A Noninvasive Approach for the Treatment of Patients with Suspected Pulmonary Embolism.

The diagnosis of pulmonary embolism is challenging because the signs and symptoms are nonspecific, the findings on ventilation-perfusion lung scans are often nondiagnostic, and pulmonary angiography, although definitive, is not always available. We previously reported that serial noninvasive leg testing provided a practical, noninvasive alternative to pulmonary angiography in patients who had nondiagnostic lung scans and adequate cardiorespiratory reserve. In this prospective cohort study of 1564 patients with suspected pulmonary embolism, ventilation-perfusion lung scanning and serial impedance plethysmography were used to objectively assess prognosis. Only 12 of 627 patients (1.9%) with nondiagnostic lung scans but normal serial leg testing results who were not given anticoagulants had venous thromboembolism during long-term follow-up. Noninvasive serial leg testing can avoid the need for pulmonary angiography for the majority of patients, identify those with proximal vein thrombosis who require anticoagulant treatment, and avert treatment and further investigation of patients who have adequate cardiorespiratory reserve.