Bottom trawl fishing footprints on the world's continental shelves.

Bottom trawlers land around 19 million tons of fish and invertebrates annually, almost one-quarter of wild marine landings. The extent of bottom trawling footprint (seabed area trawled at least once in a specified region and time period) is often contested but poorly described. We quantify footprints using high-resolution satellite vessel monitoring system (VMS) and logbook data on 24 continental shelves and slopes to 1,000-m depth over at least 2 years. Trawling footprint varied markedly among regions: from <10% of seabed area in Australian and New Zealand waters, the Aleutian Islands, East Bering Sea, South Chile, and Gulf of Alaska to >50% in some European seas. Overall, 14% of the 7.8 million-km2 study area was trawled, and 86% was not trawled. Trawling activity was aggregated; the most intensively trawled areas accounting for 90% of activity comprised 77% of footprint on average. Regional swept area ratio (SAR; ratio of total swept area trawled annually to total area of region, a metric of trawling intensity) and footprint area were related, providing an approach to estimate regional trawling footprints when high-resolution spatial data are unavailable. If SAR was ≤0.1, as in 8 of 24 regions, there was >95% probability that >90% of seabed was not trawled. If SAR was 7.9, equal to the highest SAR recorded, there was >95% probability that >70% of seabed was trawled. Footprints were smaller and SAR was ≤0.25 in regions where fishing rates consistently met international sustainability benchmarks for fish stocks, implying collateral environmental benefits from sustainable fishing.

Combining Text Messaging and Telephone Counseling to Increase Varenicline Adherence and Smoking Abstinence Among Cigarette Smokers Living with HIV: A Randomized Controlled Study.

Smoking represents an important health risk for people living with HIV (PLHIV). Low adherence to smoking cessation pharmacotherapy may limit treatment effectiveness. In this study, 158 participants recruited from three HIV care centers in New York City were randomized to receive 12-weeks of varenicline (Chantix) either alone as standard care (SC) or in combination with text message (TM) support or TM plus cell phone-delivered adherence-focused motivational and behavioral therapy (ABT). Generalized linear mixed-effect models found a significant decline in varenicline adherence from week 1-12 across treatment groups. At 12-weeks, the probability of smoking abstinence was significantly higher in SC+TM+ABT than in SC. The study demonstrates the feasibility of delivering adherence-focused interventions to PLHIV who smoke. Findings suggest intensive behavioral support is an important component of an effective smoking cessation intervention for this population, and a focus on improving adherence self-efficacy may lead to more consistent adherence and higher smoking abstinence.

Correlates of Adherence to Varenicline Among HIV+ Smokers.

INTRODUCTION: Low rates of adherence to smoking cessation pharmacotherapy may limit the effectiveness of treatment. However, few studies have examined adherence in smoking cessation trials thus, there is a limited understanding of factors that influence adherence behaviors. This brief report analyzes correlates of adherence to varenicline among people living with HIV/AIDS. METHODS: Study participants were recruited from three HIV care centers in New York City and enrolled in a three-arm randomized controlled pilot study in which all subjects received varenicline. At the 1-month study visit, there were no significant differences in adherence by study condition, therefore we combined treatment arms to examine correlates of adherence (n = 127). We used pill counts to assess varenicline adherence, defined as taking at least 80% of the prescribed dose. We conducted a multivariate path analysis to assess factors proposed by the information-motivation-behavioral skills model to predict adherence. RESULTS: Only 56% of smokers were at least 80% adherent to varenicline at 1 month. Adherence-related information, self-efficacy, a college degree, and non-Hispanic white race/ethnicity were associated with increased varenicline adherence. In path analysis, information and motivation were associated with increased adherence self-efficacy, and adherence self-efficacy was associated with increased adherence, but with marginal significance. These associations with adherence were no longer significant after controlling for race/ethnicity and education. CONCLUSIONS: Further exploration of the role of a modifiable correlates of adherence, such as adherence-related information, motivation and self-efficacy is warranted. Interventions are needed that can address disparities in these and other psychosocial factors that may mediate poor medication adherence.

Using vessel monitoring system data to improve systematic conservation planning of a multiple-use marine protected area, the Kosterhavet National Park (Sweden).

