The quiet crossing of ocean tipping points.

Anthropogenic climate change profoundly alters the ocean's environmental conditions, which, in turn, impact marine ecosystems. Some of these changes are happening fast and may be difficult to reverse. The identification and monitoring of such changes, which also includes tipping points, is an ongoing and emerging research effort. Prevention of negative impacts requires mitigation efforts based on feasible research-based pathways. Climate-induced tipping points are traditionally associated with singular catastrophic events (relative to natural variations) of dramatic negative impact. High-probability high-impact ocean tipping points due to warming, ocean acidification, and deoxygenation may be more fragmented both regionally and in time but add up to global dimensions. These tipping points in combination with gradual changes need to be addressed as seriously as singular catastrophic events in order to prevent the cumulative and often compounding negative societal and Earth system impacts.

Global mercury concentrations in biota: their use as a basis for a global biomonitoring framework.

An important provision of the Minamata Convention on Mercury is to monitor and evaluate the effectiveness of the adopted measures and its implementation. Here, we describe for the first time currently available biotic mercury (Hg) data on a global scale to improve the understanding of global efforts to reduce the impact of Hg pollution on people and the environment. Data from the peer-reviewed literature were compiled in the Global Biotic Mercury Synthesis (GBMS) database (>550,000 data points). These data provide a foundation for establishing a biomonitoring framework needed to track Hg concentrations in biota globally. We describe Hg exposure in the taxa identified by the Minamata Convention: fish, sea turtles, birds, and marine mammals. Based on the GBMS database, Hg concentrations are presented at relevant geographic scales for continents and oceanic basins. We identify some effective regional templates for monitoring methylmercury (MeHg) availability in the environment, but overall illustrate that there is a general lack of regional biomonitoring initiatives around the world, especially in Africa, Australia, Indo-Pacific, Middle East, and South Atlantic and Pacific Oceans. Temporal trend data for Hg in biota are generally limited. Ecologically sensitive sites (where biota have above average MeHg tissue concentrations) have been identified throughout the world. Efforts to model and quantify ecosystem sensitivity locally, regionally, and globally could help establish effective and efficient biomonitoring programs. We present a framework for a global Hg biomonitoring network that includes a three-step continental and oceanic approach to integrate existing biomonitoring efforts and prioritize filling regional data gaps linked with key Hg sources. We describe a standardized approach that builds on an evidence-based evaluation to assess the Minamata Convention's progress to reduce the impact of global Hg pollution on people and the environment.

Clinical outcomes of percutaneous coronary intervention for chronic total occlusion by treated segment length.

BACKGROUND: Long lesions are known to have worse outcomes following percutaneous coronary intervention (PCI), but there are limited data assessing the association between lesion length and clinical outcomes in PCI procedures undertaken in chronic total occlusions (CTO). METHODS AND RESULTS: We formed a longitudinal cohort (2006-2018, n = 27,205) of stable angina patients who underwent PCI to CTO in the British Cardiovascular Intervention Society (BCIS) database. Clinical, demographical, procedural, and outcome data were analyzed in three groups by treated segment length, < 30 mm (n = 11,782), 30-59 mm (n = 10,415), ≥ 60 mm (n = 5008). Prevalence of previous myocardial infarction and PCI were higher in patients in 30-59 mm group or ≥ 60 mm group compared with < 30 mm group. Following multivariable analysis, no significant difference was observed in in-patient death (OR = 30-59 mm group = 1.10, CI:0.55-2.19, p = 0.78) (OR ≥ 60 mm group = 0.82, CI: 0.33-2.05, p = 0.67), and 1-year death (OR = 30-59 mm group = 1.06, CI: 0.81-1.37, p = 0.69) (OR ≥ 60 mm group =1.01, CI: 0.70-1.43, p = 0.99) (< 30 mm group = reference) but in-patient MACE was higher in > = 60 mm group (OR: 1.52, CI: 1.15-2.01, p = 0.06) but similar in 30-59 mm group (OR: 1.16, CI: 0.91-1.48, p = 0.22) compared with < 30 mm group. The adjusted rates of procedural complications were higher in ≥ 60 mm group (OR: 1.61, CI: 1.40-1.85, p < 0.001) but were similar in 30-59 mm group (OR: 1.06, CI: 0.94-1.20, p < 0.31) compared with < 30 mm group. For every 10 mm increase, there was an increased adjusted risk of in-patient procedural complications and coronary perforation but not in-patient MACE or death. CONCLUSION: Patients with very long CTO lesions have higher risk of procedural complications and in-patient MACE but similar risk of short or long-term mortality compared with short CTO lesions.

