Nutritional Performance of Five Citrus Rootstocks under Different Fe Levels

Iron is an essential micronutrient for citrus, playing an important role in photosynthesis and yield. The aim of this paper was to evaluate the tolerance to Fe deficiency of five citrus rootstocks: sour orange (S), Carrizo citrange (C), Citrus macrophylla (M), Troyer citrange (T), and Volkamer lemon (V). Plants were grown for 5 weeks in nutrient solution that contained the following Fe concentrations (in µM): 0, 5, 10, 15, and 20. At the end of the experiment, biomass (dry weight-DW), leaf area, total leaf chlorophyll (CHL), and the activity of root chelate reductase (FCR) were recorded. Additionally, the mineral composition of roots (R) and shoots (S) was evaluated. Principal component analysis was used to study the relationships between all parameters and, subsequently, the relations between rootstocks. In the first component, N-S, P-S, Ca-S, Cu-S, Zn-S, Mn-S, Zn-R, and Mn-R concentrations were related to leaf CHL and FCR. Increases in leaf CHL, Mg-R, and DW (shoots and roots) were inversely related to Cu-R, which was shown in the second component. The values obtained were consistent for V10, C15, and C20, but in contrast for S0 and S5. In conclusion, micronutrient homeostasis in roots and shoots of all rootstocks were affected by Fe stress conditions. The Fe/Cu ratio was significantly related to CHL, which may be used to assist rootstock performance.

Extracellular volume fraction by computed tomography predicts long-term prognosis among patients with cardiac amyloidosis

Objective

This study sought to investigate the association of extracellular volume fraction by computed tomography (ECVCT), myocardial remodeling and mortality in patients with systemic amyloidosis.

Background

Light chain (AL) and transthyretin (ATTR) amyloid fibrils are deposited in the extracellular space of the myocardium, resulting in heart failure and premature mortality. Extracellular expansion can be quantified by CT, offering a rapid and cost-effective alternative to cardiovascular magnetic resonance (CMR), especially among patients with cardiac devices or on renal dialysis.

Methods

Patients with confirmed systemic amyloidosis and varying degrees of cardiac involvement underwent ECG-gated cardiac CT. ECVCT was analysed in the inter-ventricular septum. All patients also underwent clinical assessment, ECG, echocardiography, serum amyloid protein component (SAP) and/or technetium-99m (99mTc) 3,3-diphosphono-1,2-propanodicarboxylic acid scintigraphy. ECVCT was compared across different extents of cardiac infiltration (ATTR Perugini Grade / AL Mayo Class) and evaluated for its association with myocardial remodelling and all-cause mortality.

Results

72 patients were studied (AL n=35, ATTR n=37; age 67 (59–76) years, 71% males). Mean septal ECVCT was 42.7±13.1% and 55.8±10.9% in AL and ATTR, respectively, and correlated with indexed left ventricular (LV) mass (r=0.426, p<0.001), LV ejection fraction [LVEF, (r=0.460, p<0.001)], NT-proBNP (r=0.563, p<0.001) and hsTnT (r=0.546, p=0.02). ECVCT increased with cardiac amyloid involvement in both AL and ATTR (Figure 1). Over a mean follow-up of 5.3±2.4 years, 40 deaths occurred (AL 14 [35%]; ATTR 26 [65%]). ECVCT was independently associated with all-cause mortality in ATTR (not AL) after adjustment for age and IV septal wall thickness (HR: 1.046, 95% CI: 1.003–1.090, p=0.037).

Conclusion

Cardiac amyloid burden quantified by ECVCT is associated with adverse cardiac remodelling as well as all-cause mortality among ATTR amyloid patients. ECVCT may address the need for better identification and risk stratification of amyloid patients, using a widely-accessible imaging modality (Figure 2).

Funding Acknowledgement

Type of funding sources: None.

Further prognostic stratification in patients with oscillatory ventilation with exercise: is there more to it than just ups and downs?

Introduction

Exercise Oscillatory Ventilation (EOV) has numerous definitions, but the common foundation is the presence of an oscillatory phenomenon of the ventilation/minute graph with a given amplitude and frequency. Recently, it was proposed that the presence of a delay in O2 consumption (VO2) peak to minute ventilation (VE) peak during ventilatory oscillation was a predictor of worse prognosis in patients with heart failure (HF) and left ventricular ejection fraction (LVEF) <50%.

The aim of this work was to assess whether these characteristics add further prognostic value to the subset of patients with HF and EOV.

Methods

This was a single-centre retrospective cohort of consecutive patients with HF and LVEF <50% that underwent cardiopulmonary exercise testing (CPET) from 2016–2020. EOV was defined as per Vainshelboim 2017 (≥3 consecutive cyclic fluctuations of ventilation during exercise, average amplitude over 3 ventilatory oscillations ≥5L and an average length of three oscillatory cycles 40s to 140s). The presence of EOV was evaluated by 3 independent observers after observing a VE over time plot. For the creation of this plot, data was collected as a rolling average of 5 consecutive breaths. The presence of EOV was established if at least 2 observers agreed on the classification.

Afterwards, a second graph was plotted, with both VO2 and VE over time and the mean delay between VO2 peak to VE peak during EOV was manually calculated (Figure 1).

The primary endpoint was a composite of time to all-cause death, heart transplantation or left ventricular assistance device (LVAD) implantation.

Results

Of the 285 patients, 78 (27%) were classified as having EOV. These HF patients were mostly male (75%) with a mean age of 58±12 years, mean LVEF 31±10% with 63% having ischemic etiology. During a median follow up of 27 (17 to 43) months, 4 LVAD implantations, 12 heart transplantations and 18 deaths. The rate of primary outcome was 19% and 36% at 1- and 2-years. The amplitude, frequency, and maximum number of EOV cycles were not associated with the development of the primary endpoint. Only the mean delay between VO2 peak to VE peak during EOV was predictive of time to primary endpoint, even when adjusted for peak VO2 and VE VCO2 slope (adjusted HR 1.06 95% CI 1.009–1.114) (Figure 2). The cut-off of 5 seconds for mean VO2 peak to VE peak delay seems to be the most useful to predict the primary outcome at 2 years, with a sensitivity of 48% and specificity of 84%.

