Israel Medical Association Journal

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.

Objectives: To determine the effect of vitamin K on hip fracture patients treated with warfarin.

Methods: We retrospectively examined the management of 21 patients with hip fractures who were being treated with warfarin at the time of admission. Vitamin K was given to 11 of the 21 patients. A third group, which served as a control, consisting of 35 hip fracture patients who were not being treated with anticoagulants was also evaluated.

Results: Patients who received vitamin K took fewer days to reach target international normalized ratio (INR) (1.73 ± 0.90 vs. 4.30 ± 1.89, P < 0.001) and had less preoperative time (2.64 ± 1.12 vs. 5.10 ± 2.42 days, P < 0.008) when compared with patients who did not receive vitamin K. In addition, these patients had statistically significantly shorter hospitalization stays (9.4 ± 1.9 and 13.2 ± 4.9 days, one-sided P < 0.06). There was no difference in the amount of blood found in the wound drains (111.8 ± 68.5 vs. 103.0 ± 69.4 ml) or the number of blood units administered (1.45 ± 1.29 vs. 2.00 ± 2.75 units).

Conclusions: Treatment with vitamin K for hip fracture patients who receive warfarin shortens preoperative time, reduces the length of hospitalization and probably reduces morbidity and mortality.