[Rajiv]

Women have more risk only after Menopause ( so far as I know). The fact is different changes occur after Menopause.Like 'Estrogen' protects blood vessels prior to menopause. In post-menopausal women, the wall of blood vessel changes and shows high afinity to plaque and clot formation. Moreover fibrinogen level in blood is higher.
Many drugs which are used for heart disease in men show side effects and low or high effect in women. eg coagulation inhibitors like Heparin can lead to severe bleeding.