Aortic valve function post-replacement of severe aortic stenosis by transcatheter procedure versus surgery: a systematic review and metanalysis

Transcatheter aortic valve replacement (TAVR) has shown to reduce mortality compared to surgical aortic valve replacement (sAVR). However, it is unknown which procedure is associated with better post-procedural valvular function. We conducted a meta-analysis of randomized clinical trials that compared TAVR to sAVR for at least 2 years. The primary outcome was post-procedural patient-prosthesis-mismatch (PPM). Secondary outcomes were post-procedural and 2-year: effective orifice area (EOA), paravalvular gradient (PVG) and moderate/severe paravalvular leak (PVL). We identified 6 trials with a total of 7022 participants with severe aortic stenosis. TAVR was associated with 37% (95% CI [0.51–0.78) mean RR reduction of post-procedural PPM, a decrease that was not affected by the surgical risk at inclusion, neither by the transcatheter heart valve system. Postprocedural changes in gradient and EOA were also in favor of TAVR as there was a pooled mean difference decrease of 0.56 (95% CI [0.73–0.38]) in gradient and an increase of 0.47 (95% CI [0.38–0.56]) in EOA. Additionally, self-expandable valves were associated with a higher decrease in gradient than balloon ones (beta = 0.38; 95% CI [0.12–0.64]). However, TAVR was associated with a higher risk of moderate/severe PVL (pooled RR: 9.54, 95% CI [5.53–16.46]). All results were sustainable at 2 years

Association between air pollution and ventricular arrhythmias in high-risk patients (ARIA study): a multicentre longitudinal study

Summary Background Although the effects of air pollution on mortality have been clearly shown in many epidemiological and observational studies, the pro-arrhythmic effects remain unknown. We aimed to assess the short-term effects of air pollution on ventricular arrhythmias in a population of high-risk patients with implantable cardioverter-defibrillators (ICDs) or cardiac resynchronisation therapy defibrillators (ICD-CRT). Methods In this prospective multicentre study, we assessed 281 patients (median age 71 years) across nine centres in the Veneto region of Italy. Episodes of ventricular tachycardia and ventricular fibrillation that were recorded by the diagnostic device were considered in this analysis. Concentrations of particulate matter of less than 10 μm (PM 10 ) and less than 2·5 μm (PM 2·5 ) in aerodynamic diameter, carbon monoxide, nitrogen dioxide, sulphur dioxide, and ozone were obtained daily from monitoring stations, and the 24 h median value was considered. Each patient was associated with exposure data from the monitoring station that was closest to their residence. Patients were followed up for 1 year and then scheduled to have a closing visit, within 1 more year. This study is registered with ClinicalTrials.gov, number NCT01723761. Findings Participants were enrolled from April 1, 2011, to Sept 30, 2012, and follow-ups (completed on April 5, 2014) ranged from 637 to 1177 days (median 652 days). The incidence of episodes of ventricular tachycardia and ventricular fibrillation correlated significantly with PM 2·5 (p 10 . An analysis of ventricular fibrillation episodes alone showed a significant increase in risk of higher PM 2·5 (p=0·002) and PM 10 values (p=0·0057). None of the gaseous pollutants were significantly linked to the occurrence of ventricular tachycardia or ventricular fibrillation. In a subgroup analysis of patients with or without a previous myocardial infarction, only the first showed a significant association between particulate matter and episodes of ventricular tachycardia or ventricular fibrillation. Interpretation Particulate matter has acute pro-arrhythmic effects in a population of high-risk patients, which increase on exposure to fine particles and in patients who have experienced a previous myocardial infarction. The time sequence of the arrhythmic events suggests there is an underlying neurally mediated mechanism. From a clinical point of view, the results of our study should encourage physicians to also consider environmental risk when addressing the prevention of arrhythmic events, particularly in patients with coronary heart disease, advising them to avoid exposure to high levels of fine particulate matter. Funding There was no funding source for this study

Biophysical Behavior of Very High-Power Short-Duration Radiofrequency Ablation in Pulmonary Vein Isolation:Fast but Gently—Implications for a Successful Procedure

