Acute pulmonary thromboembolism (APE) is a common pathology that after overcoming the acute phase can present sequelae in pulmonary vascularization such as pulmonary hypertension (PHT), not always detectable with pulmonary function tests or echocardiography. Cardiopulmonary exercise testing (CPET) is a non-invasive method of evaluating pulmonary hypertension that can detect it, at very early stages. The objective was to study the presence of signs of pulmonary arterial hypertension by means of CPET, in particular PETCO2MAX and VE/VCO2 at the anaerobic threshold (AT) in patients who have had a APE and symptoms persist.

Results: A total of 22 patients who had suffered an APE diagnosed by symptons and CT scan in the previous months (median 8 months, range 4-12 months) without acute complications were recruited consecutively. The average DLCO was 68% (56-100% r.v.). The PAP estimated by echocardiography did not obtain results in 14 cases and in the other 8 the estimated mean was 33 mmHg. The mean exercise capacity was VO2max 16 ml/min/kg (SD) and was below 80% in 12 patients. The CO2 equivalent in AT was elevated above 30 in 12 patients. PETCO2 in max was below 4 Kpa (30 mmHg) in 5 patients. The EV in AT was higher than 40% of the maximum reached in all cases. VO2 in AT was less than 60% in 9 cases. In the 12 cases who had limitation to effort, all had a profile compatible with pulmonary hypertension (PHT) and only 3 had >40 mmHg by echo.

Conclusion: APE with persistent symptoms associates a limitation to effort with PHT profile in more than 50% of cases regardless of DLCO or echocardiography or lesions visualized on CT scan. All of them had some alterations in CPET, even if VO2max was normal.