Intravascular lithotripsy for treatment of calcific coronary lesions in ST elevation myocardial infarction.

AIMS: To describe the utility and safety of intravascular lithotripsy (IVL) in the setting of primary percutaneous coronary intervention (PCI) for ST elevation myocardial infarction (STEMI). METHODS AND RESULTS: We performed a retrospective analysis, across six UK sites of all patients in whom IVL was used for coronary calcium modification of the culprit lesion during primary PCI for STEMI. The 72 patients were included. IVL was used in de-novo culprit lesions in 57 (79%) of cases and culprit in-stent restenoses in 11 (15%) of cases. In four cases (6%) it was used in a newly deployed stent when this was under-expanded due to inadequate calcium modification. Of the 30 cases in which intracoronary imaging was available for stent analysis, the average stent expansion was 104%. Intra-procedural stent thrombosis occurred in one case (1%), and no-reflow in three cases (4%). The 30 day MACE rates were 18%. CONCLUSION: IVL appears to be feasible and safe for use in the treatment of calcific coronary artery disease in the setting of STEMI.

Impact of COVID-19 pandemic on the management of nonculprit lesions in patients presenting with ST-elevation myocardial infarction: Outcomes from the pan-London heart attack centers.

BACKGROUND: The impact of COVID-19 on the diagnosis and management of nonculprit lesions remains unclear. OBJECTIVES: This study sought to evaluate the management and outcomes of patients with nonculprit lesions during the COVID-19 pandemic. METHODS: We conducted a retrospective observational analysis of consecutive primary percutaneous coronary intervention (PPCI) pathway activations across the heart attack center network in London, UK. Data from the study period in 2020 were compared with prepandemic data in 2019. The primary outcome was the rate of nonculprit lesion percutaneous coronary intervention (PCI) and secondary outcomes included major adverse cardiovascular events. RESULTS: A total of 788 patients undergoing PPCI were identified, 209 (60%) in 2020 cohort and 263 (60%) in 2019 cohort had nonculprit lesions (p = .89). There was less functional assessment of the significance of nonculprit lesions in the 2020 cohort compared to 2019 cohort; in 8% 2020 cohort versus 15% 2019 cohort (p = .01). There was no difference in rates of PCI for nonculprit disease in the 2019 and 2020 cohorts (31% vs 30%, p = .11). Patients in 2020 cohort underwent nonculprit lesion PCI sooner than the 2019 cohort (p < .001). At 6 months there was higher rates of unplanned revascularization (4% vs. 2%, p = .05) and repeat myocardial infarction (4% vs. 1%, p = .02) in the 2019 cohort compared to 2020 cohort. CONCLUSION: Changes to clinical practice during the COVID-19 pandemic were associated with reduced rates of unplanned revascularization and myocardial infarction at 6-months follow-up, and despite the pandemic, there was no difference in mortality, suggesting that it is not only safe but maybe more efficacious.

Management of stent underexpansion using intravascular lithotripsy-Defining the utility of a novel device.

OBJECTIVES: This study aimed to present a case series of patient treated for stent underexpansion resistant to conventional treatment with intravascular lithotripsy (IVL). BACKGROUND: Stent underexpansion is a powerful predictor of long-term stent patency and correlates with unfavorable clinical outcomes. This case series demonstrates the utility of IVL in managing stent underexpansion resistant to conventional treatment. METHODS: We describe a case series of patients with stent underexpansion due to calcific coronary artery disease treated with IVL. Stent underexpansion was identified as an inability to adequately expand stents with conventional treatment. Only cases that failed to achieve adequate expansion with high-pressure noncompliant balloon inflation were included. RESULTS: Thirteen patients from six institutions have been included in this case series. The average age was 70.25 years with 76.9% of male patients. The average pre-IVL minimal stent area (MSA) was 2.71 mm2 , which improved to 6.44 mm2 post-IVL treatment, representing an average MSA gain of 238%. There were no procedural, peri-procedural, or 30-day major adverse cardiac and cerebrovascular event. CONCLUSION: This case series demonstrates that IVL is a feasible, safe alternative for the management of stent underexpansion due to calcific coronary disease.

