Importance of cardiac biomarkers in risk stratification in acute pulmonary embolism.

At present there is consent that patients with acute pulmonary embolism (APE) and hemodynamic instability have poor prognosis and benefit from thrombolytic therapy or embolectomy, whereas hemodynamically stable patients without echocardiographic signs of right ventricular overload/dysfunction (RVO) have good prognosis and should be treated with anticoagulation alone. The optimal treatment for stable APE patients with RVO remains a challenge, and cardiac biomarkers can probably add to risk stratification and therapeutic decision making. Troponins are indicators of irreversible cardiac cell injury, and in patients with APE even a moderate rise of the blood troponin level correlates with RVO, hemodynamic instability and cardiogenic shock. However, the positive predictive value of cardiac troponins is relatively low. It can be increased when the results of troponins and echocardiography are combined. The clinical benefits of cardiac troponins result foremost from the high negative predictive value of in-hospital events, including death. Likewise, elevated levels of natriuretic peptides such as BNP and NT-proBNP, caused by increased right ventricular stress, show close association with RVO and with increased in-hospital risk. Instead, the low level of natriuretic biomarkers indicates an uncomplicated outcome of APE. There are some proposals of algorithms that combine both biomarkers and echocardiography for risk stratification. The principal aim of ongoing studies is to find patients with hemodynamically stable APE who can be candidates for thrombolytic therapy. The usefulness of biomarkers in long-term prognosis and their value to identify APE patients in whom chronic thromboembolic pulmonary hypertension can develop should also be confirmed.