What is the recommended workup and Xarelto (rivaroxaban) dosing for an 89-year-old patient with hypertension, a history of atrial fibrillation, and ECG findings of frequent premature ventricular contractions (PVCs) and ST abnormalities?

Workup and Rivaroxaban Dosing for 89-Year-Old with Atrial Fibrillation, PVCs, and ST Abnormalities

For this 89-year-old male patient with hypertension, history of atrial fibrillation, and ECG showing frequent PVCs and ST abnormalities, rivaroxaban 15 mg once daily is recommended for stroke prevention, along with a comprehensive cardiac workup including echocardiography to assess for structural heart disease. 1, 2

Stroke Risk Assessment

• This patient has a high stroke risk based on age alone (89 years), which gives him at least 2 points on the CHA₂DS₂-VASc score, plus additional points for hypertension (+1), making anticoagulation strongly indicated 1
• The presence of atrial fibrillation with these risk factors places him at significant risk for thromboembolism, requiring definitive anticoagulation therapy 1
• ECG findings of ST abnormalities warrant evaluation for possible underlying coronary artery disease, which would further increase stroke risk 1

Recommended Workup

• Transthoracic echocardiography (TTE) should be performed to assess for:

  • Left ventricular function (systolic/diastolic)
  • Left atrial size and possible thrombus
  • Valvular heart disease (to confirm non-valvular AF)
  • Structural abnormalities that could explain the ST changes 1

• Transesophageal echocardiography (TEE) should be considered if:

  • TTE shows concerning findings
  • There is suspicion of left atrial appendage thrombus
  • Cardioversion is being considered 1

• Continuous ambulatory ECG monitoring (Holter monitor) to:

  • Quantify PVC burden
  • Assess for other arrhythmias
  • Correlate symptoms with rhythm disturbances 1

• Laboratory testing:

  • Complete blood count
  • Comprehensive metabolic panel including renal function (critical for dosing rivaroxaban)
  • Thyroid function tests
  • Electrolytes 1

Rivaroxaban Dosing Recommendations

• For this 89-year-old patient with atrial fibrillation, the recommended dose of rivaroxaban is 15 mg once daily (reduced from the standard 20 mg dose due to advanced age and presumed reduced renal function) 2, 3

• Renal function assessment is mandatory before initiating rivaroxaban:

  • If creatinine clearance (CrCl) is 15-50 mL/min: use 15 mg once daily
  • If CrCl is >50 mL/min: use 20 mg once daily
  • If CrCl is <15 mL/min: rivaroxaban is contraindicated 1, 2

• Rivaroxaban should be taken with food to enhance absorption, particularly for the 15 mg and 20 mg doses 2

Management of PVCs and ST Abnormalities

• PVCs require evaluation for underlying structural heart disease or ischemia, especially with ST abnormalities 1

• If PVCs are symptomatic and frequent (>10% of total beats):

  • Consider beta-blocker therapy if not contraindicated
  • Evaluate for possible underlying causes (electrolyte abnormalities, medication effects, ischemia) 1

• ST abnormalities warrant:

  • Evaluation for possible ischemia
  • Comparison with prior ECGs if available
  • Possible stress testing based on clinical presentation and symptoms 1

Important Considerations and Contraindications

• Rivaroxaban is contraindicated in:

  • Valvular AF (mechanical or bioprosthetic heart valves)
  • Severe renal impairment (CrCl <15 mL/min)
  • Active pathological bleeding
  • Concurrent dual antiplatelet therapy 2, 4

• No routine coagulation monitoring is required for rivaroxaban, unlike warfarin 4, 3

• If transitioning from warfarin to rivaroxaban:

  • Discontinue warfarin
  • Start rivaroxaban when INR is ≤3.0 2

• Bleeding risk should be assessed before initiating therapy, especially given the patient's advanced age 1

Follow-up Recommendations

• Renal function should be monitored at least annually and more frequently in patients with impaired renal function 1

• Regular follow-up ECGs to monitor for progression of ST abnormalities and PVCs 1

• Patient education regarding:

  • Importance of medication adherence
  • Recognition of bleeding signs/symptoms
  • Need for regular follow-up 3

• Rivaroxaban should be taken at the same time each day to establish a consistent routine 5