Factor VIII complex was studied in patients presenting arterial hypertension. Visceral involvement was quantified using a clinical index calculated from ocular fundus, renal function and left ventricular hypertrophy data. A significant correlation was found between the mean arterial pressure, the visceral involvement and the level of complex VIII. Nevertheless, other data obtained in different patients (Conn’s disease) suggest that the visceral involvement (and not the mean arterial pressure) is the main determining factor in the increase of factor VIII comple