Conclusion

This novel parameter seems to be the only EOV-related parameter to enable further stratification of prognosis in a cohort of patients with severe HF, with the best cut-off of mean delay between VO2 peak to VE peak during EOV being 5 seconds.

Funding Acknowledgement

Type of funding sources: None.

Exercise oscillatory ventilation disturbances: finding order amongst chaos

Background

Exercise Oscillatory Ventilation (EOV) during Cardiopulmonary Exercise Test (CPET) predicts prognosis in patients with Heart Failure (HF). In these patients, O2 consumption (VO2) oscillations have also been described, possibly secondary to circulatory delay. We hypothesize that in clinically meaningful EOV, cardiac output variation is mirrored by VO2 oscillation, which is then chronologically followed by a similar oscillation in minute ventilation (VE) (Figure 1). Accordingly, we aimed to assess whether this new definition surpassed that of classical EOV.

Methods

This is a single-centre cohort study of consecutive patients undergoing CPET from 2016 to 2018. Patients with LVEF >50% were excluded. CPET was performed on a treadmill to the limit of tolerance. Data was collected as a rolling average of 20 seconds and a composite VE/time and VO2/time plot was created. Classical EOV was defined as three or more regular oscillations of the VE graph with a minimal average amplitude of five litters. The addition of exercise VO2-to-VE peak-to-peak ventilation asynchrony (EVA) to the previous criteria fulfilled the new definition. The primary endpoint was a composite of time to all-cause death, heart transplantation or HF hospitalization.

Results

Overall, 177 patients were enrolled (mean age 58±11 years, LVEF 34±9%), of whom 35 had EOV and 17 had EVA. Compared to those without EVA, patients with EVA had markers of more severe HF. During a median follow-up of 32 (21–42) months, 55 patients met the primary outcome (32 all-cause deaths, 15 heart transplants, 47 HF hospitalizations). In multivariate analysis, EVA was associated with a 2.5-fold increased risk of events (HR 2.489; 95% CI: 1.302–4.759; p=0.006), adjusted for peak VO2, VE to CO2 production ratio (VE/VCO2 slope) and LVEF. EVA outperformed EOV in predicting the primary endpoint at 1 year, with a similar sensitivity and higher specificity (96.2 vs. 83.2%). The rate of events between the subgroup of patients without EVA was similar regardless of presence of EOV, contrasting with a higher rate in the EVA subgroup (Figure 2).

Conclusion

EVA is a strong predictor of hard outcomes in a broad population with HF. The new definition may outperform that of classical EOV. The incidence and prognostic value of EVA in the management algorithm and risk stratification of patients with HF is worth being further explored.

Funding Acknowledgement

Type of funding sources: None.

Effects of foliar application of organic acids on strawberry plants

The large economic costs and environmental impacts of iron-chelate treatments has led to the search for alternative methods and compounds to control iron (Fe) deficiency chlorosis. Strawberry plants (Fragaria x ananassa) were grown in Hoagland's nutrient solution in a greenhouse with two levels of Fe: 0 and 10 μM Fe(III)-EDDHA. After 20 days, plants growing without Fe showed typical symptoms of Fe deficiency chlorosis in young leaves. Then, the adaxial and abaxial sides of one mature or one young leaf in each plant were brushed with 10 mM malic (MA), citric (CA) or succinic (SA) acids. Eight applications were done over a two-week period. At the end of the experiment, the newly emerged (therefore untreated), young and mature leaves were sampled for nutritional and metabolomic analysis, to assess the effectiveness of treatments. Leaf regreening was monitored using a SPAD-502 apparatus, and the activity of the ferric chelate-reductase activity (FCR) was measured using root tips. Iron deficiency negatively affected biomass and leaf chlorophyll but did not increase FCR activity. Application of succinic acid alleviated the decrease in chlorophyll observed in other treatments, and the overall nutritional balance in the plant was also changed. The concentrations of two quinic acid derivatives increased under Fe deficiency and decreased in plants treated with succinic acid, and thus they are proposed as Fe stress markers. Data suggest that foliage treatments with carboxylates may be, in some cases, environmentally friendly alternatives to Fe(III)-chelates. The importance of Fe mobilization pathways in the formulation of new fertilizers is also discussed.

Algae as Food in Europe: An Overview of Species Diversity and Their Application

Algae have been consumed for millennia in several parts of the world as food, food supplements, and additives, due to their unique organoleptic properties and nutritional and health benefits. Algae are sustainable sources of proteins, minerals, and fiber, with well-balanced essential amino acids, pigments, and fatty acids, among other relevant metabolites for human nutrition. This review covers the historical consumption of algae in Europe, developments in the current European market, challenges when introducing new species to the market, bottlenecks in production technology, consumer acceptance, and legislation. The current algae species that are consumed and commercialized in Europe were investigated, according to their status under the European Union (EU) Novel Food legislation, along with the market perspectives in terms of the current research and development initiatives, while evaluating the interest and potential in the European market. The regular consumption of more than 150 algae species was identified, of which only 20% are approved under the EU Novel Food legislation, which demonstrates that the current legislation is not broad enough and requires an urgent update. Finally, the potential of the European algae market growth was indicated by the analysis of the trends in research, technological advances, and market initiatives to promote algae commercialization and consumption.

Predicting pacemaker dependency after TAVI with pre-procedural MSCT

Background and aim

High degree conduction disturbances is a burdensome complication of transcatheter aortic valve implantation (TAVI). There is limited data whether such disorders are permanent or reversible. Anatomic surrogates, such as membranous septum [MS, a distance marker from aortic annulus to His-bundle surge] and calcium distribution within aortic valve have been associated with pacemaker (PM) implantation. The aim of our study was to assess predictors of long-term pacemaker dependency following TAVI.

