Pulmonary angiography. Application in a new spectrum of patients.

Guidelines that are frequently used to select patients with suspected pulmonary embolus for pulmonary angiography evolved from studies conducted 10 to 15 years ago. To determine if clinical practice in a referral medical center should continue to be based on these guidelines, clinical and angiographic data on 106 patients recently studied were compared with similar data obtained from the same institution in the previous era. The need to perform angiography if a lung scan demonstrated low or high probability for embolus was also examined, along with clinical, laboratory, and hemodynamic findings previously reported to be of diagnostic utility. There has been a marked change in the spectrum of patients studied. Cancer patients and patients who have undergone abdominal and pelvic surgery comprise the preponderance of patients undergoing angiography. Lung scans had a clinically important error rate in that more than one third of these selected patients with either a high- or low-probability scan had discordant results on angiography. Clinical criteria for selecting patients for pulmonary angiography should reflect the contemporary spectrum of patients with pulmonary embolus, as well as the limitations of clinical judgment and of the lung scan.