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

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.

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.

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.

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.

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.

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.

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.

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, β-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.

Short- and long-term prognostic significance of ST-segment elevation in lead aVR in patients with non-ST-segment elevation acute coronary syndrome

We sought to evaluate the prognostic significance of ST-segment elevation (STE) in lead aVR in unselected patients with non-STE acute coronary syndrome (NSTE-ACS). We enrolled 1,042 consecutive patients with NSTE-ACS. Patients were divided into 5 groups according to the following electrocardiographic (ECG) patterns on admission: (1) normal electrocardiogram or no significant ST-T changes, (2) inverted T waves, (3) isolated ST deviation (ST depression [STD] without STE in lead aVR or transient STE), (4) STD plus STE in lead aVR, and (5) ECG confounders (pacing, right or left bundle branch block). The main angiographic end point was left main coronary artery (LM) disease as the culprit artery. Clinical end points were in-hospital and 1-year cardiovascular death defined as the composite of cardiac death, fatal stroke, and fatal bleeding. Prevalence of STD plus STE in lead aVR was 13.4%. Rates of culprit LM disease and in-hospital cardiovascular death were 8.1% and 3.8%, respectively. On multivariable analysis, patients with STD plus STE in lead aVR (group 4) showed an increased risk of culprit LM disease (odds ratio 4.72, 95% confidence interval [CI] 2.31 to 9.64, p <0.001) and in-hospital cardiovascular mortality (odds ratio 5.58, 95% CI 2.35 to 13.24, p <0.001) compared to patients without any ST deviation (pooled groups 1, 2, and 5), whereas patients with isolated ST deviation (group 3) did not. At 1-year follow-up 127 patients (12.2%) died from cardiovascular causes. On multivariable analysis, STD plus STE in lead aVR was a stronger independent predictor of cardiovascular death (hazard ratio 2.29, 95% CI 1.44 to 3.64, p <0.001) than isolated ST deviation (hazard ratio 1.52, 95% CI 0.98 to 2.36, p = 0.06). In conclusion, STD plus STE in lead aVR is associated with high-risk coronary lesions and predicts in-hospital and 1-year cardiovascular deaths in patients with NSTE-ACS. Therefore, this promptly available ECG pattern could be useful to improve risk stratification and management of patients with NSTE-ACS.

Review of tenecteplase (TNKase) in the treatment of acute myocardial infarction

TNKase is a genetically engineered variant of the alteplase molecule. Three different mutations result in an increase of the plasma half-life, of the resistance to plasminogen-activator inhibitor 1 and of the thrombolytic potency against platelet-rich thrombi. Among available agents in clinical practice, TNKase is the most fibrin-specific molecule and can be delivered as a single bolus intravenous injection. Several large-scale clinical trials have enrolled more than 27,000 patients with acute myocardial infarction, making the use of this drug truly evidence-based. TNKase is equivalent to front-loaded alteplase in terms of mortality and is the only bolus thrombolytic drug for which this equivalence has been formally demonstrated. TNKase appears more potent than alteplase when symptoms duration lasts more than 4 hours. Also, TNKase significantly reduces the rate of major bleeds and the need for blood transfusions. The efficacy of TNKase may be further improved by enoxaparin substitution for unfractionated heparin, provided that enoxaparin dose adjustment is made for patients more than 75 years old. Hitherto, the small available randomized studies and international clinical registries suggest that pre-hospital TNKase is as effective as primary angioplasty, thus laying the foundations for a new fibrinolytic, TNKase-based strategy as the backbone of reperfusion in acute myocardial infarction.

[How to manage pregnancy in cardiac patients]

An increasing number of women with cardiac disease come up with the idea of becoming pregnant. Immigrants are frequently affected by valvular heart disease. Recently, arrhythmias, high blood pressure and ischemic heart disease affect many less-young pregnant women. Finally, grown-up patients with congenital heart disease have now entered their fertility period (particularly following the Fontan operation). Pregnancy is legitimate and frequently cannot be restrained; it calls for a careful evaluation of all its treatment aspects by a multidisciplinary team and the cardiologist role is of the utmost importance. A few conditions make pregnancy a hazard to both mother and fetus: pulmonary hypertension, left ventricular failure, left-heart obstruction, Marfan syndrome with aortic dilatation, and cyanosis. Most remaining cases are compatible with an (almost) normal course whereby mothers can be reassured. However, all items covered by guidelines should be met, according to the quality imperative.

