Chest Pain with Discordant Troponin and ECG in a Cocaine User
A 34-year-old man presents 90 minutes after onset of substernal pressure at rest, radiating to the left arm, with diaphoresis. He used intranasal cocaine about 3 hours ago. He smokes 1 pack/day and has no prior cardiac history. Vitals: BP 168/98 mmHg, HR 112/min, SpO2 97% on room air, temperature 36.8 °C. ECG shows sinus tachycardia with 1 mm ST depression in leads V4–V6 but no ST elevation. High-sensitivity troponin is mildly elevated at 28 ng/L (upper reference limit 14 ng/L) and unchanged on a repeat sample 1 hour later. Bedside echo shows a mildly hypokinetic inferior wall but no pericardial effusion. The patient is anxious and requests 'something for the pain.'
1. How would you risk-stratify and initially manage this patient, and which therapies are contraindicated or require caution?
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This is cocaine-associated chest pain. Risk stratification is not by troponin alone: the history (rest pain, radiation, diaphoresis, multiple risk factors) plus ECG changes and regional wall-motion abnormality raise concern for true ischemia/ACS despite only mildly elevated and flat troponin. A single flat troponin does not exclude ACS; serial sampling and a structured pathway (HEART score plus serial troponins) are appropriate.
Initial management:
- ABCs, continuous ECG monitoring, IV access, aspirin 162–325 mg chewed (unless allergy/bleeding).
- Nitroglycerin is reasonable for ongoing pain/hypertension, but caution: cocaine-induced coronary vasospasm can be worsened by nonselective beta-blockers; nitrates are generally preferred first-line for cocaine-related chest pain.
- Benzodiazepines (e.g., lorazepam) to reduce sympathetic drive, anxiety, and hypertension.
- Avoid nonselective beta-blockers acutely (unopposed alpha stimulation risk). If a beta-blocker is needed for persistent hypertension/tachycardia after benzodiazepines and nitrates, use a combined alpha/beta agent (e.g., labetalol) with monitoring, or consult cardiology.
- Do not give thrombolytics for ST depression without STEMI.
- Arrange admission/observation with serial ECGs and troponins; consider cardiology consultation and further ischemia testing or angiography if pain persists or biomarkers rise.
2. The patient's pain resolves after nitroglycerin and lorazepam. What disposition and diagnostic plan would you choose, and what would change your mind?
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Because symptoms resolved and troponin was flat, a short observation unit pathway with serial troponins and ECGs is reasonable, but this patient is not low risk: ongoing cocaine use, multiple risk factors, ECG changes, and a regional wall-motion abnormality. I would not simply discharge from the ED after one set of tests.
Plan:
- Observe with repeat troponin at 3–6 hours and repeat ECG; if all negative and pain-free, consider outpatient or inpatient stress testing/CT coronary angiography based on local protocol.
- Address cocaine use: brief intervention, referral for substance treatment, and counseling about abstinence.
- Optimize secondary prevention: aspirin, statin, blood pressure control, smoking cessation.
Change my mind if: recurrent chest pain, dynamic ECG changes (new ST elevation or deeper depression), rising troponin, arrhythmia, heart failure, or hemodynamic instability - these mandate urgent cardiology involvement and invasive angiography. Also escalate if the patient has continued cocaine use or cannot be observed safely.