Transcatheter aortic valve implantation and bleeding: incidence, predictors and prognosis

Peri-procedural bleeding complications are feared adverse events in patients undergoing transcatheter aortic valve implantation (TAVI). Little is known about the implications of peri-procedural bleeding on clinical outcome. In a prospective single-center registry of consecutive patients undergoing TAVI, we investigated incidence, predictors and clinical consequences of life-threatening and major bleeding as defined by the Valve Academic Research Consortium. Among 389 consecutive patients undergoing TAVI by a transfemoral (79.2%), transapical (19.6%) or trans-subclavian (1.3%) approach between July 2007 and October 2011, life-threatening or major peri-procedural bleeding events occurred in 64 (16.4%) and 125 patients (32.1%), respectively. Patients with peri-procedural bleeding events had a higher logistic EuroSCORE, more advanced renal disease, and were more symptomatic as assessed by New York Heart Association functional class at baseline as compared to patients with no bleeding. Life-threatening bleeding was associated with a higher all-cause (17.2 vs. 5.6 vs. 3.0%, p < 0.001) and cardiovascular mortality (10.9 vs. 5.6 vs. 2.5%, p = 0.02) at 30 days compared to patients with major bleeding or no bleeding. Multivariate analysis identified transapical access (OR 2.6, 95% CI 1.4-4.8; p = 0.002), glomerular filtration rate <30 ml/min (OR 2.3, 95% CI 1.1-4.7, p = 0.031), and diabetes (OR 1.8, 95% CI 1.001-3.2, p = 0.049) as independent predictors of life-threatening, peri-procedural bleeding. Life-threatening bleeding complications in patients undergoing TAVI are associated with increased mortality. Renal impairment, diabetes, and transapical approach were identified as independent risk factors for life-threatening bleeding events.

Clinical and intravascular imaging outcomes at 1 and 2 years after implantation of absorb everolimus eluting bioresorbable vascular scaffolds in small vessels. Late lumen enlargement: does bioresorption matter with small vessel size? Insight from the ABSORB cohort B trial

BACKGROUND The long-term results after second generation everolimus eluting bioresorbable vascular scaffold (Absorb BVS) placement in small vessels are unknown. Therefore, we investigated the impact of vessel size on long-term outcomes, after Absorb BVS implantation. METHODS In ABSORB Cohort B Trial, out of the total study population (101 patients), 45 patients were assigned to undergo 6-month and 2-year angiographic follow-up (Cohort B1) and 56 patients to have angiographic follow-up at 1-year (Cohort B2). The pre-reference vessel diameter (RVD) was <2.5 mm (small-vessel group) in 41 patients (41 lesions) and ≥2.5 mm (large-vessel group) in 60 patients (61 lesions). Outcomes were compared according to pre-RVD. RESULTS At 2-year angiographic follow-up no differences in late lumen loss (0.29±0.16 mm vs 0.25±0.22 mm, p=0.4391), and in-segment binary restenosis (5.3% vs 5.3% p=1.0000) were demonstrated between groups. In the small-vessel group, intravascular ultrasound analysis showed a significant increase in vessel area (12.25±3.47 mm(2) vs 13.09±3.38 mm(2) p=0.0015), scaffold area (5.76±0.96 mm(2) vs 6.41±1.30 mm(2) p=0.0008) and lumen area (5.71±0.98 mm(2) vs 6.20±1.27 mm(2) p=0.0155) between 6-months and 2-year follow-up. No differences in plaque composition were reported between groups at either time point. At 2-year clinical follow-up, no differences in ischaemia-driven major adverse cardiac events (7.3% vs 10.2%, p=0.7335), myocardial infarction (4.9% vs 1.7%, p=0.5662) or ischaemia-driven target lesion revascularisation (2.4% vs 8.5%, p=0.3962) were reported between small and large vessels. No deaths or scaffold thrombosis were observed. CONCLUSIONS Similar clinical and angiographic outcomes at 2-year follow-up were reported in small and large vessel groups. A significant late lumen enlargement and positive vessel remodelling were observed in small vessels.