When spatial fishing data is fed into systematic conservation planning processes the cost to a fishery could be ensured to be minimal in the zoning of marine protected areas. We used vessel monitoring system (VMS) data to map the distribution of prawn trawling and calculate fishing intensity for 1-ha grid cells, in the Kosterhavet National Park (Sweden). We then used the software Marxan to generate cost-efficient reserve networks that represented every biotope in the Park. We asked what were the potential gains and losses in terms of fishing effort and species conservation of different planning scenarios. Given a conservation target of 10 % representation of each biotope, the fishery need not lose more than 20 % of its fishing grounds to give way to cost-efficient conservation of benthic diversity. No additional reserved area was needed to achieve conservation targets while minimizing fishing costs. We discuss the benefits of using VMS data for conservation planning.

Towards a scientific community consensus on designating Vulnerable Marine Ecosystems from imagery.

Management of deep-sea fisheries in areas beyond national jurisdiction by Regional Fisheries Management Organizations/Arrangements (RFMO/As) requires identification of areas with Vulnerable Marine Ecosystems (VMEs). Currently, fisheries data, including trawl and longline bycatch data, are used by many RFMO/As to inform the identification of VMEs. However, the collection of such data creates impacts and there is a need to collect non-invasive data for VME identification and monitoring purposes. Imagery data from scientific surveys satisfies this requirement, but there currently is no established framework for identifying VMEs from images. Thus, the goal of this study was to bring together a large international team to determine current VME assessment protocols and establish preliminary global consensus guidelines for identifying VMEs from images. An initial assessment showed a lack of consistency among RFMO/A regions regarding what is considered a VME indicator taxon, and hence variability in how VMEs might be defined. In certain cases, experts agreed that a VME could be identified from a single image, most often in areas of scleractinian reefs, dense octocoral gardens, multiple VME species' co-occurrence, and chemosynthetic ecosystems. A decision flow chart is presented that gives practical interpretation of the FAO criteria for single images. To further evaluate steps of the flow chart related to density, data were compiled to assess whether scientists perceived similar density thresholds across regions. The range of observed densities and the density values considered to be VMEs varied considerably by taxon, but in many cases, there was a statistical difference in what experts considered to be a VME compared to images not considered a VME. Further work is required to develop an areal extent index, to include a measure of confidence, and to increase our understanding of what levels of density and diversity correspond to key ecosystem functions for VME indicator taxa. Based on our results, the following recommendations are made: 1. There is a need to establish a global consensus on which taxa are VME indicators. 2. RFMO/As should consider adopting guidelines that use imagery surveys as an alternative (or complement) to using bycatch and trawl surveys for designating VMEs. 3. Imagery surveys should also be included in Impact Assessments. And 4. All industries that impact the seafloor, not just fisheries, should use imagery surveys to detect and identify VMEs.

Predicting the distribution of out-of-reach biotopes with decision trees in a Swedish marine protected area.

Through spatially explicit predictive models, knowledge of spatial patterns of biota can be generated for out-of-reach environments, where there is a paucity of survey data. This knowledge is invaluable for conservation decisions. We used distribution modeling to predict the occurrence of benthic biotopes, or megafaunal communities of the seabed, to support the spatial planning of a marine national park. Nine biotope classes were obtained prior to modeling from multivariate species data derived from point source, underwater imagery. Five map layers relating to depth and terrain were used as predictor variables. Biotope type was predicted on a pixel-by-pixel basis, where pixel size was 15 x 15 m and total modeled area was 455 km2. To choose a suitable modeling technique we compared the performance of five common models based on recursive partitioning: two types of classification and regression trees ([1] pruned by 10-fold cross-validation and [2] pruned by minimizing complexity), random forests, conditional inference (CI) trees, and CI forests. The selected model was a CI forest (an ensemble of CI trees), a machine-learning technique whose discriminatory power (class-by-class area under the curve [AUC] ranged from 0.75 to 0.86) and classification accuracy (72%) surpassed those of the other methods tested. Conditional inference trees are virtually new to the field of ecology. The final model's overall prediction error was 28%. Model predictions were also checked against a custom-built measure of dubiousness, calculated at the polygon level. Key factors other than the choice of modeling technique include: the use of a multinomial response, accounting for the heterogeneity of observations, and spatial autocorrelation. To illustrate how the model results can be implemented in spatial planning, representation of biodiversity in the national park was described and quantified. Given a goal of maximizing classification accuracy, we conclude that conditional inference trees are a promising tool to map biota. Species distribution modeling is presented as an ecological tool that can handle a wide variety of systems (e.g., the benthic system).

Role of Right Ventricular Strain Measured by Two-Dimensional Echocardiography in the Diagnosis of Cardiac Amyloidosis.

