14 research outputs found

    The Ultraviolet Imaging Telescope: Instrument and Data Characteristics

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    The Ultraviolet Imaging Telescope (UIT) was flown as part of the Astro observatory on the Space Shuttle Columbia in December 1990 and again on the Space Shuttle Endeavor in March 1995. Ultraviolet (1200-3300 Angstroms) images of a variety of astronomical objects, with a 40 arcmin field of view and a resolution of about 3 arcsec, were recorded on photographic film. The data recorded during the first flight are available to the astronomical community through the National Space Science Data Center (NSSDC); the data recorded during the second flight will soon be available as well. This paper discusses in detail the design, operation, data reduction, and calibration of UIT, providing the user of the data with information for understanding and using the data. It also provides guidelines for analyzing other astronomical imagery made with image intensifiers and photographic film.Comment: 44 pages, LaTeX, AAS preprint style and EPSF macros, accepted by PAS

    Two-year outcomes after transcatheter or surgical aortic-valve replacement.

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    BACKGROUND: The Placement of Aortic Transcatheter Valves (PARTNER) trial showed that among high-risk patients with aortic stenosis, the 1-year survival rates are similar with transcatheter aortic-valve replacement (TAVR) and surgical replacement. However, longer-term follow-up is necessary to determine whether TAVR has prolonged benefits. METHODS: At 25 centers, we randomly assigned 699 high-risk patients with severe aortic stenosis to undergo either surgical aortic-valve replacement or TAVR. All patients were followed for at least 2 years, with assessment of clinical outcomes and echocardiographic evaluation. RESULTS: The rates of death from any cause were similar in the TAVR and surgery groups (hazard ratio with TAVR, 0.90; 95% confidence interval [CI], 0.71 to 1.15; P=0.41) and at 2 years (Kaplan-Meier analysis) were 33.9% in the TAVR group and 35.0% in the surgery group (P=0.78). The frequency of all strokes during follow-up did not differ significantly between the two groups (hazard ratio, 1.22; 95% CI, 0.67 to 2.23; P=0.52). At 30 days, strokes were more frequent with TAVR than with surgical replacement (4.6% vs. 2.4%, P=0.12); subsequently, there were 8 additional strokes in the TAVR group and 12 in the surgery group. Improvement in valve areas was similar with TAVR and surgical replacement and was maintained for 2 years. Paravalvular regurgitation was more frequent after TAVR (P<0.001), and even mild paravalvular regurgitation was associated with increased late mortality (P<0.001). CONCLUSIONS: A 2-year follow-up of patients in the PARTNER trial supports TAVR as an alternative to surgery in high-risk patients. The two treatments were similar with respect to mortality, reduction in symptoms, and improved valve hemodynamics, but paravalvular regurgitation was more frequent after TAVR and was associated with increased late mortality. (Funded by Edwards Lifesciences; ClinicalTrials.gov number, NCT00530894.)

    Transcatheter or surgical aortic-valve replacement in intermediate-risk patients

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    BACKGROUND: Previous trials have shown that among high-risk patients with aortic stenosis, survival rates are similar with transcatheter aortic-valve replacement (TAVR) and surgical aorticvalve replacement. We evaluated the two procedures in a randomized trial involving intermediate-risk patients. METHODS: We randomly assigned 2032 intermediate-risk patients with severe aortic stenosis, at 57 centers, to undergo either TAVR or surgical replacement. The primary end point was death from any cause or disabling stroke at 2 years. The primary hypothesis was that TAVR would not be inferior to surgical replacement. Before randomization, patients were entered into one of two cohorts on the basis of clinical and imaging findings; 76.3% of the patients were included in the transfemoral-access cohort and 23.7% in the transthoracic-access cohort. RESULTS: The rate of death from any cause or disabling stroke was similar in the TAVR group and the surgery group (P=0.001 for noninferiority). At 2 years, the Kaplan–Meier event rates were 19.3% in the TAVR group and 21.1% in the surgery group (hazard ratio in the TAVR group, 0.89; 95% confidence interval [CI], 0.73 to 1.09; P=0.25). In the transfemoralaccess cohort, TAVR resulted in a lower rate of death or disabling stroke than surgery (hazard ratio, 0.79; 95% CI, 0.62 to 1.00; P=0.05), whereas in the transthoracic-access cohort, outcomes were similar in the two groups. TAVR resulted in larger aortic-valve areas than did surgery and also resulted in lower rates of acute kidney injury, severe bleeding, and new-onset atrial fibrillation; surgery resulted in fewer major vascular complications and less paravalvular aortic regurgitation. CONCLUSIONS: In intermediate-risk patients, TAVR was similar to surgical aortic-valve replacement with respect to the primary end point of death or disabling stroke. (Funded by Edwards Lifesciences; PARTNER 2 ClinicalTrials.gov number, NCT01314313

