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1.
Acad Med ; 98(3): 304-312, 2023 03 01.
Artículo en Inglés | MEDLINE | ID: mdl-36538673

RESUMEN

In 2015, data released by the Association of American Medical Colleges (AAMC) showed that there were more Black men applying and matriculating to medical school in 1978 than 2014. The representation of Black men in medicine is a troubling workforce issue that was identified by the National Academies of Sciences, Engineering, and Medicine as a national crisis. While premedical pathway programs have contributed to increased workforce diversity, alone they are insufficient to accelerate change. In response, the AAMC and the National Medical Association launched a new initiative in August 2020, the Action Collaborative for Black Men in Medicine, to address the systems factors that influence the trajectory to medicine for Black men. The authors provide a brief overview of the educational experiences of Black boys and men in the United States and, as members of the Action Collaborative, describe their early work. Using research, data, and collective lived experiences, the Action Collaborative members identified premedical and academic medicine systems factors that represented opportunities for change. The premedical factors include financing and funding, information access, pre-health advisors, the Medical College Admission Test, support systems, foundational academics, and alternative career paths. The academic medicine factors include early identification, medical school recruitment and admissions, and leadership accountability. The authors offer several points of intervention along the medical education continuum, starting as early as elementary school through medical school matriculation, for institutional leaders to address these factors as part of their diversity strategy. The authors also present the Action Collaborative's process for leveraging collective impact to build an equity-minded action agenda focused on Black men. They describe their initial focus on pre-health advising and leadership accountability and next steps to develop an action agenda. Collective impact and coalition building will facilitate active, broad engagement of partners across sectors to advance long-term systems change.


Asunto(s)
Negro o Afroamericano , Educación Médica , Medicina , Humanos , Masculino , Criterios de Admisión Escolar , Estados Unidos
2.
Interact Cardiovasc Thorac Surg ; 34(2): 322-325, 2022 01 18.
Artículo en Inglés | MEDLINE | ID: mdl-34849924

RESUMEN

Although the activated partial thromboplastin time (aPTT) has historically been the method of choice for anticoagulation monitoring in patients undergoing mechanical circulatory support with intravenous unfractionated heparin, it is being progressively superseded by the anti-factor Xa (anti-Xa) method. A retrospective single-arm, single-centre analysis of 20 patients who underwent total artificial heart implantation entailed simultaneous determinations of aPTT and anti-Xa. Agreement between these parameters was assessed using the Bland-Altman method. Despite a positive correlation between aPTT and anti-Xa, normal target ranges were poorly aligned: from 5th to 30th postoperative day, for anti-Xa values of 0.2 and 0.4 U/ml corresponding aPTT values were 52.1 and 65.2 s, 7.9 and 14.8 lower than predicted values, respectively. This was not associated with thromboembolic sequalae. It was not possible to demonstrate a significant relationship between the predictor variables (postoperative day; white blood cell count; C-reactive protein concentration; alanine transaminase and alkaline phosphatase level; bilirubin; haemoglobin; albumin and total protein concentration) and the agreement between aPTT and anti-Xa levels. In summary, when anti-Xa levels were used to guide anticoagulation therapy, corresponding aPTT levels were low with respect to target range. Methodology applied in this study is generalizable to other forms of mechanical circulatory support.


Asunto(s)
Corazón Artificial , Heparina , Anticoagulantes/efectos adversos , Monitoreo de Drogas/métodos , Inhibidores del Factor Xa/efectos adversos , Heparina/efectos adversos , Humanos , Tiempo de Tromboplastina Parcial , Estudios Retrospectivos
4.
Catheter Cardiovasc Interv ; 98(3): E444-E452, 2021 09.
Artículo en Inglés | MEDLINE | ID: mdl-33502784

RESUMEN

OBJECTIVES: To determine whether a permanent pacemaker (PPM) in situ can enhance survival after transcatheter aortic valve implantation (TAVI), in a predominantly inoperable or high risk cohort. BACKGROUND: New conduction disturbances are the most frequent complication of TAVI, often necessitating PPM implantation before hospital discharge. METHODS: We performed an observational cohort analysis of the UK TAVI registry (2007-2015). Primary and secondary endpoints were 30-day post-discharge all-cause mortality and long-term survival, respectively. RESULTS: Of 8,651 procedures, 6,815 complete datasets were analyzed. A PPM at hospital discharge, irrespective of when implantation occurred (PPM 1.68% [22/1309] vs. no PPM 1.47% [81/5506], odds ratio [OR] 1.14, 95% confidence interval [CI] 0.71-1.84; p = .58), or a PPM implanted peri- or post-TAVI only (PPM 1.44% [11/763] vs. no PPM 1.47% [81/5506], OR 0.98 [0.51-1.85]; p = .95) did not significantly reduce the primary endpoint. Patients with a PPM at discharge were older, male, had right bundle branch block at baseline, were more likely to have received a first-generation self-expandable prosthesis and had experienced more peri- and post-procedural complications including bailout valve-in-valve rescue, bleeding and acute kidney injury. A Cox proportional hazards model demonstrated significantly reduced long-term survival in all those with a PPM, irrespective of implantation timing (hazard ratio [HR] 1.14 [1.02-1.26]; p = .019) and those receiving a PPM only at the time of TAVI (HR 1.15 [1.02-1.31]; p = .032). The reasons underlying this observation warrant further investigation. CONCLUSIONS: A PPM did not confer a survival advantage in the first 30 days after hospital discharge following TAVI.


