The reference method influence on the sensitivity of the Clostridium difficile enzyme immunoassays: A meta analysis

The use of enzyme immunoassays to screen for toxins A and B produced by Clostridium difficile is a common procedure in algorithms designed for its detection. Moreover, the absence of a unique test capable of providing reliable results at low cost motivates a great discussion about which algorithm is the best. Thus, several studies have evaluated the performance of these enzyme immunoassays. However, all fail to provide sufficient explanations for the different behaviours observed in different studies that evaluate the same index test against a common reference method. Our main goal was to find out which factors affect the sensitivity of these assays, since the specificity is very close to 1. In this research, we verified that sensitivity increases with the prevalence rate and with the proportion of reported cases of onset diarrhea. Therefore, its use is advisable for high prevalence rates (e.g. in an epidemic setting). As far as reference methods are concerned, nucleic acid amplification tests can be used as a reference method, with a performance similar to the well-accepted toxigenic culture. The method chosen for toxigenicity screening in a toxigenic culture also seems to affect the evaluation performance of tests and should be better studied in the future.

Correlates of sedentary time in young children: A systematic review

Background: Young children appear to spend large portions of their waking time being sedentary. Understanding the correlates of sedentary time would assist in developing effective interventions among young children. The purpose of this systematic review was to summarize the current literature on the correlates of objectively measured sedentary time in young children aged 1-5.99y. Methods: This review was registered with PROSPERO (registration no. CRD42017081374) and aligned with the PRISMA Statement for systematic reviews. Five electronic databases (MEDline, CINAHL Complete, PsycINFO, SportDiscus, Scopus) were searched up to October 26, 2017 for studies investigating correlates of sedentary time measured using objective devices. A semiquantitative approach was used to synthesize data. Results: Forty-five studies were retrieved comprising 13,430 participants, and 84 correlates of sedentary time in young children were evaluated. The associations between sex, sleep habits, daily patterns (childcare vs. non-childcare hours), childcare type and sedentary time were indeterminate. Thirty-nine correlates were consistently unrelated. Forty-one potential correlates were examined in too few studies (<4) to make confident conclusions. Parental sedentary behaviour was reported 3 times and maternal sedentary behaviour was reported once. Out of these four studies, three were positively associated with child sedentary time. Conclusions: Despite reviewing 45 studies that evaluated associations for 84 correlates, this review was unable to identify any consistent correlates of sedentary time in young children. Additional research is needed in this area to provide robust evidence of the correlates of sedentary time in young children, particularly for those examined in only a small number of studies.

Screening the Drug:H+ Antiporter Family for a Role in Biofilm Formation in Candida glabrata

Biofilm formation and drug resistance are two key pathogenesis traits exhibited by Candida glabrata as a human pathogen. Interestingly, specific pathways appear to be in the crossroad between the two phenomena, making them promising targets for drug development. In this study, the 10 multidrug resistance transporters of the Drug:H⁺ Antiporter family of C. glabrata were screened for a role in biofilm formation. Besides previously identified players in this process, namely CgTpo1_2 and CgQdr2, two others are shown to contribute to biofilm formation: CgDtr1 and CgTpo4. The deletion of each of these genes was found to lead to lower biofilm formation, in both SDB and RPMI media, while their expression was found to increase during biofilm development and to be controlled by the transcription factor CgTec1, a predicted key regulator of biofilm formation. Additionally, the deletion of CgDTR1, CgTPO4, or even CgQDR2 was found to increase plasma membrane potential and lead to decreased expression of adhesin encoding genes, particularly CgALS1 and CgEPA1, during biofilm formation. Although the exact role of these drug transporters in biofilm formation remains elusive, our current model suggests that their control over membrane potential by the transport of charged molecules, may affect the perception of nutrient availability, which in turn may delay the triggering of adhesion and biofilm formation.

Behavioral effects of Bj-PRO-7a, a proline-rich oligopeptide from Bothrops jararaca venom

The heptapeptide Bj-PRO-7a, isolated and identified from Bothrops jararaca (Bj) venom, produces antihypertensive and other cardiovascular effects that are independent on angiotensin converting enzyme inhibition, possibly relying on cholinergic muscarinic receptors subtype 1 (M1R). However, whether Bj-PRO-7a acts upon the central nervous system and modifies behavior is yet to be determined. Therefore, the aims of this study were: i) to assess the effects of acute administration of Bj-PRO-7a upon behavior; ii) to reveal mechanisms involved in the effects of Bj-PRO-7a upon locomotion/exploration, anxiety, and depression-like behaviors. For this purpose, adult male Wistar (WT, wild type) and spontaneous hypertensive rats (SHR) received intraperitoneal injections of vehicle (0.9% NaCl), diazepam (2 mg/kg), imipramine (15 mg/kg), Bj-PRO-7a (71, 213 or 426 nmol/kg), pirenzepine (852 nmol/kg), α-methyl-DL-tyrosine (200 mg/kg), or chlorpromazine (2 mg/kg), and underwent elevated plus maze, open field, and forced swimming tests. The heptapeptide promoted anxiolytic and antidepressant-like effects and increased locomotion/exploration. These effects of Bj-PRO-7a seem to be dependent on M1R activation and dopaminergic receptors and rely on catecholaminergic pathways.

