ASSESSMENT OF PULMONARY ARTERY PRESSURES IN PATIENTS WITH SEVERE AORTIC STENOSIS

Usually PH is considered as the result of passive upstream transmission of the increased left ventricular pressure due to LV hypertrophy and LV diastolic dysfunction: this is ordinary post-capillary pulmonary hypertension.
Sometimes patients present with severe, out of proportion PH, thought to be due to a pre-capillary component: this is called reactive pulmonary hypertension, or pre and post capillary PH. However, the exact mechanisms of severe PH occurring in the setting of aortic stenosis are not fully understood, but according to some recent reports the left atrial reservoir function may play a key role.
The aim of our study was to try to determine the best predictor of severe PH in aortic stenosis patients: Is it the severity of aortic stenosis, the importance of LV hypertrophy, the degree of LV systolic or diastolic dysfunction, or the left atrial function?
Thirty six % of patients with AS had severe PH > 55 mmHg. PH is not predicted by AS severity, LV mass or ejection fraction. Patients with PH have worse LV diastolic function and LV longitudinal strain. In multivariate analysis LA strain measured by speckle tracking analysis is the only independent predictor of pulmonary artery pressure in patients with severe AS.