Asunto(s)
Estenosis de la Válvula Aórtica , Implantación de Prótesis de Válvulas Cardíacas , Prótesis Valvulares Cardíacas , Marcapaso Artificial , Reemplazo de la Válvula Aórtica Transcatéter , Cuidados Posteriores , Válvula Aórtica/diagnóstico por imagen , Válvula Aórtica/cirugía , Estenosis de la Válvula Aórtica/diagnóstico por imagen , Estenosis de la Válvula Aórtica/cirugía , Humanos , Masculino , Alta del Paciente , Complicaciones Posoperatorias , Estudios Retrospectivos , Reemplazo de la Válvula Aórtica Transcatéter/efectos adversos , Resultado del Tratamiento
5.
Cardiovasc Revasc Med ; 33: 26-31, 2021 12.
Artículo en Inglés | MEDLINE | ID: mdl-33451925

RESUMEN

BACKGROUND/PURPOSE: In the randomized PREPARE-CALC trial, lesion preparation of calcified lesions with upfront rotational atherectomy (RA) prior to drug-eluting stent (DES) implantation resulted in higher acute success as compared to a provisional modified balloon (MB) strategy. We aimed to investigate the impact of calcified lesion complexity on the treatment effect with either MB or RA. METHODS/MATERIALS: Two hundred patients were randomized to lesion preparation with either MB or RA. The study population was stratified according to lesion complexity into at least one type-C lesion or into exclusively non-type-C lesions. Endpoints were strategy success, need for bail-out RA, acute lumen gain, and late lumen loss (LLL) at 9 months. RESULTS: In total, 143 patients were graded as type-C (45% patients were allocated to MB), whereas 57 patients were graded as non-type-C (61% patients were allocated to MB). In patients with at least one type-C lesion, strategy success with RA was higher than with MB (97% vs 72%, p < 0.001), but superiority of RA was not observed in patients with non-type-C lesions (100% vs 97%, p = 1.00; pinteraction = 0.001). The need for bail-out RA was higher in patients with type-C lesions (n = 15) as compared with non-type-C lesions (n = 1). Acute lumen gain, LLL, and target lesion revascularization at 9 months were not dependent on lesion complexity and upfront lesion preparation strategy. CONCLUSIONS: In patients with calcified non-type-C lesions, the treatment strategy with RA or MB before DES implantation results in comparable success rates, whereas in type-C lesions upfront RA appears to be the superior upfront strategy.


Asunto(s)
Angioplastia Coronaria con Balón , Aterectomía Coronaria , Enfermedad de la Arteria Coronaria , Stents Liberadores de Fármacos , Intervención Coronaria Percutánea , Calcificación Vascular , Aterectomía Coronaria/efectos adversos , Angiografía Coronaria , Enfermedad de la Arteria Coronaria/diagnóstico por imagen , Enfermedad de la Arteria Coronaria/cirugía , Humanos , Intervención Coronaria Percutánea/efectos adversos , Estudios Retrospectivos , Resultado del Tratamiento , Calcificación Vascular/diagnóstico por imagen , Calcificación Vascular/terapia
6.
Catheter Cardiovasc Interv ; 97(4): E552-E559, 2021 03.
Artículo en Inglés | MEDLINE | ID: mdl-32779877

RESUMEN

OBJECTIVES: We sought to identify baseline demographics and procedural factors that might independently predict in-hospital stroke following transcatheter aortic valve implantation (TAVI). BACKGROUND: Stroke is a recognized, albeit infrequent, complication of TAVI. Established predictors of procedure-related in-hospital stroke; however, remain poorly defined. METHODS: We conducted an observational cohort analysis of the multicenter UK TAVI registry. The primary outcome measure was the incidence of in-hospital stroke. RESULTS: A total of 8,652 TAVI procedures were performed from 2007 to 2015. There were 205 in-hospital strokes reported by participating centers equivalent to an overall stroke incidence of 2.4%. Univariate analysis showed that the implantation of balloon-expandable valves caused significantly fewer strokes (balloon-expandable 96/4,613 [2.08%] vs. self-expandable 95/3,272 [2.90%]; p = .020). After multivariable analysis, prior cerebrovascular disease (CVD) (odds ratio [OR] 1.51, 95% confidence interval [CI 1.05-2.17]; p = .03), advanced age at time of operation (OR 1.02 [0.10-1.04]; p = .05), bailout coronary stenting (OR 5.94 [2.03-17.39]; p = .008), and earlier year of procedure (OR 0.93 [0.87-1.00]; p = .04) were associated with an increased in-hospital stroke risk. There was a reduced stroke risk in those who had prior cardiac surgery (OR 0.62 [0.41-0.93]; p = .01) and a first-generation balloon-expandable valve implanted (OR 0.72 [0.53-0.97]; p = .03). In-hospital stroke significantly increased 30-day (OR 5.22 [3.49-7.81]; p < .001) and 1-year mortality (OR 3.21 [2.15-4.78]; p < .001). CONCLUSIONS: In-hospital stroke after TAVI is associated with substantially increased early and late mortality. Factors independently associated with in-hospital stroke were previous CVD, advanced age, no prior cardiac surgery, and deployment of a predominantly first-generation self-expandable transcatheter heart valve.


