Diuretic treatment in those dying from a myocardial infarction

The relative risk of dying from a myocardial infarction according to diuretic therapy was estimated in a case control study for 189 cases, 144 dead controls and 349 living controls. The controls were matched for age (±2.5 years), sex and general practice. The study was community-based; the cases were identified from death certificates and the death certificates of the dead controls had no mention of ischaemic heart disease. The relative risk was estimated from the odds ratio and was similar whether dead or living controls were considered. Against all controls combined, the odds ratio for dying while taking a potassium-losing diuretic at 1 month prior to death (R₁) was 1.5 (95 per cent CI 0.9, 2.4) and for a combined potassium-losing + sparing diuretic (R_L+S) was 2.0 (95 per cent CI 1.1, 3.4). Potassium-sparing diuretics may be given more frequently to patients at greater risk of dying, thus masking a benefit, but the data could not provide evidence for a benefit from the addition of a potassium-sparing diuretic.