THE COST-EFFECTIVENESS OF THE DIAGNOSIS OF RENAL-ARTERY STENOSIS

The objective of this study was to assess the cost effectiveness of ei ght strategies to diagnose renovascular hypertension (RVHT) followed b y treatment with percutaneous transluminal angioplasty (PTRA) with or without stent placement. The eight diagnostic strategies were compared with a reference strategy, i.e. antihypertensive medication. The diag nostic imaging techniques under consideration were captopril renograph y, spiral computed tomography angiography (CTA), magnetic resonance an giography (MRA) and conventional angiography. Cost-effectiveness analy sis was carried out from the perspective of the health care system, ba sed on data from the literature. A model was developed to predict the reduction in 10-year morbidity and 10-year mortality owing to myocardi al infarction, stroke and chronic renal failure achieved after PTRA co mpared with the reference strategy. Life-years gained over a 10-year f ollow-up period and the incremental cost-effectiveness ratio per life- year saved were the outcome measures. The strategy CTA followed by ang iography was more effective, but more costly, than captopril renograph y followed by angiography, with an incremental cost-effectiveness rati o per life-year gained of Df1 64700. Combining captopril renography wi th CTA was even more effective, but the incremental cost-effectiveness ratio per life-year gained was Df1 236400. Strategies including MRA w ere not cost-effective. The results suggest that diagnostic strategies that include CTA. are more effective than captopril renography in det ecting renal artery stenosis (> 50%) and cost saving due to prevented myocardial infarction, stroke or chronic renal failure. MRA is even mo re effective, but in order to achieve an acceptable cost-effectiveness ratio, the costs would need to be reduced. The cost-effectiveness of the diagnostic strategies is sensitive to the pre-test probability of RVHT. So, careful clinical evaluation, in order to achieve a pre-test probability of at least 20%, is an essential component of the complete workup strategy in patients suspected to have RVHT. (C) 1998 Elsevier Science Ireland Ltd. All rights reserved.