    One-year clinical outcomes with SAPIEN 3 transcatheter aortic valve replacement in high-risk and inoperable patients with severe aortic stenosis

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    Background: In the initial PARTNER trial (Placement of Aortic Transcatheter Valves) of transcatheter aortic valve replacement for high-risk (HR) and inoperable patients, mortality at 1 year was 24% in HR and 31% in inoperable patients. A recent report of the 30-day outcomes with the low-profile SAPIEN 3 transcatheter aortic valve replacement system demonstrated very low rates of adverse events, but little is known about the longer-term outcomes with this device. Methods: Between October 2013 and September 2014, 583 HR (65%) or inoperable (35%) patients were treated via the transfemoral (84%) or transapical/transaortic (16%) access route at 29 US sites. Major clinical events at 1 year were adjudicated by an independent clinical events committee, and echocardiographic results were analyzed by a core laboratory. Results: Baseline characteristics included age of 83 years, 42% female, and median Society of Thoracic Surgeons score of 8.4%. At the 1-year follow-up, survival (all-cause) was 85.6% for all patients, 87.3% in the HR subgroup, and 82.3% in the inoperable subgroup. Survival free of all-cause and cardiovascular mortality in the transfemoral patients from the HR cohort was 87.7% and 93.3%, respectively. There was no severe paravalvular leak. Moderate paravalvular leak (2.7%) was associated with an increase in mortality at 1 year, whereas mild paravalvular leak had no significant association with mortality. Symptomatic improvement as assessed by the percentage of patients in New York Heart Association class III and IV (90.1% to 7.7% at 1 year; P<0.0001) and by Kansas City Cardiomyopathy Questionnaire overall summary score (improved from 46.9 to 72.4; P<0.0001) was marked. Multivariable predictors of 1-year mortality included alternative access, Society of Thoracic Surgeons score, and disabling stroke. Conclusions: In this large, adjudicated registry of SAPIEN 3 HR and inoperable patients, the very low rates of important complications resulted in a strikingly low mortality rate at 1 year. Between 30 and 365 days, the incidence of moderate paravalvular aortic regurgitation did not increase, and no association between mild paravalvular leak and 1-year mortality was observed, although a small increase in disabling stroke occurred. These results, which likely reflect device iteration and procedural evolution, support the use of transcatheter aortic valve replacement as the preferred therapy in HR and inoperable patients with aortic stenosis

    Early clinical and echocardiographic outcomes after SAPIEN 3 transcatheter aortic valve replacement in inoperable, high-risk and intermediate-risk patients with aortic stenosis

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    Aims: Based on randomized trials using first-generation devices, transcatheter aortic valve replacement (TAVR) is well established in the treatment of high-risk (HR) patients with severe aortic stenosis (AS). To date, there is a paucity of adjudicated, prospective data evaluating outcomes with newer generation devices and in lower risk patients. We report early outcomes of a large, multicentre registry of inoperable, HR, and intermediate-risk (IR) patients undergoing treatment with the next-generation SAPIEN 3 transcatheter heart valve (THV). Methods and results: Patients with severe, symptomatic AS (583 high surgical risk or inoperable and 1078 IR) were enrolled in a multicentre, non-randomized registry at 57 sites in the USA and Canada. All patients received TAVR with the SAPIEN 3 system via transfemoral (n = 1443, 86.9%) and transapical or transaortic (n = 218, 13.1%) access routes. The rate of 30-day all-cause mortality was 2.2% in HR/inoperable patients [mean Society of Thoracic Surgeons (STS) score 8.7%] and 1.1% in IR patients (mean STS score 5.3%); cardiovascular mortality was 1.4 and 0.9%, respectively. In HR/inoperable patients, the 30-day rate of major/disabling stroke was 0.9%, major bleeding 14.0%, major vascular complications 5.1%, and requirement for permanent pacemaker 13.3%. In IR patients, the 30-day rate of major/disabling stroke was 1.0%, major bleeding 10.6%, major vascular complications 6.1%, and requirement for permanent pacemaker 10.1%. Mean overall Kansas City Cardiomyopathy Questionnaire score increased from 47.8 to 67.8 (HR/inoperable, P < 0.0001) and 54.7 to 74.0 (IR, P < 0.0001). Overall, paravalvular regurgitation at 30 days was none/trace in 55.9% of patients, mild in 40.7%, moderate in 3.4%, and severe in 0.0%. Mean gradients among patients with paired baseline and 30-day or discharge echocardiograms decreased from 45.8 mmHg at baseline to 11.4 mmHg at 30 days, while aortic valve area increased from 0.69 to 1.67 cm2. Conclusions: The SAPIEN 3 THV system was associated with low rates of 30-day mortality and major/disabling stroke as well as low rates of moderate or severe paravalvular regurgitation

    Five-Year Outcomes of Transcatheter or Surgical Aortic-Valve Replacement.

