Emergency angiography in acute pulmonary embolism: role in clinically suspected cases

Massive and submassive pulmonary embolisms (PE) have been diagnosed by clinical suspicion according to the criteria of low, intermediate and high probability subgroups, depending on symptoms (sudden dyspnea, chest pain, syncope), signs (tachycardia, hypotension, elevated central venous pressure), electrocardiogram (right ventricle strain, right bundle branch block, S1Q3), laboratory data (hypoxia, hypocapnia, elevated plasma D-dimer, lactate dehydrogenase, fibrin degradation products) and echocardiography (right ventricular dilatation, paradoxical septal motion, pulmonary hypertension) in a patient with predisposing risk factors and diagnostic confirmation via ventilation perfusion lung scan. The latter was not done for all patients as it is diagnostic in only 30–50% of cases, and the remaining 50–70% nondiagnostic scans may represent a probability for underlying PE of between 4% and 66% depending on clinical circumstances.

Because of its invasive nature and technical complexity, pulmonary angiography (PA), the golden diagnostic standard, was not a routine procedure.

We hereby report our experience with emergency PA in clinically suspected cases of PE to highlight its merits and the limitations of clinical examination. We studied 18 patients with clinically suspected PE (six male, 12 female; mean age 49.5 years). Predisposing factors included heart disease in two patients, diabetes mellitus in five patients, polytrauma in three patients and autoimmune disease (i.e. Behcet disease) in one patient. Four patients were dehydrated and bedridden.

Following clinical evaluation, elctrocardiogram and chest X-ray, all patients were subjected to routine laboratory evaluation, arterial blood gas measurement and specific coagulation profile (fibrin, fibrin degradation products, D-dimer). All patients were then subjected to first-pass radionuclide angiography. PA was done in all patients within a mean period of 2 days (day 0–day 4). Following acute imaging, PA revealed the presence of PE in only eight patients in the form of distal cutoff and/or filling defects, while 10 patients had negative PA for PE. Compared with patients with negative PA, those with positive findings were more frequently hypotensive (50% vs 20%), more hypoxic (100% vs 90%), more congested (100% vs 80%) with more positive echocardiographic data (85% vs 60%). They also exhibited significant scintigraphic evidence of impaired RV ejection fraction than patients with negativeve PA (80% vs 20%).

Conclusion

Emergency PA is a feasible, safe, highly sensitive diagnostic tool in acute PE before starting intrapulmonary or systemic thrombolytic therapy with its potential hazards. In view of the ready availability of the catheter laboratory as well as its safety and ease of performance, emergency diagnostic PA is recommended in suspected clinical settings of PE.