9 Pregnancy loss in Holstein lactating recipient cows diagnosed pregnant by pregnancy-associated glycoprotein test in blood

The objective of this study was to evaluate the pregnancy loss (PL) between Day 30 (P30) and Day 80 (P80) of pregnancy in lactating Holstein recipients that received an invivo- (flush) or invitro-produced (IVF) embryo. The recipient cows were located at Maddox Dairy in Riverdale, CA, USA, a Holstein herd that milks 3500 cows with a 305-day mature-equivalent milk production of 12 800 kg. First-lactation cows were enrolled in a Presynch-Ovsynch oestrus-synchronization program and scheduled to be artificially bred for the first time at 80 days after calving or to receive an embryo 7 or 8 days after the expected heat (recipients). The data from 590 pregnancies (1045 embryo transfers) from embryos transferred between January 2018 and March 2019 was analysed. Only grade 1 embryos (from morula to hatched blastocyst stage) produced invivo or invitro from Holstein donor heifers, lactating or dry cows, were transferred fresh (invivo or invitro) or frozen-thawed (invivo), and pregnancy rates are shown in Table 1. The ruminant trophoblast produces pregnancy-associated glycoproteins (PAG) that can be detected by enzyme-linked immunoassay (ELISA) in the blood of pregnant cattle as early as 28 days after insemination. Various dairy herds in the USA have been using this test to supplement or replace the use of transrectal ultrasonography for early pregnancy diagnosis. Blood was sampled on P30 after expected heat day (23 days after embryo transfer) from the recipient cows and sent to IDEXX for the PAG Bovine Pregnancy Test, which was reconfirmed on P80 of pregnancy by transrectal ultrasonography. Pregnancy loss was considered to have occurred when a cow was pregnant on P30 but not pregnant on P80. The variable PL was analysed by binary logistic regression in the MINITAB program, and the model included effects of donor status (heifer vs. milk vs. dry) and embryo type. The total PL was 12.2% (72/590) and the details are shown in Table 1. No effect of donor status (P=0.80) was detected. However, there was effect of embryo type (P=0.004). The IVF embryos had a PL of 18.0% compared with 9.5% for the invivo-produced embryos. Further research should be performed to study heifer embryos PL, because currently more embryos are being produced from very young donor cows and sires due to intensive use of genomic testing. In conclusion, there is a higher PL in lactating dairy recipients receiving IVF fresh embryos compared with fresh or frozen invivo-produced embryos. Table 1.Embryo transfer (ET) pregnancy rates (PR, P30) in first-lactation Holstein cows (top) and pregnancy loss (PL) from Day 30 (P30) to 80 (P80) in first-lactation recipient Holstein cows (bottom) Item Heifer donor Lactating donor Dry donor Total ET P30 PR% ET P30 PR% ET P30 PR% ET P30 PR% Invivo - fresh 6 3 50.0 43 25 58.1 329 206 62.6 378 234 61.9 Invivo - frozen 75 38 50.7 221 129 58.4 296 167 56.4 IVF - fresh 123 61 49.6 91 42 46.2 157 86 54.8 371 189 50.9 Total 129 64 49.6 209 105 50.2 707 421 59.5 1045 590 56.5 P30 P80 PL% P30 P80 PL% P30 P80 PL% P30 P80 PL% Invivo - fresh 3 3 0.0 25 24 4.0 206 186 9.7 234 213 9.0 Invivo - frozen 38 35 7.9 129 115 10.9 167 150 10.2 IVF - fresh 61 48 21.3 42 35 16.7 86 72 16.3 189 155 18.0 Total 64 51 20.3 105 94 10.5 421 373 11.4 590 518 12.2

Signal versus Background Interference in H+ → tb for MSSM Benchmark Scenarios

In this talk an investigation into the interference effects between the process pp→t̄bH+ followed by the decay H+→tb̄ and the background process pp → tt̄bb̄ is presented. The level of interference in parts of the parameter space is shown to be high and as such it may spoil the results of typical analyses which treat signal and background as independent. This is shown for two benchmarks of the MSSM.

