Genetic Mapping of the Root Mycobiota in Rice and its Role in Drought Tolerance.

BACKGROUND: Rice is the second most produced crop worldwide, but is highly susceptible to drought. Micro-organisms can potentially alleviate the effects of drought. The aim of the present study was to unravel the genetic factors involved in the rice-microbe interaction, and whether genetics play a role in rice drought tolerance. For this purpose, the composition of the root mycobiota was characterized in 296 rice accessions (Oryza sativa L. subsp. indica) under control and drought conditions. Genome wide association mapping (GWAS) resulted in the identification of ten significant (LOD > 4) single nucleotide polymorphisms (SNPs) associated with six root-associated fungi: Ceratosphaeria spp., Cladosporium spp., Boudiera spp., Chaetomium spp., and with a few fungi from the Rhizophydiales order. Four SNPs associated with fungi-mediated drought tolerance were also found. Genes located around those SNPs, such as a DEFENSIN-LIKE (DEFL) protein, EXOCYST TETHERING COMPLEX (EXO70), RAPID ALKALINIZATION FACTOR-LIKE (RALFL) protein, peroxidase and xylosyltransferase, have been shown to be involved in pathogen defense, abiotic stress responses and cell wall remodeling processes. Our study shows that rice genetics affects the recruitment of fungi, and that some fungi affect yield under drought. We identified candidate target genes for breeding to improve rice-fungal interactions and hence drought tolerance.

High-energy-level metabolism and transport occur at the transition from closed to open flowers.

During the maturation phase of flower development, the onset of anthesis visibly marks the transition from buds to open flowers, during which petals stretch out, nectar secretion commences, and pollination occurs. Analysis of the metabolic changes occurring during this developmental transition has primarily focused on specific classes of metabolites, such as pigments and scent emission, and far less on the whole network of primary and secondary metabolites. To investigate the metabolic changes occurring at anthesis, we performed multi-platform metabolomics alongside RNA sequencing in individual florets harvested from the main inflorescence of Arabidopsis (Arabidopsis thaliana) ecotype Col-0. To trace metabolic fluxes at the level of the whole inflorescence and individual florets, we further integrated these studies with radiolabeled experiments. These extensive analyses revealed high-energy-level metabolism and transport of carbohydrates and amino acids, supporting intense metabolic rearrangements occurring at the time of this floral transition. These comprehensive data are discussed in the context of our current understanding of the metabolic shifts underlying flower opening. We envision that this analysis will facilitate the introgression of floral metabolic traits promoting pollination in crop species for which a comprehensive knowledge of flower metabolism is still limited.

Can biochemical traits bridge the gap between genomics and plant performance? A study in rice under drought.

The possibility of introducing metabolic/biochemical phenotyping to complement genomics-based predictions in breeding pipelines has been considered for years. Here we examine to what extent and under what environmental conditions metabolic/biochemical traits can effectively contribute to understanding and predicting plant performance. In this study, multivariable statistical models based on flag leaf central metabolism and oxidative stress status were used to predict grain yield (GY) performance for 271 indica rice (Oryza sativa) accessions grown in the field under well-watered and reproductive stage drought conditions. The resulting models displayed significantly higher predictability than multivariable models based on genomic data for the prediction of GY under drought (Q2 = 0.54-0.56 versus 0.35) and for stress-induced GY loss (Q2 = 0.59-0.64 versus 0.03-0.06). Models based on the combined datasets showed predictabilities similar to metabolic/biochemical-based models alone. In contrast to genetic markers, models with enzyme activities and metabolite values also quantitatively integrated the effect of physiological differences such as plant height on GY. The models highlighted antioxidant enzymes of the ascorbate-glutathione cycle and a lipid oxidation stress marker as important predictors of rice GY stability under drought at the reproductive stage, and these stress-related variables were more predictive than leaf central metabolites. These findings provide evidence that metabolic/biochemical traits can integrate dynamic cellular and physiological responses to the environment and can help bridge the gap between the genome and the phenome of crops as predictors of GY performance under drought.

