Greason, Kevin L.

BackgroundSurgical exclusion of the left atrial appendage (LAA) can be performed at the time of cardiac operation as a potential modality to decrease cardioembolic risk attributable to atrial fibrillation (AF), but it remains unclear if this decreases stroke incidence. Furthermore, it is not known whether LAA exclusion impacts the decision to discontinue anticoagulation impacting subsequent stroke risk.HypothesisLAA exclusion does not significantly alter subsequent anticoagulation use or stroke incidence.MethodsWe studied 124 patients from Olmsted County with prior history of AF who underwent cardiac surgery at our institution between 1993 and 2015. Patients were divided into two groups on the basis of LAA exclusion and matched (1:1) according to 16 pretreatment variables using propensity scores obtained from a logistic regression model. Outcome data collected through chart review for survival, stroke, and the presence and duration of anticoagulation were compared between groups.ResultsThe proportion of patients receiving anticoagulation at discharge and at 5 years was not significantly different between patients who underwent LAA exclusion and those who did not; 90% vs 81%, P = 0.156, 48% vs 49%, P = 0.722, respectively. On Kaplan‐Meier analysis there were no significant differences in time free from stroke between cases and controls. Patients discharged on oral anticoagulation (OAC) had significantly lower risk of stroke (HR = 0.19, 95% confidence interval [CI] = 0.06‐0.59, P = 0.004), independent of whether LAA closure was used.ConclusionLAA exclusion did not appear to reduce early or late stroke. Only OAC was associated with a reduction in stroke risk, underscoring the need for continued anticoagulation in high‐risk patients.

Background There are limited data on the use of venoarterial extracorporeal membrane oxygenation ( VA ‐ ECMO ) or cardiopulmonary bypass ( CPB ) to provide hemodynamic support periprocedurally during transcatheter aortic valve replacement. This study sought to evaluate patients receiving transcatheter aortic valve replacement with concomitant use of CPB / VA ‐ ECMO . Methods and Results We systematically reviewed the published literature from 2000 to 2018 for studies evaluating adult patients requiring CPB / VA ‐ ECMO periprocedurally during transcatheter aortic valve replacement. Studies reporting short‐term and long‐term mortality were included. Given the significant methodological and statistical differences between published studies, meta‐analysis of the association of CPB / VA ‐ ECMO with mortality was not performed. Of the 537 studies identified, 9 studies representing 5191 patients met our inclusion criteria. Median ages were between 75 and 87 years with 33% to 75% male patients. Where reported, the Edwards SAPIEN ™ transcatheter heart valve was the most frequently used. A total of 203 (3.9%) patients received periprocedural hemodynamic support with CPB / VA ‐ ECMO . Common indications for CPB / VA ‐ ECMO included left ventricular or aortic annular rupture, rapid hemodynamic deterioration, aortic regurgitation, cardiac arrest, and left main coronary artery obstruction. The use of CPB / VA ‐ ECMO was predominantly an emergent strategy and was used for durations of 1 to 2 hours. Short‐term mortality (in‐hospital and 30‐day) was 29.8%, and 1‐year mortality was 52.4%. Major complications such as bleeding, vascular injury, tamponade, stroke, and renal failure were noted in 10% to 50% of patients. Conclusions CPB / VA ‐ ECMO was used in 4% in the early experience of patients undergoing transcatheter aortic valve replacement, most commonly for periprocedural complications. There are limited data on preprocedural planned use of VA ‐ ECMO , and the characteristics of this population remain poorly defined.

Abstract Aims Type 2 diabetes (T2D) is strongly associated with cardiovascular morbidity and mortality in patients. Vascular large conductance Ca2+-activated potassium (BK) channels, composed of four pore-forming α subunits (BK-α), and four regulatory β1 subunits (BK-β1), are densely expressed in coronary arterial smooth muscle cells (SMCs) and play an important role in regulating vascular tone and myocardial perfusion. However, the role of BK channels in coronary microvascular dysfunction of human subjects with diabetes is unclear. In this study, we examined BK channel function and protein expression, and BK channel-mediated vasodilation in freshly isolated coronary arterioles from T2D patients. Methods and results Atrial tissues were obtained from 16 patients with T2D and 25 matched non-diabetic subjects during cardiopulmonary bypass procedure. Microvessel videomicroscopy and immunoblot analysis were performed in freshly dissected coronary arterioles and inside-out single BK channel currents was recorded in enzymatically isolated coronary arteriolar SMCs. We found that BK channel sensitivity to physiological Ca2+ concentration and voltage was downregulated in the coronary arteriolar SMCs of diabetic patients, compared with non-diabetic controls. BK channel kinetics analysis revealed that there was significant shortening of the mean open time and prolongation of the mean closed time in diabetic patients, resulting in a remarkable reduction of the channel open probability. Functional studies showed that BK channel activation by dehydrosoyasaponin-1 was diminished and that BK channel-mediated vasodilation in response to shear stress was impaired in diabetic coronary arterioles. Immunoblot experiments confirmed that the protein expressions of BK-α and BK-β1 subunits were significantly downregulated, but the ratio of BK-α/BK-β1 was unchanged in the coronary arterioles of T2D patients. Conclusions Our results demonstrated for the first time that BK channel function and BK channel-mediated vasodilation were abnormal in the coronary microvasculature of diabetic patients, due to decreased protein expression and altered intrinsic properties of BK channels.

