Evaluation of Vitamin K Antagonists Management and Control in Patients with Mechanical Prosthetic Heart Valves during the COVID-19 Pandemic.

Background: Patients with mechanical prosthetic heart valves must be treated with vitamin K antagonists (VKA) due to an increased risk of valve thrombosis and systemic embolism.

Objectives: To assess the effects of the COVID-19 pandemic on VKA treatment control in patients with mechanical prosthetic heart valves.

Methods: We conducted a retrospective nationwide cohort study using the Clalit Health Services database. The cohort included patients who underwent either aortic or mitral valve replacement using a prosthetic mechanical valve. The primary outcomes included the overall time in therapeutic range (TTR) and the percent of patients with a TTR < 50% during the first year of the COVID-19 pandemic compared to preceding year.

Results: The cohort included 2381 patients. The percentage of patients who had at least two international normalized ratio (INR) tests during the first year of the COVID-19 pandemic was significantly lower compared to the year preceding the pandemic (81% and 87%, respectively, P < 0.001). In both years, the percentage of patients without any documented INR test was high (31.5% in the first COVID-19 pandemic year and 28.9% in the preceding year, P < 0.001). TTR was significantly lower during the 1st year of the COVID-19 pandemic compared to the preceding year (68.1% ± 26 and 69.4% ± 24, P = 0.03). A TTR > 50% was demonstrated in 78% and 81% during the pandemic and the preceding year, P = 0.009.

Conclusions: We noted overall poor VKA control in patients with mechanical heart valves. During the COVID-19 pandemic, VKA control became even worse as reflected by significantly lower TTR and INR tests rates.