BACKGROUND: Cardiac amyloidosis (CA) causes restrictive cardiomyopathy usually associated with a poor prognosis. Two subtypes predominate: systemic light-chain CA (ALCA) and transthyretin-derived CA (either wild type transthyretin amyloidosis [TTRwt] or mutant transthyretin amyloidosis [TTRm]). Left ventricular (LV) apical sparing has been extensively studied using speckle-tracking echocardiography for diagnosis, but the right ventricular (RV) deformation pattern has not been described. The aims of this study were to characterize RV involvement in patients with CA and to identify parameters that may help in the differential diagnosis between ALCA and transthyretin-derived CA subtypes. METHODS: Seventy-eight patients with CA (47 with ALCA, 20 with TTRwt, and 11 with TTRm) and 24 healthy control subjects were included. Global longitudinal strain (GLS) was analyzed in 16 LV and six RV segments. LV and RV apical ratios (ARs) were obtained. GLS was expressed as an absolute value. RESULTS: LV GLS and free-wall RV longitudinal strain were impaired in all patients (LV GLS: 11.9 ± 2.9% in ALCA, 12.5 ± 3.8% in TTRwt, 14.9 ± 2.7% in TTRm, and 21.9 ± 2.6% in control subjects [P < .01]; free-wall RV longitudinal strain: 13.1 ± 6.8%, 14.9 ± 4.5%, 17.2 ± 3.4%, and 22.1 ± 3.1%, respectively [P < .01]). LV and RV ARs were higher in ALCA compared with both TTRwt, TTRm, and control subjects (LV AR: 1.1 ± 0.2, 0.8 ± 0.2, 0.9 ± 0.1, and 0.7 ± 0.1, respectively [P < .001]; RV AR: 1.1 ± 0.2, 0.6 ± 0.2, 0.6 ± 0.1, and 0.6 ± 0.1, respectively [P < .001]). Cutoff values of LV AR > 0.96 and RV AR > 0.8 showed high accuracy to differentiate between ALCA and transthyretin-derived CA. CONCLUSIONS: RV dysfunction is common in patients with CA. Analysis of RV strain showed an apical sparing pattern, as previously described in the left ventricle, with a higher AR as a specific finding in patients with ALCA. RV AR may be a parameter that can differentiate the subtypes of amyloidosis on the basis of speckle-tracking echocardiographic analysis.

Losartan Versus Atenolol for Prevention of Aortic Dilation in Patients With Marfan Syndrome.

BACKGROUND: Beta-blockers are the standard treatment in Marfan syndrome (MFS). Recent clinical trials with limited follow-up yielded conflicting results on losartan's effectiveness in MFS. OBJECTIVES: The present study aimed to evaluate the benefit of losartan compared with atenolol for the prevention of aortic dilation and complications in Marfan patients over a longer observation period (>5 years). METHODS: A total of 128 patients included in the previous LOAT (LOsartan vs ATenolol) clinical trial (64 in the atenolol and 64 in the losartan group) were followed up for an open-label extension of the study, with the initial treatment maintained. RESULTS: Mean clinical follow-up was 6.7 ± 1.5 years. A total of 9 events (14.1%) occurred in the losartan group and 12 (18.8%) in the atenolol group. Survival analysis showed no differences in the combined endpoint of need for aortic surgery, aortic dissection, or death (p = 0.462). Aortic root diameter increased with no differences between groups: 0.4 mm/year (95% confidence interval: 0.2 to 0.5) in the losartan and 0.4 mm/year (95% confidence interval: 0.3 to 0.6) in the atenolol group. In the subgroup analyses, no significant differences were observed considering age, baseline aortic root diameter, or type of dominant negative versus haploinsufficient FBN1 mutation. CONCLUSIONS: Long-term outcome of Marfan syndrome patients randomly assigned to losartan or atenolol showed no differences in aortic dilation rate or presence of clinical events between treatment groups. Therefore, losartan might be a useful, low-risk alternative to beta-blockers in the long-term management of these patients.

Differences in biological traits composition of benthic assemblages between unimpacted habitats.

