Introduction: Life expectancy in young adults undergoing mechanical or bioprosthetic aortic valve replacement (AVR) may be reduced by up to 20 years compared to age matched controls. The Ross procedure is a durable, anticoagulation-sparing alternative. We performed a systematic review and meta-analysis to compare the valve hemodynamics of the Ross procedure versus other AVR.
Evidence acquisition: We searched Cochrane CENTRAL, MEDLINE and EMBASE from inception to February 2017 for randomized controlled trials (RCTs) and observational studies (n≥10 Ross). Independently and in duplicate, we performed title and abstract screening, full-text eligibility assessment, and data collection. We evaluated the risk of bias with the Cochrane and CLARITY tools, and the quality of evidence with the GRADE framework.
Evidence synthesis: We identified 2 RCTs and 13 observational studies that met eligibility criteria (N.=1412). In observational studies, the Ross procedure was associated with a lower mean aortic gradient at discharge (MD -9 mmHg, 95% CI: -13 to -5, P<0.0001, I2=97%) and latest follow-up (MD -5 mmHg, 95% CI: -7 to -3, P<0.0001, I2=92%). There was no significant difference in the incidence of severe aortic regurgitation at latest follow-up (RR 1.3, 95% CI: 0.3 to 5.8, P=0.70, I2=30%). In RCTs, the Ross procedure was associated with a lower mean gradient at latest follow-up (MD -15 mmHg, 95% CI: -32 to 2, P=0.08, I2=99%). The mean pulmonic gradient for the Ross procedure was 18.0 mmHg (95% CI: 16 to 20, P<0.0001) at latest follow-up. The evidence for all outcomes from observational studies was deemed to be of very low quality, while the evidence from RCTs was downgraded for imprecision and moderately serious risk of bias.
Conclusions: Compared to conventional AVR, the Ross procedure was associated with better aortic valve hemodynamics. Future studies should evaluate the impact of the Ross procedure on exercise capacity and quality of life.