AbstractObjectiveThe aim of this study was to perform a systematic review and meta‐analyses of observational studies of transcatheter aortic valve replacement (TAVR) for bicuspid aortic valve stenosis (BcAV).BackgroundTAVR for BcAV stenosis has been associated with an increased incidence of paravalvular leaks, valve malposition, pacemaker placement and all‐cause mortality. The conclusions drawn have been limited by small sample sizes. The use of TAVR for BcAV stenosis remains controversial.MethodsWe searched multiple databases from the inception of the databases through September 30, 2016 for studies of TAVR for BcAV stenosis. We included all observational studies with more than one patient and at least 1 month of outcomes.ResultsWe analyzed 13 observational studies with 758 patients. Meta analyses showed device success rate of 95% [95% confidence interval (CI) 90.2% to 98.5%] and an early safety event in 16.9% [95% CI 12.2% to 22%]. At 30 days, moderate to severe paravalvular leak was seen in 12.2% [95% CI 3.1% to 24.8%] and new pacemaker implantation in 17.9% [95% CI 14.2% to 22%]. All‐cause mortality was 3.7% [95% CI 2.1% to 5.6%], which should be viewed in the context of an STS PROM of 5.0%.ConclusionsThis analysis suggests that TAVR for BcAV is not associated with excess mortality. The incidence of paravalvular leaks and pacemaker implant is increased compared to tricuspid aortic valve cohorts undergoing TAVR, and operators should weigh these potential complications against the clinical benefit provided by TAVR for BcAV patients at high risk for surgical valve replacement.

Background— The introduction of transcatheter aortic valve replacement (TAVR) led to renewed interest in balloon aortic valvuloplasty (BAV). We sought to assess contemporary trends in BAV utilization and their outcomes. Methods and Results— The Nationwide Inpatient Sample was used to identify patients who underwent BAV between 2004 and 2013. In-hospital morbidity and mortality, and predictors of death after BAV were assessed. Outcomes of propensity-matched groups of patients undergoing elective BAV or TAVR were evaluated. BAV utilization increased from 707 cases in 2004 to 3715 cases in 2013 (national estimates). Procedural and in-hospital mortality were 1.4% and 8.5%, respectively. Vascular complications occurred in 7.0% of cases, blood transfusion in 17.5%, clinical stroke in 1.8%, and pacemaker implantation in 3.0%. The strongest predictors of in-hospital death were cardiogenic shock (odds ratio, 6.01; 95% confidence interval, 4.19–8.61; P <0.001), need for left ventricular assist device (odds ratio, 3.48; 95% confidence interval, 2.25–5.36; P <0.001), coagulopathy (odds ratio, 2.19; 95% confidence interval, 1.51–3.18; P <0.001), and low institutional volume of BAV (odds ratio, 1.58; 95% confidence interval, 1.06–2.37; P =0.03). In propensity-matched patients undergoing elective BAV or TAVR, rates of in-hospital mortality (2.9% versus 3.5%; P =0.60), clinical stroke (1.6% versus 3.1%; P =0.10), and vascular complications (8.2% versus 10.9%; P =0.14) were similar. However, BAV was associated with lower rates of pacemaker implantation (2.9% versus 8.0%; P <0.001) and blood transfusion (12.8% versus 22.9%; P <0.001). Conclusions— In a contemporary national registry, BAV is associated with significant morbidity and mortality that are similar to TAVR. With the substantial increase in BAV utilization and the continuous improvement in TAVR outcomes, these data have important implications to aid clinicians in the selection of appropriate BAV candidates.