Methods

Single center prospectively included patients that underwent pacemaker implantation following TAVI (March 2017 to September 2020). Patients who were lost to follow up, with bicuspid aortic valve, previously implanted PM and non-available or low quality MSCT exam were excluded. On MSCT, MS length was measured on modified coronal view, the aortic-valvular complex (AVC) was characterized by leaflet sector and calcium distribution was assessed on a J-score threshold of 850-Hounsfield units. Pacemaker dependency was assessed by reducing ventricular pacing to 30 bpm and defined by subsequent complete AV dissociation in patients in sinus rhythm or an escape rhythm <50 bpm in atrial fibrillation, in addition of >90% pacing percentage since implantation.

Results

From the 352 patients with inclusion criteria, 67 underwent PM implantation (19%) and 55 included in the analysis (male 33.9%, median age=85) (Figure). Median time for pacemaker implantation was 3 days [interquartile range (IQR) 3–5 days], mostly due to complete auriculo-ventricular block (76.4%, N=42). PM dependency occurred in 14 out of 55 (25.5%) patients at mean follow up of 500±363 days. Patients with PM dependency tended to have deeper implantation depth, (6.2 mm vs 5.5 mm, p=0.096) and a significantly shorter MS (5.8 mm vs 6.8 mm, P-value = 0.031) (Table). Increasing MS length was independently associated with a lower risk of PM dependency [odds ratio (OR) 0.58 per mm; 95% CI: 0.35–0.98, p=0.04] regardless prosthesis choice. MS length under 5 mm had 97.6% specificity (95% CI: 87.1–99.9) and 85.7% positive predictive value for pacemaker dependency (AUC=76.7; 95% CI 63.3–87).

Conclusion

Our findings highlight the importance of MSCT-derived MS length to stratify the risk of long term need for pacemaker. Patients with short MS (<5mm) in addition to conduction abnormality following TAVI had a high likelihood of PM dependency on the long term and should be considered for prompt PM implantation.

Funding Acknowledgement

Type of funding sources: None.

The timing and mechanism of high-grade AV block post-TAVI: knowing your enemy

Background

Complete atrioventricular block (AVB) requiring permanent pacemaker implantation (PPMI) is still a major limitation of transcatheter aortic valve implantation (TAVI) procedures. Although right-bundle branch block (RBBB), membranous septum (MS) length and self-expandable prothesis are recognizable risk factors, their predictability to PPMI is far from satisfactory. While some patients develop persistent intra-procedure high-grade AVB (H-AVB), others present much later with severe bradycardia.

Purpose

This study aims to describe and compare the characteristics of patients who develop AVB during or after TAVI.

Methods

Single centre prospective registry of 506 consecutive patients submitted to TAVI with no previous pacemaker between 2017 and 2020. Post-procedure PPMI (up to 30 days after discharge) was studied and divided into two groups according to the development of persistent intra-procedure H-AVB (Group A) or post procedure H-AVB (Group B). Baseline ECG, computed tomography and TAVI-related characteristics were analyzed.

Results

A total of 88 patients (17,3%), aging 83±6 years, 36.4% male, underwent post-TAVI PPMI (6 after discharge). Previous conduction disturbances were present in 50 (56.8%) patients and 25 (28.4%) had RBBB. 83% were submitted to self-expandable TAVI. Forty-two patients (47.7%) had persistent intra-procedure H-AVB (Group A) whereas 52.3% had post-procedure H-AVB (Group B). In patients with persistent intra procedure H-AVB previous RBBB was significantly more frequent (45.2%, n=19) when compared to patients with post-procedure H-AVB (13%, n=6; p=0.001). Contrarily, AF and previous left-bundle branch block (LBBB) were more likely in Group B. No difference in valvular calcification, MS length, prosthesis type or implantation technique was noted (picture 1). In the group with post-procedure H-AVB, 21.7% had transient AVB during TAVI and all developed de novo LBBB or first-degree AVB post-TAVI. Among these, 33 patients (71.7%) developed delayed H-AVB (>48h post-procedure) while the remaining presented earlier.

Conclusions

In patients with PPMI post-TAVI, those with persistent intra-procedure H-AVB had higher rates of previous RBBB, while those with post-procedure H-AVB frequently had a normal baseline ECG. Anatomical and procedural characteristics did not differ between groups. Further studies are needed to confirm these results.

Funding Acknowledgement

Type of funding sources: None.

Nutritional and Functional Evaluation of Inula crithmoides and Mesembryanthemum nodiflorum Grown in Different Salinities for Human Consumption

The nutritional composition and productivity of halophytes is strongly related to the biotic/abiotic stress to which these extremophile salt tolerant plants are subjected during their cultivation cycle. In this study, two commercial halophyte species (Inula crithmoides and Mesembryanthemum nodiflorum) were cultivated at six levels of salinity using a soilless cultivation system. In this way, it was possible to understand the response mechanisms of these halophytes to salt stress. The relative productivity decreased from the salinities of 110 and 200 mmol L⁻¹ upwards for I. crithmoides and M. nodiflorum, respectively. Nonetheless, the nutritional profile for human consumption remained balanced. In general, I. crithmoides vitamin (B1 and B6) contents were significantly higher than those of M. nodiflorum. For both species, β-carotene and lutein were induced by salinity, possibly as a response to oxidative stress. Phenolic compounds were more abundant in plants cultivated at lower salinities, while the antioxidant activity increased as a response to salt stress. Sensory characteristics were evaluated by a panel of culinary chefs showing a preference for plants grown at the salt concentration of 350 mmol L⁻¹. In summary, salinity stress was effective in boosting important nutritional components in these species, and the soilless system promotes the sustainable and safe production of halophyte plants for human consumption.

Adapting the concepts of proportionate and disproportionate functional mitral regurgitation to clinical practice

Funding Acknowledgements

Type of funding sources: None.

Background

  Despite its theoretical appeal, the concept of Proportionate and Disproportionate FMR has been limited by the lack of a simple way to assess it and by the paucity of data showing its prognostic superiority over currently established ways of grading FMR.

Objectives

This study sought to evaluate the prognostic value of a new and individualized method of assessing Functional Mitral Regurgitation (FMR) Proportionality.

