Elevated INR predicts mortality in DOAC-treated patients

Among hospitalized patients treated with direct oral anticoagulants (DOACs), an elevated international normalized ratio (INR) upon admission may spell an increased risk for in-hospital death or mortality during the first year following hospitalization, suggests a study.

“DOACs are associated with a prolongation of the prothrombin time and an increased INR,” the authors said. “The clinical significance of these changes is unclear.”

This study was conducted to clarify the clinical importance of these changes by exploring the relationship between an elevated INR on admission and in-hospital death and long-term survival in patients treated with DOACs.

The authors retrospectively reviewed data from records of hospitalized patients at the Sheba Medical Center in Israel between November 2008 and July 2023. They selected patients based on DOAC treatment, coagulation profile, and INR test done within 48 hours of hospitalization. In-hospital death and mortality in the year following hospitalization were the main outcomes.

A total of 11,399 hospitalized patients treated with DOACs were included in the analysis. Those with elevated INR showed a 180-percent greater risk of in-hospital death (adjusted odds ratio, 2.80, 95 percent confidence interval [CI], 2.30‒3.39) and a 57-percent higher risk of death during the year after being hospitalized (adjusted hazard ratio, 1.57, 95 percent CI, 1.44‒1.71).

Subgroup analyses revealed similar findings for each DOAC.

“This highlights that elevated INR levels in patients on DOACs should not be dismissed as laboratory variations due to DOAC treatment, as they may serve as a prognostic marker,” the investigators said.