Higher baseline international normalized ratio value correlates with higher mortality in intracerebral hemorrhage during warfarin use

Background and purpose: Intracerebral hemorrhage (ICH) is the most feared complication of oral anticoagulation (OAC). Our aim was to investigate the impact of the international normalized ratio (INR) level on mortality in OAC-associated ICH compared with non-OAC-associated ICH.

Methods: A retrospective chart review of consecutive ICH patients treated at the Helsinki University Central Hospital from January 2005 to March 2010 (n = 1013) was performed. An ICH was considered to be OAC-associated if the patient was on warfarin at ICH onset. The association of INR with 3-month mortality was adjusted in a multivariable logistic regression model for factors influencing the crude odds ratios (ORs) in bivariable logistic regression by more than 5%.

Results: One in eight ICHs was OAC-associated (n = 132). Of these, 50% had therapeutic INR (2.0-3.0), 7% had INR <2.0 and 43% had high INR (>3.0) on admission. Patients on OAC were older (median 76 vs. 66 years; P < 0.001) with more severe symptoms (median National Institutes of Health Stroke Scale 14 vs. 10; P < 0.001) and larger hematomas (median 11.4 vs. 9.7 ml; P < 0.001) on admission than patients not on OAC. After adjustment for confounders, 3-month mortality in the whole cohort was associated with higher baseline INR (OR 1.06; CI 1.03-1.09 per 0.1 increment). Mortality was higher with both therapeutic (51% at 3 months; OR 3.59; CI 1.50-8.60) and high (61%; OR 5.26; CI 1.94-14.27) INR values compared with non-OAC-associated ICH (29%).

Conclusions: Patients with OAC-associated ICH had more severe strokes and higher mortality compared with patients with ICH not related to OAC. Higher baseline INR was associated with increased 3-month mortality.