VARIATION IN AORTIC PRESSURE UPSTROKE AND AMPLITUDE IN ELDERLY PATIENTS WITH SEVERE SYMPTOMATIC AORTIC STENOSIS WITH PRESERVED LEFT VENTRICULAR EJECTION FRACTION

Abstract

Aortic Stenosis (AS) is classically associated with pulsus parvus et tardus. However, with advancing arterial stiffness, pulse velocity is altered, potentially modifying the classic delay and reduced upstroke of aortic (and carotid) arterial waveform. The aims of this prospective study were 1) to evaluate the echocardiographic and hemodynamic data of patients with pure severe symptomatic AS (SSAS), and 2) to determine the parameters associated with ascending aortic calcification as assessed by computed tomography (CT). Patients with preserved left ventricular ejection fraction (PLVEF) by echocardiography were invasively assessed by cardiac catheterization (simultaneous aortic and LV pressure measurements). Peak aortic systolic and aortic pulse pressures are inverse indices for pulsus parvus. The slope of aortic pulse during systole (an inverse index of pulsus tardus) was calculated as the quotient of dP (peak aortic pressure - preceding end-diastolic aortic pressure) and dt (time difference in msec between these two pressure points). These indices were correlated with the degree of valvular stenosis based on mean pressure gradient and valve area utilizing the Pearson correlation coefficient. In a subset of 11 patients who underwent CT scanning, the amount of aortic root and ascending aortic calcification was quantified and correlated with the aortic pulse characteristics. A total of 24 elderly patients (mean age 78.4+/-7.56 years) were included. The mean aortic pressure (Cardiac Catheterization) was 48.2±17.0 mmHg with LVEF 60.42+/-9.08%. Mean peak aortic systolic pressure was 139.3±23.7 mmHg and aortic pulse pressure was 73.7±17.1 mmHg. Mean slope of aortic impulse 0.292±0.076 mmHg/msec and mean aortic rise time 256.43±37.64 msec. The slope of aortic systolic pressure upstroke (inverse measure of pulsus tardus) strongly correlated with peak aortic systolic pressure (r=0.71). However, there was no correlation between the peak aortic systolic pressure (as well as slope of aortic pulse during systole) with aortic valve mean pressure gradient (r=-0.01, for both, respectively). Correlation between the slope of aortic pulse during systole and aortic valve area was modest (r=0.27). Measures of pulsus parvus (peak aortic systolic pressure) and tardus (slope of the aortic pulse) poorly correlated with the average percent calcification of the aorta by area (r=0.24, r=0.05, respectively). There is significant variation in aortic pulse characteristics such that the classical findings of pulsus parvus et tardus are not universally present in elderly patients with SSAS. The findings are not correlated with the magnitude of the stenosis nor with the degree of calcification of the ascending aorta.