11 Invivo-derived embryo pregnancy rates at Maddox Dairy from 2008 to 2018

Maddox Dairy, located in Riverdale, CA, USA, is a Holstein herd that milks 3500 cows with a 305-day mature-equivalent milk production of 12 800 kg, and they have been producing high genetic animals by embryo transfer (ET) since the early 1980s. Invivo-derived embryos from Holstein donors were transferred fresh (grade 1 or 2) or frozen (grade 1), at morula (4), early blastocyst (5), or blastocyst (6) stage, to virgin heifers (VH, natural oestrus, 13-15 months old) or lactating cows (LC, Presynch-Ovsynch, 86 days in milk, first or second lactation) 6 to 9 days after oestrus. Pregnancy diagnosis was done by transrectal ultrasonography at 32-46 days in VH and by the IDEXX PAG test at 30 days in LC. June, July, August, September, and October were called critical months (first service AI conception rate drops below 44%) and compared with the other months. The data from 32 503 ETs between January 2008 and December 2018 are summarised on Table 1. Pregnancy rates (PR) are lower for LC recipients than for VH. Embryo transfers performed 7 or 8 days after oestrus had higher PR in both types of recipients and embryos, but Day 6 and 9 oestrus are also used with fair results. The season does not seem to affect PR. There is not enough difference in the combination of stage and days from oestrus for invivo-derived embryos. These numbers do not belong to a planned experiment. Several management changes during the years were made, which make it very difficult to apply statistical methods to analyse the data correctly. They are used as a tool to make decisions in an attempt to improve future results. Table 1.Pregnancy rate (PR) of virgin heifers (top) and lactating cows (bottom)-fresh (SH) and frozen (OZ) invivo-derived embryo transfer1 Heat-months SH-ST4 SH-ST5 SH-ST6 SH-All OZ-ST4 OZ-ST5 OZ-ST6 OZ-All PR% n PR% n PR% n PR% n PR% n PR% n PR% n PR% n Heifers 6 d-CM 62 934 66 243 68 69 63 1246 56 473 58 219 62 42 57 734 6 d-OM 62 1623 67 489 69 211 64 2323 56 600 55 296 48 137 55 1033 6 d-T 62 2557 67 732 69 280 63 3569 56 1073 57 515 51 179 56 1767 7 d-CM 64 1506 68 495 67 221 65 2222 60 822 62 340 63 156 61 1318 7 d-OM 66 2723 68 1021 69 510 67 4254 57 1120 59 581 57 231 58 1932 7 d-T 66 4229 68 1516 69 731 67 6476 58 1942 60 921 60 387 59 3250 8 d-CM 65 1348 64 518 67 322 65 2188 59 595 64 258 63 108 61 961 8 d-OM 66 2166 68 886 70 510 67 3562 61 770 60 364 51 130 60 1264 8 d-T 66 3514 67 1404 69 832 66 5750 60 1365 62 622 56 238 60 2225 9 d-CM 60 109 56 43 70 20 60 172 60 5 33 6 50 4 47 15 9 d-OM 58 129 63 57 60 40 60 226 63 16 50 18 75 4 58 38 9 d-T 59 238 60 100 63 60 60 398 62 21 46 24 63 8 55 53 All-CM 64 3897 66 1299 67 632 65 5828 58 1895 61 823 63 310 60 3028 All-OM 65 6641 67 2453 69 1271 66 10 365 58 2506 58 1259 53 502 58 4267 All-T 65 10 538 67 3752 69 1903 66 16 193 58 4401 60 2082 57 812 59 7295 Lactating cows 6 d-CM 54 265 48 86 50 12 53 363 38 141 31 77 50 10 36 228 6 d-OM 49 463 52 203 45 56 50 723 46 101 48 54 59 27 48 182 6 d-T 51 728 51 289 46 68 51 1086 41 242 38 131 57 37 42 410 7 d-CM 54 755 59 274 56 103 55 1137 43 928 48 450 43 192 45 1570 7 d-OM 55 914 66 367 54 109 58 1393 46 1052 45 564 47 353 46 1969 7 d-T 55 1669 63 641 55 212 57 2530 45 1980 46 1014 46 545 45 3539 8 d-CM 63 252 68 82 76 33 65 368 48 219 56 80 42 33 50 332 8 d-OM 61 257 64 161 53 47 61 466 50 191 53 77 56 16 51 284 8 d-T 62 509 65 243 63 80 63 834 49 410 55 157 47 49 50 616 All-CM 56 1272 58 442 60 148 57 1868 44 1288 47 607 43 235 45 2130 All-OM 55 1634 62 731 51 212 56 2582 47 1344 46 695 48 396 47 2435 All-T 55 2906 60 1173 55 360 57 4450 45 2632 47 1302 46 631 46 4565 1ST=stage; CM=critical months (June, July, August, September, and October); OM=other months.

