Unraveling the Mechanisms of Efficient Phosphorus Utilization in Popcorn (Zea mays L. var. everta): Insights from Proteomic and Metabolite Analysis.

The expansion of agriculture and the need for sustainable practices drives breeders to develop plant varieties better adapted to abiotic stress such as nutrient deficiency, which negatively impacts yields. Phosphorus (P) is crucial for photosynthesis and plant growth, but its availability in the soil is often limited, hampering crop development. In this study, we examined the response of two popcorn inbred lines, L80 and P7, which have been characterized previously as P-use inefficient and P-use efficient, respectively, under low (stress) and high P (control) availability. Physiological measurements, proteomic analysis, and metabolite assays were performed to unravel the physiological and molecular responses associated with the efficient use of P in popcorn. We observed significant differences in protein abundances in response to the P supply between the two inbred lines. A total of 421 differentially expressed proteins (DEPs) were observed in L80 and 436 DEPs in P7. These proteins were involved in photosynthesis, protein biosynthesis, biosynthesis of secondary metabolites, and energy metabolism. In addition, flavonoids accumulated in higher abundance in P7. Our results help us understand the major components of P utilization in popcorn, providing new insights for popcorn molecular breeding programs.

Decoding the effects of drought stress on popcorn (Zea mays var. everta) flowering combining proteomics and physiological analysis.

Under conditions of soil water limitation and adequate irrigation, we conducted an investigation into the growth dynamics, gas exchange performance, and proteomic profiles of two inbred popcorn lines-L71, characterized as drought-tolerant, and L61, identified as drought-sensitive. Our goal was to uncover the mechanisms associated with tolerance to soil water limitation during the flowering. The plants were cultivated until grain filling in a substrate composed of perlite and peat within 150cm long lysimeter, subjected to two water conditions (WC): i) irrigated (WW) at lysimeter capacity (LC - 100%), and ii) water-stressed (WS). Under WS conditions, the plants gradually reached 45% of LC and were maintained at this level for 10 days. Irrespective of the WC, L71 exhibited the highest values of dry biomass in both shoot and root systems, signifying its status as the most robust genotype. The imposed water limitation led to early senescence, chlorophyll degradation, and increased anthocyanin levels, with a more pronounced impact observed in L61. Traits related to gas exchange manifested differences between the lines only under WS conditions. A total of 1838 proteins were identified, with 169 differentially accumulated proteins (DAPs) in the tolerant line and 386 DAPs in the sensitive line. Notably, differences in energy metabolism, photosynthesis, oxidative stress response, and protein synthesis pathways were identified as the key distinctions between L71 and L61. Consequently, our findings offer valuable insights into the alterations in proteomic profiles associated with the adaptation to soil water limitation in popcorn.

Early selection for drought tolerance in popcorn based on gene effects estimated in seedlings.

Low rainfall rates are becoming increasingly frequent because of climate change, causing droughts and threatening world food security. For popcorn, drought is the most limiting abiotic factor for plant's growth and development. Thus, the water deficit directly impacts for crop productivity. Based on knowledge of the genetic basis of traits involved in stages of popcorn germination and seedling development under water stress, genotypes with potential for adaptation to adverse growing conditions can be selected early. Therefore, data on genetic effects and combining ability of 10 popcorn parents were compiled to propose breeding strategies for the development of cultivars with greater adaptation to water stress in the early stages. Forty-five diallel hybrids were evaluated under two different water regimes, that is, water stress and full irrigation. This corresponded to a water retention capacity of 25% and 70% of the germination paper. The plants were watered daily as needed for seven days. A range of factors were evaluated, that is, germination traits including the germination speed index and germination on the seventh day; shoot traits including length and dry weight; and root system including length, dry weight, root-to-shoot ratio, maximum root number, root network area, specific and root network length, and root volume. Breeding for drought adaption in the early stages of popcorn development can be successful when hybrids are used, because of the genetic effects of dominance (ϕs). These control the traits evaluated at the seedling stage. The combinations L61 x P2 and L71 x P3 were recommended, in view of the more successful performance estimated for traits related to the shoot and root system.

Exploring the Potential of Heterosis to Improve Nitrogen Use Efficiency in Popcorn Plants.

