Clinical course and late prognosis of treated subacute massive, acute minor, and chronic pulmonary thromboembolism

Abstract

Thirty-eight patients with pulmonary embolic disease, other than acute massive pulmonary embolism, have been assessed clinically and by right heart catheterisation and pulmonary arteriography or pulmonary embolectomy. In addition, completefollow-up information was obtained in 92 per cent (35) ofpatients 1 to 8 years after their initial illness. On the basis of the history and the pulmonary arteriographic appearances, three subgroups are described-subacute massive, acute minor, and chronic pulmonary embolism. Patients with subacute massive disease rarely had a well-defined predisposing factor to thromboembolism, had pulmonary arteriograms indistinguishable from acute massive embolism, but had long histories mainly of exertional dyspnoea which contrasts with the characteristically short, dramatic histories of patients with acute massive embolism. These patients had higher pulmonary artery pressures than patients with acute massive embolism. Patients with minor embolism usually had a well-defined predisposing cause to thromboembolism and normal haemodynamic findings. Patients with chronic embolism rarely had a well-defined predisposing factor to thromboembolism, had pulmonary arteriograms easily distinguishable from other forms of embolic disease, and had the highest pulmonary artery pressures. The late prognosis of both acute minor and subacute massive embolism is good, recurrence of embolism is rare, and late pulmonary hypertension is not seen. In contrast, patients with chronic thromboembolic disease follow a progressively worsening course with persistent pulmonary hypertension, increasing right heart failure, and eventual death.