Asunto(s)
Estenosis de la Válvula Aórtica , Prótesis Valvulares Cardíacas , Accidente Cerebrovascular , Reemplazo de la Válvula Aórtica Transcatéter , Válvula Aórtica/diagnóstico por imagen , Válvula Aórtica/cirugía , Estenosis de la Válvula Aórtica/diagnóstico por imagen , Estenosis de la Válvula Aórtica/cirugía , Estudios de Cohortes , Hospitales , Humanos , Accidente Cerebrovascular/epidemiología , Accidente Cerebrovascular/etiología , Reemplazo de la Válvula Aórtica Transcatéter/efectos adversos , Resultado del Tratamiento , Reino Unido/epidemiología
7.
Catheter Cardiovasc Interv ; 98(7): 1300-1307, 2021 12 01.
Artículo en Inglés | MEDLINE | ID: mdl-33283484

RESUMEN

OBJECTIVE: Octogenarians are a high-risk group presenting for percutaneous coronary intervention (PCI). We aimed to create a 30-day mortality risk model for octogenarians presenting with both acute coronary syndrome (ACS) and chronic stable angina (CSA), using comprehensive mandatory UK data submissions to the UK National database. BACKGROUND: Octogenarians are a high-risk group presenting for percutaneous coronary intervention, and decisions on whether or not to undertake intervention in this cohort can be challenging. The increasing number of octogenarians in the general population means they represent an important high-risk subgroup of patients. METHODS: The data group consisted of 425,897 PCI procedures undertaken in the UK between 2008 and 2012 during which time there was comprehensive data linkage to mortality via the Office of National Statistics. Of these procedures, 44,221 (10.4%) were in patients aged ≥80. These comprised the model group. Logistic regression was used to create a predictive score which ultimately consisted of the following weightings: age 80-89 (n = 1); age > 90 (n = 2); unstable angina/non-ST-elevation myocardial infraction (NSTEMI) (n = 1); STEMI (n = 2); creatinine >200 mmol/L (n = 1); preprocedural ventilation (n = 1); left ventricular ejection fraction <30% (n = 1); cardiogenic shock (n = 2). Multiple imputation was used to account for missing data. RESULTS: The patient cohort was divided into a derivation (n = 22,072) and a validation dataset (n = 22,071). Receiver operating characteristic analyses were used to derive the area-under-the-curve to assess properties of the score. The scoring system generated an AUC 0.83, (95% CI 0.80-0.85) suggesting high sensitivity and specificity. Scores of 1-4 were associated with good survival but scores ≥5 were associated with an estimated likelihood of death within 30 days of ≥40%. CONCLUSIONS: This octogenarian risk score maybe a useful tool to determine the chance of a successful outcome in elderly patients presenting for PCI.


Asunto(s)
Octogenarios , Intervención Coronaria Percutánea , Anciano , Anciano de 80 o más Años , Humanos , Intervención Coronaria Percutánea/efectos adversos , Factores de Riesgo , Volumen Sistólico , Resultado del Tratamiento , Función Ventricular Izquierda
8.
EuroIntervention ; 17(1): 67-74, 2021 May 17.
Artículo en Inglés | MEDLINE | ID: mdl-33226000

RESUMEN

BACKGROUND: Historically the elderly have been under-represented in non-ST-elevation myocardial infarction (NSTEMI) management trials. AIMS: The aim of this trial was to demonstrate that an intervention-guided strategy is superior to optimal medical therapy (OMT) alone for treating NSTEMI in elderly individuals. METHODS: Patients (≥80 years, chest pain, ischaemic ECG, and elevated troponin) were randomised 1:1 to an intervention-guided strategy plus OMT versus OMT alone. The primary endpoint was a composite of all-cause mortality and non-fatal myocardial reinfarction at 1 year. Ethics approval was obtained by the institutional review board of every recruiting centre. RESULTS: From May 2014 to September 2018, 251 patients (n=125 invasive vs n=126 conservative) were enrolled. Almost 50% of participants were female. The trial was terminated prematurely due to slow recruitment. A Kaplan-Meier estimate of event-free survival revealed no difference in the primary endpoint at 1 year (invasive 18.5% [23/124] vs conservative 22.2% [28/126]; p=0.39). No significant difference persisted after Cox proportional hazards regression analysis (hazard ratio 0.79, 95% confidence interval 0.45-1.35; p=0.39). There was greater freedom from angina at 3 months (p<0.001) after early intervention but this was similar at 1 year. Both non-fatal reinfarction (invasive 9.7% [12/124] vs conservative 14.3% [18/126]; p=0.22) and unplanned revascularisation (invasive 1.6% [2/124] vs conservative 6.4% [8/126]; p=0.10) occurred more frequently in the OMT alone cohort. CONCLUSIONS: An intervention-guided strategy was not superior to OMT alone to treat very elderly NSTEMI patients. The trial was underpowered to demonstrate this definitively. Early intervention resulted in fewer cases of reinfarction and unplanned revascularisation but did not improve survival.


Asunto(s)
Infarto del Miocardio , Anciano , Angina de Pecho , Angina Inestable , Angiografía Coronaria , Femenino , Humanos , Masculino , Infarto del Miocardio/terapia , Síndrome , Resultado del Tratamiento
9.
Ann Thorac Surg ; 111(2): 511-518, 2021 02.
Artículo en Inglés | MEDLINE | ID: mdl-32698021