Updated standardized endpoint definitions for transcatheter aortic valve implantation: the Valve Academic Research Consortium-2 consensus document

OBJECTIVES The aim of the current Valve Academic Research Consortium (VARC)-2 initiative was to revisit the selection and definitions of transcatheter aortic valve implantation (TAVI) clinical endpoints to make them more suitable to the present and future needs of clinical trials. In addition, this document is intended to expand the understanding of patient risk stratification and case selection. BACKGROUND A recent study confirmed that VARC definitions have already been incorporated into clinical and research practice and represent a new standard for consistency in reporting clinical outcomes of patients with symptomatic severe aortic stenosis (AS) undergoing TAVI. However, as the clinical experience with this technology has matured and expanded, certain definitions have become unsuitable or ambiguous. METHODS AND RESULTS Two in-person meetings (held in September 2011 in Washington, DC, and in February 2012 in Rotterdam, The Netherlands) involving VARC study group members, independent experts (including surgeons, interventional and noninterventional cardiologists, imaging specialists, neurologists, geriatric specialists, and clinical trialists), the US Food and Drug Administration (FDA), and industry representatives, provided much of the substantive discussion from which this VARC-2 consensus manuscript was derived. This document provides an overview of risk assessment and patient stratification that need to be considered for accurate patient inclusion in studies. Working groups were assigned to define the following clinical endpoints: mortality, stroke, myocardial infarction, bleeding complications, acute kidney injury, vascular complications, conduction disturbances and arrhythmias, and a miscellaneous category including relevant complications not previously categorized. Furthermore, comprehensive echocardiographic recommendations are provided for the evaluation of prosthetic valve (dys)function. Definitions for the quality of life assessments are also reported. These endpoints formed the basis for several recommended composite endpoints. CONCLUSIONS This VARC-2 document has provided further standardization of endpoint definitions for studies evaluating the use of TAVI, which will lead to improved comparability and interpretability of the study results, supplying an increasingly growing body of evidence with respect to TAVI and/or surgical aortic valve replacement. This initiative and document can furthermore be used as a model during current endeavors of applying definitions to other transcatheter valve therapies (for example, mitral valve repair).

Clinical outcomes of patients with low-flow, low-gradient, severe aortic stenosis and either preserved or reduced ejection fraction undergoing transcatheter aortic valve implantation

AIMS Our aim was to evaluate the invasive haemodynamic indices of high-risk symptomatic patients presenting with 'paradoxical' low-flow, low-gradient, severe aortic stenosis (AS) (PLF-LG) and low-flow, low-gradient severe AS (LEF-LG) and to compare clinical outcomes following transcatheter aortic valve implantation (TAVI) among these challenging AS subgroups. METHODS AND RESULTS Of 534 symptomatic patients undergoing TAVI, 385 had a full pre-procedural right and left heart catheterization. A total of 208 patients had high-gradient severe AS [HGAS; mean gradient (MG) ≥40 mmHg], 85 had PLF-LG [MG ≤ 40 mmHg, indexed aortic valve area [iAVA] ≤0.6 cm(2) m(-2), stroke volume index ≤35 mL/m(2), ejection fraction (EF) ≥50%], and 61 had LEF-LG (MG ≤ 40 mmHg, iAVA ≤0.6 cm(2) m(-2), EF ≤40%). Compared with HGAS, PLF-LG and LEF-LG had higher systemic vascular resistances (HGAS: 1912 ± 654 vs. PLF-LG 2006 ± 586 vs. LEF-LG 2216 ± 765 dyne s m(-5), P = 0.007) but lower valvulo-arterial impedances (HGAS: 7.8 ± 2.7 vs. PLF-LG 6.9 ± 1.9 vs. LEF-LG 7.7 ± 2.5 mmHg mL(-1) m(-2), P = 0.027). At 30 days, no differences in cardiac death (6.5 vs. 4.9 vs. 6.6%, P = 0.90) or death (8.4 vs. 6.1 vs. 6.6%, P = 0.88) were observed among HGAS, PLF-LG, and LEF-LG groups, respectively. At 1 year, New York Heart Association functional improvement occurred in most surviving patients (HGAS: 69.2% vs. PLF-LG 71.7% vs. LEF-LG 89.3%, P = 0.09) and no significant differences in overall mortality were observed (17.6 vs. 20.5 vs. 24.5%, P = 0.67). Compared with HGAS, LEF-LG had a higher 1 year cardiac mortality (adjusted hazard ratio 2.45, 95% confidence interval 1.04-5.75, P = 0.04). CONCLUSION TAVI in PLF-LG or LEF-LG patients is associated with overall mortality rates comparable with HGAS patients and all groups profit symptomatically to a similar extent.

