Search

The etiology of transcatheter aortic valve (TAV) degeneration is poorly understood, particularly noncalcific mechanisms. The authors sought to investigate noncalcific and calcific mechanisms of TAV degeneration and evaluate their impact on leaflet function by bench testing, imaging, and histology. TAV explants were obtained from the EXPLANT THV registry and clinical institutions. Hydrodynamic assessment was performed using a heart valve pulse duplicator system under physiological conditions. Micro-computed tomography, high-resolution photography, high speed video, and hematoxylin and eosin staining were used to evaluate the morphological appearance, leaflet kinematics, and calcium burden of TAVs. A total of 14 explants were evaluated: 10 self-expanding CoreValve/Evolut TAVs (Medtronic), 3 balloon-expandable SAPIEN 3 TAVs (Edwards Lifesciences), and 1 mechanically expandable Lotus TAV (Boston Scientific). The median patient age at explantation was 73.0 years (Q1-Q3: 64.5-80.0 years), with a time to explantation of 4 years 1 month (1 year 5 months to 4 years 11 months). Six TAV explants were found to have leaflet calcification (162.4 mm3; 58.8-603.0 mm3), and 8 had no calcification detectable by micro-computed tomography and histology. All samples had impaired leaflet kinematics. There was no significant difference in the hydrodynamic mean gradient between calcified (47.2 mm Hg; 26.6-74.1 mm Hg) and noncalcified (27.6 mm Hg; 15.2-36.7 mm Hg; P = 0.28) TAVs. Leaflet calcification had a weak but nonsignificant association with the hydrodynamic mean gradient (r = 0.42; P = 0.14). TAV function can be severely impacted by noncalcific and calcific mechanisms of tissue degeneration. Importantly, functional stenosis can occur in TAVs in the absence of obvious and significant calcification. [Display omitted] [ABSTRACT FROM AUTHOR]

There are limited data on the effect of bioprosthetic valve remodeling (BVR) on transcatheter heart valve (THV) expansion and function following valve-in-valve (VIV) transcatheter aortic valve replacement (TAVR) in a nonfracturable surgical heart valve (SHV). This study sought to assess the impact of BVR of nonfracturable SHVs on THVs after VIV implantation. VIV TAVR was performed using 23-mm SAPIEN3 (S3, Edwards Lifesciences) or 23/26-mm Evolut Pro (Medtronic) THVs implanted in 21/23-mm Trifecta (Abbott Structural Heart) and 21/23-mm Hancock (Medtronic) SHVs with BVR performed with a noncompliant TRUE balloon (Bard Peripheral Vascular Inc). Hydrodynamic assessment was performed, and multimodality imaging including micro–computed tomography was performed before and after BVR to assess THV and SHV expansion. BVR resulted in limited improvement of THV expansion. The largest gain in expansion was observed for the S3 in the 21-mm Trifecta with up to a 12.7% increase in expansion at the outflow of the valve. Minimal change was observed at the level of the sewing ring. The Hancock was less amenable to BVR with lower final expansion dimensions than the Trifecta. BVR also resulted in notable surgical post flaring of up to 17.6°, which was generally more marked with the S3 than with the Evolut Pro. Finally, BVR resulted in very limited improvement in hydrodynamic function. Severe pinwheeling was observed with the S3, which improved slightly but persisted despite BVR. When performing VIV TAVR inside a Trifecta and Hancock SHV, BVR had a limited impact on THV expansion and resulted in SHV post flaring with unknown consequences on coronary obstruction risk and long-term THV function. [Display omitted] [ABSTRACT FROM AUTHOR]

