Assessing the appropriateness and increasing the yield of renal angiography in patients undergoing coronary angiography: a scoring system.

The real appropriateness and yield of a coincident renal angiography in patients undergoing coronary angiography is still a matter of debate. We have attempted to defined a scoring system to assess the need for renal angiography in patients undergoing diagnostic coronary angiography. We retrospectively reviewed our invasive cardiology database searching for patients underwent coincident screening abdominal aorta angiography to detect occult renal artery stenosis were analyzed and entry in a development set. Univariate and multivariate logistic regression analyses were employed to determine independent predictors of extra-cardiac atherosclerotic involvement. Based on the odds ratio, identified variables were assigned to a weighted integer; the sum of integers was a total score. Thus, the scoring model was tested on a validation set based on a prospective series of consecutive patients enrolled on the basis of an identified cut-off score. In the development set (635 patients, mean age 68+/-11.2 years) an angiographically significant RAS was observed in 20% of cases (128 patients). The rate of significant angiographic findings increased proportionally with increasing risk score (Pearson coefficient 0.98). A score of >or=5 was identified to be the cut-off beyond which renal angiography seems to have a sufficiently good efficacy in detecting clinically significant renal artery diseases (>30% of patients). In the validation set the patients were enrolled on the basis of the identified cut-off score (317 patients, mean age 69+/-14.1 years): angiographic occult RAS was diagnosed in 156/317 (49.2%) patients of the validation set versus 128/635 (20%) patients of the development set, p<0.01. This scoring system, once applied in standard medium-high volume cath labs, may be effective in increasing the yield of renal artery angiography in patients undergoing coronary angiography.