10 Pregnancy rates following artificial insemination or embryo transfer in lactating Holstein cows

Excessive heat affects the fertility of high production lactating cows, and reduced pregnancy rates (PR) are observed during summer and early fall. Embryo production programs are used to produce more calves from high genetic merit animals, but could it also increase fertility by bypassing all the negative variables affecting the embryo development before Day 7 (oocyte development, ovulation, fertilization, early embryo development)? The data from AIs and embryo transfers (ET) between June 2017 and May 2019 were analysed. June, July, August, September, and October were called critical months (first-service AI conception rate dropped below 44%). The cows were located at Maddox Dairy in Riverdale, CA, USA, a Holstein herd that milks 3500 cows with a 305-day mature-equivalent milk production of 12 800 kg. First- and second-lactation cows were enrolled in a Presynch-Ovsynch oestrus-synchronization program and scheduled for the first AI at 86 days after calving or to receive an embryo 7 or 8 days after the expected heat. The embryos were produced invivo or invitro from Holstein donors and were transferred fresh or frozen. Blood was sampled on Day 30 after expected heat day (23 days after embryo transfer), and pregnancy was detected by the IDEXX PAG Bovine Pregnancy Test. Table 1 summarises the results, where ET PR% is the number of pregnant cows divided by the number of cows that received and embryo. All the cows synchronized for AI were bred, but only cows with the presence of a corpus luteum (CL) on ET day received an embryo. The presence of a CL was not detected in 28.7% (471/1642) of the cows (32.2% in the critical months and 25.7% in the others). Unfortunately, we could not detect the presence of a CL by ultrasonography every time we transferred embryos, so the nonovulation rate might be overestimated. The cows without a CL were considered open and used to calculate the adjusted PR (AdjPR%). Embryo transfer PR is superior to that of AI, especially during the critical months. Fresh invivo embryos have the most impact. When the cows without CLs are considered open, the difference between AI and ET is still evident for fresh invivo embryos. Besides producing animals with higher genetic merit, depending on the type of embryo used, ET can increase fertility in lactating Holstein cows, especially during the critical months. The other benefit of using ET is that cows that do not ovulate are synchronized right away, which is not the case for AI cows. Table 1.AI×embryo transfer in lactating Holstein cows1 from June 2017 to May 20192 Item Critical months (June to October) Other months (November to May) All year %PR n Adj PR% n %PR n Adj PR% n %PR n Adj PR% n Artificial insemination 41.2% 896 41.2% 896 47.7% 1767 47.7% 1767 45.5% 2663 2663 Fresh invivo embryo 62.7% 373 47.5% 493 69.5% 262 55.3% 329 65.5% 635 50.6% 822 Frozen invivo embryo 59.3% 221 44.8% 292 59.4% 256 47.3% 322 59.3% 477 46.1% 614 IVF fresh embryo 47.9% 167 36.2% 221 54.0% 363 43.0% 456 52.1% 530 40.8% 677 Total embryos 58.5% 761 44.2% 1006 60.2% 881 47.9% 1107 59.4% 1642 46.1% 2113 1Lactating Holstein cows, first and second lactation, first service, Presynch-Ovsynch, 85 DIM. 2PR%=the number of pregnant cows divided by the number of cows that received and embryo; AdjPR%=adjusted pregnancy rate.

Elevated trace elements in sediments and seagrasses at CO2 seeps

Seagrasses often occur around shallow marine CO2 seeps, allowing assessment of trace metal accumulation. Here, we measured Cd, Cu, Hg, Ni, Pb and Zn levels at six CO2 seeps and six reference sites in the Mediterranean. Some seep sediments had elevated metal concentrations; an extreme example was Cd which was 43x more concentrated at a seep site than its corresponding reference site. Three seeps had metal levels that were predicted to adversely affect marine biota, namely Vulcano (for Hg), Ischia (for Cu) and Paleochori (for Cd and Ni). There were higher-than-sediment levels of Zn and Ni in Posidonia oceanica and of Zn in Cymodocea nodosa, particularly in roots. High levels of Cu were found in Ischia seep sediments, yet seagrass was abundant there, and the plants contained low levels of Cu. Differences in bioavailability and toxicity of trace elements helps explain why seagrasses can be abundant at some CO2 seeps but not at others.

Pseudo-Wellens syndrome, acute pancreatitis, and an anomalous coronary artery: a case report

Background

Chest pain associated with transient electrocardiogram changes mimicking an acute myocardial infarction have been described in acute pancreatitis. These ischemic electrocardiogram changes can present a diagnostic dilemma, especially when patients present with concurrent angina pectoris and epigastric pain warranting noninvasive or invasive imaging studies.

Case presentation

A 45-year-old African-American man with a history of alcohol use disorder presented to the emergency department of our institution with 36 hours of concurrent epigastric pain and left-sided chest pain radiating to his left arm and associated with nausea and dyspnea. On physical examination, he was afebrile; his blood pressure was elevated; and he had epigastric tenderness. His laboratory test results were significant for hypokalemia, normal troponin, and elevated serum lipase and amylase levels. Serial electrocardiograms for persistent chest pain showed ST-segment elevations with dynamic T-wave changes in the right precordial electrocardiogram leads, consistent with Wellens syndrome. He was immediately taken to the cardiac catheterization laboratory, where selective coronary angiography showed normal coronary arteries with an anomalous origin of the right coronary artery from the opposite sinus. Given his elevated lipase and amylase levels, the patient was treated for acute alcohol-induced pancreatitis with intravenous fluids and pain control. His chest pain and ischemic electrocardiogram changes resolved within 24 hours of admission, and coronary computed tomography angiography showed an interarterial course of the right coronary artery without high-risk features.

