[Angiotensin-converting enzyme in pulmonary thromboembolism as a marker of vascular lesion].

UNLABELLED

In pulmonary thromboembolism (PTE) metabolic changes can occur, as in serum levels of angiotensin converting enzyme (ACE); therefore, the measurement of serum levels of this enzyme might be useful for PTE evaluation. The objective of this study was to determine changes in serum ACE in patients with PTE and their possible variations after therapy. MATERIALS AND THERAPY: Thirty-one patients with PTE were studied (15 males and 16 females). The mean age was 56 +/- 16 years (range 19-82 years). The patients were included if they had: a) a suspect diagnosis of PTE; b) confirmed by high probability V/Q gammagraphy, or c) data of intermediate or low probability with positive lower limb phlebography. Patients with associated diseases, under therapy with ACE inhibitors or lost during the six months of therapy were excluded from the study.

STUDY DESIGN

Patients were evaluated in the acute phase of PTE and after therapy (six months later). Biochemical, gasometric, spirometric, V/Q gammagraphy and ACE parameters were investigated. All of them were compared with reference values and those obtained in both phases of PTE.

STATISTICS

The Student "t" test was used for independent parameters with the Bonferroni correction for multiple contrast and a = 0.05. The Pearson regression analysis was used for correlations. The ROC curve was used to study its usefulness at diagnosis.

RESULTS

ACE decreased by a 20.5% in the acute phase (31.69% +/- 10.34 mumol/min/l) and turned to normal values (39.91 +/- 9.75 mumol/min/l) at post-therapy phase. This decrease was related with acute hypoxia and a decrease in the lung vascular bed. The analysis of the ROC curve showed an area of 0.69 and a negative predictive value of 91.67% for ACE values higher than 46 mumol/min/l.

CONCLUSIONS

ACE activity is a marker for pulmonary pathology which might be indicative of injury and/or decrease of the lung vascular bed; its measurement can be useful in the clinical follow-up of PTE. A return to normal values should be interpreted as improvement in the perfusion of the lung vascular bed.