RESUMEN

BACKGROUND: We investigated changes in estimated glomerular filtration rate (eGFR) after left ventricular assist device (LVAD) implant and the impact on long-term outcomes. METHODS: A retrospective analysis was conducted for 255 patients with LVADs, divided into 2 groups based on preimplant eGFR (<60 or >60 mL/min/1.73 m2) and into 6 grades (grade 1, >90 mL/min/1.73 m2 normal; grade 2, 60-89 mild dysfunction; grade 3, 45-59 moderate; grade 4, 30-44 moderate to severe; grade 5, 15-29 severe; or grade 6, <15 kidney failure). Changes in eGFR and the impact on long-term outcome and survival were analyzed. RESULTS: One-month postimplant eGFR of the total cohort increased from a baseline of 75.19 ± 34.35 to 118.97 ± 67.62 mL/min/1.73 m2(P < .001). eGRF 4 years postimplant was higher than baseline but not significantly (P = .48). Patients with a preimplant eGFR > 60 followed the same pattern as the entire cohort. The preimplant eGFR < 60 group had a significant increase at 1 month (P < .001), eGFR remained significantly higher than baseline 4 years postimplant (P = .032), and there was a sustained transition to improved distribution of renal function grade after LVAD implant. Post-LVAD implant survival at 1, 3, and 5 years for baseline eGFR > 60 was 76%, 54%, and 48% and for eGFR < 60 was 71%, 60%, and 48%, respectively (P = .92). CONCLUSIONS: Patients with a low preimplant eGFR derive benefit from LVAD therapy, with eGFR remaining elevated above preimplant levels. Preimplant renal dysfunction did not impact negatively on long-term morbidity and mortality.


Asunto(s)
Tasa de Filtración Glomerular , Insuficiencia Cardíaca/terapia , Corazón Auxiliar , Adulto , Anciano , Femenino , Insuficiencia Cardíaca/mortalidad , Insuficiencia Cardíaca/fisiopatología , Humanos , Masculino , Persona de Mediana Edad , Estudios Retrospectivos
10.
J Med Ethics ; 2020 Nov 20.
Artículo en Inglés | MEDLINE | ID: mdl-33219013

RESUMEN

Early in the COVID-19 pandemic there was widespread concern that healthcare systems would be overwhelmed, and specifically, that there would be insufficient critical care capacity in terms of beds, ventilators or staff to care for patients. In the UK, this was avoided by a threefold approach involving widespread, rapid expansion of critical care capacity, reduction of healthcare demand from non-COVID-19 sources by temporarily pausing much of normal healthcare delivery, and by governmental and societal responses that reduced demand through national lockdown. Despite high-level documents designed to help manage limited critical care capacity, none provided sufficient operational direction to enable use at the bedside in situations requiring triage. We present and describe the development of a structured process for fair allocation of critical care resources in the setting of insufficient capacity. The document combines a wide variety of factors known to impact on outcome from critical illness, integrated with broad-based clinical judgement to enable structured, explicit, transparent decision-making founded on robust ethical principles. It aims to improve communication and allocate resources fairly, while avoiding triage decisions based on a single disease, comorbidity, patient age or degree of frailty. It is designed to support and document decision-making. The document has not been needed to date, nor adopted as hospital policy. However, as the pandemic evolves, the resumption of necessary non-COVID-19 healthcare and economic activity mean capacity issues and the potential need for triage may yet return. The document is presented as a starting point for stakeholder feedback and discussion.

11.
Sci Total Environ ; 729: 138320, 2020 Aug 10.
Artículo en Inglés | MEDLINE | ID: mdl-32387767

RESUMEN

Distributed measurements of agricultural erosion at the farm-scale are needed to evaluate both the on and off-site impacts of sediment redistribution. While best management practices have been shown to reduce surface erosion rates and improve water quality, their farm-scale effects can be difficult to quantify. In this study we use imagery from an unmanned aerial vehicle (UAV) and structure-from-motion multi-view stereo (SfM-MVS) to quantify erosion rates and their effects on crop yield across a 15.9-ha agricultural field. Our results highlight that the installation of catch basins were able to stop 159.52 t of sediment and associated nutrients from entering the waterway adjacent to the study site over the course of one year, corresponding to an erosion rate of 18.83 t ha-1 yr-1 across six study basins. Poor soil structure resulting from downslope tillage reduced crop yields on topographic shoulders of the study site, while accelerated water erosion processes were responsible for large areas of washout that caused highly variable crop growth in footslopes. The highest crop yields were associated with backslopes and topographically flat regions of the field which experienced minimal erosion. Change-detection results showed that UAV imagery was able to reliably quantify depositional plumes and was comparable to that of a terrestrial laser scanner (TLS) using a ± 0.04 m confidence interval.

12.
JACC Cardiovasc Interv ; 13(9): 1071-1082, 2020 05 11.
Artículo en Inglés | MEDLINE | ID: mdl-32305398

RESUMEN

OBJECTIVES: The purpose of this study was to evaluate clinical and echocardiographic outcome data of the CHOICE (Randomized Comparison of Transcatheter Heart Valves in High Risk Patients with Severe Aortic Stenosis: Medtronic CoreValve Versus Edwards SAPIEN XT) trial at 5 years. BACKGROUND: The CHOICE trial was designed to compare device performance of a balloon-expandable (BE) transcatheter heart valve (THV) versus a self-expanding (SE) THV. METHODS: The CHOICE trial is an investigator-initiated trial that randomized 241 high-risk patients with severe symptomatic aortic stenosis and an anatomy suitable for treatment with both BE and SE THVs to transfemoral transcatheter aortic valve replacement with either device. The primary endpoint was device success. Patients were followed up to 5 years, with assessment of clinical outcomes, and echocardiographic evaluation of valve function and THV durability. RESULTS: After 5 years, there were no statistically significant differences between BE and SE valves in the cumulative incidence of death from any cause (53.4% vs. 47.6%; p = 0.38), death from cardiovascular causes (31.6% vs. 21.5%; p = 0.12), all strokes (17.5% vs. 16.5%; p = 0.73), and repeat hospitalization for heart failure (28.9% vs. 22.5%; p = 0.75). SE patients had larger prosthetic valve area (1.6 ± 0.5 cm2 vs. 1.9 ± 0.5 cm2; p = 0.02) with a lower mean transprosthetic gradient (12.2 ± 8.7 mm Hg vs. 6.9 ± 2.7 mm Hg; p = 0.001) at 5 years. No differences were observed in the rates of paravalvular regurgitation. Clinical valve thrombosis occurred in 7 BE patients (7.3%) and 1 SE patient (0.8%; p = 0.06), and moderate or severe structural valve deterioration in 6 BE patients (6.6%) and no SE patient (0%; p = 0.018). The rate of bioprosthetic valve failure was low and not significantly different between both groups (4.1% vs. 3.4%; p = 0.63). CONCLUSIONS: Five-year follow-up of patients in the CHOICE trial revealed clinical outcomes after transfemoral transcatheter aortic valve replacement with early-generation BE and SE valves that were not statistically significantly different, with limited statistical power. Forward flow hemodynamics were significantly better with the SE valve. Moderate or severe structural valve deterioration was uncommon but occurred more frequently with the BE valve. (A Comparison of Transcatheter Heart Valves in High Risk Patients With Severe Aortic Stenosis: The CHOICE Trial [CHOICE]; NCT01645202).