The very high-power short-duration (vHP-SD) ablation strategy is an alternative for pulmonary vein isolation (PVI) in patients with paroxysmal atrial fibrillation (PAF). However, the acute procedural biophysical behavior of successful lesion creation by means of this technique is still unexplored. We performed a retrospective case–control study aimed at evaluating the behavior of vHP-SD ablation parameters with the QDOT MICRO™ ablation catheter (Biosense Webster) compared with standard radiofrequency (RF) ablation with the THERMOCOOL SMARTTOUCH® ablation catheter. Twenty consecutive cases of symptomatic PAF treated with the QDOT MICRO™ ablation catheter from December 2022 to March 2023 were compared with cases treated with the standard technique. The acute procedural success of PVI was obtained in all cases with 2192 RF applications, and no adverse events occurred. Compared with the controls, vHP-SD cases featured a significant reduction in procedural time (47 ± 10 vs. 56 ± 12 min, p = 0.023), total RF time (3.8 [CI 3.4–4.6] vs. 21.2 [CI 18.4–24.9] min, p &lt; 0.001), ablation phase time (25 ± 5 vs. 39 ± 9 min, p &lt; 0.001), and irrigation volume (165 [CI 139–185] vs. 404 [CI 336–472] ml, p &lt; 0.001). In vHP-SD RF ablation, a contact force of 5 g minimum throughout the 4 s of RF application appeared to be statistically significant in terms of an impedance drop of at least 10 Ohm (OR 2.63 [CI 1.37; 5.07], p = 0.003). In contrast, in the control group, the impedance drop depended linearly on the contact force. This suggests a different biophysical behavior of vHP-SD ablation. A maximum temperature and minimum contact force of &gt;5 g independently predicted an effective impedance drop in vHP-SD. Increasing the contact force over 5 g during 4 s of vHP RF application might not be necessary to achieve a successful lesion.</p

Comparison of Three Methods for Distinguishing Glacier Zones Using Satellite SAR Data

Changes in glacier zones (e.g., firn, superimposed ice, ice) are good indicators of glacier response to climate change. There are few studies of glacier zone detection by SAR that are focused on more than one ice body and validated by terrestrial data. This study is unique in terms of the dataset collected&mdash;four C- and L-band quad-pol satellite SAR images, Ground Penetrating Radar data, shallow glacier cores&mdash;and the number of land ice bodies analyzed, namely, three tidewater glaciers in Svalbard and one ice cap in Iceland. The main aim is to assess how well popular methods of SAR analysis perform in distinguishing glacier zones, regardless of factors such as the morphologic differences of the ice bodies, or differences in SAR data. We test and validate three methods of glacier zone detection: (1) Gaussian Mixture Model&ndash;Expectation Maximization (GMM-EM) clustering of dual-pol backscattering coefficient (sigma0); (2) GMM-EM of quad-pol Pauli decomposition; and (3) quad-pol H/&alpha; Wishart segmentation. The main findings are that the unsupervised classification of both sigma0 and Pauli decomposition are promising methods for distinguishing glacier zones. The former performs better at detecting the firn zone on SAR images, and the latter in the superimposed ice zone. Additionally, C-band SAR data perform better than L-band at detecting firn, but the latter can potentially separate crevasses via the classification of sigma0 or Pauli decomposition. H/&alpha; Wishart segmentation resulted in inconsistent results across the tested cases and did not detect crevasses on L-band SAR data

Changes of glacier facies on Hornsund glaciers (Svalbard) during the decade 2007–2017

Changes in glacier facies (glacier zones), such as firn or superimposed ice (SI), are good indicators of glacier response to climate change. They are especially important for fast-warming Svalbard, where only a few glaciers are under glaciological mass balance monitoring. This paper presents a first study of changes of glacier facies extent for three tidewater glaciers located in southern Spitsbergen (Svalbard) and it is based on both satellite remote sensing and terrestrial data analysis, covering two time spans: 2007–2017 for Hansbreen and 2012–2017 for Storbreen and Hornbreen. Satellite remote sensing analysis include unsupervised classification of Synthetic Aperture Radar (SAR) data from both decommissioned (ENVISAT ASAR) and modern satellite missions (RADARSAT-2, Sentinel-1). The results of the SAR classification are compared to the information on glacier zones retrieved from terrestrial data, i.e. shallow cores and visual interpretation of 800 MHz Ground Penetrating Radar (GPR) profiles. In addition, a novel application of the Internal Reflection Power (IRP) coefficient as an objective method of distinguishing glacier zones based on GPR data is discussed. Changes in glacier facies areas over time are analysed, as well as their correlation to Hansbreen's mass balance. The main finding of the study is that firn and SI of Hansbreen, Storbreen and Hornbreen significantly decreased over the study period. For example, due to continuous negative mass balance between 2010 and 2017, the contribution of firn area to Hansbreen's total area decreased ca. 14% (cumulative firn area loss during that time: ~45%) whereas since 2012 SI has not been distinguished as a vast area on this glacier. In addition, an east–west gradient of firn area loss was observed as a result of differences in local climate conditions. Therefore, for the common time span (i.e. 2012–2017) Hansbreen recorded a ca. 12% loss of firn contribution to glacier area whereas Hornbreen recorded ca. 9%. Finally, application of the IRP coefficient as an objective method of glacier zones discrimination by GPR data gave very good results, so the method is recommended for future analysis of glacier zones instead, or as a support, to popular visual interpretation of the GPR profiles