Antithrombotic Effects of Combined PAR (Protease-Activated Receptor)-4 Antagonism and Factor Xa Inhibition.

OBJECTIVE: PAR (protease-activated receptor)-4 antagonism has antiplatelet effects under conditions of high shear stress. We aimed to establish whether PAR4 antagonism had additive antithrombotic activity in the presence of factor Xa inhibition in an ex vivo model of acute arterial injury. Approach and Results: Fifteen healthy volunteers (29±6 years, 7 women) completed a phase zero double-blind randomized controlled crossover trial. Ex vivo platelet activation, platelet aggregation, and thrombus formation were measured following blood perfusion of low shear and high shear stress chambers. Upstream of the chambers, extracorporeal blood was admixed with (1) vehicle, (2) low-dose apixaban (20 ng/mL), (3) high-dose apixaban (80 ng/mL), (4) BMS-986141 (400 ng/mL), (5) BMS-968141 and low-dose apixaban, or (6) BMS-968141 and high-dose apixaban in 6 sequential studies performed in random order. Compared with vehicle, BMS-986141 demonstrated selective inhibition of PAR4-AP (agonist peptide)-stimulated platelet aggregation, platelet-monocyte aggregates, and P-selectin expression (P≤0.01 for all). Total thrombus area was reduced under both low shear and high shear stress conditions for all drug infusions (P<0.0001 for all versus vehicle). BMS-968141 reduced total (≤44.4%) and platelet-rich (≤39.3%) thrombus area, whereas apixaban reduced total (≤42.9%) and fibrin-rich (≤31.6%) thrombus area. Combination of BMS-986141 with apixaban caused a further modest reduction in total thrombus area (9.6%-12.4%), especially under conditions of high shear stress (P≤0.027). CONCLUSIONS: In the presence of factor Xa inhibition, PAR4 antagonism with BMS-986141 further reduces thrombus formation, especially under conditions of high shear stress. This suggests the potential for additive efficacy of combination PAR4 antagonism and factor Xa inhibition in the prevention of atherothrombotic events.

Passive Sampling of SARS-CoV-2 for Wastewater Surveillance.

The shedding of pathogens by infected humans enables the use of sewage monitoring to conduct wastewater-based epidemiology (WBE). Although most WBE studies use data from large sewage treatment plants, timely data from smaller catchments are needed for targeted public health action. Traditional sampling methods, like autosamplers or grab sampling, are not conducive to quick ad hoc deployments and high-resolution monitoring at these smaller scales. This study develops and validates a cheap and easily deployable passive sampler unit, made from readily available consumables, with relevance to the COVID-19 pandemic but with broader use for WBE. We provide the first evidence that passive samplers can be used to detect SARS-CoV-2 in wastewater from populations with low prevalence of active COVID-19 infections (0.034 to 0.34 per 10,000), demonstrating their ability for early detection of infections at three different scales (lot, suburb, and city). A side by side evaluation of passive samplers (n = 245) and traditionally collected wastewater samples (n = 183) verified that the passive samplers were sensitive at detecting SARS-CoV-2 in wastewater. On all 33 days where we directly compared traditional and passive sampling techniques, at least one passive sampler was positive when the average SARS-CoV-2 concentration in the wastewater equaled or exceeded the quantification limit of 1.8 gene copies per mL (n = 7). Moreover, on 13 occasions where wastewater SARS-CoV-2 concentrations were less than 1.8 gene copies per mL, one or more passive samplers were positive. Finally, there was a statistically significant (p < 0.001) positive relationship between the concentrations of SARS-CoV-2 in wastewater and the levels found on the passive samplers, indicating that with further evaluation, these devices could yield semi-quantitative results in the future. Passive samplers have the potential for wide use in WBE with attractive feasibility attributes of cost, ease of deployment at small-scale locations, and continuous sampling of the wastewater. Further research will focus on the optimization of laboratory methods including elution and extraction and continued parallel deployment and evaluations in a variety of settings to inform optimal use in wastewater surveillance.