Assessing Drought and Heat Stress-Induced Changes in the Cotton Leaf Metabolome and Their Relationship With Hyperspectral Reflectance.

The study of phenotypes that reveal mechanisms of adaptation to drought and heat stress is crucial for the development of climate resilient crops in the face of climate uncertainty. The leaf metabolome effectively summarizes stress-driven perturbations of the plant physiological status and represents an intermediate phenotype that bridges the plant genome and phenome. The objective of this study was to analyze the effect of water deficit and heat stress on the leaf metabolome of 22 genetically diverse accessions of upland cotton grown in the Arizona low desert over two consecutive years. Results revealed that membrane lipid remodeling was the main leaf mechanism of adaptation to drought. The magnitude of metabolic adaptations to drought, which had an impact on fiber traits, was found to be quantitatively and qualitatively associated with different stress severity levels during the two years of the field trial. Leaf-level hyperspectral reflectance data were also used to predict the leaf metabolite profiles of the cotton accessions. Multivariate statistical models using hyperspectral data accurately estimated (R 2 > 0.7 in ∼34% of the metabolites) and predicted (Q 2 > 0.5 in 15-25% of the metabolites) many leaf metabolites. Predicted values of metabolites could efficiently discriminate stressed and non-stressed samples and reveal which regions of the reflectance spectrum were the most informative for predictions. Combined together, these findings suggest that hyperspectral sensors can be used for the rapid, non-destructive estimation of leaf metabolites, which can summarize the plant physiological status.

Drought tolerance in selected aerobic and upland rice varieties is driven by different metabolic and antioxidative responses.

MAIN CONCLUSIONS: Sugar-mediated osmotic acclimation and a strong antioxidative response reduce drought-induced biomass loss at the vegetative stage in rice. A clear understanding of the physiological and biochemical adaptations to water limitation in upland and aerobic rice can help to identify the mechanisms underlying their tolerance to low water availability. In this study, three indica rice varieties-IR64 (lowland), Apo (aerobic), and UPL Ri-7 (upland)-, that are characterized by contrasting levels of drought tolerance, were exposed to drought at the vegetative stage. Drought-induced changes in biomass, leaf metabolites and oxidative stress markers/enzyme activities were analyzed in each variety at multiple time points. The two drought-tolerant varieties, Apo and UPL Ri-7 displayed a reduced water use in contrast to the susceptible variety IR64 that displayed high water consumption and consequent strong leaf dehydration upon drought treatment. A sugar-mediated osmotic acclimation in UPL Ri-7 and a strong antioxidative response in Apo were both effective in limiting the drought-induced biomass loss in these two varieties, while biomass loss was high in IR64, also after recovery. A qualitative comparison of these results with the ones of a similar experiment conducted in the field at the reproductive stage showed that only Apo, which also in this stage showed the highest antioxidant power, was able to maintain a stable grain yield under stress. Our results show that different metabolic and antioxidant adaptations confer drought tolerance to aerobic and upland rice varieties in the vegetative stage. The effectiveness of these adaptations differs between developmental stages. Unraveling the genetic control of these mechanisms might be exploited in breeding for new rice varieties adapted to water-limited environments.

Multiple Small-Effect Alleles of Indica Origin Enhance High Iron-Associated Stress Tolerance in Rice Under Field Conditions in West Africa.

Understanding the genetics of field-based tolerance to high iron-associated (HIA) stress in rice can accelerate the development of new varieties with enhanced yield performance in West African lowland ecosystems. To date, few field-based studies have been undertaken to rigorously evaluate rice yield performance under HIA stress conditions. In this study, two NERICA × O. sativa bi-parental rice populations and one O.sativa diversity panel consisting of 296 rice accessions were evaluated for grain yield and leaf bronzing symptoms over multiple years in four West African HIA stress and control sites. Mapping of these traits identified a large number of QTLs and single nucleotide polymorphisms (SNPs) associated with stress tolerance in the field. Favorable alleles associated with tolerance to high levels of iron in anaerobic rice soils were rare and almost exclusively derived from the indica subpopulation, including the most favorable alleles identified in NERICA varieties. These findings highlight the complex genetic architecture underlying rice response to HIA stress and suggest that a recurrent selection program focusing on an expanded indica genepool could be productively used in combination with genomic selection to increase the efficiency of selection in breeding programs designed to enhance tolerance to this prevalent abiotic stress in West Africa.