Limited evidence is available regarding valve-in-valve (VIV) intervention with the ACURATE neo transcatheter heart valve (THV). Low implantation has demonstrated leaflet interaction between the surgical bioprosthesis and the THV, leading to impaired hydrodynamic performance. It is unknown if commissural alignment (CA) can affect this phenomenon. Novel techniques have now been developed to achieve CA with the ACURATE neo THV. The aim of this study was to assess the impact of commissural misalignment (CMA) on hydrodynamic function following VIV intervention with the ACURATE neo THV using a bench model. VIV intervention was performed with the ACURATE neo (a self-expanding THV with supra-annular leaflet position) implanted deep in the surgical bioprosthetic aortic valve (Mitroflow). Hydrodynamic function at CA (0°) and 3 different degrees of CMA (30°, 60°, and 90°) was tested. As per the International Organization for Standardization, a regurgitant fraction <20% is considered optimal. Following VIV, the central THV regurgitant fraction at 0°, 30°, 60°, and 90° of CMA was 8.6% ± 2.0%, 30.3% ± 12.0%, 42.6% ± 11.9%, and 66.7% ± 25.4% (P < 0.0001), respectively. On high-speed video there was no evidence of leaflet interaction at CA, whereas at 30°, 60°, and 90° of CMA there was clear evidence of THV leaflet interaction with those of the surgical valve, leading to impaired leaflet closure and to severe central THV regurgitation. In VIV using the ACURATE neo THV at deep implantation, increasing degree of CMA was associated with THV leaflet interaction with those of the surgical valve and worsening regurgitant fraction. THV leaflet interaction was prevented when there was CA. [Display omitted] [ABSTRACT FROM AUTHOR]

The implications and potential challenges of coronary access after redo transcatheter aortic valve replacement (TAVR) are unknown. The authors sought to evaluate the impact of different transcatheter heart valve (THV) designs, neoskirt height, implant technique, and cell misalignment on coronary access after redo TAVR. Different THV designs (Sapien 3 [Edwards Lifesciences LLC], Evolut Pro [Medtronic], ACURATE neo [Boston Scientific Corporation], and Portico [Abbott Structural Heart]) and sizes were implanted inside Sapien XT (Edwards Lifesciences LLC) and Evolut R (Medtronic) THVs, which were modeled as the "failed" THVs, at different implant depths. Valve combinations underwent micro–computed tomography to determine the neoskirt height and dimensions of the lowest accessible cell for potential coronary access. This was compared with dimensions of 6-F/7-F/8-F coronary guiding catheters. Redo TAVR combinations resulted in a wide range of neoskirt heights (15.4-31.6 mm) and a variable diameter of the lowest accessible cell (1.9-21.8 mm). An ACURATE neo implanted in a Sapien XT resulted in the largest accessible cells, whereas a Portico implanted in a Sapien XT resulted in the lowest neoskirt heights. The smallest accessible cell was observed in the Evolut Pro–in–Evolut R configuration with higher neoskirt heights. Redo TAVR in a tall frame valve with supra-annular leaflets caused a taller neoskirt height. In Evolut-in-Evolut combinations, misalignment of the cells of the 2 THVs reduced the cell area by 30% to 50% compared with an aligned configuration. This study demonstrates that different redo TAVR combinations are not equivalent in terms of future coronary access. Redo TAVR using a tall frame valve in a failed tall frame valve and misaligned cells may lead to potentially challenging coronary access. [Display omitted] [ABSTRACT FROM AUTHOR]

