[Increased acceptance of the International Normalized Ratio (INR) as a monitoring parameter of oral anticoagulation therapy in Germany. GELIA Study Group].

In 1994 the German Cardiac Society recommended the International Normalized Ratio (INR) instead of "Quick's test" for the long-term management of oral anticoagulation therapy. Parallel cardiac surgical centers in Germany and Switzerland started patient recruitment for the GELIA study (German Experience with Low Intensity Anticoagulation). By the end of 1996, 862 consecutive patients with mechanical heart valve replacement had been enrolled. According to the protocol of the GELIA study, intensity of anticoagulation, methods used to control the oral anticoagulation therapy as well as other factors relevant for the anticoagulation management are reported every three months. The so far accumulated data material of the GELIA study seemed, therefore, appropriate to analyze potential changes in the acceptance of INR during the time period 1993-1996. Potential differences in the anticoagulation management were analyzed separately according to the time of enrollment of patients and changes during the follow up period, e. g., a switch from "Quick's test" to INR. Taking the time of enrollment into account, the percentage of patients who had INR-controlled oral anticoagulation therapy increased from 0% (1993), 14.3% (1994), 63.2% (1995) to 74.2% in 1996. During the follow up, there was a change from "Quick's test" to INR controls in 7 patients (1994; 2.1%), 67 patients (1995; 10.5%) and 142 patients (1996; 17.3%) with a consequent increase of INR controlled patients to a total of 34.2% in 1994, 52.0% in 1995, and 73.9% in 1996.