Echocardiographic Hemodynamics After Aortic Valve Replacement, Wheat, and Bentall Procedure

TL;DR

This study compares heart valve replacement procedures using echocardiography to assess blood flow and pressure differences.

Contribution

The study provides new insights into hemodynamic differences between aortic valve replacement and more complex procedures like Wheat and Bentall.

Findings

The Bentall group had lower energy loss compared to other groups.

A smaller ascending aortic area was linked to higher pressure gradients in the AVR group.

Echocardiographic pressure gradients were overestimated in AVR but not in Wheat or Bentall groups.

Abstract

Background: Compared with isolated aortic valve replacement (AVR), echocardiographic hemodynamics after Wheat and Bentall procedures, both involving replacement of the proximal ascending aorta with a smaller-diameter graft, have been less thoroughly investigated. Methods: We analyzed 213 patients who received 21 mm or 23 mm aortic bioprostheses (AVR, n = 138; Wheat, n = 43; Bentall, n = 32). Transthoracic echocardiography was performed before and after surgery, and the proximal ascending aortic area (Aa) was assessed using contrast-enhanced computed tomography. Results: The maximal pressure gradient (PG max), derived from the simplified Bernoulli equation, was significantly lower in the Bentall group, whereas pressure recovery (PR), calculated using Voelker’s equation, was lower in the AVR group. A smaller Aa was associated with a higher PG max in the AVR group. The Bentall group exhibited significantly lower energy loss (EL). In propensity score-matched analyses to minimize potential confounding factors, the AVR group showed a significantly lower PR and higher EL than the Wheat group; a significantly higher PG max, lower PR, and higher EL than the Bentall group; and a significantly similar PR but lower EL in the Bentall group compared with the Wheat group. Conclusions: Although limited to bioprosthetic valves, caution is warranted when interpreting echocardiographic PG max after AVR in patients with a small ascending aorta. However, overestimation of PG max was not observed in either the Wheat or Bentall groups, even though both demonstrated higher PR and lower EL compared with the AVR group.

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