The 19,000 patient Anglo-Scandinavian Cardiac Outcomes Trial (ASCOT), which began in 1997, has been comparing the two treatment strategies to discover which is better at preventing various cardiovascular events, such as heart attacks and strokes.

'Important Significant Differences'

The older treatment strategy was based on atenolol (beta-blocker) and bendroflumethiazide (thiazide diuretic). It was compared with a newer treatment strategy using amlodipine (calcium channel blocker) and perindopril (angiotensin converting enzyme inhibitor).

The blood pressure part of the trial was terminated because of comparative cardiovascular benefits in favor of the newer treatment. The Steering Committee of ASCOT accepted the November 18 recommendation of its Data Safety Monitoring Board that the blood pressure arm of the trial should be stopped and the majority of patients have been informed.

The main clinical elements of the ASCOT trial have now ended.

"This is excellent news for the many people who suffer from high blood pressure," comment ASCOT study co-chairmen Björn Dahlöf, from the Sahlgrenska University Hospital, Östra, Sweden, and Peter Sever from Imperial College London, UK. "Although at the moment we are unable to provide any definite figures on the effectiveness of the new treatments compared with the old, we have seen important significant differences."

Complete Results Pending Analysis

Over the next few months all ASCOT patients will be seen for a final visit, when they will be given advice about future treatment of their hypertension. Prior to their final visit, all patients are advised to stay on their existing drugs until they see their trial physician to ensure their blood pressure remains controlled. The ASCOT trial doctors remind patients that sudden withdrawal of any treatment regimen could be harmful to them.

The complete results of the ASCOT trial will be made available when all data up to and including the last individual patient visit have been collected and analyzed. Investigators and patients will be informed of the final results of ASCOT when the data become available, and the results will be published in the scientific press.

Earlier Trial Stopped Due to Statin Benefits

Of over 19,000 patients randomized to the two different blood pressure strategies, approximately 10,000 patients were also randomized to treatment with either atorvastatin or placebo in the ASCOT Lipid Lowering Arm (ASCOT-LLA). The ASCOT-LLA was stopped prematurely in October 2002 as a result of substantial benefits associated with statin use in the prevention of heart attacks and strokes.

The principal sponsor of ASCOT is Pfizer Inc., New York. Support has also been provided by Servier Research Group, Paris, and Leo Laboratories, Copenhagen.