Objectives: To elucidate potential mechanisms for the clarithromycin-induced excess mortality observed in the CLARICOR trial during 2.6 year follow-up of patients with stable coronary artery disease.

Methods: Cox analyses using out-of-hospital death as a proxy for sudden death compared to in-hospital (nonsudden) death.

Result: In 100 of 189 (53%) cardiovascular (CV) deaths in which it was possible to examine the question, there was a strong association between place of death and the classification of CV death as sudden or not-sudden. The excess mortality in the clarithromycin group was confined to sudden CV death in patients not on statins at trial entry (HR: 2.61, 95% CI: 1.69-4.05, p < 0.0005). Other categories of deaths showed no marked drug-placebo difference.

Conclusions: Short-term clarithromycin administration was significantly associated with increased risk of sudden CV death in stable coronary heart disease patients not using statins.