Which laboratory tests should be included in a routine cardiac evaluation panel?

Cardiac Panel Laboratory Tests

A routine cardiac evaluation panel should include: complete blood count, lipid profile (total cholesterol, LDL, HDL, triglycerides), fasting glucose and HbA1c, creatinine with estimated renal function, and high-sensitivity troponin if acute coronary syndrome is suspected, with BNP/NT-proBNP added when heart failure is a consideration. 1

Core Laboratory Tests (Class I Recommendations)

Essential Tests for All Cardiac Patients

• Complete blood count including hemoglobin and white cell count is mandatory in all patients with known or suspected cardiac disease, as anemia can exacerbate ischemia and white cell count provides prognostic information 1

• Lipid profile must be obtained, including total cholesterol, LDL cholesterol, HDL cholesterol, and triglycerides, as dyslipidemia remains the strongest modifiable risk factor for coronary artery disease 1

• Glucose metabolism screening requires both HbA1c and fasting plasma glucose in every patient with suspected coronary artery disease; if both are inconclusive, add an oral glucose tolerance test, given the well-established link between dysglycemia and adverse cardiovascular outcomes 1

• Creatinine measurement with estimated renal function (creatinine clearance) is required in all patients, as renal dysfunction significantly impacts prognosis in cardiac disease and affects medication dosing 1

Troponin Testing: Context-Dependent

• High-sensitivity troponin (preferably) or ultrasensitive assays should be measured with repeated testing if there is any clinical suspicion of instability or acute coronary syndrome to rule out myocardial necrosis 1

• For hospitalized patients with symptomatic stable coronary artery disease, troponin measurements are recommended given their central role in identifying unstable patients 1

• Critical caveat: Routine troponin measurement is NOT recommended in stable outpatient settings, as very low levels detected by high-sensitivity assays lack sufficient independent prognostic value to justify systematic measurement 1

Conditional Tests Based on Clinical Context

Heart Failure Evaluation

• BNP or NT-proBNP should be considered (Class IIa recommendation) in patients with suspected heart failure to confirm diagnosis, especially when clinical uncertainty exists 1, 2

• The American Heart Association emphasizes that BNP/NT-proBNP is particularly useful for determining prognosis and severity in hospitalized patients with acute decompensation 2

• Important limitations: BNP and NT-proBNP can be falsely elevated in advanced age, renal dysfunction, atrial fibrillation, pulmonary hypertension, and pulmonary embolism; conversely, levels can be falsely low in obesity, flash pulmonary edema, and heart failure with preserved ejection fraction 2

Additional Electrolyte Monitoring

• Serum electrolytes including calcium, magnesium, and particularly potassium require immediate measurement in acute decompensation, as hypokalemia can cause fatal arrhythmias and increase digitalis toxicity, while hyperkalemia complicates therapy with ACE inhibitors, ARBs, and aldosterone antagonists 2

Thyroid and Liver Function

• Thyroid function tests are recommended only when there is clinical suspicion of thyroid disorder, as both hypothyroidism and hyperthyroidism can cause or exacerbate cardiac symptoms 1

• Liver function tests are specifically recommended in patients early after beginning statin therapy 1

• Creatine kinase measurements are indicated in patients taking statins who complain of symptoms suggestive of myopathy 1

Annual Monitoring for Established Coronary Disease

For patients with known stable coronary artery disease, the European Society of Cardiology recommends annual control of:

• Lipid profile 1
• Glucose metabolism parameters (HbA1c and fasting glucose) 1
• Creatinine and renal function 1

Tests NOT Recommended

High-sensitivity C-reactive protein (hs-CRP) should NOT be routinely measured despite some association with increased event risk, as a recent analysis of 83 studies found multiple types of reporting and publication bias, making the magnitude of any independent association sufficiently uncertain 1

Common Pitfalls to Avoid

• Do not order troponin routinely in stable outpatients—reserve for suspected acute coronary syndrome or hospitalized symptomatic patients 1

• Do not interpret BNP/NT-proBNP in isolation—consider renal function, age, obesity, and other confounding conditions 2

• Do not skip glucose screening—both fasting glucose AND HbA1c are required, not just one 1

• Do not forget to monitor electrolytes and renal function regularly after initiating or adjusting diuretics, ACE inhibitors, ARBs, or aldosterone antagonists 2