To compare the percutaneous Rotarex and Angiojet thrombectomy devices with regard to effectiveness and in vitro safety. The Rotarex and Angiojet devices were evaluated in an established in vitro pulsatile flow model with a human femoropopliteal vessel phantom. First pass recanalisation and thrombus weight were assessed after thrombectomy, as well as micro- and macro-emboli. Further, histological evaluation of the vascular phantom was performed to analyse vascular injuries. Thrombus weight did not differ significantly prior to the thrombectomy between the groups, but the Rotarex showed slight advantages in thrombus removal vs. the Angiojet regarding first pass recanalisation. Micro- and macro-emboli occurred in most of the endovascular manoeuvres performed; however, significantly more macro-emboli (2.37 ± 1.51 vs. 0.87 ± 0.83; p =.048) were observed using the Rotarex than the Angiojet. Macroscopic dissections were detected in the Rotarex group (n = 3) but not in the Angiojet group. Microscopic vascular injuries were detected significantly more often in the Rotarex group (Rotarex: 531.61 μm ± 102.81 μm; Angiojet: 705.42 μm ± 61.68 μm p =.001]). Both devices showed a comparable performance, with a slight advantage for the Rotarex regarding first pass recanalisation. Significantly more thrombo-emboli, and vascular injuries were observed in the Rotarex group with the latter being obviously the more tissue preserving procedure but potentially with a lower rate of recanalisation. Based on the present results, clinical randomised trials, including long term follow up, are needed to optimise and improve the use of catheter based procedures, taking into account the thrombus entity, localisation, and clinical history. [ABSTRACT FROM AUTHOR]

Background: Various studies evaluated the relationship between hypothermic circulatory arrest and neurological outcome in patients undergoing replacement of ascending aorta. The current analysis focuses on the effect of moderate hypothermic circulatory arrest (MHCA) on elderly patients. The aim of our study was to evaluate the impact of MHCA on neurological outcomes in elderly patients undergoing replacement of the ascending aorta. Results: We retrospectively analyzed 905 consecutive patients, who underwent elective replacement of ascending aorta in MHCA (24 ± 2 °C, nasopharyngeal) between 2001 and 2015. Patients with acute aortic dissection were excluded from this study. Patients were divided into two groups: those aged 75 years and older (elderly group 22.4%, n = 203) and those younger than 75 years (younger group 77.6%, n = 702). The average age was 63.2 ± 10.2 in the young group vs. 78.7 ± 3.0 years in elderly group (p < 0.001). The elderly group had a significantly higher EuroSCORE II [26.7% (18.1, 36.3) vs. 11.6% (7.4, 19.9); p < 0.001)]. The incidence of coronary heart disease (49.8% vs. 35.6%, p < 0.001) and chronic renal failure (17.2% vs. 9.1%, p = 0.001) was significantly higher in the elderly group. Intraoperatively, the time of MHCA [14 min (12, 17) vs. 15 min (12, 18); p = 0.42], cardiopulmonary bypass [139 min (110, 183) vs. 144 min (113, 189); p = 0.225], and cross-clamping [91 min (63, 116) vs. 92 min (65, 127); p = 0.348] was similar in both groups. Postoperatively, a higher incidence of delirium was significantly reported in the elderly group (24.1% vs. 9.0%, p < 0.001). However, there was no significant difference regarding neurological complications between both groups. A 30-day mortality was acceptable for the elderly group, but significantly higher compared with the younger group (7.1% vs. 3.5%, p = 0.031). Conclusions: Our study suggests that surgical replacement of the ascending aorta in MHCA can also be applied safely in elderly patients without increasing the risk of severe neurological complications. [ABSTRACT FROM AUTHOR]

Abstract: Background: Chronic rejection (CR) after lung transplantation (LTX) manifests pathologically by fibrotic airway remodelling and bronchiolitis obliterans (BO). The role of the mammalian target of rapamycin inhibitor everolimus in preventing this process is poorly understood. Methods: A rat model of left lung allo-transplantation (Fisher 344 to Wistar Kyoto) was used to analyze the effect of everolimus (2.5mg/kg/day) on the development of CR. Drug therapy began on postoperative day (POD) 0, 7 and 14 characterizing different grade of acute rejection (AR) of the allograft before drug treatment. Results: Non-treated recipients developed severe acute rejection (AR) and first signs of CR on POD 20 and a pronounced CR on POD 60. On POD 20, only application of everolimus from POD 0 to 60 significantly reduced acute inflammatory infiltration (p <0.001). Independent of treatment scheme, everolimus suppressed the development of early signs of chronic alterations (POD 20). However, neither early (POD 7–60) nor late (POD 14–60) application of everolimus affected the progression of CR (POD 60). Only its initial treatment (POD 0–60) inhibited the development of BO and vasculopathy (p <0.001). An additional finding was a decrease in body weight after drug application. Conclusion: The effectiveness of everolimus after rat LTX depended on the grade of inflammation of the allograft before initiation of drug treatment. Only allografts with no or low grade AR benefit from long-term treatment with everolilmus in the prevention of BO after LTX. It could be speculated that conversion to an everolimus-based immunosuppression after LTX might only be successful in patients free of BO. [Copyright &y& Elsevier]