Conclusions

Clinicians may consider deferring immediate cardiac catheterization and attribute electrocardiogram changes to acute pancreatitis in patients presenting with angina pectoris and acute pancreatitis if confirmed by normal cardiac enzymes and elevated levels of lipase and amylase. However, when clinical signs and electrocardiogram findings are highly suggestive of myocardial ischemia/injury, immediate noninvasive coronary computed tomography angiography may be the best approach to make an early diagnosis.

Temperature amplifies the effect of high CO2 on the photosynthesis, respiration, and calcification of the coralline algae Phymatolithon lusitanicum

The combination of ocean acidification (OA) and global warming is expected to have a significant effect on the diversity and functioning of marine ecosystems, particularly on calcifying algae such as rhodoliths (maërl) that form extensive beds worldwide, from polar to tropical regions. In addition, the increasing frequency of extreme events, such as heat waves, threatens coastal ecosystems and may affect their capacity to fix blue carbon. The few studies where the simultaneous effects of both temperature and CO2 were investigated have revealed contradictory results. To assess the effect that high temperature spells can have on the maërl beds under OA, we tested the short-time effects of temperature and CO2 on the net photosynthesis, respiration, and calcification of the recently described species Phymatolithon lusitanicum, the most common maërl species of southern Portugal. Photosynthesis, calcification, and respiration increased with temperature, and the differences among treatments were enhanced under high CO2. We found that in the short term, the metabolic rates of Phymatolithon lusitanicum will increase with CO2 and temperature as will the coupling between calcification and photosynthesis. However, under high CO2, this coupling will favor photosynthesis over calcification, which, in the long term, can have a negative effect on the blue carbon fixing capacity of the maërl beds from southern Portugal.

P3808iBox-CRT: Better response, less complicated, equally fast

Introduction

The optimization of the left ventricle (LV) pacing site guided by the electrical delay increases CRT response rate (RR), however it's necessary to develop technology that allows its universal use.

Purpose

The aim is automatically, and operator-independent, access the conduction delay between the right ventricular (RV) stimulus and the LV available veins in order to select the LV pacing site. It is further intended to compare the total procedure and radiation times in relation to an historical control group.

Methods

Prospective, single-center study that included patients undergoing CRT implant according to the current ESC Guidelines. All patients were submitted to a clinical, electrocardiographic and echocardiographic basal evaluation prior to CRT implantation and at 6 months of follow-up.

To evaluate conduction delays between the RV lead and the LV available veins (RV-LV delay), an external interface - intelligent Box for CRT (iBox-CRT) was used. Four measurements in at least two different tributary veins were made. The implant of all the LV leads was guided by the longest measured delay.

A positive response to CRT was defined as an improvement of >10% in left ventricle ejection fraction (LVEF) or a reduction of end-systolic volume (ESV)>15%. The results were compared to a control group (CG) of pts submitted to CRT implantation in the conventional way.

Results

60 patients were included (68.3% males, 38% ischemic, mean age 67.4±10.2 years) and submitted to CRT implant (37 CRT-P; 23 CRT-D). At basal evaluation, LVEF was 28±7%, end-diastolic volume (EDV) was 200±73ml and ESV 145±64ml. CG (n=51) had similar characteristics.

The RR was 85.7%, significantly higher compared to the CG (55.9%, p=0.003). The ESV reduced 38.2±3% in responders vs 5.7±2% in non-responders (NR) (p=0,005), EDV reduced 33.3±16% in responders vs 13.6±10% in NR (p=0.002), the mean LVEF improved 11% in responders vs −1% in NR (p=0.02).

At follow-up, the mean ESV in the study group (SG) was 89±44 ml vs 132±75ml in the CG (p=0.002) and the EDV 136±51 vs 190±78 (p=0.007).

In addition to a much better response rate, the responders in the study group had significantly higher mean LVEF at follow-up (39±11% vs 37±7%, p=0.032).

The mean intra-procedure RV-LV delay was 187±34mseg. In the responder group the baseline delay was usually higher (190±35 msec) vs NR group RV-LV delay (165±23 msec; p=NS).

Compared with CG, the automatic assessment of RV-LV delay with iBox-CRT did not increase fluoroscopy time (15±16min vs 18±16; p=NS) and shortened procedure time (65±34 vs 108±83min, p<0.005).

Conclusions

The iBox-CRT use enabled an automatic and operator independent RV-LV delays measurement, in order to implant the LV lead at the most delayed site. This technique translated into a major increase in CTR response rate, not compromising the procedure duration nor increasing the radiation exposure.

P5689First intention epicardial VT ablation: what are the results?

Introduction

Ventricular tachycardia (VT) endocardial mapping and ablation may not be sufficient in several arrhythmogenic contexts, because ventricular myocardium may comprise intricate endocardial, intramural and epicardial substract. Thus, epicardial ablation has lately become a complementary and necessary tool to approach some VTs in different types of cardiomyopathies.

Purposes

To evaluate the clinical characteristics of patient most suitable for first intention epicardial VT ablation and to describe our centre experience.