Nitrogen is crucial for plant growth and development, and improving nitrogen use efficiency (NUE) is a viable strategy for reducing dependence on nitrogen inputs and promoting sustainability. While the benefits of heterosis in corn are well known, the physiological mechanisms underlying this phenomenon in popcorn are less understood. We aimed to investigate the effects of heterosis on growth and physiological traits in four popcorn lines and their hybrids under two contrasting nitrogen conditions. We evaluated morpho-agronomic and physiological traits such as leaf pigments, the maximum photochemical efficiency of PSII, and leaf gas exchange. Components associated with NUE were also evaluated. N deprivation caused reductions of up to 65% in terms of plant architecture, 37% in terms of leaf pigments, and 42% in terms of photosynthesis-related traits. Heterosis had significant effects on growth traits, NUE, and foliar pigments, particularly under low soil nitrogen conditions. N-utilization efficiency was found to be the mechanism favoring superior hybrid performance for NUE. Non-additive genetic effects were predominant in controlling the studied traits, indicating that exploring heterosis is the most effective strategy for obtaining superior hybrids to promote NUE. The findings are relevant and beneficial for agro farmers seeking sustainable agricultural practices and improved crop productivity through the optimization of nitrogen utilization.

Additive and Non-Additive Effects on the Control of Key Agronomic Traits in Popcorn Lines under Contrasting Phosphorus Conditions.

Phosphorus is a non-renewable natural resource that will run out of reserves in the upcoming decades, making it essential to understanding the inheritance of nutrient use efficiency for selecting superior genotypes. This study investigated the additive and non-additive effects of commercially relevant traits for the popcorn crop (grain yield-GY, popping expansion-PE, and expanded popcorn volume per hectare-PV) in different conditions of phosphorus (P) availability in two locations in Rio de Janeiro State, Brazil. Six S7 lines previously selected for P use-L59, L70, and P7, efficient and responsive; and L54, L75, and L80, inefficient and non-responsive-were used as testers in crosses with 15 progenies from the fifth cycle of intrapopulation recurrent selection of UENF-14, with adaptation to the North and Northwest regions of Rio de Janeiro State. Using the Griffing diallel analysis, P use efficiency was predominantly additive in the expression of PE, and non-additive effects were prominent for GY and PV. For obtaining genotypes that are efficient for phosphorus use, it is recommended that heterosis with parents that provide additive gene accumulation for PE be explored.

Revealing the differential protein profiles behind the nitrogen use efficiency in popcorn (Zea mays var. everta).

We investigated the proteomic profiles of two popcorn inbred lines, P2 (N-efficient and N-responsive) and L80 (N-inefficient and nonresponsive to N), under low (10% of N supply) and high (100% of N supply) nitrogen environments, associated with agronomic- and physiological-related traits to NUE. The comparative proteomic analysis allowed the identification of 79 differentially accumulated proteins (DAPs) in the comparison of high/low N for P2 and 96 DAPs in the comparison of high/low N for L80. The NUE and N uptake efficiency (NUpE) presented high means in P2 in comparison to L80 at both N levels, but the NUE, NUpE, and N utilization efficiency (NUtE) rates decreased in P2 under a high N supply. DAPs involved in energy and carbohydrate metabolism suggested that N regulates enzymes of alternative pathways to adapt to energy shortages and that fructose-bisphosphate aldolase may act as one of the key primary nitrate responsive proteins in P2. Proteins related to ascorbate biosynthesis and nitrogen metabolism increased their regulation in P2, and the interaction of L-ascorbate peroxidase and Fd-NiR may play an important role in the NUE trait. Taken together, our results provide new insights into the proteomic changes taking place in contrasting inbred lines, providing useful information on the genetic improvement of NUE in popcorn.

Driving Sustainable Popcorn Breeding for Drought Tolerance in Brazil.