Methods

Patients with at least mild FMR and reduced left ventricular ejection fraction (< 50%) under optimal guideline-directed medical therapy were retrospectively identified at a single-center. To determine FMR proportionality status, we used a novel approach where two simple equations establish an individual cut-off of regurgitant volume/effective regurgitant orifice area, categorizing the study population into non-severe, proportionate and disproportionate FMR (Figure 1). The primary endpoint was all-cause mortality.

Results

A total of 572 patients (median age 70 years; 76% male) were included. Median LVEF was 35% (IQR 28-40) and LVEDV was 169 ml (IQR 132-215). Disproportionate FMR was present in 109 patients (19%) with a median EROA of 26 mm2 (IQR 22-31) and a median RegVol of 40 ml (IQR 34-48), proportionate FMR in 148 patients (26%) with a median EROA of 16mm2 (IQR 12-21) and a median RegVol of 26 ml (IQR 19-32). During a median follow-up of 3.8 years (interquartile range: 1.8 to 6.2 years) there were 254 deaths (44%). The unadjusted mortality incidence per 100 persons-year rose as the degree of FMR disproportionality worsened. On multivariable analysis, disproportionate FMR remained independently associated with all-cause mortality (adjusted hazard ratio: 1.785; 95% confidence interval [CI]: 1.249 to 2.550; P = 0.001). The FMR proportionality concept showed greater discriminative power (C-statistic 0.639; 95% CI: 0.597 to 0.680) than the American (C-statistic 0.588; 95% CI: 0.550 to 0.626; P for comparison = .001) and European guidelines (C-statistic 0.563; 95% CI: 0.534 to 0.591; P for comparison < .001). It was also able to increase the net reclassification index (0.167 [P < 0.001] and 0.084 [P = 0.001], respectively).

Conclusions

A new, simplified and individualized method of assessing FMR Proportionality showed that disproportionate FMR is independently associated with all-cause mortality. This approach seems to outperform the risk stratification of current guidelines.

Abstract Figure 1

Risk stratification in hf with mid-range LVEF: the role of cardiopulmonary exercise testing

Background

Cardiopulmonary exercise testing (CPET) is recommended in the evaluation of selected patients with Heart Failure (HF). Notwithstanding, its prognostic significance has mainly been ascertained in those with left ventricular ejection fraction (LVEF) <40% (i.e., HFrEF). The main goal of our study was to assess the role of CPET in risk stratification of HF with mid-range (40–49%) LVEF (i.e., HFmrEF) compared to HFrEF.

Methods

We conducted a single-center retrospective study of consecutive patients with HF and LVEF <50% who underwent CPET from 2003–2018. The primary composite endpoint of death, heart transplant or HF hospitalization was assessed.

Results

Overall, 404 HF patients (mean age 57±11 years, 78.2% male, 55.4% ischemic HF) were included, of whom 321 (79.5%) had HFrEF and 83 (20.5%) HFmrEF. Compared to the former, those with HFmrEF had a significantly higher mean peak oxygen uptake (pVO2) (20.2±6.1 vs 16.1±5.0 mL/kg/min; p<0.001), lower median minute ventilation/carbon dioxide production (VE/VCO2) [35.0 (IQR: 29.1–41.2) vs 39.0 (IQR: 32.0–47.0); p=0.002) and fewer patients with exercise oscillatory ventilation (EOV) (22.0 vs 46.3%; p<0.001). Over a median follow-up of 28.7 (IQR: 13.0–92.3) months, 117 (28.9%) patients died, 53 (13.1%) underwent heart transplantation, and 134 (33.2%) had at least one HF hospitalization. In both HFmrEF and HFrEF, pVO2 <12 mL/kg/min, VE/VCO2 >35 and EOV identified patients at higher risk for events (all p<0.05). In Cox regression multivariate analysis, pVO2 was predictive of the primary endpoint in both HFmrEF and HFrEF (HR per +1 mL/kg/min: 0.81; CI: 0.72–0.92; p=0.001; and HR per +1 mL/kg/min: 0.92; CI: 0.87–0.97; p=0.004), as was EOV (HR: 4.79; CI: 1.41–16.39; p=0.012; and HR: 2.15; CI: 1.51–3.07; p<0.001). VE/VCO2, on the other hand, was predictive of events in HFrEF but not in HFmrEF (HR per unit: 1.03; CI: 1.02–1.05; p<0.001; and HR per unit: 0.99; CI: 0.95–1.03; p=0.512, respectively). ROC curve analysis demonstrated that a pVO2 >16.7 and >15.8 mL/kg/min more accurately identified patients at lower risk for the primary endpoint (NPV: 91.2 and 60.5% for HFmrEF and HFrEF, respectively; both p<0.001).

Conclusions

CPET is a useful tool in HFmrEF. Both pVO2 and EOV independently predicted the primary endpoint in HFmrEF and HFrEF, contrasting with VE/VCO2, which remained predictive only in latter group. Our findings strengthen the prognostic role of CPET in HF with either reduced or mid-range LVEF.

Funding Acknowledgement

Type of funding source: None

Idiopathic HFrEF. Is there room left for defibrillators?

Background and aim

Prophylactic implantation of an implantable cardioverter-defibrillator (ICD) is class 1 recommendation for heart failure (HF) patients with reduced ejection fraction (HFrEF) even though its proven advantage is weaker among nonischemic aetiology. In fact, in an era where both optimal medical therapy (OMT) and cardiac resynchronization therapy (CRT) significantly reduce sudden cardiac death (SCD), it is questionable whether ICD still have additional value. The aim of this study was to assess the current benefit of ICDs in preventing sudden cardiac death through resuscitated cardiac arrest (RCA), appropriate therapy for sustained ventricular tachycardia (VT) or fibrillation (VF) in a contemporary population of idiopathic HFrEF patients.