There is an implicit requirement under contemporary policy drivers to understand the characteristics of benthic communities under anthropogenically-unimpacted scenarios. We used a trait-based approach on a large dataset from across the European shelf to determine how functional characteristics of unimpacted benthic assemblages vary between different sedimentary habitats. Assemblages in deep, muddy environments unaffected by anthropogenic disturbance show increased proportions of downward conveyors and surface deposit-feeders, while burrowing, diffusive mixing, scavenging and predation traits assume greater numerical proportions in shallower habitats. Deep, coarser sediments are numerically more dominated by sessile, upward conveyors and suspension feeders. In contrast, unimpacted assemblages of coarse sediments in shallower regions are proportionally dominated by the diffusive mixers, burrowers, scavengers and predators. Finally, assemblages of gravelly sediments exhibit a relatively greater numerical dominance of non-bioturbators and asexual reproducers. These findings may be used to form the basis of ranking habitats along a functional sensitivity gradient.

Usefulness of Two-Dimensional Strain Parameters to Diagnose Acute Rejection after Heart Transplantation.

BACKGROUND: Acute cellular rejection (ACR) is still a relevant complication after orthotopic heart transplantation. The diagnosis of ACR is based on endomyocardial biopsy (EMB). Recent advances in two-dimensional strain imaging may allow early noninvasive detection of ACR. The objective of this study was to analyze the usefulness of conventional and new echocardiographic parameters to exclude ACR after orthotopic heart transplantation. METHODS: Thirty-four consecutive adult heart transplant recipients admitted to a single center between January 2010 and December 2012 for orthotopic heart transplantation were prospectively included. A total of 235 pairs of EMB and echocardiographic examination were performed. A median of seven studies per patient (interquartile range, six to eight studies per patient) were performed during the first year of follow-up. Classic echocardiographic parameters; speckle-tracking-derived left ventricular (LV) longitudinal, radial, and circumferential strain; and global and free wall right ventricular (RV) longitudinal strain were analyzed. RESULTS: ACR was detected in 26.4% of EMB samples (n = 62); 5.1% (n = 12) required specific treatment (ACR degree ≥ 2R). Lower absolute values of global LV longitudinal strain and free wall RV longitudinal strain were present in patients with ACR degree ≥ 2R compared with those without ACR (13.7 ± 2.7% vs 17.8 ± 3.4% and 16.6 ± 3.6% vs 23.3 ± 5.2%, respectively). An average LV longitudinal strain < 15.5% had 85.7% sensitivity, 81.4% specificity, 98.8% negative predictive value, 25.0% positive predictive value, and 81.7% accuracy for the presence of ACR degree ≥ 2R. Free wall RV longitudinal strain < 17% had 85.7% sensitivity, 91.1% specificity, 98.8% negative predictive value, 42.9% positive predictive value, and 90.7% accuracy for ACR degree ≥ 2R. Both variables were normal in 106 echocardiograms (57.6%); none of these patients presented with ACR degree ≥ 2R. CONCLUSIONS: The combination of two new echocardiographic measures, global LV and RV free wall longitudinal strain, may be able to identify a group of heart transplant patients who are unlikely to have ACR. If these findings are confirmed independently, it may be possible to use LV and RV strain measures as reliable tools to exclude ACR and to reduce the burden of repeated EMB.

Noninvasive monitoring of serial changes in pulmonary vascular resistance and acute vasodilator testing using cardiac magnetic resonance.

OBJECTIVES: The study sought to evaluate the ability of cardiac magnetic resonance (CMR) to monitor acute and long-term changes in pulmonary vascular resistance (PVR) noninvasively. BACKGROUND: PVR monitoring during the follow-up of patients with pulmonary hypertension (PH) and the response to vasodilator testing require invasive right heart catheterization. METHODS: An experimental study in pigs was designed to evaluate the ability of CMR to monitor: 1) an acute increase in PVR generated by acute pulmonary embolization (n = 10); 2) serial changes in PVR in chronic PH (n = 22); and 3) changes in PVR during vasodilator testing in chronic PH (n = 10). CMR studies were performed with simultaneous hemodynamic assessment using a CMR-compatible Swan-Ganz catheter. Average flow velocity in the main pulmonary artery (PA) was quantified with phase contrast imaging. Pearson correlation and mixed model analysis were used to correlate changes in PVR with changes in CMR-quantified PA velocity. Additionally, PVR was estimated from CMR data (PA velocity and right ventricular ejection fraction) using a formula previously validated. RESULTS: Changes in PA velocity strongly and inversely correlated with acute increases in PVR induced by pulmonary embolization (r = -0.92), serial PVR fluctuations in chronic PH (r = -0.89), and acute reductions during vasodilator testing (r = -0.89, p ≤ 0.01 for all). CMR-estimated PVR showed adequate agreement with invasive PVR (mean bias -1.1 Wood units,; 95% confidence interval: -5.9 to 3.7) and changes in both indices correlated strongly (r = 0.86, p < 0.01). CONCLUSIONS: CMR allows for noninvasive monitoring of acute and chronic changes in PVR in PH. This capability may be valuable in the evaluation and follow-up of patients with PH.

