The CORAL trial is currently enrolling patients to compare aggressive medical treatment of hypertension with an angiotensin receptor blocker (ARB), along with a statin and aspirin, to angioplasty with stent placement followed by aggressive medical treatment along with the antiplatelet agent clopidogrel. Results are expected, after up to 5.5 years followup, in 2010. The trial is powered and designed to address the bulk of the Key Questions posed by this report, including effects on clinical outcomes, adverse events, and possibly through secondary analyses the interaction of baseline features such as diagnostic test results, patient characteristics, or cointerventions with outcomes.

The CORAL trial will not address the following issues

Additional randomized controlled trials would be required to address the issues that will not be covered by the CORAL trial. A potential risk without such trials will be that the findings of the CORAL trial will be broadened to be considered applicable to patients with less or more severe ARAS than those patients included in the CORAL trial. Without confirmatory evidence, it will be unclear whether this will be appropriate. For example, if angioplasty with stent is found to be of benefit in the CORAL trial, it is likely that the procedure will become more common also in patients with mild disease, even though there will not be evidence to support this.

There are additional topics of interest the CORAL trial may be able to evaluate, that primarily through post hoc analyses, but may require additional studies to adequately address. These include

The ARAS research community should consider how to improve and/or standardize definitions of ARAS and severity of disease. These considerations should be based on how these definitions and disease severity scale would correlate with clinical outcomes.

The CORAL trial and other studies of ARAS should use the current suggested methods for estimating kidney function, including preferential use of estimated glomerular filtration rate over serum creatinine, and stage of chronic kidney disease.

The community of clinicians and professional organizations involved in performing renal artery angioplasty should consider how to improve procedural techniques and minimize variations in techniques and clinical outcomes across interventionalists, as clinically warranted. This may require quality improvement and other types of studies.