Morbidity and mortality of isolated aortic valve replacement have fallen, despite gradual increases in patient age and overall risk profile. There has been a shift toward bioprostheses. Women, patients older than 70 years, and patients with ejection fraction less than 30% have worse outcomes for mortality, stroke, and postoperative stay.
Objectives
This study sought to demonstrate that short-term cardiac unloading with a left ventricular (LV) assist device (LVAD) after acute myocardial infarction (MI) can conserve calcium cycling and improve heart function.
Background
Heart failure secondary to MI remains a major source of morbidity and mortality. Alterations in calcium cycling are linked to cardiac dysfunction in the failing heart.
Methods
Adult Dorsett hybrid sheep underwent acute MI and were mechanically unloaded with an axial-flow LVAD (Impella 5.0) for 2 weeks (n = 6). Six sheep with MI only and 4 sham sheep were used as controls. All animals were followed for 12 weeks post-MI. Regional strains in the LV were measured by sonomicrometry. Major calcium-handling proteins (CHPs), including sarco-/endoplasmic reticulum calcium ATPase-2α (SERCA-2α), Na+-Ca2+ exchanger-1, and phospholamban, and Ca2+-ATPase activity were investigated. The electrophysiological calcium cycling in single isolated cardiomyocytes was measured with the patch-clamp technique. The related ultrastructures were studied with electron microscopy.
Results
LVAD unloading alleviated LV dilation and improved global cardiac function and regional contractility compared with the MI group. The regional myocardial strain (stretch) was minimized during the unloading period and even attenuated compared with the MI group at 12 weeks. Impaired calcium cycling was evident in the adjacent noninfarcted zone in the MI group, whereas CHP expression was normalized and Ca2+-ATPase activity was preserved in the LVAD unloading group. The electrophysiological calcium cycling was also conserved, and the ultrastructural damage was ameliorated in the unloaded animals.
Conclusions
Short-term LVAD unloading may conserve calcium cycling and improve heart function during the post-infarct period.
Transcatheter aortic valve replacement (TAVR) is a safe and effective therapy for aortic valve replacement in patients ineligible for or at high risk for surgery. However, outcomes after TAVR based on an individual's sex remain to be fully elucidated. We searched PUBMED and EMBASE using the keywords: "transcatheter aortic valve replacement," "transcatheter aortic valve implantation," "sex differences," "gender," "sex characteristics" and collected information on baseline features, procedural characteristics, and postprocedural outcomes in women. Inclusion/exclusion resulted in 23 publications. Women had less preexisting comorbidities than men. Most studies reported better survival in women (range of hazard ratio [95% CI] = 0.27 [0.09-0.84] to 0.91 [0.75-1.10]). At 30 days, women also had more vascular complications (6-20% vs 2-14%) and higher bleeding rates (10-44% vs 8-25%). Stroke rates were similar at 30 days (women, 1-7%; men, 1-5%). This literature review showed better survival in women than men after TAVR. However, women had more vascular complications and bleeding; stroke rates were similar. These findings may partly be explained by fewer baseline comorbidities in women. These results should be interpreted with caution as most measures only include unadjusted percentages.
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