ACE and diabetes mellitus: To study the relation between the prescription rates of selected cardiovascular drugs (ACE-inhibitors and Angiotensin receptor blockers, beta-blockers, diuretics, and combinations), sociodemographic factors (age, gender and socioeconomic class) and concomitant diseases (hypertension, coronary heart disease, cerebrovascular accident, heart valve disease, atrial fibrillation, diabetes mellitus and asthma/COPD) among patients with heart failure cared for in general practice.