Transcatheter aortic valve implantation: patient selection

Transcatheter aortic valve implantation (TAVI) is a disruptive technology as it satisfies a previously unmet need which is associated with a profound therapeutic benefit. In randomized clinical trials, TAVI has been shown to improve survival compared with medical treatment among patients considered not suitable candidates for surgical aortic valve replacement (SAVR), and to provide similar outcomes as SAVR in selected high-risk patients. Currently, TAVI is limited to selected elderly patients with symptomatic severe aortic stenosis. As this patient population frequently suffers from comorbid conditions, which may influence outcomes, the selection of patients to undergo TAVI underlies a complex decision process. Several clinical risk score algorithms are routinely used, although they fall short to fully appreciate the true risk among patients currently referred for TAVI. Beyond traditional risk scores, the clinical assessment by an interdisciplinary Heart Team as well as detailed imaging of the aortic valve, aortic root, descending and abdominal aorta as well as peripheral vasculature are important prerequisites to plan a successful procedure. This review will familiarize the reader with the concepts of the interdisciplinary Heart team, risk scores as well as the most important imaging algorithms suited to select appropriate TAVI patients.

Transcatheter aortic valve implantation: the transfemoral access route is the default access

Transcatheter aortic valve implantation (TAVI) is a widely accepted alternative to surgical aortic valve replacement (SAVR) among non-operable patients or selected high-risk patients with degenerative, severe aortic stenosis. TAVI is considered less invasive when compared with SAVR; however, there remain significant differences between different TAVI access routes. The transfemoral approach is considered the least invasive access route, and can be performed as a fully percutaneous procedure in a spontaneously breathing patient under local anaesthesia and mild sedation only. Moreover, transfemoral TAVI patients are typically transferred to coronary care rather than to an intensive care unit after the procedure, and benefit from early ambulation and a reduction in overall length of hospital stay. Considering these patient-specific and health-economic advantages, several TAVI centres follow the least invasive strategy for their patients and have implemented the transfemoral access route as the default access in their institutions. This article provides an overview on the prerequisites for a successful transfemoral TAVI procedure, describes the procedural advantages compared to alternative access routes, and highlights differences in clinical outcomes.

Integration of merged delayed-enhanced magnetic resonance imaging and multidetector computed tomography for the guidance of ventricular tachycardia ablation: a pilot study

BACKGROUND Delayed enhancement (DE) MRI can assess the fibrotic substrate of scar-related VT. MDCT has the advantage of inframillimetric spatial resolution and better 3D reconstructions. We sought to evaluate the feasibility and usefulness of integrating merged MDCT/MRI data in 3D-mapping systems for structure-function assessment and multimodal guidance of VT mapping and ablation. METHODS Nine patients, including 3 ischemic cardiomyopathy (ICM), 3 nonischemic cardiomyopathy (NICM), 2 myocarditis, and 1 redo procedure for idiopathic VT, underwent MRI and MDCT before VT ablation. Merged MRI/MDCT data were integrated in 3D-mapping systems and registered to high-density endocardial and epicardial maps. Low-voltage areas (<1.5 mV) and local abnormal ventricular activities (LAVA) during sinus rhythm were correlated to DE at MRI, and wall-thinning (WT) at MDCT. RESULTS Endocardium and epicardium were mapped with 391 ± 388 and 1098 ± 734 points per map, respectively. Registration of MDCT allowed visualization of coronary arteries during epicardial mapping/ablation. In the idiopathic patient, integration of MRI data identified previously ablated regions. In ICM patients, both DE at MRI and WT at MDCT matched areas of low voltage (overlap 94 ± 6% and 79 ± 5%, respectively). In NICM patients, wall-thinning areas matched areas of low voltage (overlap 63 ± 21%). In patients with myocarditis, subepicardial DE matched areas of epicardial low voltage (overlap 92 ± 12%). A total number of 266 LAVA sites were found in 7/9 patients. All LAVA sites were associated to structural substrate at imaging (90% inside, 100% within 18 mm). CONCLUSION The integration of merged MDCT and DEMRI data is feasible and allows combining substrate assessment with high-spatial resolution to better define structure-function relationship in scar-related VT.

Time courses and quantitative analysis of atrial fibrillation episode number and duration after circular plus linear left atrial lesions: trigger elimination or substrate modification: early or delayed cure?

