Exercise hemodynamic performance of the pulmonary autograft following the Ross procedure

The Ross procedure, in which the aortic valve is replaced with the patient's own pulmonary valve (pulmonary autograft), is considered an excellent alternative for younger patients requiring elective aortic valve replacement. Although resting pulmonary autograft hemodynamics are excellent, exercise hemodynamic data are lacking. The study aim was to measure the hemodynamic performance of the pulmonary autograft with exercise Doppler echocardiography (DE).

Twenty-four Ross procedure patients (20 males, four females; mean age 46 +/- 11 years) were studied at 25 +/- 14 months after aortic valve replacement with a pulmonary autograft. Patients had baseline supine DE to measure the maximum velocity (Vmax), and the peak and mean pressure gradient across the pulmonary autograft. Effective orifice area was calculated from the continuity equation and indexed to body surface area (EOAi). Patients then underwent symptom-limited upright bicycle exercise with supine DE repeated immediately on stopping exercise. For comparison, 10 normal controls (age 41 +/-10 years) and five mechanical aortic valve patients (mean age 55 +/- 10 years) were studied.

At rest: Ross procedure patients had similar Vmax (1.2 +/- 0.2 m/s), peak gradient (6 +/- 2 mmHg), mean gradient (4 +/- 1 mmHg) and EOAi (1.7 +/- 0.4 cm2/m2) to those of normal controls. Mechanical-valve patients had significantly higher Vmax (2.5 +/- 0.2 m/s, p <0.001), peak gradient (25 +/- 4 mmHg, p <0.001) and mean gradient (14 +/- 3 mmHg, p <0.001) than Ross patients and normal controls. At exercise: Ross procedure patients had similar Vmax (1.8 +/- 0.4 m/s versus 2.1 +/- 0.2, p = NS), peak gradient (14 +/- 6 mmHg versus 17 +/- 4, p = NS) and mean gradient (8 +/- 4 mmHg versus 10 +/- 2, p = NS) to normal controls, with no significant change in EOAi. Mechanical-valve patients had significantly higher Vmax (3.4 +/- 0.3, p <0.001), peak gradient (48 +/- 7 mmHg, p <0.001) and mean gradient (30 +/- 5 mmHg, p <0.001) than Ross patients and normal controls.

Aortic valve replacement using the Ross procedure provides excellent hemodynamic results at rest and on exercise, with DE parameters indistinguishable from those of normal controls. This study provides further support for the use of the Ross procedure as a preferred method of aortic valve replacement in younger patients.