Matrix metalloproteinases in premature coronary atherosclerosis: influence of inhibitors, inflammation, and genetic polymorphisms

Matrix metalloproteinases (MMPs) are thought to participate in the pathogenesis of coronary artery disease (CAD), particularly in the occurrence of acute coronary syndrome (ACS). Little is known about human in vivo MMP regulation in CAD. The expression and regulation of MMPs and their tissue inhibitors (TIMPs) were evaluated in premature CAD. The distribution of MMP-3 5A/6A and MMP-9 C/T promoter polymorphisms and MMP-9 A/G exon-6 polymorphism were investigated in 200 consecutive male premature CAD patients (aged < or = 55 years) and 201 age-matched male blood donors. Plasma concentrations/activities of MMP-2 and MMP-9 were also measured, as were plasma concentrations of MMP-3, TIMP-1, and TIMP-2 in 80 patients (49 with ACSs and 31 with stable CAD) and 40 controls. Inflammation markers were also obtained. MMP genetic polymorphism distributions did not vary between patients and controls and did not seem to influence their respective MMP plasma levels. Patients showed increased MMP-9 and TIMP-1 concentrations and decreased TIMP-2 concentration and MMP-2 total activity (all P < or = 0.002). Overall, TIMP-1 correlated with C-reactive protein (CPR) (r = 0.594, P < 0.001) and haptoglobin (r = 0.276, P = 0.005), whereas MMP-2 activity correlated inversely with haptoglobin (r = -0.195, P = 0.032). Blood glucose correlated positively with TIMP-1 concentration (r = 0.711, P < 0.001) and negatively with MMP-2 activity (r = -0.250, P = 0.006). In conclusion, MMP and TIMP plasma levels in premature CAD are linked to clinical presentation and markers of inflammation and metabolic disorders rather than to genetic polymorphisms.

Periodontal health improves systemic inflammatory and haemostatic status in subjects with coronary heart disease

OBJECTIVES

A relationship between poor oral health and coronary heart disease (CHD) and systemic inflammatory and haemostatic factors has been recently documented in an Italian population. The present study was performed to assess whether intensive dental care may produce a periodontal improvement along with a change in systemic inflammatory and haemostatic factors.

MATERIAL AND METHODS

The study population consisted of 18 males aged 40-65 years with proven CHD and elevated values of systemic inflammatory and haemostatic factors. A detailed description of their oral status was given by using two different dental indices (clinical periodontal sum score and clinical and radiographic sum score). Blood samples were taken for measurement of the following systemic markers of inflammation [(C-reactive protein (CRP), leucocytes, fibrinogen)] and haemostatic factors [(von Willebrand factor, fibrin D-dimer and oxidized-low density lipoprotein (Ox-LDL)]. All parameters were determined in each subject at baseline, after 4 months as a control and 3 months after an intensive protocol of scaling and root planing. anova for repeated measures was used for the statistical analysis.

RESULTS

No statistical difference was found between values at baseline and at the 4-month-control. All oral indexes showed a significant decrease (p< .01) 3 months after periodontal treatment. All systemic inflammatory indexes decreased but only the decrease in CRP reached statistical significance (p< .05). A significant decrease (p< .01) was also found as regards Ox-LDL among haemostatic factors.

CONCLUSIONS

Preliminary results from the present study suggest an association between poor oral status and CHD, and provide evidence that the improvement of periodontal status may influence the systemic inflammatory and haemostatic situation.

Clinical use of novel antithrombotic agents in the management of acute coronary syndromes

Among patients with ST elevation-acute coronary syndrome (ACS) novel thrombolytic agents can be given as a bolus (reteplase, tenecteplase) and their delivery is easier and may shorten the time to treatment, providing the ideal tool in the pre-hospital setting. Reinfarction after thrombolysis occurs in the 3-5% range in all major trials. Reinfarction after thrombolysis rate may be reduced by abciximab and enoxaparin. However major hemorrhage is doubled by abciximab (but not by enoxaparin). When primary angioplasty is preferred to thrombolysis, adjunctive abciximab decreases the need for urgent target vessel revascularization. A whole body of literature tells that aspirin is not enough in patients without ST elevation ACS. Most patients benefit from concomitant clopidogrel. High-risk patients are candidate to the use GP IIb-IIIA blockers, particularly if they need coronary angioplasty. All patients with glomerular filtration rate > or = 30 ml/min should receive low molecular weight heparin. Evidence for that is mainly driven by studies using enoxaparin.

[Late-appearing cholestatic icterus after a month of treatment with ticlopidine]

A 65-year-old man was submitted to coronary angioplasty and stent implantation for stable angina. The treatment included a 30-day therapy with ticlopidine (in addition to aspirin, metoprolol, ramipril, amlodipine and nitrates). One month after ticlopidine withdrawal a progressive cholestatic jaundice took place. Viral, immunogenic as well as nutritional causes were ruled out. The abdominal echography disclosed a normal biliary tree and the liver biopsy showed a centrolobular cholestasis pattern. Drug-induced cholestatic reaction was diagnosed and attributed to ticlopidine. There was a progressive improvement in clinical and laboratory findings 4 months after steroid treatment. The clinical picture was normalized after 6 months. When considering the option ticlopidine, even for a short time after coronary angioplasty, the possibility of drug-induced hepatotoxicity should be kept in mind. Consequently, markers of liver toxicity should be monitored carefully.

