Prognostic factors in medically treated patients with chronic pulmonary embolism

To evaluate risk factors in medically treated patients with chronic pulmonary embolism (CPE) who are not suitable candidates for definitive surgical therapy.

A total of 53 consecutive patients with angiographically confirmed CPE were involved. Four patients underwent pulmonary endarterectomy, and 49 patients received continuous anticoagulation therapy and were followed up over an average period of 18.7 months (range, 6 to 72 months).

Sixteen patients died during the follow-up period, mostly from progressive right ventricle failure. Among the nonsurvivors, 12.5% had distal CPE and 87.5% had proximal CPE (p = 0.03). The survivors had a higher (mean +/- SD) level of PaO(2) (59.3 +/- 11 mm Hg) than the nonsurvivors (50.8 +/- 9 mm Hg; p = 0.02), a lower mean pulmonary artery pressure (mPAP; 30.3 +/- 15 mm Hg vs 51 +/- 21 mm Hg; p = 0.0004), a lower hematocrit value (40.0 +/- 6 vs 44.2 +/- 6; p = 0.03), and better exercise tolerance (4.8 +/- 3 multiples of resting O(2) consumption [METs] vs 2.5 +/- 1 METs; p = 0.02) achieved during the maximal symptom-limited exercise. The patients with coexisting COPD had a higher mortality rate (62.5%) than those without COPD (37.5%; p = 0.04). Independent risk factors in the Cox analysis were as follows: mPAP (p = 0.04), exercise tolerance (p = 0.02), and COPD (p = 0.04). In the Kaplan-Meier analysis, the patient group with lower mortality achieved > 2 METs (p = 0.02) and had mPAP < 30 mm Hg (p = 0.04).

The prognosis for the medically treated CPE patients, particularly those with pulmonary hypertension, was unfavorable. The prognostic factors for these patients were mPAP, coexistence of COPD, and severe exercise intolerance.