Methods

Single-centre retrospective study of consecutive symptomatic (NYHA class II to IV) idiopathic HFrEF patients with an ICD (either alone or in association with CRT), and remote monitoring with the corresponding software (MerlinTM, LatitudeTM, CarelinkTM, MicroPortTM or BiotronikTM) to assure appropriate event supervising. Idiopathic aetiology was assumed after excluding other probable causes. Coronary angiogram was required to exclude ischemic aetiology. Only those with prophylactic ICD implantation were included. RCA was defined as collapse with clinical signs of cardiac arrest and VF or VT appropriately terminated by ICD. In order to be sustained, VT episode had to have last at least 30 seconds.

Results

From 781 remote monitoring controlled patients, a total of 187 consecutive symptomatic idiopathic HFrEF patients with an ICD (125 men, mean age 64±18 years) were enrolled. Patients were on optimal medical therapy (ACEi/ARB: n=168, 90%; BB: n=154, 82%; mineralocorticoid antagonists: n=91, 49%; CRT: n=130, 70%; see Table). After a median follow-up of 99 months (IQR 62.2), RCA occurred in 10.7% (n=20) and 36.9% (n=69) had appropriately terminated VT. Both left ventricular ejection fraction (LVEF) improvement and CRT implantation did not independently reduce the incidence of RCA and VT requiring ICD therapy (OR, 1.02; 95% CI, 0.99–1.05; P=0.146 and OR, 0.85; 95% CI, 0.34–2.13; P=0.728; respectively). All cause mortality was 20 (10.7%). Inappropriate therapy was given as shocks to 41 patients (21.9%) and as antitachycardia pacing (ATP) to 30 (16%), opposing with appropriately given therapy to 43 (23%) and 63 (33.7%) patients, respectively (see Figure), contributing to a net clinical benefit (NCB) of 18.8%, favouring ICD implantation.

Conclusion

In this contemporaneous real-world population of symptomatic idiopathic HFrEF patients, episodes of impending cardiac death were frequent. Prophylactic ICD implantation seems to have added further benefit reducing SCD on top of optimal medical therapy, LVEF improvement and coexisting CRT.

Funding Acknowledgement

Type of funding source: None

Predicting pacemaker implantation after TAVR with procedural CT

Background and aim

The need for permanent pacemaker implantation (PPMI) is a burdensome complication of transcatheter aortic valve replacement (TAVR). Calcium distribution in the aortic-valvular complex (AVC) and, more recently, membranous septum (MS) length seem to be surrogate markers for conduction abnormalities after specific last generation balloon and self-expandable expandable valves. We sough to evaluate whether such pre-procedural association remains across the entire device spectrum.

Methods

Single-centre prospective study of 239 consecutive patients (140 women, median age of 84) with severe symptomatic aortic stenosis patients who underwent ECG-gated contrast-enhanced multi-detector computed tomography (MSCT) before TAVR since Jun/2017. Exclusion criteria were those with previous PPMI, previous bioprothesis, congenital bicuspid valve, and poor imaging quality. The J-score with an 850-Hounsfield unit threshold was used to detect areas of calcium in the region of interest. AVC was characterized by leaflet sector and region, using 3mensio Valves software 7.0 TM. An independent team retrospectively measured MS length blindly by determining the thinnest part of the interventricular septum in the coronal view in the better-defined systolic phase (usually at 40% of the R-R interval, Figure). Device selection (75.8% self-expandable devices, 20.1% balloon expandable, 3.1% other) and positioning were performed according to the operator criteria. Final implant depth was assessed based on the pre-release angiogram or final aortography.

Results

Mortality at 30-days was 1.3% and PPMI occurred in 43 patients (18%). Median MS length was 9.59mm (IQR: 3.11mm). After multivariable logistic regression analysis, MS length emerged as the single significant protective predictor for PPMI (OR: 0.14; 95% 95% CI: 0.05–0.42; p<0.001), independently of the device used (p<0.001). MS length showed strong discriminatory ability for PPMI (c-statistic 0.93; 95% CI 0.88–0.99). Sensitivity/specificity decision plots yielded an MS length of 6.9 mm as the optimal cut-off point for predicting the need for PPMI with a positive and negative predictive value of 91% and 93%, respectively (Figure). There wasn't any calcium accumulation within a specific region of AVC that independently predicted the outcome.

Conclusion

In our experience, a short membranous septum was strongly and independently associated with new permanent pacemaker implantation, regardless of the device type.

Our findings suggest that this simple measure should be routinely made to help device selection and implantation technique.

Funding Acknowledgement

Type of funding source: None

Downstream testing after an halted coronary CT angiography due to high coronary artery calcium score

Background and aim

In many centers, coronary artery calcium score (CACS) is performed immediately before coronary CT angiography (CCTA) in order to exclude heavy calcification that could hamper test performance. When high CACS values are found, CCTA is usually aborted and other tests suggested. However, there are no recommendations on which test to pursue, and little data on their diagnostic yield in this setting. The aim of this study was to assess the type and results of downstream testing among patients whose CCTA study was halted due to high CACS.

Methods

Single-centre retrospective study of consecutive patients undergoing CCTA for suspected obstructive coronary artery disease (CAD). A CACS threshold of >400 was generally used to cancel CCTA. Downstream testing and its results were assessed using electronic medical records. A group of consecutive patients with CACS <400 who underwent CCTA was used for comparison.

Results

Of the 795 patients who performed CCTA for suspected CAD, 86 (10.8%), had their test halted due to high CACS (57 men, mean age 71±11 years). In this subgroup, the median pre-test probability for CAD was 27% (interquartile range 25) and the median CACS was 983 (interquartile range 930). Compared to patients who underwent CCTA, those who saw their tests cancelled were older, more frequently male, and had higher prevalence of cardiovascular risk factors and higher pre-test probability for CAD.

Patient's downstream testing is illustrated in Figure. From the 86 patients enrolled, 12 are currently waiting for downstream tests and were excluded from further analysis. Overall, 35 patients ended up performing invasive coronary angiography (ICA, 47.3%) of whom 19 (54.3%) had significant CAD. Among those who underwent non-invasive testing (N=19, 25.7%), 10 (52.6%) had significant ischemia and 4 (21%) underwent additional testing with ICA. In 24 patients (32.4%), no downstream testing was pursued. Finally, 17 (22.3%) patients underwent coronary revascularization, either percutaneous (N=10, 13.5%) or surgical (N=7, 10.8%).