OBJECTIVES We sought to analyze the time course of atrial fibrillation (AF) episodes before and after circular plus linear left atrial ablation and the percentage of patients with complete freedom from AF after ablation by using serial seven-day electrocardiograms (ECGs). BACKGROUND The curative treatment of AF targets the pathophysiological corner stones of AF (i.e., the initiating triggers and/or the perpetuation of AF). The pathophysiological complexity of both may not result in an "all-or-nothing" response but may modify number and duration of AF episodes. METHODS In patients with highly symptomatic AF, circular plus linear ablation lesions were placed around the left and right pulmonary veins, between the two circles, and from the left circle to the mitral annulus using the electroanatomic mapping system. Repetitive continuous 7-day ECGs administered before and after catheter ablation were used for rhythm follow-up. RESULTS In 100 patients with paroxysmal (n = 80) and persistent (n = 20) AF, relative duration of time spent in AF significantly decreased over time (35 +/- 37% before ablation, 26 +/- 41% directly after ablation, and 10 +/- 22% after 12 months). Freedom from AF stepwise increased in patients with paroxysmal AF and after 12 months measured at 88% or 74% depending on whether 24-h ECG or 7-day ECG was used. Complete pulmonary vein isolation was demonstrated in <20% of the circular lesions. CONCLUSIONS The results obtained in patients with AF treated with circular plus linear left atrial lesions strongly indicate that substrate modification is the main underlying pathophysiologic mechanism and that it results in a delayed cure instead of an immediate cure.

Natural history of optical coherence tomography-detected non-flow-limiting edge dissections following drug-eluting stent implantation

Aims: Angiographic evidence of edge dissections has been associated with a risk of early stent thrombosis. Optical coherence tomography (OCT) is a high-resolution technology detecting a greater number of edge dissections -particularly non-flow-limiting- compared to angiography. Their natural history and clinical implications remain unclear. The objectives of the present study were to assess the morphology, healing response, and clinical outcomes of OCT-detected edge dissections using serial OCT imaging at baseline and at one year following drug-eluting stent (DES) implantation. Methods and results: Edge dissections were defined as disruptions of the luminal surface in the 5 mm segments proximal and distal to the stent, and categorised as flaps, cavities, double-lumen dissections or fissures. Qualitative and quantitative OCT analyses were performed every 0.5 mm at baseline and one year, and clinical outcomes were assessed. Sixty-three lesions (57 patients) were studied with OCT at baseline and one-year follow-up. Twenty-two non-flow-limiting edge dissections in 21 lesions (20 patients) were identified by OCT; only two (9%) were angiographically visible. Flaps were found in 96% of cases. The median longitudinal dissection length was 2.9 mm (interquartile range [IQR] 1.6-4.2 mm), whereas the circumferential and axial extensions amounted to 1.2 mm (IQR: 0.9-1.7 mm) and 0.6 mm (IQR: 0.4-0.7 mm), respectively. Dissections extended into the media and adventitia in seven (33%) and four (20%) cases, respectively. Eighteen (82%) OCT-detected edge dissections were also evaluated with intravascular ultrasound which identified nine (50%) of these OCT-detected dissections. No stent thrombosis or target lesion revascularisation occurred up to one year. At follow-up, 20 (90%) edge dissections were completely healed on OCT. The two cases exhibiting persistent dissection had the longest flaps (2.81 mm and 2.42 mm) at baseline. Conclusions: OCT-detected edge dissections which are angiographically silent in the majority of cases are not associated with acute stent thrombosis or restenosis up to one-year follow-up.

Tissue coverage and neointimal hyperplasia in overlap versus nonoverlap segments of drug-eluting stents 9 to 13 months after implantation: in vivo assessment with optical coherence tomography

BACKGROUND Histologic experimental studies have reported incomplete neointimal healing in overlapping with respect to nonoverlapping segments in drug-eluting stents (DESs), but these observations have not been confirmed in human coronary arteries hitherto. On the contrary, angiographic and optical coherence tomography studies suggest that DES overlap elicits rather an exaggerated than an incomplete neointimal reaction. METHODS Optical coherence tomography studies from 2 randomized trials including sirolimus-eluting, biolimus-eluting, everolimus-eluting, and zotarolimus-eluting stents were analyzed at 9- to 13-month follow-up. Coverage in overlapping segments was compared versus the corresponding nonoverlapping segments of the same stents, using statistical pooled analysis. RESULTS Forty-two overlaps were found in 31 patients: 11 in sirolimus-eluting stents, 3 in biolimus-eluting stents, 17 in everolimus-eluting stents, and 11 in zotarolimus-eluting stents. The risk ratio of incomplete coverage was 2.35 (95% CI 1.86-2.98) in overlapping versus nonoverlapping segments. Thickness of coverage in overlaps was only 85% (95% CI 81%-90%) of the thickness in nonoverlaps. Significant heterogeneity of the effect was observed, especially pronounced in the comparison of thickness of coverage (I(2) = 90.31). CONCLUSIONS The effect of overlapping DES on neointimal inhibition is markedly heterogeneous: on average, DES overlap is associated with more incomplete and thinner coverage, but in some cases, the overlap elicits an exaggerated neointimal reaction, thicker than in the corresponding nonoverlapping segments. These results might help to understand why overlapping DES is associated with worse clinical outcomes, both in terms of thrombotic phenomena and in terms of restenosis and revascularization.