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    BACKGROUND: There are scant data on long-term clinical outcomes and bioprosthetic-valve function after transcatheter aortic-valve replacement (TAVR) as compared with surgical aortic-valve replacement in patients with severe aortic stenosis and intermediate surgical risk. METHODS: We enrolled 2032 intermediate-risk patients with severe, symptomatic aortic stenosis at 57 centers. Patients were stratified according to intended transfemoral or transthoracic access (76.3% and 23.7%, respectively) and were randomly assigned to undergo either TAVR or surgical replacement. Clinical, echocardiographic, and health-status outcomes were followed for 5 years. The primary end point was death from any cause or disabling stroke. RESULTS: At 5 years, there was no significant difference in the incidence of death from any cause or disabling stroke between the TAVR group and the surgery group (47.9% and 43.4%, respectively; hazard ratio, 1.09; 95% confidence interval [CI], 0.95 to 1.25; P = 0.21). Results were similar for the transfemoral-access cohort (44.5% and 42.0%, respectively; hazard ratio, 1.02; 95% CI, 0.87 to 1.20), but the incidence of death or disabling stroke was higher after TAVR than after surgery in the transthoracic-access cohort (59.3% vs. 48.3%; hazard ratio, 1.32; 95% CI, 1.02 to 1.71). At 5 years, more patients in the TAVR group than in the surgery group had at least mild paravalvular aortic regurgitation (33.3% vs. 6.3%). Repeat hospitalizations were more frequent after TAVR than after surgery (33.3% vs. 25.2%), as were aortic-valve reinterventions (3.2% vs. 0.8%). Improvement in health status at 5 years was similar for TAVR and surgery. CONCLUSIONS: Among patients with aortic stenosis who were at intermediate surgical risk, there was no significant difference in the incidence of death or disabling stroke at 5 years after TAVR as compared with surgical aortic-valve replacement. (Funded by Edwards Lifesciences; PARTNER 2 ClinicalTrials.gov number, NCT01314313.)

    Transcathter aortic valve replacement versus surgical valve replacement in intermediate-risk patients : a propensity score analysis

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    Background: Transcatheter aortic valve replacement (TAVR) with the SAPIEN 3 valve demonstrates good 30 day clinical outcomes in patients with severe aortic stenosis who are at intermediate risk of surgical mortality. Here we report longer-term data in intermediate-risk patients given SAPIEN 3 TAVR and compare outcomes to those of intermediaterisk patients given surgical aortic valve replacement. Methods: In the SAPIEN 3 observational study, 1077 intermediate-risk patients at 51 sites in the USA and Canada were assigned to receive TAVR with the SAPIEN 3 valve [952 [88%] via transfemoral access) between Feb 17, 2014, and Sept 3, 2014. In this population we assessed all-cause mortality and incidence of strokes, re-intervention, and aortic valve regurgitation at 1 year after implantation. Then we compared 1 year outcomes in this population with those for intermediate-risk patients treated with surgical valve replacement in the PARTNER 2A trial between Dec 23, 2011, and Nov 6, 2013, using a prespecifi ed propensity score analysis to account for between-trial diff erences in baseline characteristics. The clinical events committee and echocardiographic core laboratory methods were the same for both studies. The primary endpoint was the composite of death from any cause, all strokes, and incidence of moderate or severe aortic regurgitation. We did non-inferiority (margin 7·5%) and superiority analyses in propensity score quintiles to calculate pooled weighted proportion diff erences for outcomes. Findings: At 1 year follow-up of the SAPIEN 3 observational study, 79 of 1077 patients who initiated the TAVR procedure had died (all-cause mortality 7·4%; 6·5% in the transfemoral access subgroup), and disabling strokes had occurred in 24 (2%), aortic valve re-intervention in six (1%), and moderate or severe paravalvular regurgitation in 13 (2%). In the propensity-score analysis we included 963 patients treated with SAPIEN 3 TAVR and 747 with surgical valve replacement. For the primary composite endpoint of mortality, strokes, and moderate or severe aortic regurgitation, TAVR was both non-inferior (pooled weighted proportion diff erence of –9·2%; 90% CI –12·4 to –6; p<0·0001) and superior (–9·2%, 95% CI –13·0 to –5·4; p<0·0001) to surgical valve replacement. Interpretation: TAVR with SAPIEN 3 in intermediate-risk patients with severe aortic stenosis is associated with low mortality, strokes, and regurgitation at 1 year. The propensity score analysis indicates a signifi cant superiority for our composite outcome with TAVR compared with surgery, suggesting that TAVR might be the preferred treatment alternative in intermediate-risk patients
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