519 research outputs found
A comprehensive review of the PARTNER trial
ObjectivePercutaneous transcatheter aortic valve replacement was introduced in 2002, but its effectiveness remained to be assessed.MethodsA prospective, randomized trial (the Placement of Aortic Transcatheter Valves, or PARTNER) was designed with 2 arms: PARTNER A (n = 699) for high-risk surgical patients (Society of Thoracic Surgeons score >10%, surgeon assessed risk of mortality >15%) and PARTNER B (n = 358, patients inoperable by assessment of 2 surgeons). PARTNER A patients were divided into femoral artery access transcatheter aortic valve replacement or none (n = 207), and then randomized to open aortic valve replacement (n = 351) or device (n = 348). Inclusion criteria included valve area <0.8 cm2, gradient >40 mm Hg or peak >64 mm Hg, and survival >1 year. The end point of the study was 1-year mortality.ResultsThirty-day mortality for PARTNER A was 3.4% for transcatheter aortic valve replacement and 6.5% for aortic valve replacement; 1-year mortality was 24.2% and 26.8%, respectively (P = .001 for noninferiority). The respective prevalence of stroke was 3.8% and 2.1% (P = .2), although for all neurologic events, the difference between transcatheter aortic valve replacement and aortic valve replacement was significant (P = .04), including 4.6% for femoral artery access transcatheter aortic valve replacement versus 1.4% for open aortic valve replacement (P = .05). For PARTNER B—transcatheter aortic valve replacement versus medical treatment—30-day mortality was 5.0% versus 2.8% (P = .41), and at 1 year, mortality was 30.7% versus 50.7% (P < .001), respectively. Hospitalization cost of transcatheter aortic valve replacement for PARTNER B was 50,200 per year of life gained. Analysis of PARTNER A strokes showed that hazard with transcatheter aortic valve replacement peaked early, but thereafter remained constant in relation to aortic valve replacement. Two-year PARTNER A data showed paravalvular regurgitation was associated with increased mortality, even when mild (P < .001). Continued access to transapical transcatheter aortic valve replacement (n = 853) showed a mortality of 8.2% and decline in strokes to 2.0%. Of the 1801 Cleveland Clinic patients reviewed to December 2010, 214 (12%) underwent transcatheter aortic valve replacement with a mortality of 1%; in 2011, 105 underwent transcatheter aortic valve replacement: 34 transapical aortic valve replacement, with no deaths, and 71 femoral artery access aortic valve replacement with 1 death.ConclusionsThe PARTNER A and B trials showed that survival has been remarkably good, but stroke and perivalvular leakage require further device development
Outcomes of less invasive J-incision approach to aortic valve surgery
ObjectiveLess invasive approaches to aortic valve surgery are increasingly used; however, few studies have investigated their impact on outcome. We sought to compare clinical outcomes after these approaches with full sternotomy using propensity-matching methods.MethodsFrom January 1995 to January 2004, a total of 2689 patients underwent isolated aortic valve surgery, 1193 via upper J-hemisternotomy and 1496 via full sternotomy. Because of important differences in patient characteristics between these groups, a propensity score based on 42 variables was used to obtain 832 well-matched patient pairs (70% of possible cases).ResultsIn-hospital mortality was identical for propensity-matched patients, 0.96% (8 in each). Occurrences of stroke (P > .9), renal failure (P = .8), and myocardial infarction (P = .7) were similar. However, 24-hour mediastinal drainage was a third less after less invasive surgery (median, 250 vs 350 mL; P < .0001), and fewer patients received transfusions (24% vs 34%; P < .0001). More patients undergoing less invasive surgery were extubated in the operating room (12% vs 1.6%; P < .0001), postoperative forced 1-second expiratory volume was higher (P = .009), and fewer had respiratory failure (P = .01). Early after operation, pain scores were lower (P < .0001) after less-invasive surgery and postoperative length of stay shorter (P < .0001).ConclusionsWithin that portion of the spectrum of isolated aortic valve surgery where propensity matching was possible, minimally invasive aortic valve surgery had not only cosmetic advantages, but blood product use, respiratory, pain, and resource utilization advantages over full sternotomy, and no apparent detriments. Less invasive aortic valve surgery should be considered for most aortic valve operations
Structural barriers to comprehensive, coordinated HIV care: Geographic accessibility in the US South
