Can troponin levels rise in a patient with extensive pulmonary embolism (PE)?

Can Troponin Rise in Extensive Pulmonary Embolism?

Yes, troponin levels frequently rise in patients with extensive pulmonary embolism, occurring in approximately 30-50% of cases, with higher rates in more severe PE. 1

Mechanism of Troponin Elevation in PE

The elevation of cardiac troponins in PE results from transmural right ventricular (RV) infarction despite patent coronary arteries, a finding confirmed on autopsy studies of patients who died from massive PE. 1 The mechanism involves:

• Increased RV afterload from acute pulmonary vascular obstruction leading to RV strain and myocardial injury 2
• RV myocardial ischemia from the mismatch between increased oxygen demand and reduced coronary perfusion pressure 1
• The RV myocardium is the primary source of troponin release, though not necessarily the only source 1

Prevalence Based on PE Severity

The prevalence of troponin elevation correlates directly with PE severity 1:

• Non-massive PE: 0-35% of patients have positive troponin T (>0.1 ng/mL) 1
• Submassive PE: 13.5% have cardiac troponin I >0.5 ng/mL within 24 hours of presentation 1, 3
• Massive/clinically severe PE: Up to 50% have elevated troponin 1
• Overall: Approximately 70% of PE patients may have elevated troponin when sensitive assays are used 4

Prognostic Significance

Elevated troponin in PE is a powerful predictor of adverse outcomes and should trigger intensified monitoring. 1

Mortality Risk

• Positive troponin T is associated with 44% in-hospital mortality versus 3% with negative troponin (OR 15.2; 95% CI 1.2-190.4) 1
• Elevated troponin I >0.5 ng/mL confers a 3.5-fold increased risk of all-cause death at 3-month follow-up (95% CI 1.0-11.9) 1, 3
• In hemodynamically stable patients, elevated troponin increases mortality risk 5.9-fold (OR 5.9; 95% CI 2.7-12.9) 1
• Combined elevation of troponin I and RV enlargement yields 10.2% mortality versus 1.9% in patients with neither finding 5

Clinical Course Complications

Elevated troponin levels correlate with 6:

• Need for inotropic support (OR 3.02; 95% CI 1.03-8.85)
• Need for mechanical ventilation (OR 5.00; 95% CI 1.42-17.57)
• Need for thrombolysis (OR 5.71; 95% CI 1.63-19.92)
• Hypotension (OR 7.37; 95% CI 2.31-23.28)

Optimal Cutoff Values and Testing Strategy

Serial troponin measurements are essential, as initially negative results may convert to positive with prognostic implications. 1

Recommended Approach

• Measure troponin at presentation and repeat 6-12 hours after admission 1
• Low cutoff values (troponin T as low as 0.01 ng/mL) can predict increased mortality in normotensive patients (OR 21.0; 95% CI 1.2-389.0) 1
• High-sensitivity troponin T ≥60 ng/L has been proposed as an optimal cutoff for risk stratification (AUC 0.74,95% CI 0.61-0.85) 7
• Troponin I >0.5 ng/mL is a validated threshold for identifying myocardial injury in submassive PE 1, 3

Risk Stratification Integration

Troponin should be combined with imaging markers of RV dysfunction for optimal risk stratification, even in patients with low clinical risk scores. 1

Combined Assessment Strategy

The European Society of Cardiology recommends 1:

• Assessment of RV by imaging or laboratory biomarkers should be considered even with low PESI or negative sPESI
• Combination of troponin and NT-proBNP provides superior risk stratification: PE-related 40-day mortality exceeds 30% when both are elevated 1
• Troponin I >0.1 ng/L plus RV/LV ratio >0.9 on echocardiography identifies patients with 38% 30-day all-cause mortality 1

Risk Categories

Patients should be classified as 1:

• Intermediate-low risk: Elevated troponin or RV dysfunction alone, despite low PESI/sPESI
• Intermediate-high risk: Both elevated troponin AND RV dysfunction on imaging
• This classification guides intensity of monitoring and consideration of advanced therapies

Important Clinical Caveats

Troponin Pattern in PE

Troponin elevation in PE typically persists until the clot burden is reduced through anticoagulation or thrombolysis, rather than spontaneously decreasing. 2 This distinguishes PE from other causes:

• Spontaneously decreasing troponin without specific PE treatment suggests alternative diagnoses like septic cardiomyopathy 2
• The persistent elevation reflects ongoing RV strain until pulmonary vascular obstruction resolves 2

Predictive Value Characteristics

• Positive predictive value for PE-related early mortality is modest (12-44%) across various cutoff values 1
• Negative predictive value is excellent (99-100%), making normal troponin highly reassuring 1
• This means elevated troponin identifies a higher-risk subset but doesn't mandate routine thrombolytic therapy in all cases 5

Associated Clinical Features

Patients with elevated troponin in PE typically present with 4, 7:

• Earlier symptom onset (median 24 vs 144 hours)
• Higher prevalence of proximal vessel emboli (pulmonary trunk, main pulmonary arteries)
• More severe vital sign abnormalities at presentation
• Older age and higher creatinine levels
• Signs of RV dysfunction on imaging