Asunto(s)
Estenosis de la Válvula Aórtica/cirugía , Válvula Aórtica/cirugía , Valvuloplastia con Balón , Prótesis Valvulares Cardíacas , Reemplazo de la Válvula Aórtica Transcatéter/instrumentación , Anciano , Anciano de 80 o más Años , Válvula Aórtica/diagnóstico por imagen , Válvula Aórtica/fisiopatología , Estenosis de la Válvula Aórtica/diagnóstico por imagen , Estenosis de la Válvula Aórtica/mortalidad , Estenosis de la Válvula Aórtica/fisiopatología , Valvuloplastia con Balón/efectos adversos , Valvuloplastia con Balón/mortalidad , Femenino , Alemania , Hemodinámica , Humanos , Masculino , Complicaciones Posoperatorias/mortalidad , Complicaciones Posoperatorias/terapia , Diseño de Prótesis , Falla de Prótesis , Recuperación de la Función , Factores de Riesgo , Índice de Severidad de la Enfermedad , Factores de Tiempo , Reemplazo de la Válvula Aórtica Transcatéter/efectos adversos , Reemplazo de la Válvula Aórtica Transcatéter/mortalidad , Resultado del Tratamiento
13.
PLoS One ; 14(5): e0216343, 2019.
Artículo en Inglés | MEDLINE | ID: mdl-31150421

RESUMEN

Concordance among wetland physicochemical conditions, vegetation, and surrounding land cover may result from the influence of land cover on the sources of plant propagules, on physicochemical conditions, and their subsequent determination of growing conditions. Alternatively, concordance may result if differences in climate, soils, and species pools are spatially confounded with differences in human population density and land conversion. Further, we expect that land cover within catchment boundaries will be more predictive than land cover in symmetrical buffers if runoff is a major pathway. We measured concordance between land cover, wetland vegetation and physicochemical conditions in 48 prairie pothole wetlands, controlling for inter-wetland distance. We contrasted land-cover data collected over a four-year period by multiple extraction approaches including topographically-delineated catchments and nested 30 m to 5,000 m radius buffers. After factoring out inter-wetland distance, physiochemical conditions were significantly concordant with land cover. Vegetation was not significantly concordant with land cover, though it was strongly and significantly concordant with physicochemical conditions. More, concordance was as strong when land cover was extracted from buffers <500 m in radius as from catchments, indicating the mechanism responsible is not topographically constrained. We conclude that local landscape structure does not directly influence wetland vegetation composition, but rather that vegetation depends on 1) physicochemical conditions in the wetland that are affected by surrounding land cover and on 2) regional factors such as the vegetation species pool and geographic gradients in climate, soil type, and land use.


Asunto(s)
Ecosistema , Humedales , Fenómenos Químicos , Clima , Plantas , Suelo
14.
Circ Cardiovasc Interv ; 11(10): e007415, 2018 10.
Artículo en Inglés | MEDLINE | ID: mdl-30354632

RESUMEN

BACKGROUND: Balloon dilatation or debulking seems to be essential to allow successful stent implantation in calcified coronary lesions. Compared with standard balloon predilatation, debulking using high-speed rotational atherectomy (RA) is associated with higher initial procedural success albeit with higher in-stent late lumen loss at intermediate-term follow-up. Whether modified (scoring or cutting) balloons (MB) could achieve similar procedural success compared with RA is not known. In addition, whether new-generation drug-eluting stents could counterbalance the excessive neointimal proliferation triggered by RA remains to be determined. METHODS AND RESULTS: We randomly assigned patients with documented myocardial ischemia and severely calcified native coronary lesions undergoing percutaneous coronary intervention to a strategy of lesion preparation using MB or RA followed by drug-eluting stent implantation. Stenting was performed using a third-generation sirolimus-eluting stent with a bioabsorbable polymer. The trial had 2 primary end points: strategy success (defined as successful stent delivery and expansion with attainment of <20% in-stent residual stenosis in the presence of TIMI [Thrombolysis in Myocardial Infarction] 3 flow without crossover or stent failure; powered for superiority) and in-stent late lumen loss at 9 months (powered for noninferiority). Two hundred patients were enrolled at 2 centers in Germany (n=100 in each treatment group). The mean age of the study population was 74.9±7.0 years; 76% were men, and 33.5% had diabetes mellitus. Strategy success was significantly more common in the RA group (81% versus 98%; relative risk of failure with an MB- versus RA-based strategy, 9.5; 95% CI, 2.3-39.7; P=0.0001), but mean fluoroscopy time was longer (19.6±13.4 versus 23.9±12.2 minutes; P=0.03). At 9 months, mean in-stent late lumen loss was 0.16±0.39 mm in the MB group and 0.22±0.40 mm in the RA group ( P=0.21, P=0.02 for noninferiority). Target lesion revascularization (7% versus 2%; P=0.17), definite or probable stent thrombosis (0% versus 0%; P=1.00), and target vessel failure (8% versus 6%; P=0.78) were low and not significantly different between the MB and RA groups. CONCLUSIONS: Lesion preparation with upfront RA before drug-eluting stent implantation is feasible in nearly all patients with severely calcified coronary lesions, is more commonly successful as a primary strategy compared with MB, and is not associated with excessive late lumen loss. A strategy of provisional MB remains feasible, safe, and effective as long as bailout RA is readily available and may offer the advantages of compatibility with smaller sized catheters and less irradiation. Both strategies are associated with excellent clinical outcome at 9 months. CLINICAL TRIAL REGISTRATION: URL: https://www.clinicaltrials.gov . Unique identifier: NCT02502851.