Biomarkers for grain yield stability in rice under drought stress.

Crop yield stability requires an attenuation of the reduction of yield losses caused by environmental stresses such as drought. Using a combination of metabolomics and high-throughput colorimetric assays, we analysed central metabolism and oxidative stress status in the flag leaf of 292 indica rice (Oryza sativa) accessions. Plants were grown in the field and were, at the reproductive stage, exposed to either well-watered or drought conditions to identify the metabolic processes associated with drought-induced grain yield loss. Photorespiration, protein degradation, and nitrogen recycling were the main processes involved in the drought-induced leaf metabolic reprogramming. Molecular markers of drought tolerance and sensitivity in terms of grain yield were identified using a multivariate model based on the values of the metabolites and enzyme activities across the population. The model highlights the central role of the ascorbate-glutathione cycle, particularly dehydroascorbate reductase, in minimizing drought-induced grain yield loss. In contrast, malondialdehyde was an accurate biomarker for grain yield loss, suggesting that drought-induced lipid peroxidation is the major constraint under these conditions. These findings highlight new breeding targets for improved rice grain yield stability under drought.

Association mapping and genetic dissection of drought-induced canopy temperature differences in rice.

Drought-stressed plants display reduced stomatal conductance, which results in increased leaf temperature by limiting transpiration. In this study, thermal imaging was used to quantify the differences in canopy temperature under drought in a rice diversity panel consisting of 293 indica accessions. The population was grown under paddy field conditions and drought stress was imposed for 2 weeks at flowering. The canopy temperature of the accessions during stress negatively correlated with grain yield (r= -0.48) and positively with plant height (r=0.56). Temperature values were used to perform a genome-wide association (GWA) analysis using a 45K single nucleotide polynmorphism (SNP) map. A quantitative trait locus (QTL) for canopy temperature under drought was detected on chromosome 3 and fine-mapped using a high-density imputed SNP map. The candidate genes underlying the QTL point towards differences in the regulation of guard cell solute intake for stomatal opening as the possible source of temperature variation. Genetic variation for the significant markers of the QTL was present only within the tall, low-yielding landraces adapted to drought-prone environments. The absence of variation in the shorter genotypes, which showed lower leaf temperature and higher grain yield, suggests that breeding for high grain yield in rice under paddy conditions has reduced genetic variation for stomatal response under drought.

Long-term Follow up of Patients with Acute Aortic Syndromes: Relevance of both Aortic and Non-aortic Events.

BACKGROUND: The aim was to assess the long-term outcome of patients diagnosed with type A and type B acute aortic syndromes (AAS) and the mortality risk predictors. METHODS: A single centre retrospective observational study was performed on consecutive patients diagnosed with AAS and discharged between 2000 and 2016: 242 surgically treated type A, 87 uncomplicated, medically treated type B, and 80 complicated type B who received endovascular/surgical/hybrid treatment. Follow up of discharged patients (5 ± 3.9 years) was almost complete by the end of the study (December 2017). RESULTS: The mean age was 65.3 ± 12.5 years, and 70.2% were men. Long-term all cause mortality was 5.4 per 100 patients per year in surgically treated type A AAS patients and 6.7 per 100 patients per year in type B AAS patients (p = .236). The rates of major aorta related events were 6.1 per 100 patients per year and 13.4 per 100 patients per year, respectively (p < .001). Non-aorta related events during long-term follow up occurred in 18.2 per 100 patients per year in type A and 13.8 per 100 patients per year in type B (p = .055). At the end of follow up 279/409 (68.2%) patients (165/242 type A and 114/167 type B) experienced at least one event. CONCLUSIONS: Among patients with either type A or type B AAS surviving the acute phase, the risk of adverse aorta and non-aorta related events, including death, persists during follow up, so that eventually two thirds of patients will experience at least one event. Notably, all cause mortality after type B AAS exceeds that of type A AAS after three years.