Objective: Late complications can develop in patients after surgery for aortic type A dissection, mandating redo surgery on the ascending aorta and arch. Methods: From 2006 to 2010, 23 patients (aged 41–69 years) who had late complications related to previous aortic surgery for acute type A dissection underwent redo surgery. Initial surgery included ascending aorta replacement in all cases. Results: The main indications for reoperation were progressive enlargement of the false lumen of the aortic arch or descending aorta and suture line dehiscence in 10 patients each. All patients with progressive aneurysm formation in nonresected aortic segments had persistent dissection within the aortic arch since initial surgery. Suture line dehiscence led to a localized hematoma in most cases. Three patients presented with graft infection and extensive perigraft hematoma. The average time interval from the initial repair to the redo procedure was 71 ± 56 months. Exchange of the formerly implanted Dacron graft in the ascending aorta was the most frequently used surgical procedure. Implantation of a valved conduit was deemed necessary in 4 cases, and isolated aortic valve replacement was necessary in 2 cases. A hybrid stent graft was used in 6 patients. All patients survived surgery, and 1 patient died of postoperative low output cardiac failure in hospital. Only 1 major stroke was noted. Conclusions: Complex reoperations for repaired acute type A dissection can be performed safely. The concern for the reoperative risk should not dictate the operative strategy during the initial procedure in acute type A dissection. [ABSTRACT FROM AUTHOR]

Background: YC-1 (3-(5′-hydroxymethyl-2′furyl)-1-benzyl-indazole) is an allosteric activator of soluble guanylyl cyclase (sGC) and a vasodilator. This study describes a paradoxical action of YC-1 in isolated vessels of patients with coronary artery disease (CAD) that appears to trigger an endothelium-dependent vasoconstrictor pathway present in vessels with endothelial dysfunction. Methods: Effects of YC-1 on the tensions of isolated vessels were investigated in an organ bath. Vasoconstrictors released from the vessels were quantified through enzyme-linked immunosorbent assay. Results: YC-1 elicited long-lasting constriction in saphenous veins and radial arteries from patients with CAD, but not in human umbilical veins. The half-maximal effective dose was 1.0 μmol/L. Constriction was attenuated by nifedipine (an L-type Ca2+-channel blocker), bosentan (an endothelin [ET]A/ETB inhibitor), BQ-788 (N-[(cis-2,6-Dimethyl-1-piperidinyl)carbonyl]-4-methyl-L-leucyl-1-(methoxycarbonyl)-D-tryptophyl-D-norleucine; an ETB inhibitor), and by denuding, but not by ODQ (1H-(1,2,4)oxadiazolo[4,3-a]quinoxalin-1-one; an inhibitor of sGC), BQ-123 (cyclo(-D-Trp-D-Asp-Pro-D-Val-Leu); an ETA inhibitor), or phosphoramidon (an endothelin converting enzyme inhibitor). Indomethacin (an inhibitor of cyclooxygenase-1 and -2) and SQ29,548 ([1S-[1α,2α(Z),3α,4α]]-7-[3-[[2-[(phenylamino)carbonyl]hydrazino]methyl]-7-oxabicyclo[2.2.1]hept-2-yl]-5-heptenoic acid; a thromboxane receptor antagonist) suppressed YC-1–induced constriction, whereas DFU (5,5-dimethyl-3-(3-fluorophenyl)-4-(4-methylsulfonyl)phenyl-2(5H)-furanone; a cyclooxygenase-2 inhibitor) had no effect. Rings of saphenous vein released significantly more endothelin-1 in the presence than in the absence of YC-1. Conclusions: YC-1–induced vasoconstriction demonstrates the existence of an endothelium-dependent vasoconstrictor pathway in the blood vessels of patients with CAD that to date has been described only in animal models of hypertension. Patients with CAD who have elevated plasma levels of endothelin-1 are thus prone to endothelium-dependent vasoconstriction, which may also play a role in vasospasm in vascular grafts. [Copyright &y& Elsevier]

