Elena Lotti, Alessandro Masi, Chiara Cappugi, Alessandra Fanelli, Lucia Mannini, Rossella Marcucci, Daniela Poli. Anti-SARS-CoV-2 vaccination does not influence anticoagulation levels in stable long-term warfarin treatment.
Blood Transfus 2022;
20. [PMID:
35302478 DOI:
10.2450/2022.0271-21]
[Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Subscribe] [Scholar Register] [Received: 10/13/2021] [Accepted: 01/21/2022] [Indexed: 12/14/2022]
Abstract
BACKGROUND
Since the outbreak of the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) pandemic, administration of the currently available vaccines has mostly been recommended for subjects at high risk, including elderly populations on long-term oral anticoagulation therapy (OAT) with warfarin. However, there is no clear evidence of the stability of the International Normalised Ratio (INR) after vaccine administration in those subjects on long-term OAT. The present study aimed to investigate the effects of COVID-19 vaccination on anticoagulation levels in patients on long-term OAT.
MATERIALS AND METHODS
INR values of patients on long-term OAT who had undergone anti-SARS-CoV-2 vaccination from January to June 2021 were monitored for a total of 90 days follow-up after the first vaccination dose. These were then compared with INR values before vaccination. The second dose, when required, was administered during follow-up. Inclusion criterion was stable long-term INR for at least 6 months before vaccination. Exclusion criteria were recent surgery, intercurrent diseases, or treatment with medication that could compromise findings in the 3 months before vaccination and during follow-up.
RESULTS
No differences were observed in the anticoagulation levels before and after COVID-19 vaccination in any of the patients studied: mean INR values were 2.39 (range 2.20-2.63) before vaccination and 2.40 (range 2.16-2.76) after vaccination (p=0.5). There was no difference in anticoagulation levels in relation to age, sex, indication for OAT, or type of vaccine (p>0.5). No bleeding or thrombotic complications were documented during follow-up.
DISCUSSION
These are the first data to be reported on anticoagulation levels in patients on stable OAT after COVID-19 vaccination. No influence on the quality of OAT was detected after the vaccination; no bleeding or thrombotic complications were recorded in the follow-up. No difference between the four available COVID vaccines was found. Dose adjustment was only required in a few cases, thus confirming the stability of anticoagulation levels.
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