PAR4 (Protease-Activated Receptor 4) Antagonism With BMS-986120 Inhibits Human Ex Vivo Thrombus Formation.

OBJECTIVE: BMS-986120 is a novel first-in-class oral PAR4 (protease-activated receptor 4) antagonist with potent and selective antiplatelet effects. We sought to determine for the first time, the effect of BMS-986120 on human ex vivo thrombus formation. APPROACH AND RESULTS: Forty healthy volunteers completed a phase 1 parallel-group PROBE trial (Prospective Randomized Open-Label Blinded End Point). Ex vivo platelet activation, platelet aggregation, and thrombus formation were measured at 0, 2, and 24 hours after (1) oral BMS-986120 (60 mg) or (2) oral aspirin (600 mg) followed at 18 hours with oral aspirin (600 mg) and oral clopidogrel (600 mg). BMS-986120 demonstrated highly selective and reversible inhibition of PAR4 agonist peptide (100 µM)-stimulated P-selectin expression, platelet-monocyte aggregates, and platelet aggregation (P<0.001 for all). Compared with pretreatment, total thrombus area (µm2/mm) at high shear was reduced by 29.2% (95% confidence interval, 18.3%-38.7%; P<0.001) at 2 hours and by 21.4% (9.3%-32.0%; P=0.002) at 24 hours. Reductions in thrombus formation were driven by a decrease in platelet-rich thrombus deposition: 34.8% (19.3%-47.3%; P<0.001) at 2 hours and 23.3% (5.1%-38.0%; P=0.016) at 24 hours. In contrast to aspirin alone, or in combination with clopidogrel, BMS-986120 had no effect on thrombus formation at low shear (P=nonsignificant). BMS-986120 administration was not associated with an increase in coagulation times or serious adverse events. CONCLUSIONS: BMS-986120 is a highly selective and reversible oral PAR4 antagonist that substantially reduces platelet-rich thrombus formation under conditions of high shear stress. Our results suggest PAR4 antagonism has major potential as a therapeutic antiplatelet strategy. CLINICAL TRIAL REGISTRATION: URL: http://www.clinicaltrials.gov. Unique identifier: NCT02439190.

Cardiovascular Outcomes Following Rotational Atherectomy: A UK Multicentre Experience.

OBJECTIVES: To identify factors associated with outcomes following rotational atherectomy (RA). BACKGROUND: RA is an effective way to mechanically modify heavily calcified lesions before stenting; however its outcomes are not well defined. METHODS AND RESULTS: Retrospective evaluation of all patients who underwent RA in three large UK centers (Leeds General Infirmary (LGI), Royal Infirmary of Edinburgh (RIE) and University Hospital of North Staffordshire (UHNS)) from March 2005 to January 2013. Five hundred and eighteen patients had RA with median follow-up period of 22 months. About 68.3% were male, 28.7% had DM and 34.6% were treated because of ACS. Stents were deployed in 97.3% of the patients while 30.7% of the procedures were performed transradially. Maximum burr was ≤1.75 mm in 85.5% and the mean SYNTAX score was 19.5 ± 11.6. Peri-procedural complications occurred in 6.4% and vascular access complications in 1.9%. Outcomes in the follow-up period were: MACE 17.8%, cardiac death 7.1%, MI 11.7%, TVR 7.5%, all-cause death 13.7%, definite stent thrombosis (ST) 1.4% and stroke 2.9%. Patients with intermediate and high SYNTAX scores were more likely to suffer MACE, cardiac death, MI, all-cause death and ST. Patients with a SYNTAX score >32 were also more likely to have a peri-procedural complication. Multiple logistic regression analysis showed that the presence of PVD (P = 0.026, OR = 2.0), DM (P = 0.008, OR = 2.1), ACS presentation (P = 0.011, OR = 2.1) and SYNTAX score ≥23 (P = 0.02, OR = 1.9) had a significant association with MACE. CONCLUSIONS: RA is safe and effective, with high rate of procedural success and relatively low incidence of MACE. PVD, DM, ACS presentation and SYNTAX score were significant predictors for MACE. © 2016 Wiley Periodicals, Inc.