Utility of stress perfusion-cardiac magnetic resonance in follow-up of patients undergoing percutaneous coronary interventions of the left main coronary artery.

To assess the accuracy of cardiac magnetic resonance (CMR) for the diagnosis of angiographic stenosis after percutaneous coronary intervention (PCI) of left main coronary artery (LMCA). Patients undergone in the last year PCI of unprotected LMCA and scheduled for conventional X-ray coronary angiography (CXA) were evaluated with stress perfusion CMR within 2 weeks before CXA. Main contraindications to CMR were exclusion criteria. Stress perfusion CMR was performed to follow a bolus of contrast Gadobutrol after 3 min of adenosine infusion. Between the 50 patients enrolled, only 1 did not finish the CMR protocol and 49 patients with median age 71 (65-75) years (38 male, 11 female) were analyzed. Between 784 coronary angiographic segments evaluated we found 75 stenosis or occlusions (prevalence 9.5%), but only 13 stenosis or occlusions in proximal segments (prevalence 6.6%). Patients with coronary stenosis (n = 12, 24%) showed a significantly (p = 0.002) higher prevalence of diabetes (7 of 12, 58%). At CMR examination, late gadolinium enhancement was present in 25 (51%), reversible perfusion defects in 12 (24%), and fixed perfusion defects in 6 subjects (12%). The only patient with LMCA restenosis resulted positive at perfusion CMR. The accuracy of stress perfusion CMR in diagnosis of coronary stenosis was higher when the analysis was performed only in proximal coronary arteries (95%, CI 86-99) compared to overall vessels (84%, CI 70-92). Stress perfusion CMR could strongly reduce the need for elective CXA in follow up of LMCA PCI and should be validated in further multicenter prospective studies.

Inferior Q waves in apparently healthy subjects: Should we take a deep breath? An electrocardiographic, echocardiographic and cardiac magnetic resonance study.

AIM: To evaluate the diagnostic accuracy of electrocardiographic inferior Q waves persistence during inspiration and echocardiographic segmental wall motion abnormalities for the detection of previously unsuspected silent myocardial infarction, by using cardiac magnetic resonance as the gold standard. METHODS: We prospectively enrolled 50 apparently healthy subjects with inferior Q waves on routine electrocardiogram and high atherosclerotic risk profile. Patients underwent electrocardiogram during deep inspiration, standard transthoracic echocardiography, and cardiac magnetic resonance. RESULTS: Inferior Q waves during deep inspiration persisted in 10 subjects (20%) and cardiac magnetic resonance was positive in 10 (20%). Between the 10 positive cardiac magnetic resonance subjects 8 showed persistence of inferior Q waves, giving a sensitivity of 80% (95%;CI 44.4-97.5%) and a specificity of 95% (95%;CI 83.1-99.4%). Segmental wall motion abnormalities were present overall in 10 subjects (20%), but only in 5 of the 10 positive cardiac magnetic resonance subjects, giving a sensitivity of 87.5% (95% CI 73.2-95.8) and specificity of 50% (95% CI 18.7-81.3). CONCLUSIONS: Electrocardiographic inferior Q waves persistence during deep inspiration is a simple test with a high accuracy for diagnosis of silent myocardial infarction. Standard echocardiography resulted less accurate.

Long-term prognostic role of cerebrovascular disease and peripheral arterial disease across the spectrum of acute coronary syndromes.