Methods

Single-centre prospective study of consecutive patients (pts) undergoing isolated first intention epicardial VT mapping and ablation since August 2015. All pts had clinical assessment, electrocardiogram (ECG), echocardiogram and cardiac magnetic resonance when feasible. Pts with a previous endocardial ablation were excluded. Epicardial subxiphoid access utilizing a tuhoy needle was performed under fluoroscopic guidance. High-density mapping was performed using CARTO® V4 and EnSite PrecisionTM systems and multipolar catheters. Radiofrequency energy was applied with an irrigated-tip catheter.

Results

First intention epicardial VT ablation was attempted in 12 pts (mean age 57.6±14.6 years, 91% male). The majority had non-ischemic dilated cardiomyopathy, of unknown aetiology in 59%, hereditary dilated cardiomyopathy in 17% ethanolic origin in 8% and post-myocarditis in 8%. Right Ventricular Arrhythmogenic Cardiomyopathy was present in 1 patient. As expected, our population presented a mean ejection fraction of 29% and 11 pts (92%) had an implantable cardioverter defibrillator - ICD (55% as primary prevention, 45% as secondary prevention). All pts had experienced symptomatic VT, with all ICD carriers receiving appropriate shocks. Only 4 pts had an available 12 lead ECG of the VT, and all of them had a QS pattern in lead aVL and a slurred initial QRS complex. The majority of patients presented low voltage areas and local abnormal ventricular activities at the epicardial surface, with the exception of 2 pts in whom ablation was not performed (one non-ischemic cardiomyopathy of ethanolic aetiology and the other of unknown origin). Mean ablation application time was 68 minutes, with an average maximum power of 39.9 watts. Mean overall procedure and fluoroscopic time was 132 and 24 minutes, respectively, with no major intraprocedural complications. During a mean follow-up of 307±328 days, 3 pts died (mean 121 days after procedure), 3 had recurrent VT episodes and ICD shocks, and 2 received heart transplant.

Conclusion

In selected pts, with non-ischemic dilated cardiomyopathy and ECG with QS pattern in aVL and slurred QRS, epicardial VT mapping and ablation may be used as first approach, preventing unnecessary endocardial mapping. This procedure demonstrated to be safe.

P983Long-standing persistent atrial fibrillation: what can we achieve with ablation?

Introduction

Atrial fibrillation (AF) ablation presents suboptimal results in patients (pts) with persistent long-lasting forms (LSPAF, AF ≥12 months). Recently, the STAR AF-II trial has shown that in these pts complex additional strategies do not improve success compared to only performing pulmonary vein isolation (PVI).

Objectives

To evaluate the success of AF ablation, particularly in long-standing persistent AF

Methods

Single-center prospective study of pts with AF submitted to ablation. The strategy, regardless of the type of AF, was based on PVI, complemented by cavo-tricuspid isthmus line (CTI) in pts with history of flutter. Additional ablation strategies were selectively considered in pts with stable atypical flutter conversion, persistent triggers or no electrograms in the VPs. Pts were monitored with Holter/7-day event loop recorder (3, 6, 12 months and annually up to 5 years). Success was assessed from the 90th day after ablation, with the absence of recurrences of any sustained atrial arrhythmias (>30 sec). Cox regression and Kaplan-Meier survival were used to compare the success of ablation as a function of the clinical type of AF in our population and with pts included in STAR-II AF trial.

Results

620 patients were submitted to AF ablation, 67% male, 58±12 years, including 78 pts (13%) with LSPAF - pts with paroxysmal and persistent short duration AF represented 61% and 26% of the population. In LSPAF, VPI was performed with irrigated catheter (N=33), PVAC (N=44) or nMARQ (N=1), complemented by CTI ablation in 15, linear left atrial lesions in 3, ablation of areas of low voltage in 3 and elimination of fractionated electrograms in 1 patient.

With a median follow-up of 426 days (94–989), the 3-year success rate after a single procedure was 53% in LSPAF, lower than that observed in patients with paroxysmal AF (69%) or short-duration persistent AF (61%) - LogRank P=0.002. The risk of arrhythmias was double in LSPAF vs paroxysmal AF (HR: 2.0; P=0.001). However, after an average of 1.2 procedures/patient, the success rate in LSPAF was 80% at 3 years, comparable to that observed for other types of AF (Log Rank 2.5, p=0.29). Effectively, the long-term success rate of our LSPAF pts treated with PVI and very selective additional strategies was higher than that observed in the STAR-II AF pts treated with PVI and indiscriminate complex ablations (80% vs. 69%, t-test p<0.001, with similar mean follow-up).

Conclusions

AF ablation is more effective if it is performed earlier in the natural history of the disease. However, even in LSPAF, high success rates are achieved through PVI-based ablation strategies, although more procedures are required.

P309R' wave in precordial leads V1-V2 in patients from the young SCD-SOS cohort

Introduction

Sudden Cardiac Death – Screening Of risk factorS (SCD-SOS) survey aimed to screen for warning signs of potential channelopathies and cardiomyopathies that may course with sudden cardiac death in the young (≤40 years old) and consisted in an ECG and a digital-based previously validated questionnaire.