Structural barriers to HIV care are particularly challenging in the US South, which has higher HIV diagnosis rates, poverty, uninsurance, HIV stigma, and rurality, and fewer comprehensive public health programs versus other US regions. Focusing on one structural barrier, we examined geographic accessibility to comprehensive, coordinated HIV care (HIVCCC) in the US South. We integrated publicly available data to study travel time to HIVCCC in 16 Southern states and District of Columbia. We geocoded HIVCCC service locations and estimated drive time between the population-weighted county centroid and closest HIVCCC facility. We evaluated drive time in aggregate, and by county-level HIV prevalence quintile, urbanicity, and race/ethnicity. Optimal drive time was ≤30 min, a common primary care accessibility threshold. We identified 228 service locations providing HIVCCC across 1422 Southern counties, with median drive time to care of 70 min (IQR 64 min). For 368 counties in the top HIV prevalence quintile, median drive time is 50 min (IQR 61 min), exceeding 60 min in over one-third of these counties. Among counties in the top HIV prevalence quintile, drive time to care is six-folder higher for rural versus super-urban counties. Counties in the top HIV prevalence quintiles for non-Hispanic Blacks and for Hispanics have >50% longer drive time to care versus for non-Hispanic Whites. Including another potential care source—publicly-funded health centers serving low-income populations— could double the number of high-HIV burden counties with drive time ≤30 min, representing nearly 35,000 additional people living with HIV with accessible HIVCCC. Geographic accessibility to HIVCCC is inadequate in the US South, even in high HIV burden areas, and geographic and racial/ethnic disparities exist. Structural factors, such as geographic accessibility to care, may drive disparities in health outcomes. Further research on programmatic policies, and evidence-based alternative HIV care delivery models improving access to care, is critical
Determination of the Jet Energy Scale at the Collider Detector at Fermilab
A precise determination of the energy scale of jets at the Collider Detector
at Fermilab at the Tevatron collider is described. Jets are used in
many analyses to estimate the energies of partons resulting from the underlying
physics process. Several correction factors are developed to estimate the
original parton energy from the observed jet energy in the calorimeter. The jet
energy response is compared between data and Monte Carlo simulation for various
physics processes, and systematic uncertainties on the jet energy scale are
determined. For jets with transverse momenta above 50 GeV the jet energy scale
is determined with a 3% systematic uncertainty
Various clinical scenarios leading to development of the string sign of the internal thoracic artery after coronary bypass surgery: the role of competitive flow, a case series
<p>Abstract</p> <p>Background</p> <p>The left internal mammary artery (LIMA) is the choice for grafting of the left anterior descending coronary artery (LAD). One possible mechanism of the rare graft failure involve the presence of competitive flow.</p> <p>Method</p> <p>105 patients who had undergone coronary bypass grafting between 1998 and 2000 were included in this observational study. The recatheterizations were performed 28 months after the operations. The rate of patency the LIMA grafts was determined, and the cases with graft failure were analyzed.</p> <p>Results</p> <p>The LIMA graft was patent in 99 patients (94%). Six patients (6%) exhibited diffuse involution of the graft (string sign). The string sign was always associated with competitive flow as the basis of the LIMA graft involution. In one case quantitative re-evaluation of the preoperative coronary angiography revealed merely less than 50% diameter stenosis on the LAD with a nonligated side-branch of the LIMA. At recatheterization in two patients the pressure wire measurements demonstrated only a non-significant decrease of the fractional flow reserve (0.83 and 0.89), despite the 53% and 57% diameter stenosis in the angiogram. Another patient displayeda significant regression of the LAD lesion between the pre- and postoperative coronary angiography (from 76% to 44%) as the cause of the development of the competitive flow. In one instance, a radial artery graft on the LAD during a redo bypass operation resulted in competitive flow in the radial graft due to the greater diameter than that of the LIMA. In a further patient, competitive flow developed from a short sequential part of the LIMA graft between the nonsignificantly stenosed diagonal branch and the LAD, with involution of the main part of the graft to the diagonal branch.</p> <p>Conclusions</p> <p>The most common cause of the development of the string sign of a LIMA graft due to competitive flow is overassessment of the lesion of the LAD. Regression of a previous lesion or some other neighboring graft can also cause the phenomenon.</p
