoing coronary angioplasty-A study from a tertiary care center in South India.

OBJECTIVE: To study the incidence and predictors of Contrast induced nephropathy (CIN) in high risk patients undergoing coronary angioplasty. To study the applicability of the Mehran Risk Score (MRS) in the prediction of CIN in our population.

METHODS: This was a prospective observational study where patients with an estimated glomerular filtration rate (eGFR) between 30 and 60ml/mt undergoing elective percutaneous coronary intervention (PCI) over a period of 15 months were evaluated prospectively for the development of CIN. The patients who developed CIN were then analysed for the presence of specific risk factors. The patients were categorized into the 4 risk groups based on the MRS.

RESULTS: 100 high risk patients underwent PCI during the study period. The incidence of CIN was 29%. On multivariate analysis, the presence of anemia (p=0.007), increased contrast volume usage (as defined by >5* B.Wt/S.cr) (p=0.012) and usage of loop diuretics (p=0.033) were independently found to confer a significant risk of CIN. In patients belonging to the high Mehran risk group (MRS10- 15) and very high risk group (MRS >15) the risk of CIN was 3 fold (OR: 3.055, 95% CI: 1.18-7.94, p=0.022) and 24 fold (OR: 24, 95% CI: 2.53-228.28, p=0.006) higher respectively when compared to intermediate and low risk patients (MRS <10).

CONCLUSION: The incidence of CIN in high risk patients undergoing PCI is substantially higher in our population compared to similar studies in the west. The MRS risk prediction is pertinent even in an Indian population.