An Echocardiographic Comparison of Sutureless and Conventional Aortic Valve Replacement: a Matched Case-Control Study

Background Patients at a high operative risk for conventional aortic valve replacement (AVR) may be offered sutureless valve implantation. Sutureless valves resemble conventional valves but incorporate an anchoring mechanism without using annular sutures. Methods Pre-operative and six month post-operative echocardiography data from our first year, single centre experience of sutureless valves was compared to conventional aortic valve replacements in patients matched for operative risk. Left ventricular ejection fraction, mean and peak AV gradients and inter-ventricular septal thickness, effective orifice area (EOA) and indexed effective orifice area (iEOA) were measured.  Results The drops in mean and peak pre- to post-operative gradients were greater in the sutureless group, p=0.039 and p=0.001 respectively. Post-operative EOA was 1.69 cm 2 and 1.26 cm 2 (p=0.001) in the sutureless and conventional groups. Similarly iEOA was 0.93 cm 2 and 0.74 cm 2 (p=0.001) in the sutureless and conventional groups. There was also a reduction in patient prosthesis mismatch (PPM) in the sutureless group as compared to the conventional group (Chi square test p=0.026). Post-operative inter-ventricular septal thickness was 1.13 cm 2 in the sutureless group and 1.35 cm 2 in the conventional group (p=0.011). Conclusions Use of sutureless valves with a stent framework resulted in larger EOA and iEOA and a diminution in PPM; and lead to a statistically significant faster regression in inter-ventricular septal thickness that is a measure of left ventricular mass. The rate and extent of regression in  left ventricular hypertrophy after AVR is important since it determines long-term survival including mortality, heart failure and decreased admission rates.