Purpose

We aimed to study clinical and electrocardiographic characteristics of young patients from the SCD-SOS cohort who presented with an r'-wave in precordial leads V1 and V2.

Methods

All the ECG were screened for the detection of an r'-wave in precordial leads V1 and V2. The ECGs selected were reviewed by a second investigator (agreed in 97.7% of the cases). We performed classical descriptive statistics and multivariate logistic regression to compare patients with and without r'-wave in these leads.

Results

From a total of 14669 patients who had an ECG performed as part of the SCD-SOS survey, 17% displayed an r'-wave in precordial leads V1 and V2 and 0.4% had complete right bundle branch block (RBBB). Patients with rSr' pattern had a mean age of 20±5 years old, 54% of them were male, they had a mean body mass index (BMI) of 22±3kg/m2, and 54% practiced sports regularly, with a mean of 5±4 hours of physical activity per week. Regarding previous symptoms reported by these individuals, 24% (n=487) reported a transient loss of consciousness, 15% (n=310) a reflex syncope, 3% (n=58) had unexplained syncope and 21% (n=425) palpitations. Sudden death in relatives before 50 years-old was present in 11% (n=172) of the patients with an r'-wave in V1-V2. After adjusting for heart rate and physical activity, PQ interval (OR 1.007 - CI95% 1.004–1.010, p<0.001), QTc interval (OR 1.009 - CI95% 1.005–1.012, p<0.001), male gender (OR 2.438 - CI95% 2.144–2.772, p<0.001) and BMI (OR 0.881 - CI95% 0.864–0.900, p<0.001) were independently associated with the presence of r'wave in precordial leads V1-V2. Unexplained syncope, palpitations and family history of sudden death were not associated with r'-wave in the young SCD-SOS population.

Conclusions

We conclude that r'-wave in V1-V2 is a frequent finding in the young population and that it is associated with higher PQ and QTc intervals. The prognostic implications of this pattern are unknown, but thorough differential diagnosis is warranted since this pattern may correspond to incomplete RBBB/athlete's ECG, and may also be suggestive of other potentially serious conditions such as Type 2 Brugada pattern and multiple causes of right ventricular enlargement. Finally, this pattern is also associated with male gender and lower BMI, suggesting a dependence on anatomical factors.

P603Cardiac Magnetic Resonance evaluation and risk stratification of patients with unexplained or suspected arrhythmias

Introduction

The etiological diagnosis of cardiac arrhythmias is often difficult. Cardiac Magnetic Resonance (CMR) is the gold standard exam for anatomical and functional cardiac evaluation and it may be indicated in patients with ventricular arrhythmias when echocardiography does not provide an accurate assessment of left and right ventricles (LV, RV).

Purpose

The aim of this study was to determine the impact of CMR in the diagnosis and stratification of arrhythmic risk in patients with confirmed or suspected arrhythmias, as well as to describe the changes observed.

Methods

We performed a prospective registry over a 5-year period of all the patients with arrhythmias who underwent CMR for diagnostic and risk stratification purposes. We followed a protocol to evaluate both anatomically and functionally the ventricles and to look for the presence of late gadolinium enhancement (LGE).

Results

A total of 78 patients were included, of which 65% were male and a mean age of 46±17 years-old was observed. The indications for CMR evaluation of patients with confirmed or suspected arrhythmias were as follows: 33% (n=26) of the patients had very frequent premature ventricular complexes (PVC), 23% (n=18) had sustained ventricular tachycardia (VT), 17% (n=13) suspected structural heart disease with high arrhythmic potential, 12% (n=9) unexplained recurrent syncope, 6% (n=5) supraventricular tachycardia, 5% (n=4) non-sustained VT and 4% (n=3) aborted sudden cardiac death. Depressed ventricular ejection fraction (<50%) was present in 9% (n=7) for the LV and in 14% (n=11)for the RV. Dilation of the LV was found in 24% of the patients (n=19, mean LV volume: 115±4ml/m2) and RV dilation was present in only 1 patient who had right ventricle arrhythmogenic dysplasia (RVAD) (RV volume: 152ml/m2). Cardiac synchronization artifacts due to the presence of very frequent PVC compromised the calculation of v volumes in only 4% (n=3) of the patients. In total, 6% (n=5) had interventricular septum hypertrophy (mean 15±6g/m2), 10% (n=8) had a slight prolapse of the anterior leaflet of the mitral valve and 19% (n=15) had a dilated left auricle. LGE was present in 13% (n=10) and slight pericardium effusion was detected in 12% (n=9). CMR was considered normal in 65% (n=51), in 15% (n=12) we found nonspecific changes deserving follow-up and in 20% (n=15) it was possible to establish a diagnosis which was previously unknown: 5% (n=4) had hypertrophic cardiomyopathy, 4% (n=3) LV non-compaction, 4% (n=3) a myocarditis sequelae, 3% (n=2) RVAD, 3% (n=2) a myocardial infarction scar and 1 had non-ischemic dilated cardiomyopathy.

