Objectives: Native valve-preserving procedures are evolving strategies in well-selected young patients undergoing aortic valve (AV) surgery aimed at overcoming the limitations of prosthetic valve substitutes. We aimed to prospectively evaluate the correlation of echocardiographic performance and exercise capacity after native valve-preserving surgery vs. conventional prosthetic valve replacement.

Methods: From November 2018 to August 2020, 65 consecutive non-elderly patients (mean age: 43±13 years, 83% male) with severe AV dysfunction scheduled for surgery were prospectively included. Transthoracic echocardiography and cardiopulmonary exercise testing were performed upon admission, at discharge and at 3 months and 1 year postoperatively.

Results: 45 patients underwent native valve-preserving procedures (NV group), including AV repair (n=31) or the Ross procedure (n=14), and 20 conventional prosthetic valve replacement (PV group) with biological (n=19) or mechanical valve substitutes (n=1). At discharge, transvalvular AV gradients and diastolic left ventricular (LV) function (i.e., early diastolic septal and lateral mitral annular velocity (e’)) were comparable in both groups. At 1 year postoperatively, NV patients showed significantly lower peak (NV group: 12±8 mmHg vs. PV group: 17±7 mmHg, p=0.048) and mean (NV group: 6±5 mmHg vs. PV group: 10±3 mmHg, p=0.011) transvalvular gradients and significantly better diastolic LV function (i.e., septal e’ in NV group: 10±3 cm/s vs. PV group: 8±2 cm/s, p=0.031; lateral e’ in NV group: 15±3 cm/s vs. PV group: 12±3 cm/s, p<0.001). Simultaneously, NV patients had markedly better maximum work rate (WR_max: NV group: 198±56 W vs. PV group: 134±56 W, p<0.001) and peak oxygen consumption (VO₂max/kg: NV group: 25±7 ml/kg/min vs. PV group: 21±7 ml/kg/min, p=0.063) at 1-year exercise testing. We found a significant linear correlation between exercise capacity parameters (i.e., VO₂max/kg and WR_max) and diastolic LV function (i.e., septal e’ and lateral e’). The strongest correlation was found between lateral e’ and WR_max (r=0.410, p=0.003) and between lateral e’ and VO₂max/kg (r=0.422, p=0.002) at 1-year follow-up.

Conclusion: In AV surgery in non-elderly adults, native valve preservation is associated with lower transvalvular gradients compared to conventional prosthetic valve replacement at 1-year postoperatively. More favorable transvalvular hemodynamics may enable faster LV reverse remodeling and consequently greater improvement in diastolic LV function. This, in turn, correlates with a better functional performance at exercise testing.