Quality Assessment and Glaciological Applications of Digital Elevation Models Derived from Space-Borne and Aerial Images over Two Tidewater Glaciers of Southern Spitsbergen

In this study, we assess the accuracy and precision of digital elevation models (DEM) retrieved from aerial photographs taken in 2011 and from Very High Resolution satellite images (WorldView-2 and Pl&#233;iades) from the period 2012&#8722;2017. Additionally, the accuracy of the freely available Strip product of ArcticDEM was verified. We use the DEMs to characterize geometry changes over Hansbreen and Hornbreen, two tidewater glaciers in southern Spitsbergen, Svalbard. The satellite-based DEMs from WorldView-2 and Pl&#233;iades stereo pairs were processed using the Rational Function Model (RFM) without and with one ground control point. The elevation quality of the DEMs over glacierized areas was validated with in situ data: static differential GPS survey of mass balance stakes and GPS kinematic data acquired during ground penetrating radar survey. Results demonstrate the usefulness of the analyzed sources of DEMs for estimation of the total geodetic mass balance of the Svalbard glaciers. DEM accuracy is sufficient to investigate glacier surface elevation changes above 1 m. Strips from the ArcticDEM are generally precise, but some of them showed gross errors and need to be handled with caution. The surface of Hansbreen and Hornbreen has been lowering in recent years. The average annual elevation changes for Hansbreen were more negative in the period 2015&#8722;2017 (&#8722;2.4 m a&#8722;1) than in the period 2011&#8722;2015 (&#8722;1.7 m a&#8722;1). The average annual elevation changes over the studied area of Hornbreen for the period 2012&#8722;2017 amounted to &#8722;1.6 m a&#8722;1. The geodetic mass balance for Hansbreen was more negative than the climatic mass balance estimated using the mass budget method, probably due to underestimation of the ice discharge. From 2011 to 2017, Hansbreen lost on average over 1% of its volume each year. Such a high rate of relative loss illustrates how fast these glaciers are responding to climate change

Association between air pollution and ventricular arrhythmias in high-risk patients (ARIA study): a multicentre longitudinal study

Background Although the effects of air pollution on mortality have been clearly shown in many epidemiological and observational studies, the pro-arrhythmic effects remain unknown. We aimed to assess the short-term effects of air pollution on ventricular arrhythmias in a population of high-risk patients with implantable cardioverter-defibrillators (ICDs) or cardiac resynchronisation therapy defibrillators (ICD-CRT). Methods In this prospective multicentre study, we assessed 281 patients (median age 71 years) across nine centres in the Veneto region of Italy. Episodes of ventricular tachycardia and ventricular fibrillation that were recorded by the diagnostic device were considered in this analysis. Concentrations of particulate matter of less than 10 \u3bcm (PM10) and less than 2\ub75 \u3bcm (PM2\ub75) in aerodynamic diameter, carbon monoxide, nitrogen dioxide, sulphur dioxide, and ozone were obtained daily from monitoring stations, and the 24 h median value was considered. Each patient was associated with exposure data from the monitoring station that was closest to their residence. Patients were followed up for 1 year and then scheduled to have a closing visit, within 1 more year. This study is registered with ClinicalTrials.gov, number NCT01723761. Findings Participants were enrolled from April 1, 2011, to Sept 30, 2012, and follow-ups (completed on April 5, 2014) ranged from 637 to 1177 days (median 652 days). The incidence of episodes of ventricular tachycardia and ventricular fibrillation correlated significantly with PM2\ub75 (p<0\ub70001) but not PM10. An analysis of ventricular fibrillation episodes alone showed a significant increase in risk of higher PM2\ub75 (p=0\ub7002) and PM10 values (p=0\ub70057). None of the gaseous pollutants were significantly linked to the occurrence of ventricular tachycardia or ventricular fibrillation. In a subgroup analysis of patients with or without a previous myocardial infarction, only the first showed a significant association between particulate matter and episodes of ventricular tachycardia or ventricular fibrillation. Interpretation Particulate matter has acute pro-arrhythmic effects in a population of high-risk patients, which increase on exposure to fine particles and in patients who have experienced a previous myocardial infarction. The time sequence of the arrhythmic events suggests there is an underlying neurally mediated mechanism. From a clinical point of view, the results of our study should encourage physicians to also consider environmental risk when addressing the prevention of arrhythmic events, particularly in patients with coronary heart disease, advising them to avoid exposure to high levels of fine particulate matter. Funding There was no funding source for this study. \ua9 2017 The Author(s). Published by Elsevier Ltd. This is an Open Access article under the CC BY-NC-ND 4.0 licens