Conclusions

CMR is a technique with high spatial resolution, feasible and safe, which allowed an increase in diagnosis in 20% of the patients, thus contributing to the risk stratification of our study population with suspected high arrhythmic potential when the first-line complementary exams were inconclusive.

P987Dilated cardiomyopathy - a group that does not benefit from ICD?

Introduction

The prevalence of sudden death in patients with heart failure with reduced ejection fraction has been declining in the last decade, not only due to better optimization of pharmacological therapy, but also due to the high rate of cardiac resynchronization responders. Overall, based on recent studies demonstrating a lack of improvement in mortality in some patients with dilated cardiomyopathy, the CRT-P/CRT-D implantation ratio has been increasing across Europe.

Objective

To evaluate the evolution of the CRT-P/CRT-D implantation ratio and to evaluate the impact on mortality of dilated cardiomyopathy (DCM) patients who underwent resynchronization therapy.

Methods

A single-center prospective study of non-randomized patients who underwent CRT implantation since 2015. Demographic and clinical data from patients with dilated cardiomyopathy were assessed. The mortality of these patients and the predictors of mortality by the Cox and Kaplan-Meier regression method were evaluated.

Results

486 CRTs were implanted since 2015 (male 73.9%, age 72.06±9.9 years, median follow-up time of 487 days IIQ [175, 749].) During the last 3 years, occurred an increased in CRT-P/CRT-D ratio with the CRT-P implant rate increasing from 36% of the total devices in 2015 to 47% in 2018. Of the patients submitted to CRT implantation, 256 (55%) had dilated cardiomyopathy as the etiology of heart failure. In this population, by multivariate Cox analysis, age (HR 1.1, 95% CI 1.0–1.1, p=0.003) and GFR <60ml/min/1.73m2 (HR 1.8 IC 95% 1, 2–2.6, p=0.01) were independent predictors of mortality. In addition, CRT-D implantation in these patients was associated with a significant reduction in all-cause mortality (HR 0.33 95% CI 0.15–0.73, p<0.01) with a required number to treat only 10 patients. Similar results were obtained in the subgroup of patients aged ≥59 years.

Mortality in DMC – CRT-P vs CRT-D

Conclusion

The CRT-P implant rate has been increasing at the expense of the CRT-D implant after some studies suggest no benefit in the population aged ≥59 years. However, in our population of patients with DCM, CRT-D implantation demonstrated a 67% mortality reduction. These results may demonstrate a good selection of patients for this therapy, but should also motivate further studies in the evaluation of mortality in this subgroup of patients.

The future of Blue Carbon science

The term Blue Carbon (BC) was first coined a decade ago to describe the disproportionately large contribution of coastal vegetated ecosystems to global carbon sequestration. The role of BC in climate change mitigation and adaptation has now reached international prominence. To help prioritise future research, we assembled leading experts in the field to agree upon the top-ten pending questions in BC science. Understanding how climate change affects carbon accumulation in mature BC ecosystems and during their restoration was a high priority. Controversial questions included the role of carbonate and macroalgae in BC cycling, and the degree to which greenhouse gases are released following disturbance of BC ecosystems. Scientists seek improved precision of the extent of BC ecosystems; techniques to determine BC provenance; understanding of the factors that influence sequestration in BC ecosystems, with the corresponding value of BC; and the management actions that are effective in enhancing this value. Overall this overview provides a comprehensive road map for the coming decades on future research in BC science.

The role of Blue Carbon in climate change mitigation and adaptation has now reached international prominence. Here the authors identified the top-ten unresolved questions in the field and find that most questions relate to the precise role blue carbon can play in mitigating climate change and the most effective management actions in maximising this.

Characterization of CCDC103 expression profiles: further insights in primary ciliary dyskinesia and in human reproduction

PROPOSE

To study CCDC103 expression profiles and understand how pathogenic variants in CCDC103 affect its expression profile at mRNA and protein level.

METHODS

To increase the knowledge about the CCDC103, we attempted genotype-phenotype correlations in two patients carrying novel homozygous (missense and frameshift) CCDC103 variants. Whole-exome sequencing, quantitative PCR, Western blot, electron microscopy, immunohistochemistry, immunocytochemistry, and immunogold labelling were performed to characterize CCDC103 expression profiles in reproductive and somatic cells.

RESULTS

Our data demonstrate that pathogenic variants in CCDC103 gene negatively affect gene and protein expression in both patients who presented absence of DA on their axonemes. Further, we firstly report that CCDC103 is expressed at different levels in reproductive tissues and somatic cells and described that CCDC103 protein forms oligomers with tissue-specific sizes, which suggests that CCDC103 possibly undergoes post-translational modifications. Moreover, we reported that CCDC103 was restricted to the midpiece of sperm and is present at the cytoplasm of the other cells.

CONCLUSIONS

Overall, our data support the CCDC103 involvement in PCD and suggest that CCDC103 may have different assemblies and roles in cilia and sperm flagella biology that are still unexplored.