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Results of ramipril trial questioned

LONDON, UNITED KINGDOM. A major clinical trial recently concluded that the ACE inhibitor ramipril (Altace) is highly effective in preventing stroke. The trial involved 9296 patients with vascular disease or diabetes. At the end of the study the researchers concluded that ramipril lowers the risk of non-fatal stroke by 32 per cent and the risk of fatal stroke by 61 per cent. What was not highlighted in the report was that the non-fatal stroke rate in the placebo group was 3.9 per cent or about 0.9 per cent a year compared with 3.0 per cent or 0.7 per cent a year in the ramipril group, i.e. an absolute difference of about 0.2 per cent in the annual incidence of non-fatal stroke. The difference in the annual incidence of fatal stroke was even less impressive at 0.13 per cent.

The presentation of the data for ramipril, i.e. claiming reductions of 32 per cent and 61 per cent in stroke risk, is somewhat similar to the presentation used in the promotion of warfarin (Coumadin). Here a relative risk reduction of 64 per cent is claimed even though the absolute risk reduction when taking warfarin is only about 1.7 per cent a year.

Several medical doctors have expressed concern about the study and point out that the benefits of ramipril treatment have been vastly overstated by the use of relative rather than absolute risk reduction percentages. One doctor points out that the cost of preventing one single stroke with ramipril over a 4.5-year period would be somewhere in the range of US$ 64,000 – 160,000. NOTE: The original ramipril study was sponsored by several pharmaceutical companies.
Bosch, Jackie, et al. Use of ramipril in preventing stroke: double blind randomised trial. British Medical Journal, Vol. 324, March 23, 2002, pp. 1-5
Preventing stroke with ramipril. British Medical Journal, Vol. 325, August 24, 2002, pp. 439-41 (letters to the editor)

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