Pathways to poor anticoagulation control

Abstract

Summary. Background: While a considerable amount is known about which patient-level factors predict poor anticoagulation control with warfarin, measured by percent time in therapeutic range (TTR), less is known about predictors of time above or below target. Objective: To identify predictors of different patterns of international normalized ratio (INR) values that account for poor control, including 'erratic' patterns, where more time is spent both above and below INR target, and unidirectional patterns, where time out of range is predominantly in one direction (low or high). Methods: We studied 103 897 patients receiving warfarin with a target INR of 2-3 from 100 Veterans Health Administration sites between October 2006 and September 2008. Our outcomes were percent time above and below the target range. Predictors included patients' demographics, comorbidities, and other clinical data. Results: Predictors of erratic patterns included alcohol abuse (5.2% more time below and 3.7% more time above, P < 0.001 for all results), taking > 16 medications (4.6% more time below and 1.8% more time above compared to taking seven or fewer medications), and four or more hospitalizations during the study (6.6% more time below and 2% more time above compared to no hospitalization). In contrast, predictors like cancer, non-alcohol drug abuse, dementia, and bipolar disorder were associated with more time below the target range (3.4%, 5.2%, 2.6%, and 3.2%, respectively) and less (or similar) time above range. Conclusion: Different patientlevel factors predicted unidirectional below-target and 'erratic' patterns of INR control. Distinct interventions are necessary to address these two separate pathways to poor anticoagulation.

Clinical Prediction Model for Time in Therapeutic Range While on Warfarin in Newly Diagnosed Atrial Fibrillation

“…The efficacy and safety of warfarin is highly dependent on the quality of anticoagulation achieved as measured by the TTR, so among newly diagnosed, warfarin‐naïve AF patients, it may be clinically valuable to identify those individuals likely to have poor TTRs on warfarin so alternative therapies such as DOACs can be applied. Multiple studies have examined predictors of poor TTR, and our study shows many consistencies with, yet extends, previous findings . In particular, our study affirms younger age, lower body mass, lung disease, application of a rhythm control treatment strategy, kidney dysfunction, and alcohol problems as predictors of poor TTR .…”

“…Multiple studies have examined predictors of poor TTR, and our study shows many consistencies with, yet extends, previous findings . In particular, our study affirms younger age, lower body mass, lung disease, application of a rhythm control treatment strategy, kidney dysfunction, and alcohol problems as predictors of poor TTR . Our study advances prior work by considering an extended list of historical diagnoses and several inexpensively attained, commonly measured laboratory tests that serve as markers of potentially salient physiologic features such as kidney function, liver function, inflammation, nutritional status, metabolic derangements, coagulation propensity, red blood cell production and function, volume status, and frailty.…”

Choosing the right drug to fit the patient when selecting oral anticoagulation for stroke prevention in atrial fibrillation

“…Various patient factors including alcohol abuse, polypharmacy and hospitalization have been associated with erratic INR control. Furthermore, factors including concurrent diagnoses of dementia, cancer, nonalcohol substance misuse and bipolar disease have been associated with suboptimal anticoagulation . The SAMeTT 2 R 2 score [sex female, age <60 years, medical history (more than two comorbidities), treatment (interacting drugs, e.g.…”

Control de la anticoagulación en pacientes con fibrilación auricular no valvular asistidos en atención primaria en España. Estudio PAULA

“…Variables asociadas con el control de la razó n internacional normalizada (aná lisis bivariable) segú n el mé todo directo y el mé todo de Rosendaal (n = polimedicació n y haber tenido mú ltiples hospitalizaciones 33 . En otro estudio, las variables asociadas a buen control fueron el consumo regular de vitamina K, el sexo masculino, duració n del tratamiento anticoagulante > 2 meses, tener un apoyo familiar adecuado, presentar capacidades funcional y cognitiva adecuadas y no consumir alcohol habitualmente 34 .…”