Asunto(s)
Angioplastia Coronaria con Balón , Aterectomía Coronaria , Enfermedad de la Arteria Coronaria/terapia , Stents Liberadores de Fármacos , Intervención Coronaria Percutánea/instrumentación , Calcificación Vascular/terapia , Implantes Absorbibles , Anciano , Anciano de 80 o más Años , Angioplastia Coronaria con Balón/efectos adversos , Angioplastia Coronaria con Balón/mortalidad , Aterectomía Coronaria/efectos adversos , Aterectomía Coronaria/mortalidad , Fármacos Cardiovasculares/administración & dosificación , Angiografía Coronaria , Enfermedad de la Arteria Coronaria/diagnóstico por imagen , Enfermedad de la Arteria Coronaria/mortalidad , Reestenosis Coronaria/etiología , Trombosis Coronaria/etiología , Femenino , Alemania , Humanos , Masculino , Neointima , Intervención Coronaria Percutánea/efectos adversos , Intervención Coronaria Percutánea/mortalidad , Diseño de Prótesis , Factores de Riesgo , Índice de Severidad de la Enfermedad , Sirolimus/administración & dosificación , Factores de Tiempo , Resultado del Tratamiento , Calcificación Vascular/diagnóstico por imagen , Calcificación Vascular/mortalidad
15.
Artículo en Inglés | MEDLINE | ID: mdl-28469902

RESUMEN

The Royal United Hospital, Bath, admits approximately 550 patients with neck of femur fractures per year. The risks from returning to theatre for this patient group are often life-threatening. Post-operative wound ooze was noted to cause a significant rate of return to theatre, with increased lengths of stay and patient morbidity. A wound closure protocol was agreed by the consultant body. This information was disseminated by email and teaching sessions to all members of the multidisciplinary team, including surgeons, theatre staff and ortho-geriatricians. The plan-do-study-act model for improvement was used to reduce rates of returns to theatre for wound ooze. Interventions included cyclical teaching during each trainee rotation, updated inductions, posters, email reminders and scrub team involvement to open the protocol sutures unprompted. The primary outcome measure was returns to theatre for wound complications. Baseline data showed 4 returns to theatre over a two month period (4.40% of patients). Length of stay for each patient affected by wound ooze was also compared to the departmental mean. In the 6 month intervention period there was one return to theatre (0.36% of patients). The observed reduction saved the department an estimated £13,831 in length of stay alone. The standardisation of wound closure protocol, with continued reinforcement to all members of the multidisciplinary team, improves patient outcome in this group. Mobilising a group of clinicians across a variety of specialities, with one common goal, is highly effective for patients, improves multidisciplinary working and reduces cost.

16.
Laryngoscope ; 127(11): 2490-2494, 2017 11.
Artículo en Inglés | MEDLINE | ID: mdl-28407264

RESUMEN

OBJECTIVES/HYPOTHESIS: To compare the effectiveness of massed versus interval training when teaching otolaryngology residents microvascular suturing on a validated microsurgical model. STUDY DESIGN: Otolaryngology residents were placed into interval (n = 7) or massed (n = 7) training groups. The interval group performed three separate 30-minute practice sessions separated by at least 1 week, and the massed group performed a single 90-minute practice session. Both groups viewed a video demonstration and recorded a pretest prior to the first training session. A post-test was administered following the last practice session. METHODS: At an academic medical center, 14 otolaryngology residents were assigned using stratified randomization to interval or massed training. Blinded evaluators graded performance using a validated microvascular Objective Structured Assessment of Technical Skill tool. The tool is comprised of two major components: task-specific score (TSS) and global rating scale (GRS). Participants also received pre- and poststudy surveys to compare subjective confidence in multiple aspects of microvascular skill acquisition. RESULTS: Overall, all residents showed increased TSS and GRS on post- versus pretest. After completion of training, the interval group had a statistically significant increase in both TSS and GRS, whereas the massed group's increase was not significant. Residents in both groups reported significantly increased levels of confidence after completion of the study. CONCLUSIONS: Self-directed learning using a chicken thigh artery model may benefit microsurgical skills, competence, and confidence for resident surgeons. Interval training results in significant improvement in early development of microvascular anastomosis skills, whereas massed training does not. LEVEL OF EVIDENCE: NA. Laryngoscope, 127:2490-2494, 2017.