Neoatherosclerosis as reason for stent failures beyond 5 years after drug-eluting stent implantation

A 69-year-old male (case 1) was admitted due to acute non-ST-segment elevation myocardial infarction (NSTEMI). Eight years earlier, he had previously undergone treatment with a sirolimus-eluting stent (SES). Four years after stent implantation, a follow-up angiography was obtained showing a patent stent without obstructive in-stent restenosis (Panel A). Angiograms obtained at the time of NSTEMI (Panel B) disclosed subtotal occlusion in the middle of the SES (arrowheads). Optical coherence tomography revealed a signal intense luminal layer with an underlying, highly attenuating, diffusely demarcated area, suggestive for an instent fibroatheroma (Panel D) with a minimal cap thickness of 80 µm. Accordingly, ischaemia was caused by the high degree of stenosis (Panel E). Similarly, a 59-year-old male (case 2) was admitted due to STEMI. Nine years before, he had received a paclitaxel-eluting stent (PES). Five years after stent implantation, a follow-up angiography revealed a patent stent (Panel F). Angiograms obtained at the time of STEMI (Panel G) disclosed total occlusion in the proximal of PES (arrowheads). Optical coherence tomography showed a rupture of thin cap fibroatheroma within the stented segment (Panel I). The thin cap fibroatheroma caused a severe stenosis with superimposed thrombus (Panel J). Neoatherosclerosis has been recently described as particular disease entity being responsible for very late stent failures. These two cases illustrate that the presence of a favourable long-term angiographic result years after DES implantation does not exclude a future neoatherosclerosis-related event (restenosis or stent thrombosis). Large observational and long-term intracoronary imaging studies are required to fully elucidate the dynamics and clinical relevance of neoatherosclerosis.

Cochlear implantation in children and adults in Switzerland

The cochlear implant (CI) is one of the most successful neural prostheses developed to date. It offers artificial hearing to individuals with profound sensorineural hearing loss and with insufficient benefit from conventional hearing aids. The first implants available some 30 years ago provided a limited sensation of sound. The benefit for users of these early systems was mostly a facilitation of lip-reading based communication rather than an understanding of speech. Considerable progress has been made since then. Modern, multichannel implant systems feature complex speech processing strategies, high stimulation rates and multiple sites of stimulation in the cochlea. Equipped with such a state-of-the-art system, the majority of recipients today can communicate orally without visual cues and can even use the telephone. The impact of CIs on deaf individuals and on the deaf community has thus been exceptional. To date, more than 300,000 patients worldwide have received CIs. In Switzerland, the first implantation was performed in 1977 and, as of 2012, over 2,000 systems have been implanted with a current rate of around 150 CIs per year. The primary purpose of this article is to provide a contemporary overview of cochlear implantation, emphasising the situation in Switzerland.

A bone-thickness map as a guide for bone-anchored port implantation surgery in the temporal bone

The bone-anchored port (BAP) is an investigational implant, which is intended to be fixed on the temporal bone and provide vascular access. There are a number of implants taking advantage of the stability and available room in the temporal bone. These devices range from implantable hearing aids to percutaneous ports. During temporal bone surgery, injuring critical anatomical structures must be avoided. Several methods for computer-assisted temporal bone surgery are reported, which typically add an additional procedure for the patient. We propose a surgical guide in the form of a bone-thickness map displaying anatomical landmarks that can be used for planning of the surgery, and for the intra-operative decision of the implant’s location. The retro-auricular region of the temporal and parietal bone was marked on cone-beam computed tomography scans and tridimensional surfaces displaying the bone thickness were created from this space. We compared this method using a thickness map (n = 10) with conventional surgery without assistance (n = 5) in isolated human anatomical whole head specimens. The use of the thickness map reduced the rate of Dura Mater exposition from 100% to 20% and OPEN ACCESS Materials 2013, 6 5292 suppressed sigmoid sinus exposures. The study shows that a bone-thickness map can be used as a low-complexity method to improve patient’s safety during BAP surgery in the temporal bone.