Review Question - QID 102699

This patient presents in sudden distress with evidence of a pulmonary embolism (PE). Elevated cardiac enzymes such as troponin confer poor prognosis in patients with PEs.

PE are morbid, and potentially fatal complications of hypercoagulable states. This patient's ongoing malignancy places her at increased risk of thrombosis and PE. Significant PEs can result in right sided cardiac strain, which can be seen with electrocardiographic and ultrasonographic studies. Risk stratification models for patients with PEs have been developed. Elevated cardiac markers, cor pulmonale, cardiogenic shock, as well as ongoing malignancy all confer poor prognostic trajectories for patients.

Wilbur et al. review the diagnostic pathway for deep venous thrombosis (DVT) and PEs. The authors conclude that venous thromboemboli carry a mortality risk as high as 12%. With regard to the use of d-dimers, the authors suggest that when there is a low pretest probability, a negative d-dimer excludes the diagnosis of a PE.

Bajaj et al. explored the prognostic value of elevated troponin in patients with non-massive PE. The authors found that elevated troponin levels were significantly associated with the increased risk for short term mortality.

Figure A shows an EKG with evidence of right heart strain, typical for PEs (S wave in lead 1, and Q wave and T wave inversion in lead 3). Figure B is an axial reconstruction of a helical CT scan with contrast, note the filling defect in the main pulmonary arteries, indicative of a massive PE.

Incorrect Answers:
Answer 1: Elevated white blood cell count has not been demonstrated to carry prognostic value in PEs.
Answer 2 and 3: As discussed above, D-dimer can be used to rule out a PE when there is a low pretest probability. It carries no prognostic value once the diagnosis of a PE is made.
Answer 5: Hypocalcemia has not been demonstrated to carry prognostic value in PEs.