What labs would you recommend for a patient with a history of clotting disorder, migraines, nausea, depression/anxiety, hyperlipidemia, vitamin D deficiency, memory problems, burning sensations in the feet, and a recent imaging finding of a severed artery in the abdomen?

Annual Laboratory Testing for Complex Medical History

For this patient with multiple vascular risk factors, clotting disorder, and recent arterial injury, I recommend a comprehensive metabolic panel, lipid panel, HbA1c, complete blood count, coagulation studies (PT/APTT with specific factor assays if abnormal), vitamin D level, vitamin B12, thyroid function tests, and inflammatory markers (CRP). 1, 2

Core Metabolic and Cardiovascular Risk Assessment

Essential Baseline Labs

• Complete metabolic panel including electrolytes, renal function (creatinine/eGFR), liver function, and fasting glucose to assess kidney function and metabolic status, particularly given the peripheral arterial disease findings 1
• Lipid profile (total cholesterol, LDL-C, HDL-C, triglycerides) with target LDL-C <55 mg/dL (<1.4 mmol/L) given the very high cardiovascular risk from arterial disease 1
• Lipoprotein(a) measurement at least once in lifetime for comprehensive cardiovascular risk assessment 1
• HbA1c to screen for diabetes and assess glycemic control, as diabetes significantly impacts peripheral arterial disease progression 1

Inflammatory and Coagulation Assessment

• C-reactive protein (CRP) and erythrocyte sedimentation rate to assess inflammatory burden and cardiovascular risk 1
• Complete blood count (CBC) to evaluate platelet count and rule out thrombocytopenia, which is essential before interpreting coagulation studies 2

Clotting Disorder Monitoring

Initial Coagulation Screening

• Prothrombin time (PT) and activated partial thromboplastin time (APTT) as first-line screening tests for clotting factor deficiencies 2
• Fibrinogen level (Clauss method) to identify consumptive coagulopathies 2
• 50:50 mixing study if PT or APTT is prolonged, to differentiate factor deficiency from inhibitor 2

Specific Factor Assays (if screening abnormal)

• If PT prolonged: measure Factors II, V, VII, and X 2
• If APTT prolonged: measure Factors VIII, IX, XI, and XII 2
• If both prolonged: prioritize common pathway factors (II, V, X) and fibrinogen 2
• Factor activity levels below 20% correlate with bleeding risk and are clinically significant 2

Peripheral Neuropathy Evaluation

Vitamin and Metabolic Causes

• Vitamin B12 level to evaluate for deficiency causing peripheral neuropathy (burning feet) 1
• Thyroid function tests (TSH, free T4) as thyroid dysfunction can cause neuropathy and cognitive symptoms 1
• Fasting glucose and HbA1c to assess for diabetic neuropathy 1

Vitamin D and Bone Health

Vitamin D Assessment

• 25-hydroxyvitamin D level given known deficiency history and strong association with dyslipidemia and arterial disease 3, 4, 5
• Vitamin D deficiency is independently associated with higher carotid intima-media thickness, lower ankle-brachial index, and higher CRP in arterial disease patients 4
• Serum 25(OH)D inversely correlates with LDL cholesterol and triglycerides, and positively correlates with HDL cholesterol 3

Cognitive Function Considerations

Laboratory Evaluation for Memory Problems

• TSH and free T4 as thyroid dysfunction commonly causes cognitive impairment 1
• Vitamin B12 deficiency can cause cognitive decline and memory problems 1
• Fasting glucose/HbA1c as diabetes is associated with vascular cognitive impairment 1
• Lipid profile since hyperlipidemia contributes to vascular cognitive impairment 1

Peripheral Arterial Disease Monitoring

Vascular Risk Assessment

• Ankle-brachial index (ABI) measurement should be performed annually with clinical assessment in patients with known arterial disease 1
• Bilateral arm blood pressure measurement as a brachial SBP difference >15 mmHg raises cardiovascular death risk by 50% 1
• Renal function (creatinine/eGFR) as chronic kidney disease is associated with highest cardiovascular risk 1

Critical Pitfalls to Avoid

• Do not skip coagulation studies in a patient with known clotting disorder, even if asymptomatic, as factor levels can fluctuate and affect bleeding risk with the recent arterial injury 2
• Do not assume vitamin D is adequate without testing, as 45% of arterial disease patients have moderate-to-severe deficiency, and it independently affects cardiovascular outcomes 4, 5
• Do not overlook B12 testing when evaluating burning feet and memory problems, as this is a reversible cause of both symptoms 1
• Do not delay lipid assessment as this patient requires aggressive LDL-C lowering to <55 mg/dL given very high cardiovascular risk from arterial disease 1