Asunto(s)
Anastomosis Quirúrgica/educación , Anastomosis Quirúrgica/métodos , Educación de Postgrado en Medicina/métodos , Microcirugia/educación , Otolaringología/educación , Entrenamiento Simulado/métodos , Animales , Pollos , Competencia Clínica , Evaluación Educacional , Humanos , Internado y Residencia , Muslo , Grabación en Video
17.
JAMA Otolaryngol Head Neck Surg ; 143(7): 679-684, 2017 07 01.
Artículo en Inglés | MEDLINE | ID: mdl-28418509

RESUMEN

Importance: Hypocalcemia is the most common complication after total thyroidectomy and can result in prolonged hospital admissions and increased hospital charges. Objective: To determine the effectiveness of preoperative calcium and calcitriol supplementation in reducing hypocalcemia following total thyroidectomy. Design, Setting, and Participants: A retrospective cohort study was conducted at a tertiary care center in 65 patients undergoing total thyroidectomy by a single surgeon. Patients were divided into 2 groups: those receiving preoperative as well as postoperative supplementation with calcium carbonate, 1000 to 1500 mg, 3 times daily and calcitriol, 0.25 to 0.5 µg, twice daily, and those receiving only postoperative supplementation with those agents at the same dosages. Data on patients who underwent surgery between January 1, 2008, and December 31, 2011, were acquired, and data analyses were conducted from March through June 2012, and from October through December 2016. Interventions: Calcium and calcitriol therapy. Main Outcomes and Measures: Postoperative serum calcium levels and development of postoperative hypocalcemia. Results: Of the 65 patients who underwent total thyroidectomy 27 (42%) were men; mean (SD) age was 49.7 (16.7) years. Thirty-three patients received preoperative calcium and calcitriol supplementation, and 32 patients received only postoperative therapy. In the preoperative supplementation group, 15 of 33 (45%) patients underwent complete central compartment neck dissection and 11 of 33 (33%) had lateral neck dissection, compared with 16 of 32 (50%) and 12 of 32 (38%), respectively, patients without preoperative supplementation. The mean measured serum calcium level in those without preoperative supplementation vs those with supplementation are as follows: preoperative, 9.6 vs 9.4 mg/dL (absolute difference, 0.16; 95% CI, -0.12 to 0.49 mg/dL); 12 hours postoperative, 8.3 vs 8.6 mg/dL (absolute difference, -0.30; 95% CI, -0.63 to 0.02 mg/dL); and 24 hours postoperative, 8.4 vs 8.5 mg/dL (absolute difference, -0.13; 95% CI, -0.43 to 0.16 mg/dL). In patients not receiving preoperative supplementation, 5 of 32 (16%) individuals became symptomatically hypocalcemic vs 2 of 33 (6%) in the preoperative supplementation group; an absolute difference of 10% (95% CI, -6.6% to 26.3%). Compared with the group not receiving preoperative supplementation, the mean [SD] length of stay was significantly shorter in the preoperative supplementation group (3.8 [1.8] vs 2.9 [1.4] days; absolute difference, -0.9; 95% CI, -1.70 to -0.105 days). Preoperative supplementation resulted in an estimated $2819 savings in charges per patient undergoing total thyroidectomy. Conclusions and Relevance: Preoperative calcium and calcitriol supplementation, in addition to routine postoperative supplementation, was associated with a reduced incidence of symptomatic hypocalcemia, length of hospital stay, and overall charges following total thyroidectomy.


Asunto(s)
Calcitriol/uso terapéutico , Calcio/uso terapéutico , Hipocalcemia/prevención & control , Complicaciones Posoperatorias/prevención & control , Tiroidectomía , Calcitriol/sangre , Calcio/sangre , Femenino , Precios de Hospital , Humanos , Hipocalcemia/epidemiología , Incidencia , Tiempo de Internación/estadística & datos numéricos , Masculino , Persona de Mediana Edad , Disección del Cuello , Cuidados Posoperatorios , Complicaciones Posoperatorias/epidemiología , Cuidados Preoperatorios , Estudios Retrospectivos
18.
Ecol Appl ; 26(5): 1421-1436, 2016 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-27755762

RESUMEN

Exurban residential land (one housing unit per 0.2-16.2 ha) is growing in importance as a human-dominated land use. Carbon storage in the soils and vegetation of exurban land is poorly known, as are the effects on C storage of choices made by developers and residents. We studied C storage in exurban yards in southeastern Michigan, USA, across a range of parcel sizes and different types of neighborhoods. We divided each residential parcel into ecological zones (EZ) characterized by vegetation, soil, and human behavior such as mowing, irrigation, and raking. We found a heterogeneous mixture of trees and shrubs, turfgrasses, mulched gardens, old-field vegetation, and impervious surfaces. The most extensive zone type was turfgrass with sparse woody vegetation (mean 26% of parcel area), followed by dense woody vegetation (mean 21% of parcel area). Areas of turfgrass with sparse woody vegetation had trees in larger size classes (> 50 cm dbh) than did areas of dense woody vegetation. Using aerial photointerpretation, we scaled up C storage to neighborhoods. Varying C storage by neighborhood type resulted from differences in impervious area (8-26% of parcel area) and area of dense woody vegetation (11-28%). Averaged and multiplied across areas in differing neighborhood types, exurban residential land contained 5240 ± 865 g C/m2 in vegetation, highly sensitive to large trees, and 13 800 ± 1290 g C/m2 in soils (based on a combined sampling and modeling approach). These contents are greater than for agricultural land in the region, but lower than for mature forest stands. Compared with mature forests, exurban land contained more shrubs and less downed woody debris and it had similar tree size-class distributions up to 40 cm dbh but far fewer trees in larger size classes. If the trees continue to grow, exurban residential land could sequester additional C for decades. Patterns and processes of C storage in exurban residential land were driven by land management practices that affect soil and vegetation, reflecting the choices of designers, developers, and residents. This study provides an example of human-mediated C storage in a coupled human-natural system.