Background: Hypothermia-induced changes in endothelial cell (EC) morphology and function after organ storage may influence the initial outcome and development of transplant-associated coronary artery disease. Methods: Human saphenous vein ECs were incubated with saline (NaCl), University of Wisconsin (UW), and histidine-tryptophan-ketoglutarate (HTK) solution, with and without protein additives, at 4°C and 37°C. After 6 hours, ECs were recultivated for 24 and 48 hours with culture medium (reperfusion). Mitochondrial activity, adenosine triphosphate concentration, cell count, and inflammatory responses were analyzed. Results: Cold preservation did not affect the mitochondrial activity of ECs and allowed a complete regeneration of the metabolic turnover after reperfusion. However, under normothermic conditions the metabolism of the cells was influenced by time and type of preservation solution. While both the mitochondrial activity and cell count did not change after treatment with NaCl and culture medium, the metabolic turnover of cells treated with HTK and UW solution significantly increased (twofold) and decreased (twofold, p < 0.05), respectively, after reperfusion. The endothelial reactivity remained unchanged after treatment with NaCl and HTK. The addition of serum proteins significantly improved mitochondrial activity of cells treated with warm NaCl and HTK (p < 0.05). The UW-treated cells burned out through a significant up-regulation of the ATP concentration resulting in a complete metabolic regression after reperfusion and induction of apoptosis. Conclusions: Normothermic preservation in UW prevented regeneration of ECs, while treatment with HKT solution did not irreversibly affect mitochondrial activity of ECs and allowed complete regeneration of metabolism and function. Serum proteins improved the preservation effect of HTK and NaCl. [Copyright &y& Elsevier]

Background: Coronary artery bypass surgery employing minimal extracorporeal circulation (MECC) was compared with standard extracorporeal circulation (ECC) and off-pump coronary artery bypass graft surgery (OPCABG) with regard to the perioperative course. Methods: From January 2004 to December 2007, 1,674 patients (n = 558 MECC, n = 558 ECC, n = 558 OPCABG) who underwent coronary bypass surgery were studied. The primary end point was in-hospital mortality; secondary end points were perioperative variables, intensive care, and in-hospital course. Results: Demographic data, comorbidity, and the European System for Cardiac Operative Risk Evaluation score (MECC 3.0%, ECC 3.5%, OPCABG 3.2%) were similar among the groups, but in-hospital mortality for elective and urgent/emergent patients was lower in the MECC and OPCABG groups (MECC 3.2%, OPCABG 3.7%, ECC 6.9%; p < 0.05). The number of distal anastomoses was lowest in the OPCABG group, but comparable for MECC and ECC patients. Postoperative ventilation time, release of creatinine kinase, catecholamine therapy, drainage loss, and transfusion requirements were lower in the MECC and OPCABG groups, whereas stay in the intensive care unit was shorter only in the latter (p < 0.05). Conclusions: Minimal extracorporeal circulation is an easy and safe procedure for coronary artery bypass graft surgery. In selected patients, the advantages of MECC equal those of OPCABG. MECC should be considered as an alternative to OPCABG and standard ECC procedures. [Copyright &y& Elsevier]

In this case series, we describe our successful use of a reduced hirudin dosage as an anticoagulant during cardiac surgery using minimized extracorporeal circulation in patients with heparin-induced thrombocytopenia. [ABSTRACT FROM AUTHOR]