BACKGROUND: In acute coronary syndromes (ACS), the influence of cerebro-vascular disease (CVD) and/or peripheral artery disease (PAD) on short-midterm outcome has been well established. Data on long-term outcome however, are limited. Our study aimed to explore the effect of CVD and PAD on long-term outcome in a cohort of unselected ACS patients, including ST-elevation (STE-ACS) and non-ST-elevation (NSTE-ACS). METHODS AND RESULTS: The population consisted of 2046 consecutive patients with a confirmed final diagnosis of ACS; 896 (44%) had STE-ACS and 1150 (66%) NSTE-ACS. CVD alone was present in 98 patients (5%), 282 (14%) had PAD alone, and 30 (1.5%) had both. All cause mortality at 5 years was lowest in patients without CVD/PAD (33%), intermediate in patients with either CVD or PAD (62% and 63%, respectively) reaching 80% in those with both CVD and PAD. These findings were confirmed in the STE-ACS and NSTE-ACS subgroups. CVD and PAD remained independent predictors of mortality after multivariable analysis, the combined presence of both carrying the highest risk within each ACS type (HR 4.15, 95% CI 1.83-9.44 for STE-ACS; HR 2.14, 1.29-3.54 for NSTE-ACS). Patients with CVD and/or PAD were less likely to be treated invasively and received less evidence-based treatment at discharge. CONCLUSIONS: Across the spectrum of ACS, extracardiac vascular disease harbors a negative long-term prognosis that worsens progressively with the number of affected arterial beds.

Troponin T elevation in acute aortic syndromes: Frequency and impact on diagnostic delay and misdiagnosis.

AIMS: Despite troponin assay being a part of the diagnostic work up in many conditions with acute chest pain, little is known about its frequency and clinical implications in acute aortic syndromes (AASs). In our study we assessed frequency, impact on diagnostic delay, inappropriate treatments, and prognosis of troponin elevation in AAS. METHODS AND RESULTS: Data were collected from a prospective metropolitan AAS registry (398 patients diagnosed between 2000 and 2013). Cardiac troponin test, using either standard or high sensitivity assay, was performed according to standard protocol used in chest pain units. Troponin T values were available in 248 patients (60%) of the registry population; the overall frequency of troponin positivity was 28% (ranging from 16% to 54%, using standard or high sensitivity assay respectively, p = 0.001). Troponin positivity was frequently associated with acute coronary syndromes (ACS)-like electrocardiogram findings, and with a twofold increased risk of long in-hospital diagnostic time (odds ratio (OR) 1.92, 95% confidence interval (CI) 1.05-3.52, p = 0.03). The combination of positive troponin and ACS-like electrocardiogram abnormalities resulted in a significantly increased risk of in-hospital delay/coronary angiography/antithrombotic therapy due to a misdiagnosis of ACS (OR 2.48, 95% CI 1.12-5.54, p = 0.02). However, troponin positivity was not associated with in-hospital mortality (OR 1.63, 95% CI 0.86-3.10, p = 0.131). CONCLUSIONS: Troponin positivity was a frequent finding in AAS patients, particularly when a high sensitivity assay was employed. Abnormal troponin values were strongly associated with ACS-like electrocardiogram findings and with in-hospital diagnostic delay but apparently they did not influence in-hospital mortality.

Acute heart failure in patients with acute aortic syndrome: pathophysiology and clinical-prognostic implications.

AIMS: Although acute heart failure (AHF) is a potential complication of acute aortic syndromes (AAS), its clinical details and management implications have been scarcely evaluated. This study aimed to assess prevalence, pathophysiological mechanisms, impact on treatment, and in-hospital mortality of AHF in AAS. METHODS AND RESULTS: Data were collected from a prospective AAS registry (398 patients diagnosed between 2000 and 2013). Patients with AHF were identified by the presence of dyspnoea as the presentation symptom or radiological signs of pulmonary congestion or cardiogenic shock, including patients with cardiac tamponade (CT). AHF frequency was 28% (Stanford type A 32% vs. type B 20%, P = 0.01). Four mechanisms leading to AHF were identified, alone or in combination: CT (26%), aortic regurgitation (25%), myocardial ischaemia (17%), and hypertensive crisis (10%). In type A patients, aortic regurgitation and CT were the most frequent mechanisms, whereas myocardial ischaemia and hypertensive crisis were the most frequent in type B patients. Although no difference was noted for diagnostic times, AHF at presentation led to a longer surgical delay in type A AAS. In-hospital mortality was higher in patients with AHF compared with those without (34% vs. 17%, P < 0.001). After multivariable analysis, AHF was associated with increased risk of in-hospital death (adjusted odds ratio 1.97, 95% confidence interval 1.14-3.36, P = 0.014). CONCLUSION: AHF occurs in more than a quarter of patients with AAS of both type A and type B, is due to a variety of pathophysiological mechanisms, and is associated with increased surgical delay and in-hospital mortality.

