OHRI -- Aprotinin is associated with a 50 per cent increase in the relative risk of death, according to a major Canadian clinical trial comparing three drugs routinely used to prevent blood loss during heart surgery. The trial, published in the New England Journal of Medicine, shows that approximately six per cent of patients who received aprotinin died within 30 days of surgery compared to four per cent of patients who received tranexamic acid or aminocaproic acid.