[Epidemiological analysis of the improving areas for blood pressure control at Primary Care practice]. / Análisis de las áreas de mejora del control de la hipertensión arterial en Atención Primaria.

BACKGROUND AND OBJECTIVES: Most hypertensive patients do not have their blood pressure (BP) under control. This study aims to evaluate Primary Care physicians' management of hypertension by analyzing the four main areas proposed by experts to improve BP control. MATERIAL AND METHODS: From February to May 2003 a questionnaire was completed by 195 Primary Care physicians from 33 Primary Care centers of Madrid, Spain. Four aspects of clinical practice were examined: a) knowledge of hypertension guidelines and objectives; b) diagnosis and follow-up of patients; c) hypertension treatment, and d) drug compliance. RESULTS: Guidelines were followed by 90.6% of the physicians. Twenty six percent of the physicians perceived that guideline objectives are too strict and only 32% identified systolic BP as the component that provides more risk. Only 14% used automatic devices to measure BP while 89% still use the mercury sphygmomanometer. Diuretics were included among the 3 most used antihypertensive drugs by 94% of the physicians, ACEI by 91%, beta blockers by 62% and combinations only by 24%. Eighty eight percent believed that more than 40% of their patients have their BP under control and 53% felt that less than 20% of their patients were non-compliant with antihypertensive treatment. CONCLUSIONS: Hypertension management among Primary Care physicians showed some deficiencies in the 4 analyzed areas. Thus, perception of excessively rigorous guideline objectives, underrating of systolic BP, underuse of automatic devices and drug associations, and the overestimation of BP control and therapeutic compliance are specific areas that should be modified to improve BP control.

[Cost savings derived from the participation in clinical trials]. / Ahorro derivado de la participación en ensayos clínicos.

BACKGROUND: Medical care of patients with essential hypertension implies considerable expenses for the National Health System (NHS). During the performance of clinical trials (CT), the promoter (usually the pharmaceutical industry) covers the expenses of patient care, which implies savings for the NHS. In this work, we quantitated cost savings derived from the participation of patients in clinical trials on essential hypertension in a tertiary care level Insalud hospital. PATIENTS AND METHODS: Savings were defined as the difference between the economical expenses of a patient before being enrolled in a clinical trial (CT) and that generated during his/her participation in the CT. Expenses of a given patient to the NHS were calculated from his/her clinical record during a time period equal to CT length in which the patient participated. Three financial allottments in four CT were analyzed (three with a 52-week duration and one of 14 weeks) that meant cost savings (total or partial): a) antihypertensive drugs; b) complementary tests, and c) medical visits. RESULTS: Seventy-three patients with essential hypertension were enrolled in the 4 CT; 59 (81%) patients were randomly assigned and 57 patients concluded the CT. The overall savings derived from the participation of the 57 patients was 2,950,423 pesetas. Most of these savings corresponded to drugs (70.7%). Savings derived from laboratory tests (14.1%) and medical visits (15.1%) were similar. The mean savings derived from the participation of one patient in a CT for 12 months was, at least, 70,564 pesetas (5,880 pesetas/patient/month). CONCLUSIONS: The participation of patients with essential AH implies considerable savings for the NHS.

Análisis de las áreas de mejora del control de la hipertensión arterial en Atención Primaria / Epidemiological analysis of the improving areas for blood pressure control at Primary Care practice

