Prosthetic valve dysfunction in patients with mechanical heart valves: Results from the Emergency Salam Centre cohort

Mechanical heart valve (MHV) replacement requires long-life anticoagulation due to the risk of Prosthetic Valve Dysfunction (PVD) and cardioembolism.

We report data from a prospective observational study conducted on MHV patients in the Khartoum Salam Centre for Cardiac Surgery built by 'Emergency,' an Italian Non-Governmental Organization, to evaluate the occurrence of PVD and associated risk factors.

We prospectively followed 3647 patients, and 38 patients (rate 1.04 × 100 pt-years) had PVD during follow-up. The time in therapeutic range (TTR) among patients without PVD was 53 % (IQR 37-67), and it was 43 % (IQR 19-58) among patients with PVD (p = 0.04). Twenty-three over 38 patients (60.5 %) were symptomatic, 18 (47.4 %) had obstructive valvular stenosis, 24 patients (63.2 %) had INR <2.0 at diagnosis, and 21 patients (55.3 %) had been off warfarin for a long time: 3 patients for 1 week, 1 patient for 2 weeks, and 17 patients for >4 weeks (6 patients were off warfarin from 3 to 12 months). Ten were uncompliant to treatment, and 8 were pregnant women. Ten patients (26.3 %) with PVD had had a previous episode of PVD, and 14 patients (36.8 %) had 2 or more associated risk factors. Only in 6 cases were no associate risk factors found.

Among MHV patients on warfarin treatment with a sub-optimal quality of anticoagulation, the rate of PVD is 1.04 % pt-years, and the most frequent associated risk factor for PVD occurrence is warfarin withdrawal lasting more than one week.