Postoperative peri-axillary seroma following axillary artery cannulation for surgical treatment of acute type A aortic dissection
The arterial cannulation site for optimal tissue perfusion and cerebral protection during cardiopulmonary bypass (CPB) for surgical treatment of acute type A aortic dissection remains controversial. Right axillary artery cannulation confers significant advantages, because it provides antegrade arterial perfusion during cardiopulmonary bypass, and allows continuous antegrade cerebral perfusion during hypothermic circulatory arrest, thereby minimizing global cerebral ischemia. However, right axillary artery cannulation has been associated with serious complications, including problems with systemic perfusion during cardiopulmonary bypass, problems with postoperative patency of the artery due to stenosis, thrombosis or dissection, and brachial plexus injury. We herein present the case of a 36-year-old Caucasian man with known Marfan syndrome and acute type A aortic dissection, who had direct right axillary artery cannulation for surgery of the ascending aorta. Postoperatively, the patient developed an axillary perigraft seroma. As this complication has, not, to our knowledge, been reported before in cardiothoracic surgery, we describe this unusual complication and discuss conservative and surgical treatment options
Mortality after coronary artery bypass grafting versus percutaneous coronary intervention with stenting for coronary artery disease: a pooled analysis of individual patient data
Background: Numerous randomised trials have compared coronary artery bypass grafting (CABG) with percutaneous coronary intervention (PCI) for patients with coronary artery disease. However, no studies have been powered to detect a difference in mortality between the revascularisation strategies. Methods: We did a systematic review up to July 19, 2017, to identify randomised clinical trials comparing CABG with PCI using stents. Eligible studies included patients with multivessel or left main coronary artery disease who did not present with acute myocardial infarction, did PCI with stents (bare-metal or drug-eluting), and had more than 1 year of follow-up for all-cause mortality. In a collaborative, pooled analysis of individual patient data from the identified trials, we estimated all-cause mortality up to 5 years using Kaplan-Meier analyses and compared PCI with CABG using a random-effects Cox proportional-hazards model stratified by trial. Consistency of treatment effect was explored in subgroup analyses, with subgroups defined according to baseline clinical and anatomical characteristics. Findings: We included 11 randomised trials involving 11 518 patients selected by heart teams who were assigned to PCI (n=5753) or to CABG (n=5765). 976 patients died over a mean follow-up of 3·8 years (SD 1·4). Mean Synergy between PCI with Taxus and Cardiac Surgery (SYNTAX) score was 26·0 (SD 9·5), with 1798 (22·1%) of 8138 patients having a SYNTAX score of 33 or higher. 5 year all-cause mortality was 11·2% after PCI and 9·2% after CABG (hazard ratio [HR] 1·20, 95% CI 1·06–1·37; p=0·0038). 5 year all-cause mortality was significantly different between the interventions in patients with multivessel disease (11·5% after PCI vs 8·9% after CABG; HR 1·28, 95% CI 1·09–1·49; p=0·0019), including in those with diabetes (15·5% vs 10·0%; 1·48, 1·19–1·84; p=0·0004), but not in those without diabetes (8·7% vs 8·0%; 1·08, 0·86–1·36; p=0·49). SYNTAX score had a significant effect on the difference between the interventions in multivessel disease. 5 year all-cause mortality was similar between the interventions in patients with left main disease (10·7% after PCI vs 10·5% after CABG; 1·07, 0·87–1·33; p=0·52), regardless of diabetes status and SYNTAX score. Interpretation: CABG had a mortality benefit over PCI in patients with multivessel disease, particularly those with diabetes and higher coronary complexity. No benefit for CABG over PCI was seen in patients with left main disease. Longer follow-up is needed to better define mortality differences between the revascularisation strategies
Measurement of and Production in Collisions at = 1.96 TeV
The Standard Model predictions for and production are
tested using an integrated luminosity of 200 pb of \ppbar collision data
collected at the Collider Detector at Fermilab. The cross sections are measured
selecting leptonic decays of the and bosons, and photons with
transverse energy GeV that are well separated from leptons. The
production cross sections and kinematic distributions for the and
are compared to SM predictions.Comment: 7 pages, 4 figures, submitted to PR
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