Fundamento y objetivo. La mayoría de los hipertensos no tienen sus cifras de presión arterial (PA) controladas. Este estudio pretende conocer el manejo de la hipertensión arterial (HTA) por médicos de Atención Primaria en su práctica diaria analizando las cuatro grandes áreas de mejora del control propuestas por los expertos. Material y métodos. Desde febrero a mayo de 2003 se administró una encuesta a 195 médicos de Atención Primaria procedentes de 33 Centros de Salud de la Comunidad de Madrid. El cuestionario estudia 4 aspectos de la práctica clínica: a) conocimiento de las guías de HTA y objetivos terapéuticos; b) diagnóstico y seguimiento de pacientes hipertensos; c) tratamiento de la HTA, y d) cumplimiento terapéutico. Resultados. El 90,6% de los médicos sigue alguna guía acreditada. Para el 26% los objetivos terapéuticos de las guías son demasiado rigurosos y sólo el 32% identificó la presión sistólica como la que mayor riesgo confiere. Sólo el 14% utiliza dispositivos automáticos de brazo para medir la PA y el 89% utiliza esfigmomanómetros de mercurio. Para el 94% los diuréticos están entre los 3 fármacos más utilizados, los inhibidores de la enzima conversora de la angiotensina (IECA) para el 91%, los bloqueadores beta para el 62% y las combinaciones sólo para el 24%. El 88% cree que más del 40% de sus pacientes tienen su PA controlada. El 53% opina que menos del 20% de sus pacientes incumple/abandona el tratamiento antihipertensivo. Conclusiones. Se han identificado deficiencias en el manejo de la HTA en las 4 áreas analizadas. Así, la percepción de un excesivo rigor en los objetivos de las guías, el menosprecio de la presión sistólica, la infrautilización de los tensiómetros automáticos y de las asociaciones farmacológicas y la sobreestimación del control y del cumplimiento terapéutico son aspectos a corregir para incrementar el control de la PA (AU)

Background and objectives. Most hypertensive patients do not have their blood pressure (BP) under control. This study aims to evaluate Primary Care physicians' management of hypertension by analyzing the four main areas proposed by experts to improve BP control. Material and methods. From February to May 2003 a questionnaire was completed by 195 Primary Care physicians from 33 Primary Care centers of Madrid, Spain. Four aspects of clinical practice were examined: a) knowledge of hypertension guidelines and objectives; b) diagnosis and follow-up of patients; c) hypertension treatment, and d) drug compliance. Results. Guidelines were followed by 90.6% of the physicians. Twenty six percent of the physicians perceived that guideline objectives are too strict and only 32% identified systolic BP as the component that provides more risk. Only 14% used automatic devices to measure BP while 89% still use the mercury sphygmomanometer. Diuretics were included among the 3 most used antihypertensive drugs by 94% of the physicians, ACEI by 91%, beta blockers by 62% and combinations only by 24%. Eighty eight percent believed that more than 40% of their patients have their BP under control and 53% felt that less than 20% of their patients were non-compliant with antihypertensive treatment. Conclusions. Hypertension management among Primary Care physicians showed some deficiencies in the 4 analyzed areas. Thus, perception of excessively rigorous guideline objectives, underrating of systolic BP, underuse of automatic devices and drug associations, and the overestimation of BP control and therapeutic compliance are specific areas that should be modified to improve BP control (AU)

Ahorro derivado de la participación en ensayos clínicos / Cost savings derived from the participation in clinical trials

Fundamento. El cuidado de los pacientes con hipertensión arterial (HTA) esencial supone para el Sistema Nacional de la Salud (SNS) un gasto económico considerable. Durante la realización de ensayos clínicos (EECC) el promotor (habitualmente la industria farmacéutica) suele cubrir los gastos que conlleva la atención de los enfermos, lo que supone un ahorro para el SNS. Hemos cuantificado el ahorro derivado de la participación en EECC sobre HTA esencial en un hospital de nivel terciario del Insalud. Pacientes y métodos: El ahorro se ha definido como la diferencia entre el gasto económico que suponía el cuidado de un paciente antes de ser incluido en un ensayo clínico (EC) y el que se genera durante su participación en el EC. El gasto que un paciente determinado estaba suponiendo para el SNS se ha calculado a partir de su historia clínica durante un período de tiempo igual a la duración del EC en el que participó. Se analizaron en cuatro EECC (tres con una duración de 52 semanas y uno de 14 semanas) tres partidas económicas que suponen un ahorro (total o parcial): a) fármacos antihipertensivos; b) pruebas complementarias, y c) visitas médicas. Resultados: En los cuatro EECC se incluyeron 73 pacientes con HTA esencial, de los cuales 59 enfermos fueron aleatorizados (81 por ciento) y 57 pacientes concluyeron los EECC. El ahorro global derivado de la participación de los 57 enfermos fue de 2.950.423 pesetas. La mayor parte de este ahorro correspondió a fármacos (70,7 por ciento). El ahorro en pruebas de laboratorio (14,1 por ciento) y visitas médicas (15,1 por ciento) fue similar. El ahorro medio derivado de la participación de un paciente en un EC durante 12 meses fue, como mínimo, de 70.564 pesetas corrientes (5.880 pesetas/paciente/mes).Conclusiones: La participación de pacientes con HTA esencial en EECC supone un ahorro considerable para el SNS (AU)