What is the purpose of the REGISCAR (Rivaroxaban, Edoxaban, Gastrointestinal bleeding, Intracranial hemorrhage, Stroke, Cardiovascular events, Age, Renal dysfunction) score in patients with atrial fibrillation?

REGISCAR Score in Atrial Fibrillation Management

The REGISCAR score is not a validated or recognized risk assessment tool in atrial fibrillation management according to current clinical guidelines. Instead, the CHA₂DS₂-VASc score for stroke risk assessment and the HAS-BLED score for bleeding risk assessment are the recommended tools in patients with atrial fibrillation 1.

Established Risk Assessment Tools in Atrial Fibrillation

Stroke Risk Assessment

• CHA₂DS₂-VASc score is the recommended tool by both the European Society of Cardiology and the American College of Cardiology 1
• Components include:
  • Congestive heart failure (1 point)
  • Hypertension (1 point)
  • Age ≥75 years (2 points)
  • Diabetes mellitus (1 point)
  • Stroke/TIA/thromboembolism (2 points)
  • Vascular disease (1 point)
  • Age 65-74 years (1 point)
  • Sex category (female) (1 point)

Bleeding Risk Assessment

Several validated bleeding risk scores are available:

1. HAS-BLED score 1:

   • Hypertension (1 point)
   • Abnormal renal/liver function (1-2 points)
   • Stroke (1 point)
   • Bleeding history (1 point)
   • Labile INR (1 point)
   • Elderly >65 years (1 point)
   • Drugs/alcohol (1-2 points)

2. ORBIT score 2:

   • Older age (75+ years)
   • Reduced hemoglobin/hematocrit/history of anemia
   • Bleeding history
   • Insufficient kidney function
   • Treatment with antiplatelet

3. ABC-bleeding score 3:

   • Age
   • Biomarkers (GDF-15, cardiac troponin T, hemoglobin)
   • Clinical history (previous bleeding)

Performance of Bleeding Risk Scores

The ORBIT score has shown better discrimination compared to HAS-BLED in some studies, with a C-index of 0.67 in the original validation cohort 2. The ABC-bleeding score demonstrated even better performance with C-indices of 0.68 in derivation and 0.71 in validation cohorts, outperforming both HAS-BLED and ORBIT scores 3.

A 2018 study evaluating six bleeding risk scores found that only HEMORR₂HAGES and ATRIA scores showed acceptable discrimination for major bleeding events (C-statistics of 0.71 and 0.70, respectively) 4.

Clinical Approach to Risk Assessment

1. Assess stroke risk using CHA₂DS₂-VASc score 1
2. Assess bleeding risk using a validated bleeding risk score (HAS-BLED, ORBIT, or ABC-bleeding) 1
3. Select appropriate anticoagulation based on risk assessment:
   • DOACs are preferred over warfarin for eligible patients 1
   • Consider dose adjustments based on renal function and other factors 1

Important Caveats

• The term "REGISCAR" in your question may be a misunderstanding or confusion with:

  • The ROCKET-AF trial (evaluating Rivaroxaban) 5
  • The RE-LY trial (evaluating dabigatran) 3
  • Various bleeding risk scores that include factors like age, renal function, etc.

• Regular reassessment of both stroke and bleeding risks is essential as risk factors may develop over time 1

• A newer bleeding risk score developed in 2021 for patients on both warfarin and DOACs includes age >75 years, history of cancer, prior major hemorrhage, and arterial hypertension, showing good calibration and discrimination 6