Drought currently affects several regions worldwide and tends to be more frequent due to climate change. It might compromise food security and the economic structure related to agribusiness. Popcorn has a crucial role in the Brazilian economy, but the cultivars that adapt to water stress, the most prejudicial abiotic stress for crop productivity, are unknown to date. This deficit of popcorn varieties adapted to heat and drought stresses will become more limiting with climate change. Given this scenario, knowing the genetic basis of agronomic traits under stress conditions is essential in promoting crop productivity and plant adaptation to abiotic stresses. Under two contrasting water conditions (WC) and different crop seasons (CS), we aimed to generate information about the combining ability of 10 popcorn progenitors and 15 hybrids through a partial diallel-mating design. The water stress was initiated at the male pre-anthesis stage. Significant genotype*crop seasons (G*CS), genotype*water condition (G*WC), and genotype*crop seasons*water condition (G*CS*WC) interactions were present. Regardless of CS and WC, non-additive effects controlled grain yield (GY), grain number per row (GN), ear length and diameter (ED), and 100-grain weight, while additive effects were present for popping expansion (PE). For each CS, regardless of WC, the cause-effect of GN (2018) and ED (2020) on GY seems to be an opportunity for indirect selection. Utilizing genetically broad-based hybrids is also a good opportunity for obtaining superior genotypes for GY and PE as it is possible to select inbred lines for both of these traits. We recommend the L76 × L61 hybrid for the Brazilian agribusiness context due to its greater productivity and dominance deviations.

Regional Heritability Mapping of Quantitative Trait Loci Controlling Traits Related to Growth and Productivity in Popcorn (Zea mays L.).

The method of regional heritability mapping (RHM) has become an important tool in the identification of quantitative trait loci (QTLs) controlling traits of interest in plants. Here, RHM was first applied in a breeding population of popcorn, to identify the QTLs and candidate genes involved in grain yield, plant height, kernel popping expansion, and first ear height, as well as determining the heritability of each significant genomic region. The study population consisted of 98 S1 families derived from the 9th recurrent selection cycle (C-9) of the open-pollinated variety UENF-14, which were genetically evaluated in two environments (ENV1 and ENV2). Seventeen and five genomic regions were mapped by the RHM method in ENV1 and ENV2, respectively. Subsequent genome-wide analysis based on the reference genome B73 revealed associations with forty-six candidate genes within these genomic regions, some of them are considered to be biologically important due to the proteins that they encode. The results obtained by the RHM method have the potential to contribute to knowledge on the genetic architecture of the growth and yield traits of popcorn, which might be used for marker-assisted selection in breeding programs.

Comparative Performance of High-Yielding European Wheat Cultivars Under Contrasting Mediterranean Conditions.

Understanding the interaction between genotype performance and the target environment is the key to improving genetic gain, particularly in the context of climate change. Wheat production is seriously compromised in agricultural regions affected by water and heat stress, such as the Mediterranean basin. Moreover, wheat production may be also limited by the nitrogen availability in the soil. We have sought to dissect the agronomic and physiological traits related to the performance of 12 high-yield European bread wheat varieties under Mediterranean rainfed conditions and different levels of N fertilization during two contrasting crop seasons. Grain yield was more than two times higher in the first season than the second season and was associated with much greater rainfall and lower temperatures. However, the nitrogen effect was rather minor. Genotypic effects existed for the two seasons. While several of the varieties from central/northern Europe yielded more than those from southern Europe during the optimal season, the opposite trend occurred in the dry season. The varieties from central/northern Europe were associated with delayed phenology and a longer crop cycle, while the varieties from southern Europe were characterized by a shorter crop cycle but comparatively higher duration of the reproductive period, associated with an earlier beginning of stem elongation and a greater number of ears per area. However, some of the cultivars from northern Europe maintained a relatively high yield capacity in both seasons. Thus, KWS Siskin from the UK exhibited intermediate phenology, resulting in a relatively long reproductive period, together with a high green area throughout the crop cycle.

Comparison of Selection Traits for Effective Popcorn (Zea mays L. var. Everta) Breeding Under Water Limiting Conditions.