Conclusion

Invasive coronary angiography is the most frequently used downstream test when CCTA is halted due to high CACS values, and shows significant CAD in roughly half of the cases. Considering the high prevalence of significant CAD, direct referral for ICA (with the possibility of invasive functional testing) seems a reasonable approach.

Funding Acknowledgement

Type of funding source: None

Disproportionate functional mitral regurgitation: clinical validation of a new conceptual framework

Background

Disproportionate functional mitral regurgitation (FMR) is a novel concept that tries to identify hemodynamically significant FMR by readjusting the effective regurgitant orifice area (EROA) and regurgitant volume (RegVol) cut-offs according to left ventricular end-diastolic volume (LVEDV) and left ventricular ejection fraction (LVEF). However, this theoretical concept lacks clinical validation. The aim of this study was to assess the clinical significance of disproportionate FMR.

Methods

Patients with at least mild FMR and reduced LVEF (<50%) who underwent transthoracic echocardiography between 2010 and 2014 were retrospectively identified in our laboratory database. Optimal medical therapy (including cardiac resynchronization when indicated) for ≥3 months was a prerequisite for inclusion. Hemodynamically significant FMR was defined as regurgitant fraction >50% and the patient-specific theoretical RegVol cut-off was calculated according to the formula presented in Fig. 1a. The difference between the estimated RegVol by the PISA method and the theoretical RegVol cut-off was considered to represent the haemodynamic burden of MR. The primary endpoint was all-cause death. Patients were censured if mitral intervention or heart transplant was undertaken. Survival analysis was used to assess the effect of disproportionate FMR on mortality in 2 subgroups (LVEF <30% and 30–49%).

Results

A total of 289 patients (median age 69 years [IQR 60–77], 75% male, 53% of ischemic aetiology) were included. More than 90% were on beta-blockers and renin-angiotensin inhibitors, 44% on aldosterone receptor antagonists, and 73% had implanted devices. The median LVEF and LVEDV were 34% (IQR 27–41) and 170mL (IQR 128–220), respectively. Median EROA was 10mm2 (IQR 3–21) and RegVol was 15 mL (IQR 4–30). RegVol distribution across the cohort was: <10mL: 41%; 10–20mL: 18%; 20–30mL: 15% and >30mL: 26%. Disproportionate FMR was present in 83 patients (29%). These patients had significantly higher SPAP values (41mmHg [IQR 33–50] vs. 33mmHg [IQR 29–40]; p<0.001).

During a median follow-up of 44 months (IQR 19–73), 106 patients died. In the LVEF <30% subgroup, age (HR 1.05 per year [1.02–1.08]; p<0.001), LVEF (HR 0.94 per 1% [0.89–0.99]; p=0.042) and TAPSE (HR 0.92 per mm [0.86–0.99]; p=0.030) were independent predictors of mortality. In the LVEF 30–49% subgroup, age (HR 1.05 per year [1.02–1.08]; p=0.003), LVEF (HR 0.94 per 1% [0.89–0.99]; p=0.020) and disproportionate FMR (HR 1.02 per mL [1.01–1.03]; p=0.01) were independently associated with increased mortality.

Conclusions

Disproportionate FMR proved to be an important independent predictor of mortality in patients with LVEF between 30–49%. These findings were not replicated in those with LVEF<30%, where the degree of biventricular dysfunction seems to outweigh all other echocardiographic parameters, leaving FMR as a bystander.

Figure 1

Funding Acknowledgement

Type of funding source: None

Wild vs cultivated halophytes: Nutritional and functional differences

Some halophyte plants are currently used in gourmet cuisine due to their unique organoleptic properties. Moreover, they exhibit excellent nutritional and functional properties, being rich in polyphenolics and vitamins. These compounds are associated to strong antioxidant activity and enhanced health benefits. This work compared the nutritional properties and antioxidant potential of three species (Mesembryanthemum nodiflorum, Suaeda maritima and Sarcocornia fruticosa) collected in saltmarshes from Portugal and Spain with those of cultivated plants. The latter were generally more succulent and had higher contents of minerals than plants obtained from the wild and contained less fibre. All species assayed are a good source of proteins, fibres and minerals. Additionally, they are good sources of carotenoids and vitamins A, C and B₆ and showed good antioxidant potential particularly S. maritima. Chromatographic analysis of the phenolic profile revealed that ferulic and caffeic acids as the most relevant phenolic compounds detected in the halophytes tested.

459Direct oral anticoagulants are an effective therapy for left ventricular thrombus formation

Background and aim

Left ventricular thrombus is a frequent complication of myocardial infarction (MI) and heart failure with severely depressed ejection fraction. Once diagnosed, anticoagulation for up to 6-months is recommended, but clinical experience with direct oral anticoagulation (DOAC) is limited to a few case reports. Our aim is to test DOAC LV thrombus resolution efficacy against warfarin.

Methods

Single-centre retrospective cohort study of consecutive patients with recently diagnosed LV thrombus, either after acute myocardial infarction or heart failure with reduced ejection fraction, from January 2009 till December 2018. Thrombus diagnosis and subsequent assessments were performed with echocardiography and complemented with cardiac magnetic resonance, when appropriate. Decisions regarding the type, dose and duration of anticoagulation and any concomitant antiplatelet therapy were left to physician's judgement.

Results

In a population of 66 patients (51 male, mean age 69±12 years), 13 received DOAC therapy, with the remainder receiving vit. K antagonists. One from each group was lost to follow up. The DOAC subgroup had higher prevalence of atrial fibrillation, higher left ventricular end-diastolic volumes and worse wall motion severity score index (WMSI). The duration of anticoagulant therapy, concomitant single or dual antiplatelet therapy and overall follow up were similar between strategies. Thrombus remission was observed in 91.7% (n=11) and 59.6% (n=31) patients within DOAC and warfarin group, respectively. Risk of unsuccessful resolution was reduced by 35% relative to the warfarin group (RR 0.65; 95% CI [0.491–0.862]; p-value 0.035) (figure).

figure

Conclusion

DOAC seems to be an effective alternative to vitamin-K antagonists in patients with LV thrombus.