Asunto(s)
Carbono/química , Plantas/química , Suelo/química , Ciclo del Carbono , Monitoreo del Ambiente , Humanos , Michigan
19.
Eur Heart J ; 37(16): 1312-20, 2016 Apr 21.
Artículo en Inglés | MEDLINE | ID: mdl-26685133

RESUMEN

AIMS: The HORIZONS trial reported a survival advantage for bivalirudin over heparin-with-glycoprotein inhibitors (GPIs) in primary PCI for ST elevation myocardial infarction. This drove an international shift in clinical practice. Subsequent studies have produced divergent findings on mortality benefits with bivalirudin. We investigated this issue in a larger population than studied in any of these trials, using the United Kingdom national PCI registry. METHODS AND RESULTS: 61 136 primary PCI procedures were performed between January 2008 and January 2012. Demographic and procedural data were obtained from the registry. Mortality information was obtained through the UK Office of National Statistics. Multivariable logistic regression and propensity analysis modelling were utilized to study the association of different anti-thrombotic strategies with outcomes. Unadjusted data demonstrated near-identical survival curves for bivalirudin and heparin-plus-GPI groups. Significantly higher early and late mortality was found in patients treated with heparin alone ( ITALIC! P < 0.0001) but this group had a markedly higher baseline risk. After propensity matching, the bivalirudin vs. heparin-plus-GPI groups still demonstrated very similar adjusted mortality (odds ratio 1.00 at 30 days, and 0.96 at 1 year). Patients treated with heparin alone continued to show higher mortality after adjustment, although effect size was considerably diminished (odds ratio vs. other groups 1.17-1.24 at 30 days). CONCLUSIONS: Analysis of recent UK data showed no significant difference in short- or medium-term mortality between ST elevation myocardial infarction patients treated with bivalirudin vs. heparin-plus-GPI at primary PCI.


Asunto(s)
Intervención Coronaria Percutánea , Anticoagulantes , Heparina , Hirudinas , Humanos , Infarto del Miocardio , Fragmentos de Péptidos , Complejo GPIIb-IIIa de Glicoproteína Plaquetaria , Proteínas Recombinantes , Resultado del Tratamiento , Reino Unido
20.
J Am Coll Cardiol ; 66(7): 791-800, 2015 Aug 18.
Artículo en Inglés | MEDLINE | ID: mdl-26271061

RESUMEN

BACKGROUND: The use of a balloon-expandable transcatheter heart valve previously resulted in a greater rate of device success compared with a self-expandable transcatheter heart valve. OBJECTIVES: The aim of this study was to evaluate clinical and echocardiographic outcome data at longer term follow-up. METHODS: The investigator-initiated trial randomized 241 high-risk patients with symptomatic severe aortic stenosis and anatomy suitable for treatment with both balloon- and self-expandable transcatheter heart valves to transfemoral transcatheter aortic valve replacement with either device. Patients were followed-up for 1 year, with assessment of clinical outcomes and echocardiographic evaluation of valve function. RESULTS: At 1 year, the rates of death of any cause (17.4% vs. 12.8%; relative risk [RR]: 1.35; 95% confidence interval [CI]: 0.73 to 2.50; p = 0.37) and of cardiovascular causes (12.4% vs. 9.4%; RR: 1.32; 95% CI: 0.63 to 2.75; p = 0.54) were not statistically significantly different in the balloon- and self-expandable groups, respectively. The frequencies of all strokes (9.1% vs. 3.4%; RR: 2.66; 95% CI: 0.87 to 8.12; p = 0.11) and repeat hospitalization for heart failure (7.4% vs. 12.8%; RR: 0.58; 95% CI: 0.26 to 1.27; p = 0.19) did not statistically significantly differ between the 2 groups. Elevated transvalvular gradients during follow-up were observed in 4 patients in the balloon-expandable group (3.4% vs. 0%; p = 0.12); all were resolved with anticoagulant therapy, suggesting a thrombotic etiology. More than mild paravalvular regurgitation was more frequent in the self-expandable group (1.1% vs. 12.1%; p = 0.005). CONCLUSIONS: Despite the higher device success rate with the balloon-expandable valve, 1-year follow-up of patients in CHOICE (Randomized Comparison of Transcatheter Heart Valves in High Risk Patients With Severe Aortic Stenosis: Medtronic CoreValve Versus Edwards SAPIEN XT Trial), with limited statistical power, revealed clinical outcomes after transfemoral transcatheter aortic valve replacement with both balloon- and self-expandable prostheses that were not statistically significantly different. (A Comparison of Transcatheter Heart Valves in High Risk Patients With Severe Aortic Stenosis: The CHOICE Trial; NCT01645202).


Asunto(s)
Estenosis de la Válvula Aórtica/diagnóstico , Estenosis de la Válvula Aórtica/cirugía , Valvuloplastia con Balón/tendencias , Prótesis Valvulares Cardíacas/tendencias , Diseño de Prótesis/tendencias , Reemplazo de la Válvula Aórtica Transcatéter/tendencias , Anciano , Anciano de 80 o más Años , Valvuloplastia con Balón/normas , Femenino , Estudios de Seguimiento , Prótesis Valvulares Cardíacas/normas , Humanos , Masculino , Persona de Mediana Edad , Estudios Prospectivos , Diseño de Prótesis/normas , Factores de Tiempo , Reemplazo de la Válvula Aórtica Transcatéter/normas , Resultado del Tratamiento
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