Acute Effects of Transcatheter Aortic Valve Replacement on Central Aortic Hemodynamics in Patients With Severe Aortic Stenosis

Abstract

Severe aortic stenosis induces abnormalities in central aortic pressure, with consequent impaired organ and tissue perfusion. Relief of aortic stenosis by transcatheter aortic valve replacement (TAVR) is associated with both a short- and long-term hypertensive response. Counterintuitively, patients who are long-term normotensive post-TAVR have a worsened prognosis compared with patients with hypertension, yet the underlying mechanisms are not understood. We investigated immediate changes in invasively measured left ventricular and central aortic pressure post-TAVR in patients with severe aortic stenosis using aortic reservoir pressure, wave intensity analysis, and indices of aortic function. Fifty-four patients (mean age 83.6±6.2 years, 50.0% female) undergoing TAVR were included. We performed reservoir pressure and wave intensity analysis on invasively acquired pressure waveforms from the ascending aorta and left ventricle immediately pre- and post-TAVR. Following TAVR, there were increases in systolic, diastolic, mean, and pulse aortic pressures (all P <0.05). Post-TAVR reservoir pressure was unchanged (54.5±12.4 versus 56.6±14.0 mm Hg, P =0.30) whereas excess pressure increased 47% (29.0±10.9 versus 42.6±15.5 mm Hg, P <0.001). Wave intensity analysis (arbitrary units, au) demonstrated increased forward compression wave (64.9±35.5 versus 124.4±58.9, ×10 3 au, P <0.001), backward compression wave (11.6±5.5 versus 14.4±6.9, ×10 3 au, P =0.01) and forward expansion wave energies (43.2±27.3 versus 82.8±53.1, ×10 3 au, P <0.001). Subendocardial viability ratio improved with aortic function effectively unchanged post-TAVR. Increased central aortic pressure following TAVR relates to increased transmitted power and energy to the proximal aorta with increased excess pressure but unchanged reservoir pressure. These changes provide a potential mechanism for the improved prognosis associated with relative hypertension post-TAVR.