Survival and Outcomes Following Bioprosthetic vs Mechanical Mitral Valve Replacement in Patients Aged 50 to 69 Years

Chikwe, Joanna; Chiang, Yu-Ting; Egorova, Natalia; Itagaki, Shinobu; Adams, David H.

doi:10.1001/jama.2015.3164

Cited by 115 publications

(126 citation statements)

References 26 publications

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“…These findings are fully consistent with the clinical literature, which, even if it reports nearly identical fatality rates for the follow-up of mitral replacement with mechanical valves or bioprostheses (Hammermeister et al 2000;Chikwe et al 2015), indicates that the causes of death are very different. In addition, Cen et al (2001) confirm that for ejection fractions in the range of 50 %, both the mechanical and the prosthetic valves perform adequately, while De Bacco et al (2009) state that an impaired ventricle is among the most negative prognostic factors for a mitral valve replacement with a mechanical prosthesis.…”

Section: Closing Remarkssupporting

confidence: 90%

“…. lower in the mechanical prosthesis group' (Chikwe et al 2015). More quantitatively, for the bileaflet implantations, strokes accounted for 15 % of lethal events, while for bioprosthetic valves they were only 6.8 %, thus evidencing a higher propensity of the mechanical valves to thromboembolism.…”

Section: Discussionmentioning

confidence: 81%

“…On the other hand, bioprosthetic valves degenerate more rapidly, especially in non-elderly patients, and the deaths caused by reoperation amounted to 5 % for the mechanical and 11 % for the bioprosthetic valves. It appears that these numbers miraculously balance, so that the overall fatality rates are roughly the same (Chikwe et al 2015). Analogous figures come from Hammermeister et al (2000), who analysed two groups of 88 and 93 patients who had the mitral valve replaced with a mechanical or a biological prosthesis respectively.…”

Section: Discussionmentioning

confidence: 95%

“…Before concluding this discussion, we wish to comment on how the present findings relate to the clinical literature, according to which the free event survival curves of mitral valve replacement in a five-year follow-up (but also 10 or 15 years) are very similar for mechanical bileaflet and bioprosthetic valves despite the superior haemodynamics of the latter claimed in this study. In the paper by Chikwe et al (2015), a cohort of 3433 patients, all in the age range 50-69 and with mitral disease requiring valve replacement, showed that indeed 'no survival difference was observed between use of mechanical prosthetic and bioprosthetic mitral valves'. However, the breakdown of the data evidenced that the causes of deaths were very different for the two classes of prostheses with 'the incidences of stroke and bleeding events .…”

Section: Discussionmentioning

confidence: 99%

“…Unfortunately, the analyses of Hammermeister et al (2000) and Chikwe et al (2015) do not distinguish the patients with different ejection fractions, while Qiu et al (2010), who considered mechanical and biological mitral valve replacements in dysfunctional ventricles, did not separate the deaths that occurred with different valve models. Nevertheless, the statistics reported in Cen et al (2001) confirm that for physiological ejection fractions (in the range of 50 %), both the mechanical and the prosthetic valves perform adequately, while De Bacco et al (2009) reported that in mechanical mitral valve replacement, a low-ejection-fraction ventricle is one of the most negative prognostic factors.…”

Section: Discussionmentioning

confidence: 99%

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Flow structure in healthy and pathological left ventricles with natural and prosthetic mitral valves

Meschini

Tullio²,

Querzoli

et al. 2017

J. Fluid Mech.

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In this paper, the structure and the dynamics of the flow in the left heart ventricle are studied for different pumping efficiencies and mitral valve types (natural, biological and mechanical prosthetic). The problem is investigated by direct numerical simulation of the Navier-Stokes equations, two-way coupled with a structural solver for the ventricle and mitral valve dynamics. The whole solver is preliminarily validated by comparisons with ad hoc experiments. It is found that the system works in a highly synergistic way and the left ventricular flow is heavily affected by the specific type of mitral valve, with effects that are more pronounced for ventricles with reduced pumping efficiency. When the ventricle ejection fraction (ratio of the ejected fluid volume to maximum ventricle volume over the cycle) is within the physiological range (50 %-70 %), regardless of the mitral valve geometry, the mitral jet sweeps the inner ventricle surface up to the apex, thus preventing undesired flow stagnation. In contrast, for pathological ejection fractions ( 40 %), the flow disturbances introduced by the bileaflet mechanical valve reduce the penetration capability of the mitral jet and weaken the recirculation in the ventricular apex. Although in clinical practice the fatality rates in the five-year follow-ups for mechanical and biological mitral valve replacements are essentially the same, a breakdown of the deaths shows that the causes are very different for the two classes of prostheses and the present findings are consistent with the clinical data. This might have important clinical implications for the choice of prosthetic device in patients needing mitral valve replacement.

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Section: Closing Remarkssupporting

confidence: 90%

Section: Discussionmentioning

confidence: 81%