Prognostic Factors in Medically Treated Patients With Chronic Pulmonary Embolism

Objective:

To evaluate risk factors in medicallytreated patients with chronic pulmonary embolism (CPE) who are notsuitable candidates for definitive surgical therapy.

Studydesign:

A total of 53 consecutive patients with angiographicallyconfirmed CPE were involved. Four patients underwent pulmonaryendarterectomy, and 49 patients received continuous anticoagulationtherapy and were followed up over an average period of 18.7 months(range, 6 to 72 months).

Results:

Sixteen patientsdied during the follow-up period, mostly from progressive rightventricle failure. Among the nonsurvivors, 12.5% had distal CPE and87.5% had proximal CPE (p = 0.03). The survivors had a higher(mean ± SD) level of Pao₂ (59.3 ± 11 mmHg) than the nonsurvivors (50.8 ± 9 mm Hg; p = 0.02), a lower meanpulmonary artery pressure (mPAP; 30.3 ± 15 mm Hg vs 51 ± 21 mmHg; p = 0.0004), a lower hematocrit value (40.0 ± 6 vs44.2 ± 6; p = 0.03), and better exercise tolerance (4.8 ± 3multiples of resting O₂ consumption [METs] vs 2.5 ± 1METs; p = 0.02) achieved during the maximal symptom-limited exercise. The patients with coexisting COPD had a higher mortality rate (62.5%)than those with out COPD (37.5%; p = 0.04). Independent risk factorsin the Cox analysis were as follows: mPAP (p = 0.04), exercisetolerance (p = 0.02), and COPD (p = 0.04). In the Kaplan-Meieranalysis, the patient group with lower mortality achieved > 2 METs(p = 0.02) and had mPAP < 30 mm Hg (p = 0.04).

Conclusion:

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