Long-term outcomes and causes of death after acute coronary syndrome in patients in the Bologna, Italy, area.

We sought to evaluate the rates, time course, and causes of death in the long-term follow-up of unselected patients with acute coronary syndromes (ACS). We enrolled 2046 consecutive patients hospitalized from January 2004 to December 2005 with an audited final diagnosis of ACS. The primary study end point was 5-year all-cause mortality. In our series, 896 patients had ST-segment elevation (STE) and 1,150 non-ST-segment elevation (NSTE). Mean age of the study population was 71.6 years. Primary percutaneous coronary intervention was performed in 86% of STE-ACS, and 70% of NSTE-ACS was managed invasively. The 5-year all-cause mortality was 36.4% for STE-ACS and 42.0% for NSTE-ACS, with patients with STE-ACS showing a trend boarding statistical significance toward a lower risk of mortality (hazard ratio [HR] = 0.88, 95% confidence interval [CI] 0.76 to 1.02, p = 0.08). Landmark analysis demonstrated that patients with STE-ACS had a higher risk of 30-day mortality (STE-ACS vs NSTE-ACS HR = 1.53, 95% CI 1.16 to 2.06, p = 0.003) whereas the risk of NSTE-ACS increased markedly after 1 year (STE-ACS vs NSTE-ACS HR = 0.67, 95% CI 0.53 to 0.84, p = 0.001). The contribution of noncardiovascular (CV) causes to overall mortality increased from 3% at 30 days to 34% at 5 years, with cancer and infections being the most common causes of non-CV death both in STE-ACS and NSTE-ACS. In conclusion, long-term mortality after ACS is still too high both for STE-ACS and NSTE-ACS. Although patients with STE-ACS have a higher mortality during the first year, the mortality of patients with NSTE-ACS increases later, when non-CV co-morbidities gain greater importance.

Impact of high-sensitivity Troponin T on hospital admission, resources utilization, and outcomes.

AIMS: The use of high-sensitivity cardiac Troponin T (hs-cTnT) assay might lead to overdiagnosis and overtreatment of Acute Coronary Syndromes (ACS). This study assessed the epidemiological, clinical and prognostic impact of introducing hs-cTnT in the everyday clinical practice of an Emergency Department. METHODS AND RESULTS: We compared all consecutive patients presenting with suspected ACS at the Emergency Department, for whom troponin levels were measured. In particular, we considered 597 patients presenting during March 2010, when standard cardiac Troponin T (cTnT) assay was used, and 629 patients presenting during March 2011, when hs-cTnT test was used. Patients with suspected ACS and troponin levels above the 99th percentile (Upper Reference Limit, URL) significantly increased when using an hs-cTnT assay (17.2% vs. 37.4%, p< 0.001). Accordingly, also the mean GRACE risk score increased (124.2 ± 37.2 vs. 136.7 ± 32.2; p< 0.001). However, the final diagnosis of Acute Myocardial Infarction (AMI) did not change significantly (8.7% vs. 6.8%, p=0.263) by using a rising and/or falling pattern of hs-cTnT (change ≥ 50% or ≥ 20% depending on baseline values). In addition, no significant differences were found between the two study groups with respect to in-hospital (2.7% vs. 1.9%, p=0.366) and 1-year mortality (9.8% vs. 7.6%, p=0.216). CONCLUSIONS: We did not observe overdiagnosis and overtreatment issues in presenters with suspected ACS managed by appropriate changes in hs-cTnT levels, despite the increase in the number of patients presenting with abnormal troponin levels. This occurred without a rise in short-term and mid-term mortality.

