Supra-annular versus intra-annular prostheses in aortic valve replacement: impact on haemodynamics and clinical outcomes†

OBJECTIVES: The superiority of supra-annular aortic prostheses over intra-annular equivalents in long-term haemodynamics and clinical outcomes remains controversial. This study compared outcomes among patients receiving supra-annular or intra-annular prostheses during aortic valve replacement. METHODS: We enrolled 587 consecutive patients (mean age 55.1 ± 11.3 years; 188 women) undergoing aortic valve replacement with either supra-annular (n = 316) or intra-annular (n = 271) mechanical prostheses between 2000 and 2016 in our institute. Clinical outcomes and haemodynamic profiles in the 2 groups were compared after propensity score adjustment. RESULTS: Early death (1.1% vs 0.6%; P = 0.863) was equivalent for both groups. Patients receiving supra-annular prostheses showed a lower rate of patient-prosthesis mismatch (1.2% vs 25.8%; P < 0.001). During a median follow-up of 65 months (quartile 1-3, 30-108 months), overall deaths occurred in 84 (14.3%) patients. The latest echocardiographic assessment in the 136 propensity score-matched pairs demonstrated superior haemodynamics with implantation of supra-annular prostheses: peak velocity (2.7 ± 0.6 vs 2.3 ± 0.5 m/s; P < 0.001), mean pressure gradient (16.5 ± 9.0 vs 12.0 ± 6.2 mmHg; P < 0.001) and left ventricular mass index (113.6 ± 30.3 vs 105.3 ± 26.3 g/m2; P = 0.016). After adjusting with inverse-probability-of-treatment weighting, however, the choice of supra-annular over intra-annular prosthesis did not significantly affect the risk of overall mortality (P = 0.693) or major adverse events: stroke (P = 0.944), infective endocarditis (P = 0.958) and reoperation (P = 0.944). CONCLUSIONS: The implantation of supra-annular prostheses resulted in superior haemodynamics and left ventricular mass regression, while conferring no apparent clinical benefits. Follow-up studies are required to further evaluate the impact of superior haemodynamics associated with supra-annular prostheses on long-term clinical outcomes.