How should a patient with crushing chest pain, a normal electrocardiogram, and a normal troponin level be managed?

Management of Crushing Chest Pain with Normal ECG and Normal Troponin

This patient requires serial troponin testing at 3-6 hour intervals and observation in a chest pain unit or monitored setting, as a single normal troponin—especially within 6 hours of symptom onset—does not exclude myocardial infarction. 1

Immediate Actions and Serial Testing Protocol

Serial troponin measurements are mandatory because:

• A normal troponin on initial presentation, particularly within 6 hours of chest pain onset, does not exclude MI 1
• Repeat troponin should be obtained at 3-6 hours after the initial measurement for conventional assays 1
• For high-sensitivity troponin assays, repeat testing at 1-3 hours is acceptable if symptoms began ≥3 hours before presentation 1, 2
• Additional troponin levels beyond 6 hours should be obtained in patients with initial normal serial troponins who have intermediate/high-risk clinical features 1

Observation Setting

Observe the patient in a chest pain unit or telemetry unit with:

• Serial ECGs at 3-6 hour intervals to detect evolving ischemic changes 1
• Continuous cardiac monitoring for arrhythmias 1
• This approach is reasonable for patients with symptoms consistent with ACS without objective evidence of myocardial ischemia 1

Initial Medical Management During Observation

While awaiting serial testing, initiate:

• Sublingual nitroglycerin (0.3-0.4 mg) every 5 minutes for up to 3 doses if pain continues, then assess need for IV nitroglycerin 1
• Aspirin should be given as soon as possible if ACS is suspected 1
• Supplemental oxygen only if oxygen saturation <90%, respiratory distress, or other high-risk features of hypoxemia 1
• IV morphine sulfate may be reasonable for continued ischemic chest pain despite maximally tolerated anti-ischemic medications 1

Risk Stratification After Serial Testing

If serial troponins remain normal and ECG remains non-ischemic:

• Calculate a validated risk score such as HEART score or TIMI score 1, 3
• Low-risk patients (HEART score ≤3) with negative serial troponins can be discharged with outpatient follow-up within 1-2 weeks 1, 2
• Intermediate-risk patients require additional evaluation with noninvasive testing (stress testing, coronary CT angiography) before or shortly after discharge 1

Noninvasive Testing Strategy

For patients with negative serial troponins who require further evaluation:

• Exercise treadmill testing is appropriate if the patient can exercise and has an interpretable baseline ECG 1, 3
• Stress echocardiography or myocardial perfusion imaging for patients unable to exercise or with uninterpretable ECGs 1, 4
• Coronary CT angiography has excellent negative predictive value but may increase downstream invasive testing 1

Critical Pitfalls to Avoid

Do not discharge based on a single troponin measurement alone, especially if:

• Symptoms began <6 hours before presentation 1
• The patient has intermediate or high-risk features (ongoing pain, hemodynamic instability, diabetes, known CAD) 1
• Serial testing has not been completed per protocol 1

Consider alternative life-threatening diagnoses in patients with crushing chest pain:

• Pulmonary embolism, aortic dissection, acute pericarditis, and pneumothorax can all present with chest pain and normal initial cardiac workup 1, 5
• Elevated troponin with normal coronaries should prompt evaluation for these conditions 5

Clinical history alone has significant limitations for risk stratification in this population:

• Clinical predictive models show good discrimination for long-term major events (C statistic 0.80) but perform less well for short-term outcomes including revascularization 6
• Therefore, objective testing (serial troponins, stress testing) should not be bypassed based on reassuring history alone 6

Disposition Decision Algorithm

After completing serial troponin protocol:

• All troponins normal + low-risk score (HEART ≤3) + non-ischemic ECG → Discharge with outpatient follow-up and possible outpatient stress testing 1, 2
• Any troponin elevation → Admit for ACS management per standard guidelines 1
• Normal troponins + intermediate/high-risk features → Admit for inpatient noninvasive testing or observation unit with testing before discharge 1