P6326Which results of the cardiopulmonary exercise test deserve greatest attention to establish the prognosis in heart failure?

Background and aim

Limitation of exercise tolerance is one of the cardinal manifestations of heart failure (HF). Cardiopulmonary exercise testing (CPET) provides a thorough assessment of exercise integrative physiology involving the pulmonary, muscular, and oxidative cellular systems. We aimed to identify which data collected during a CPET shows the best prognostic performance with respect to predicting mortality or the need for heart transplantation (HT).

Methods

Single-centre retrospective cohort study of consecutive HF patients performing a CPET for functional and prognostic HF evaluation from October 1996 till May 2018. Left ventricular ejection fraction was not an exclusion criterion. A Cox model was fit with time to death or heart transplantation (whichever recorded first within 5 years) as the dependent variable and CPET parameters as the independent variables. Both unadjusted and adjusted covariate Cox regressions were performed. ROC curve analysis was used to determine whether the significant variables, as a model, could reliably predict the study endpoint.

Results

The study population consisted of 513 patients, median age 58 (IQ 16) years, and 74.9% male. The majority had reduced ejection fraction (75.4%), and the most common HF aetiology was ischemic heart disease (55.8%). During the 5-years follow up, 126 patients died and 60 underwent heart transplantation. In unadjusted Cox regression, nearly all CPET variables were significantly associated with the study endpoint. After covariate adjustment, with prior exclusion of redundant variables, three measures remained associated with the study endpoint: peak VO2 consumption (hazard ratio [HR] 0.85; 95% confidence interval [CI], 0.81–0.90); VE/VCO2 slope (HR 1.02; 95% CI, 1.00–1.02); presence of oscillatory ventilatory pattern (HR 3.73; 95% CI, 2.43–5.72). As a model, these 3 variables showed a strong discriminatory ability (c-statistic 0.87; 95% CI, 0.83–0.90) (see figure) for the study endpoint.

Figure 1

Conclusion

When using the CPET for prognostic stratification of HF patients, the presence of an oscillatory ventilatory pattern, the peak VO2 and the VE/VCO2 slope are the most important tools on which clinicians should focus.

P5423Exercise oscillatory ventilation improves the performance of prognosis scores currently used for heart failure

Background and aim

Several prognostic risk scores are available for heart failure with reduced ejection fraction (HFrEF), and are used, together with other criteria, to help decide the ideal timing for listing candidates for a heart transplant. The detection of an oscillatory ventilatory pattern (OVP) during cardiopulmonary exercise testing (CPET) has been associated with more advanced HF and a worse prognosis, but was not considered in the development of all the current risk scores. We evaluated whether OVP adds significant prognostic information to four contemporary HF scores.

Methods

Single-centre retrospective cohort study of consecutive HFrEF patients undergoing CPET for functional and prognostic assessment from October 1996 till May 2018. The Heart Failure Survival Score (HFSS), Seattle Heart Failure Model (SHFM), Meta-analysis Global Group in Chronic Heart Failure (MAGGIC) and Metabolic Exercise Cardiac Kidney Index (MECKI) were obtained in each patient. Cox model was fit with time to death or urgent transplant (whichever came first within 2 years) as the dependent variable and OVP and respective HF score as the independent variables. We further assessed the added discriminative power by performing ROC curve comparisons.

Results

We studied 387 patients, median age 58 (IQR 49; 65) years, and 77% were male. The most common HFrEF aetiology was ischemic heart disease (54%). Median peak oxygen consumption was 15,7 mL/kg/min (IQR 12,8; 20,0). OVP was present in 150 (39%) patients. Over the 2-year follow-up period, 48 patients died, and 52 underwent heart transplantation (of which 25 were urgent). HFSS showed the weakest (c-statistic 0,625; 95% [CI] 0,54–0,71) and MECKI score the strongest (c-statistic 0,819; 95% [CI] 0,76–0,88) discriminatory ability. Contrasting with NTproBNP value, the presence of OVP predicted the study endpoint independently of the HF prognosis score used (see table). Adding the occurrence of OVP to the HFSS and the MAGGIC scores significantly improved their prognostic performance (see Table).

Conclusion

An OVP is a common finding in HFrEF patients undergoing CPET, and adds prognostic information to contemporary HF prognosis scores. Systematic evaluation of this easily available criterion may assist the decision on the appropriate timing for heart transplantation listing.

Silencing of the FRO1 gene and its effects on iron partition in Nicotiana benthamiana

To evaluate the dynamic role of the ferric-chelate reductase enzyme (FCR) and to identify possible pathways of regulation of its activity in different plant organs an investigation was conducted by virus-induced gene silencing (VIGS) using tobacco rattle virus (TRV) to silence the ferric reductase oxidase gene (FRO1) that encodes the FCR enzyme. Half of Nicotiana benthamiana plants received the VIGS vector and the rest remained as control. Four treatments were imposed: two levels of Fe in the nutrient solution (0 or 2.5 μM of Fe), each one with silenced or non-silenced (VIGS-0; VIGS-2.5) plants. Plants grown without iron (0; VIGS-0) developed typical symptoms of iron deficiency in the youngest leaves. To prove that FRO1 silencing had occurred, resupply of Fe (R) was done by adding 2.5 μM of Fe to the nutrient solution in a subset of chlorotic plants (0-R; VIGS-R). Twelve days after resupply, 0-R plants had recovered from Fe deficiency while plants containing the VIGS vector (VIGS-R) remained chlorotic and both FRO1 gene expression and FCR activity were considerably reduced, consequently preventing Fe uptake. With the VIGS technique we were able to silence the FRO1 gene in N. benthamiana and point out its importance in chlorophyll synthesis and Fe partition.