Climate change is expected to intensify water restriction to crops, impacting on the yield potential of crops such as popcorn. This work aimed to evaluate the performance of 10 field cultivated popcorn inbred lines during two growing seasons, under well-watered (WW) and water stressed (WS) (ψsoil≥ -1.5 MPa) conditions. Water stress was applied by withholding irrigation in the phenological phase of male pre-anthesis. Additionally, two contrasting inbred lines, P7 (superior line) and L75 (low performer) were compared for grain yield (GY) and expanded popcorn volume (EPV), selected from previous studies, were tested under greenhouse conditions. In the field, no genotype x water condition x crop season (G×WC×CS) interaction was observed, whereas GY (-51%), EPV (-55%) and leaf greenness (SPAD index) measured 17 days after anthesis (DAA) (> -10%) were highly affected by water limitation. In general, root traits (angles, number, and density) presented G×WC×CS interaction, which did not support their use as selection parameters. In relation to leaf senescence, for both WS and WW conditions, the superior inbred lines maintained a stay-green condition (higher SPAD index) until physiological maturity, but maximum SPAD index values were observed later in WW (48.7 by 14 DAA) than in WS (43.9 by 7 DAA). Under both water conditions, negative associations were observed between SPAD index values 15 and 8 days before anthesis DBA), and GY and EPV (r ≥ -0.69), as well as between SPAD index 7, 17, and 22 DAA, and angles of brace root (AB), number of crown roots (NC) and crown root density (CD), in WS (r ≥ -0.69), and AB and CD, in WW (r ≥ -0.70). Lower NC and CD values may allow further root deepening in WS conditions. Under WS P7 maintained higher net photosynthesis values, stomatal conductance, and transpiration, than L75. Additionally, L75 exhibited a lower (i.e., more negative) carbon isotope composition value than P7 under WS, confirming a lower stomatal aperture in L75. In summary, besides leaf greenness, traits related to leaf photosynthetic status, and stomatal conductance were shown to be good indicators of the agronomic performance of popcorn under water constraint.

Genetic effects on the efficiency and responsiveness to phosphorus use in popcorn as estimated by diallel analysis.

Agricultural expansion and the need for sustainable cultivation are challenges faced by researchers involved in the generation of new cultivars that can adapt to abiotic stress. Knowledge of the genetic effects of characteristics related to efficiency and responsiveness to phosphorus use must be considered when implementing methods to obtain better genotypes. The aim of this study was to characterize and select popcorn hybrids based on their efficiency and responsiveness to phosphorus use, and estimate their combining abilities and genetic effects via diallel analysis to implement improvement programs for sustainable agriculture. Eight contrasting inbred lines were used to obtain simple hybrids for diallel analysis. Twenty-eight diallelic hybrids plus the popcorn parental lines were evaluated at two different sites under two contrasting environments for soil phosphorus availability (6 × 6 lattice design). Grain yield, popping expansion, and volume of expanded popcorn per hectare were measured. A combined analysis of variance and a test of means were performed. The classification and utilization of the phosphorus use efficiency index, according to the grain yield performance of the hybrids under contrasting environments, was considered. Through model 2 of the Griffing's diallel analysis method, the general and specific combining abilities were estimated, along with their environmental interactions. The best strategy to obtain genotypes that are efficient and responsive to phosphorus involves exploring popcorn hybrids using genitors that result in the accumulation of additive genes that promote popping expansion. Hybrids P7 × L80, P7 × L59, P7 × L76, and P6 × L80 presented promising results and may be evaluated as cultivation options in phosphorus-deficient soils.

Left ventricular mass and cardiothoracic index in patients with chronic renal disease on hemodialysis.

INTRODUCTION: Left ventricular hypertrophy (LVH) is an independent predictor of cardiovascular risk in patients with chronic renal disease (CRD) on hemodialysis (HD). OBJECTIVE: To show the usefulness of chest radiography in the diagnosis of LVH in CRD patients on HD. METHODS: Cross-sectional study including 100 patients (58 men and 42 women), mean age 46.2 ± 14.0 years, with CRD of all causes, for at least six months on HD. Were obtained echocardiogram and chest x-rays of patients, always up to one hour after the end of HD sessions. RESULTS: LVH was detected in 83 patients (83%), of whom 56 (67.4%) had the concentric pattern and 27 (32.6%) with eccentric pattern of LVH. Cardiomegaly - defined by cardiothoracic index (CTI) > 0.5 - was present in 61 patients (61%). The following were the sensitivity, specificity and accuracy, respectively, for the variable ICT: 66.2%, 70.5% and 68.0%. The Pearson correlation between ICT and index of left ventricular mass (LVMI) was 0.552 (p < 0.05) and positive likelihood ratio of 2.2. CONCLUSION: Chest radiography is a safe and useful as a diagnostic tool of LVH in CKD patients on HD.

[Prevalence of subclinical atherosclerosis and cardiovascular risk reclassification by measure of carotid intima-media thickness in ambulatory hypertensive patients]. / Prevalência de aterosclerose subclínica e reclassificação de risco cardiovascular pela medida da espessura íntimo-medial carotídea em pacientes hipertensos ambulatoriais.

