Objective: To evaluate risk factors in medically
treated patients with chronic pulmonary embolism (CPE) who are not
suitable candidates for definitive surgical therapy.
design: 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).
Results: 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 Pao2 (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 O2 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).
Conclusion: 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.