The memory of iron stress in strawberry plants

To provide information towards optimization of strategies to treat Fe deficiency, experiments were conducted to study the responses of Fe-deficient plants to the resupply of Fe. Strawberry (Fragaria × ananassa Duch.) was used as model plant. Bare-root transplants of strawberry (cv. 'Diamante') were grown for 42 days in Hoagland's nutrient solutions without Fe (Fe0) and containing 10 μM of Fe as Fe-EDDHA (control, Fe10). For plants under Fe0 the total chlorophyll concentration of young leaves decreased progressively on time, showing the typical symptoms of iron chlorosis. After 35 days the Fe concentration was 6% of that observed for plants growing under Fe10. Half of plants growing under Fe0 were then Fe-resupplied by adding 10 μM of Fe to the Fe0 nutrient solution (FeR). Full Chlorophyll recovery of young leaves took place within 12 days. Root ferric chelate-reductase activity (FCR) and succinic and citric acid concentrations increased in FeR plants. Fe partition revealed that FeR plants expressively accumulated this nutrient in the crown and flowers. This observation can be due to a passive deactivation mechanism of the FCR activity, associated with continuous synthesis of succinic and citric acids at root level, and consequent greater uptake of Fe.

Changes in the concentration of organic acids in roots and leaves of carob-tree under Fe deficiency

Several fruit trees are able to cope with iron (Fe) deficiency when grown in calcareous soils in the Mediterranean region, although information regarding well adapted slow-growing species is scarce, and the mechanisms activated by these species are not described in the literature. A crucial issue related to tolerance is the need to transport Fe over relatively long distances inside the plant. To evaluate the possible role of organic acids in the movement of Fe in tolerant plants, we studied the concentration of low molecular weight organic acids in several organs of 1-year old carob plants grown for 55 days in nutrient solutions without Fe (0µM Fe) or with 1µM Fe and 10µM Fe. Roots, stems and leaves were harvested, and the biomass, Fe and organic acid contents quantified. Total leaf chlorophyll (Chl) was evaluated in young leaves over the experimental period and the activity of root ferric chelate-reductase (FC-R; EC 1.16.1.17) was determined after 35 days, when deficiency symptoms appeared. Iron chlorosis was observed only at the end of the experiment in plants grown in the absence of Fe, and these plants had a smaller DW of leaves and also significant greater activity of root FC-R. Iron deficiency (Fe0 and Fe1 treatments) induced significant changes in the concentrations of succinic, malic, citric and fumaric acids, which increased in roots, or in basal, middle and apical leaves. There were significant correlations between most organic acids (with the exceptions of 2-oxoglutaric and tartaric acids) and leaf Chl. Analysis of each type of leaf showed that more succinic and malic acids were present in young chlorotic leaves while the reverse was true for quinic acid. These changes in organic acids followed a root-to-foliage pathway that was similar in all leaf types and particularly evident in young chlorotic leaves. We hypothesised that it was associated with Fe transport from roots to aboveground tissues, as there were significant differences in Fe contents between treatments with and without Fe.

Development and recovery of iron deficiency by iron resupply to roots or leaves of strawberry plants

Bare-root transplants of strawberry (Fragaria ananassa Duch. cv. 'Selva') were transferred to nutrient solutions with or without iron (Fe). After six weeks of growth, plants grown in solution lacking Fe were chlorotic and showed morphological changes in roots typical of Fe deficiency. Subsequently, four treatments were applied for nine days: plants grown in continued absence of Fe (Fe0); plants grown in continued presence of 10 μM Fe (Fe10); foliar application of ferrous sulphate every two days to chlorotic plants (Fe-leaves); and growth of chlorotic plants in solution with ferrous sulphate (Fe-solution). After six days, the chlorophyll (Chl) content in leaves of Fe-solution plants was similar to that in Fe10 plants. Under the Fe-leaves treatment, a slight regreening of new leaves was observed only by the end of the experiment. After nine days, ferric chelate reductase (FC-R) activity was unchanged in Fe10 but increased in Fe0 plants. The FC-R activity of Fe-solution plants was similar to the initial value for chlorotic plants, whereas it was reduced drastically under the Fe-leaves treatment. The Fe concentration in leaves of Fe0 and Fe10 was similar, whereas the Fe-solution and Fe-leaves treatments enhanced leaf Fe concentration. In contrast to the Fe-solution treatment, foliar application of Fe did not increase the Fe concentration in roots. Under our experimental conditions, FC-R activity in strawberry appeared to be deactivated rapidly by pulses of Fe applied by foliar sprays. Deactivation was slower if Fe was applied directly to roots, which suggested that the plants had greater opportunity to take Fe.

Distribution of domestic triatominae and stratification of Chagas Disease transmission in Oaxaca, Mexico

Mexico has 18 species of Triatomine bugs (Hemiptera: Reduviidae) reported to be vectors of Trypanosoma cruzi. Chagas Disease is widespread in Mexico, with up to 3.5% seropositivity of human transfusion blood. The State of Oaxaca has the longest history of endemic Chagas Disease, based on acute and chronic case reports, and of entomological surveys in the country. However, the State health care services need more information on current risks of vector transmission. In order to identify and characterize areas of transmission in Oaxaca and to stratify the vector potential, the distribution of domestic Triatominae was surveyed during 1996-98 in collaboration with the primary health care services and local communities. Villages were studied in 11% of 570 municipalities in Oaxaca. Eight triatomine species were found in domestic and peri-domestic habitats: Triatoma barberi Usinger, T. bolivari Carcavallo et al., T. dimidiata (Latreille), T. mazzottii Usinger, T. nitida Usinger, T. pallidipennis (Stal), T. phyllosoma (Burmeister) and Rhodnius prolixus Stal. For each triatomine species in Oaxaca, the range of distribution and habitat characteristics are described. Habitat partitioning, principally based on altitude and mean annual precipitation, limited the overlap of distribution between species. Relatively consistent altitude of human settlements facilitates the dispersion of individual species within microregions. Entomological indices of house infestation were used to estimate that approximately 50% of the human population (1,874,320 inhabitants) would be at risk of vector transmission, with a minimum of 134,320 infected people and 40,280 chronic cases of Chagas Disease currently in Oaxaca.