INTRODUCTION AND OBJECTIVES: Although carotid intima-media thickness (CIMT) is considered a surrogate marker of subclinical atherosclerosis, with known value in risk stratification, its routine use in hypertensive patients is not recommended. The aim of this study was to determine the prevalence of subclinical atherosclerosis through measurement of CIMT and its impact on reclassification of risk in hypertensive patients. METHODS: This was a cross-sectional study of 94 middle-aged (56.99±11.89 years) hypertensive outpatients without overt cardiovascular disease, 68.1% female. All participants underwent clinical examination, biochemical tests, echocardiogram and measurement of CIMT by high-resolution ultrasound. RESULTS: Although the majority of patients were stratified as low (63.5%) or intermediate risk (23%) according to their Framingham score, a high prevalence (75.3%) of increased CIMT was observed in the overall sample, including in the low (61%) and intermediate risk groups (93.8%). CIMT measurement resulted in risk reclassification of 70.31% of the patients, 61% of those at low risk being reclassified as intermediate risk and 93.8% of those at intermediate risk being reclassified as high risk. CONCLUSION: In these hypertensive outpatients, predominantly middle-aged and female, CIMT measurement revealed a high prevalence of subclinical atherosclerosis and resulted in risk reclassification in the majority of cases.

Correlação entre o índice de massa ventricular esquerda e a função endotelial em pacientes hipertensos / Correlation between left ventricular mass index and endothelial function in hypertensive patients

Fundamentos: Tanto a hipertrofia ventricular esquerda (HVE) como a disfunção endotelial representam importantes fatores de risco cardiovascular. No entanto, a correlação entre HVE e disfunção endotelial tem sido pouco explorada e ainda é motivo de controvérsias. Objetivo: Investigar a correlação entre o índice de massa do ventrículo esquerdo (IMVE) e a dilatação mediada por fluxo de artéria braquial (DMF), adotada como estimativa da função endotelial, em indivíduos hipertensos. Materiais e Métodos: Trata-se de estudo transversal envolvendo 94 hipertensos sem doença cardiovascular manifesta, com média de idade de 56,99 ± 11,89 anos, sendo 68,1% do sexo feminino. Todos os participantes foram submetidos a exame clínico, pesquisa de fatores de risco cardiovascular, dosagens bioquímicas, ecodopplercardiografia para determinação do IMVE e pesquisa da DMF por ultra-sonografia de alta resolução. Utilizouse a regressão linear múltipla para pesquisa da associação entre IMVE e DMF. Resultados: A média do IMVE foi de 104,4 ± 26,2 g/m2 e a da DMF, de 5,2 ± 5,7%. Na análise de regressão linear simples, observou-se uma correlação inversa significativa entre o IMVE e a DMF (ß = -0,389, p = 0,007). Após análise de regressão multivariada, a associação persistiu independentemente da pressão arterial, tanto sistólica quanto diastólica, proteína C reativa ultrassensível (PCR-US) e de outros fatores de risco cardiovascular. Conclusão: Observou-se correlação inversa significativa entre IMVE e DMF em hipertensos sem doença cardiovascular manifesta, independentemente da pressão arterial e do status inflamatório.

Background: Both left ventricular hypertrophy (LVH) and endothelial dysfunction represent important cardiovascular risk factors. However, the correlation between LVH and endothelial dysfunction has been little explored and is still a matter of controversies. Objective: To investigate the correlation between left ventricular mass index (LVMI) and flow-mediated dilation (FMD) of brachial artery , used as an estimative measure of endothelial dysfunction, in hypertensive patients. Materials and Methods: This is a cross-sectional study involving 94 middle-aged (56,99 ± 11,89 years) hypertensive outpatients without overt cardiovascular disease, being 68,1% female. All the participants underwent clinical examination, biochemical analyses, search for cardiovascular risk factors, transthoracic echocardiography for the determination of LVMI and assessment of FMD using a high-resolution Doppler B-mode ultrasound equipment. A multiple linear regression model was used to analyse the association between LVMI and DMF. Results: Mean LVMI was 104,4 ± 26,2 g/m2 and mean DMF, 5,2 ± 5,7%. Using simple linear regression, it was observed a significant inverse correlation between LVMI and FMD (ß = -0,389, p =0,007). This association remained significant even after adjustment for systolic and diastolic blood pressure, high sensitivity C-reactive protein (hs-CRP) and many other cardiovascular risk factors. Conclusions: In these hypertensive patients without overt cardiovascular disease, it was observed a significant inverse correlation between LVMI and FMD, which was independent of blood pressure and inflammatory status.

