Time course of reversed cardiac remodeling after pulmonary endarterectomy in patients with chronic pulmonary thromboembolism.

To evaluate the time course of reversed remodeling after pulmonary endarterectomy (PEA) in patients with chronic thromboembolic pulmonary hypertension(CTPEH), we studied 22 patients (age: 60 +/- 13 years) with MRI immediately before, 1 month, 3 months, and 6 months after PEA. MRI included assessment of biventricular function, aortic and pulmonary artery(PA) flow, and right ventricular (RV) overload using the ratio of RV-to-biventricular diameter. Except in one patient, who died 2 months post-surgery, clinical improvement occurred early after PEA (NYHA class: 3.3 +/- 0.6 to 1.5 +/- 0.8, p < 0.0001) with a decrease of systolic pulmonary artery pressures (79 +/- 14 to 44 +/- 14 mmHg, p < 0.0001). At 1 month post PEA, RV end-diastolic volumes decreased (198 +/- 72 to 137 +/- 59 ml, p < 0.0001), and the RV ejection fraction (EF) improved (31 +/- 9 to 47 +/- 10%, p < 0.0001). No further significant improvement in pulmonary pressures or RV function occurred at 3 months or 6 months. Although no significant change was found in LV volumes or function, aortic flow increased early after surgery. PEA had only a beneficial effect on right PA flow. RV overload decreased early after PEA (ratio RV-to-biventricular diameter: before: 0.67 +/- 0.04, after: 0.54 +/- 0.06, p < 0.0001), showing a good correlation with the improvement in RVEF (r = 0.7, P < 0.0001). In conclusion, reversed cardiac remodeling occurs early after PEA, to slow down after 1 month. At 6 months, cardiac remodeling is incomplete as witnessed by low-normal RV function and residually elevated PA pressures.