Pulmonary hypertension in severe aortic stenosis. Incidence, mechanisms, clinical and surgical implications.

Pulmonary arterial hypertension in aortic stenosis (AS) is considered uncommon, and the possible mechanisms involved in its insorgence are only speculative. We analyzed a group of 95 patients with severe AS (mean systolic gradient greater than or equal to 50 mmHg and/or aortic valve area less than or equal to 0.7 cm2) studied by standard hemodynamic techniques. In the study group the incidence of pulmonary hypertension was 50.5%. We divided the overall population in: Group I (47 patients), with systolic pulmonary artery pressure (PAP) less than or equal to 30 mmHg; Group II (33 patients), with moderate hypertension (PAP 31-50 mmHg); Group III (15 patients), with severe hypertension (PAP greater than 50 mmHg). Subjects with pulmonary hypertension were slightly older, and had more severe obstruction to left ventricular (LV) outflow. Impairment of LV diastolic function in the presence of pulmonary hypertension was expressed by a highly significant increase of LV end-diastolic pressure (p less than .001); reduced ejection performance was represented by a significant decrease of ejection fraction (p less than .01). Pulmonary vascular resistances also appeared to be increased. The correlation between variables showed PAP to be strongly correlated in a positive way to the LV end-diastolic pressure, and in an inverse way to the LV systolic performance (p less than .001 for both). Less striking was the correlation of pulmonary vascular resistances to LV diastolic and systolic function: a reactive and reversible vasoconstriction seemed likely. Surgery was not performed in 8 of the 95 patients: 5 of them died shortly after diagnosis.(ABSTRACT TRUNCATED AT 250 WORDS)