Are grown-up patients with congenital heart disease and mechanical valve using self-testing INR device? Experience feedback in a French population

Abstract

The Coaguchek INRange® is a self-testing meter to measure the INR, that is reimbursed in France since August 2017 for patients with mechanical valve. We evaluated the use of this anticoagulation method in a French population of GUCH (Grown-Up patients with Congenital Heart Disease) with mechanical valve. Since September 2018, 52 patients of 37 ± 11 years old were asked to attend a training course of 2 hours on anticoagulation and Coaguchek INRange® use, provided by specialized nurses, before getting home with the device. Patients had to attend a 3 months’ medical re-evaluation appointment. 29 (56%) patients had an aortic mechanical valve, 12 (23%) a mitral one, 8 (15%) a double aortic and mitral one, 2 (4%) a double aortic and pulmonary one and 1 (2%) a tricuspid one. 28 patients (54%) had a mechanical valve for ≥ 10 years (group 1). In group 1, patients were older (41 ± 10 years old vs. 34 ± 10, P = 0.01). Fluindione was the preferred oral anticoagulant (30 patients, 57%), and was more frequent in group 1 (18 patients, 64%). In group 1, 61% of patients usually managed themselves dosage adjustment whereas in the other group, 52% of patients referred to their doctor. Thirty-one patients (62%) had a higher target of INR than recommended in last European guidelines. Concerning follow-up, 26 patients (50%) did not attend the 3 months appointment and had to be rescheduled or contacted by phone. 8 patients (15%) did not use the device at 3 months: 5 for variation > 15% compared to laboratory plasma technique and 3 for not trusting the new device. INR at 3 months was obtained in only 40 (77%) patients, and was in the attended target in 62% of cases. GUCH patients with mechanical valves, especially when present for ≥ 10 years, seem to validate Coaguchek, even though evaluation remains hard since a great proportion of them did not attend follow-up appointment, stick to their old INR target and did not use the device as often as recommended.