The cost-effectiveness of the diagnosis of renal artery stenosis

The objective of this study was to assess the cost effectiveness of eight strategies to diagnose renovascular hypertension (RVHT) followed by 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 diagnostic imaging techniques under consideration were captopril renography, spiral computed tomography angiography (CTA), magnetic resonance angiography (MRA) and conventional angiography. Cost-effectiveness analysis was carried out from the perspective of the health care system, based on data from the literature. A model was developed to predict the reduction in 10-year morbidity and 10-year mortality owing to myocardial infarction, stroke and chronic renal failure achieved after PTRA compared with the reference strategy. Life-years gained over a 10-year follow-up period and the incremental cost-effectiveness ratio per life-year saved were the outcome measures. The strategy CTA followed by angiography was more effective, but more costly, than captopril renography followed by angiography, with an incremental cost-effectiveness ratio per life-year gained of Dfl 64700. Combining captopril renography with CTA was even more effective, but the incremental cost-effectiveness ratio per life-year gained was Dfl 236400. Strategies including MRA were not cost-effective. The results suggest that diagnostic strategies that include CTA are more effective than captopril renography in detecting renal artery stenosis (> 50%) and cost saving due to prevented myocardial infarction, stroke or chronic renal failure. MRA is even more 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.