Association of circulating levels of nicotinamide phosphoribosyltransferase (NAMPT/Visfatin) and of a frequent polymorphism in the promoter of the NAMPT gene with coronary artery disease in diabetic and non-diabetic subjects.

BACKGROUND: Nicotinamide phosphoribosyltransferase (NAMPT) is the limiting enzyme in one of pathways of synthesis of Nicotinamide Adenine Dinucleotide, a redox coenzyme. NAMPT is considered as an insulin-mimetic factor and a potential regulatory factor in inflammatory and immune processes. Associations of circulating NAMPT levels with cardiovascular disease (CVD) and insulin resistance have been reported. We investigated association of circulating NAMPT levels and the rs9770242 NAMPT gene polymorphism with coronary artery disease (CAD). METHODS: We studied 594 Brazilian subjects undergoing a coronary angiography (49% of whom had type 2 diabetes). CAD, defined as stenosis greater than 50% in one major coronary vessel or branch, was observed in 68% of subjects. Genetic studies were also performed in 858 North-American Non-Hispanic White subjects with type 2 diabetes (49% with CAD). RESULTS: We observed an interaction between glycemic and CAD status on the comparison of NAMPT levels by CAD status. NAMPT levels were higher in type 2 diabetic patients with CAD as compared to those without CAD: 5.27 ± 2.93 ng/ml vs. 4.43 ± 2.94 ng/ml, p = 0.006 (mean ± SD). NAMPT levels were not significantly different in non-diabetic subjects with or without CAD. The T-allele of rs9770242 was associated with CAD in the Brazilian cohort (OR 1.46, 95% CI 1.06 - 2.01, p = 0.02) while no association was observed in the North-American cohort. CONCLUSIONS: Our data suggest that circulating NAMPT levels are associated with CAD in type 2 diabetic patients. NAMPT rs9770242 polymorphism may be associated with CAD in some populations.

Percutaneous mechanical assistance for the failing heart.

One of the most challenging situations in contemporary medicine is, doubtlessly, the approach and treatment of patients presenting with severe left ventricle failure. Since its first clinical application in patients with cardiogenic shock in 1968, the intraaortic balloon pump (IABP) has been widely accepted by heart failure physicians. Although IABP therapy has been shown to be effective for the support and stabilization of hemodynamically compromised patients, it has failed to promote any improvements in patient outcomes. For this reason, much attention has been invested in the development of external devices that can collaborate with the treatment of this condition. In this context, the percutaneous left ventricle assist device (pLVAD), like TandemHeart (Cardiac Assist, Inc.; Pittsburgh, PA, USA), and, more recently, the Impella 2.5 (Abiomed Europe, Aachen, Germany) has emerged. The purpose of this review is to describe the history of pLVAD, from its beginning, to the other devices currently available, including those created for right ventricle and biventricular support.

Feasibility, safety and accuracy of dobutamine/atropine stress echocardiography for the detection of coronary artery disease in renal transplant candidates.

OBJECTIVE: To evaluate the feasibility, safety and accuracy of dobutamine/atropine stress echocardiography (DASE) for the detection of coronary artery disease (CAD) in renal transplant candidates. METHODS: Patients candidates to renal transplant were submitted consecutively to DASE and coronary angiography. The adopted angiographic criteria for CAD were an obstructive lesion of > or = 50% and > or = 70%. RESULTS: 148 patients underwent the DASE and the coronary angiography. Mean age was 52 +/- 9 years, 69% of the patients were males; 27% had diabetic nephropathy and 73% had LVH; 63% were asymptomatic; 36% and 22% presented coronary obstructions > or = 50% and 70%, respectively. The DASE performance was 91% and major complication rate was 2.7%. The sensibility, specificity and accuracy for the diagnosis of coronary obstruction > 50% were 53% (CI:45-61), 87% (CI:81-93), and 75% (CI:63-83) respectively. For coronary obstruction > or = 70% these values were, respectively, 71% (CI:64-92), 85% (CI:79-91) and 81% (CI:75-87). The sensibility to detect univessel and multivessel disease was 41% (CI:19-63) and 78% (CI:64-92), respectively. CONCLUSION: The DASE was practical and safe; however, it presented a poor result for the detection of CAD regarding obstructions > or = 50%. It can be a useful screening for the detection of CAD in candidates with obstructions > or = 70% and multivessel disease.