Long-term arterial patency after coronary reperfusion

Coronary reocclusion is a frequent event after reperfusion and may be responsible for the deterioration of left ventricular function. It may occur early as well as in the chronic phase after hospital discharge. Current, evidence based, strategies to prevent reocclusion include antiplatelet and anticoagulant agents as well as the use of intracoronary stenting in those patients who are treated by PTCA. The combination of aspirin and ticlopidine adds on the results of stenting. Further treatments are currently investigated and may significantly improve the long-term coronary patency.

Prognostic value of the admission electrocardiogram in acute coronary syndromes

CONTEXT

The presence of ischemic changes on electrocardiogram (ECG) correlates with poorer outcomes in patients with acute chest pain.

OBJECTIVE

To determine the prognostic value of various ECG presentations of acute myocardial ischemia.

DESIGN

Retrospective analysis of the presenting ECGs of patients enrolled in Global Use of Strategies To Open Occluded Arteries in Acute Coronary Syndromes (GUSTO-IIb).

SETTING

Three hundred seventy-three hospitals in 13 countries in North America, Europe, Australia, and New Zealand.

PATIENTS

A total of 12142 patients who reported symptoms of cardiac ischemia at rest within 12 hours of admission and had signs of myocardial ischemia confirmed by ECG. On presenting ECG, 22% of patients had T-wave inversion, 28% had ST-segment elevation, 35% had ST-segment depression, and 15% had a combination of ST-segment elevation and depression.

MAIN OUTCOME MEASURE

Ability of presenting ECG to predict death or myocardial reinfarction during the first 30 days of follow-up.

RESULTS

The 30-day incidence of death or myocardial reinfarction was 5.5% in patients with T-wave inversion, 9.4% in those with ST-segment elevation, 10.5% in those with ST-segment depression, and 12.4% in those with ST-segment elevation and depression (P<.001). After adjusting for factors associated with an increased risk of 30-day death or reinfarction, compared with those who had T-wave inversion only, the odds of 30-day death or reinfarction were 1.68 (95% confidence interval [CI], 1.36-2.08) in those with ST-segment elevation, 1.62 (95% CI, 1.32-1.98) for those with ST-segment depression, and 2.27 (95% CI, 1.80-2.86) for those with combined elevation and depression. An elevated creatine kinase level at admission correlated with a higher risk of death (odds ratio [OR], 2.36; 95% CI, 1.92-2.91) and death or reinfarction (OR, 1.56; 95% CI, 1.32-1.85). The ECG category and creatine kinase level at admission remained highly predictive of death and myocardial infarction after multivariate adjustment for the significant baseline predictors of events.

CONCLUSIONS

The ECG at presentation allows immediate risk stratification across the spectrum of acute coronary syndromes. An elevated creatine kinase level at admission is associated with worse outcomes.

Randomised comparison of subcutaneous heparin, intravenous heparin, and aspirin in unstable angina. Studio Epoorine Sottocutanea nell'Angina Instobile (SESAIR) Refrattorie Group

Intravenous heparin has been used in the control of myocardial ischaemia in patients with unstable angina. We set out to assess the efficacy of subcutaneous heparin in reducing myocardial ischaemia in patients with unstable angina. 343 of 399 patients with unstable angina were monitored for 24 h and 108 were refractory to conventional antianginal treatment and were entered into a randomised multicentre trial. 37 patients were assigned to heparin infusion (partial thromboplastin time 1.5-2 times baseline), 35 to subcutaneous heparin (adjusted dose with partial thromboplastin time 1.5-2 times baseline), and 36 to aspirin (325 mg daily). All had additional conventional antianginal therapy. After the run-in patients were monitored for 3 days. The primary endpoint was reduced myocardial ischaemia assessed by the number of anginal attacks, silent ischaemic episodes, and duration of ischaemia per day. At 1 week and 1 month we accounted for anginal attacks and other clinical events (myocardial infarction, revascularisation procedures, and death). Aspirin did not significantly affect the incidence of myocardial ischaemia. On the first 3 days, infused and subcutaneous heparin significantly decreased the frequency of angina (on average by 91% and 86%, respectively), episodes of silent ischaemia (by 56% and 46%), and the overall duration of ischaemia (66% and 61%) versus run-in day and aspirin (p < 0.001 for all variables). The favourable effects of heparin therapy remained evident during follow-up. Only minor bleeding complications occurred. Subcutaneous heparin is effective in the control of myocardial ischaemia in patients with unstable angina.