Recent temporal trends for first-time hospitalization for acute myocardial infarction. Treatment patterns and clinical outcome in a large cohort study.

BACKGROUND: The objective was to report recent trends in the incidence, adoption of evidence-based treatment, and clinical outcomes for first-time hospitalization for acute myocardial infarction. METHODS: This is a large retrospective population-based cohort study using medical administrative data (International Classification of Diseases, Ninth Revision, Clinical Modification, codes) performed in the Emilia-Romagna Region of Italy (approximately 4.5 million inhabitants). We identified 60,673 patients with a first hospitalization for acute myocardial infarction from 2002 through 2009. RESULTS: The standardized incidence rate per 100,000 person-years of acute myocardial infarction increased from 173 cases in 2002 to a peak of 197 cases in 2004 and then decreased each year thereafter to 167 cases in 2009. The proportion of patients who underwent coronary angiography and angioplasty in the acute phase increased over time, respectively, from 45.4% and 27.1% to 72.3% and 57.2% (P < .001). Medication use within 12 months of discharge increased for aspirin, ß-blockers, and statins. A reduction in crude and adjusted in-hospital all-cause (16.1% in 2002 vs 12.8% in 2009, P < .001) and cardiovascular mortality (13.6% in 2002 vs 9.5% in 2009, P < .001) was observed over time. At 1 year after hospital discharge, no significant variations occurred in adjusted risk for all-cause mortality or cardiovascular mortality. Notably, crude and adjusted risk for in-hospital and postdischarge bleeding showed a significant increment. CONCLUSIONS: The utilization of evidence-based treatments in patients with myocardial infarction increased between 2002 and 2009. These changes in practice over time favored a reduction in early case fatality at the cost of a significant increase in bleeding.

Prognostic significance of mean platelet volume on admission in an unselected cohort of patients with non ST-segment elevation acute coronary syndrome.

Mean platelet volume (MPV) has been proposed as a marker of platelet reactivity and cardiovascular risk. Its prognostic significance has not been thoroughly investigated in patients with non-ST elevation acute coronary syndrome (NSTE-ACS). We included 1,041 consecutive patients with NSTE-ACS. Patients were divided in quartiles according to the MPV value on admission (fl) i.e. Q1<7.5; Q2=7.5-8.0; Q3=8.1-8.8; Q4≥8.9. The primary study endpoint was the composite of cardiovascular death and re-myocardial infarction (MI) at one year. Secondary study endpoints were individual cardiovascular death and re-MI. Patients in Q4 were older, had a higher prevalence of previous MI, peripheral artery disease and advanced Killip class compared to patients in Q1-Q3. Elevated MPV levels (Q4) was independently associated with gender, smoking status, platelet count and creatinine level. Overall, 210 patients (20.2%) reached the primary endpoint, 124 (12.1%) died from cardiovascular causes and 125 (12.0%) suffered from re-MI. On multivariable analysis patients in Q4 were at higher risk of primary endpoint (HR=1.41; 95%CI 1.06-1.89; p=0.02) whilst the association with cardiovascular death and re-MI was attenuated. MPV as continuous variable was independently associated with both primary endpoint (HR=1.19; 95%CI 1.06-1.33; p=0.003) and cardiovascular death (HR=1.23; 95%CI 1.06-1.42, p=0.006). The incorporation of MPV into a comprehensive model of risk significantly increased the likelihood ratio chi-square for prediction of both the composite endpoint (p=0.004) and cardiovascular death (p=0.009). Therefore, MPV may be useful to improve risk stratification in NSTE-ACS patients and should be included in future prospective studies evaluating the role of platelet function in promoting cardiovascular events.