What follow-up is recommended for an elderly male with macrocytic anemia and impaired renal function after TAVR?

Post-TAVR Follow-Up for Macrocytic Anemia and Elevated BUN/Creatinine

This elderly male patient requires structured follow-up per ACC guidelines with specific attention to monitoring renal function and investigating the macrocytic anemia, which may improve post-TAVR but warrants evaluation for B12/folate deficiency given the MCV of 103.6.

Required Follow-Up Schedule

Structured post-TAVR surveillance is mandatory regardless of baseline laboratory abnormalities:

• TAVR team evaluation at 30 days to assess for procedural complications and establish baseline post-procedure status 1
• Primary cardiologist at 6 months, then annually for ongoing cardiac management 1
• Primary care physician or geriatrician at 3 months, then as needed for management of comorbidities including renal disease and anemia 1

Laboratory Monitoring Requirements

The ACC recommends specific laboratory surveillance post-TAVR:

• Monitor blood counts, metabolic panel, and renal function as part of routine post-TAVR care 1
• Repeat CBC and comprehensive metabolic panel at the 30-day TAVR team visit to track trends in MCV, hemoglobin, BUN, and creatinine 1
• Serial renal function monitoring is particularly important as 80% of patients show stable or improved kidney function after TAVR, but 26% may experience ≥10% deterioration in eGFR at 1 month 2

Explanation of Laboratory Values

Macrocytic Anemia (MCV 103.6, MCH 33.5)

The elevated MCV warrants investigation despite being baseline:

• Macrocytosis may improve post-TAVR as anemia rates decrease significantly (from 67.5% to 53.9%) at 5-12 months following the procedure, likely due to resolution of gastrointestinal blood loss from AS-associated angiodysplasia 3
• Evaluate for B12 and folate deficiency as these are common in elderly patients and require specific treatment 4
• B12 deficiency allowed to progress >3 months produces permanent spinal cord damage, making early diagnosis critical 4
• If B12 deficiency is confirmed, lifelong monthly intramuscular B12 100 mcg injections are required, as oral forms are unreliable in elderly patients with absorption issues 4

Elevated BUN (34) with BUN/Creatinine Ratio of 31

The elevated BUN/Cr ratio suggests a prerenal component but requires ongoing monitoring:

• Baseline renal dysfunction is common in TAVR patients (mean eGFR 65.1 mL/min in large cohorts), and this appears to be this patient's baseline 2
• Renal function may improve post-TAVR in patients with cardiorenal syndrome; 36.8% show ≥10% improvement in eGFR at 1 month, and those with CKD resolution have mortality rates similar to patients with normal baseline renal function 2, 5
• However, 26% experience ≥10% deterioration in eGFR, which is associated with a 2.16-fold increased hazard ratio for 2-year mortality 2
• Worsening renal function at 3-6 months occurs in only 15% of patients with baseline CKD but carries significant mortality risk (HR 2.2) 6

Critical Monitoring Points

Key factors to assess at follow-up visits:

• Volume status and heart failure symptoms, as improved cardiac output post-TAVR may improve prerenal azotemia 1, 2
• Medication review to ensure nephrotoxic agents are minimized and appropriate antithrombotic therapy (aspirin 75-100 mg daily lifelong, clopidogrel 75 mg daily for 3-6 months) is maintained 1, 7, 8
• Signs of B12 deficiency progression including neurologic symptoms (paresthesias, ataxia, cognitive changes) that can become irreversible if untreated 4
• Echocardiography at 30 days and annually to assess valve function and cardiac output, which directly impacts renal perfusion 1, 7

Common Pitfalls to Avoid

Critical errors in post-TAVR management:

• Do not assume stable baseline values require no investigation—macrocytosis warrants B12/folate evaluation regardless of chronicity 4
• Do not attribute all renal dysfunction to chronic disease—15-40% of patients show improvement post-TAVR, suggesting reversible cardiorenal syndrome 2, 5
• Do not delay B12 supplementation if deficiency is confirmed—neurologic damage becomes irreversible after 3 months 4
• Do not miss the 30-day TAVR team evaluation—this is when procedural complications and baseline changes are best identified 1, 7