Nasal Foreign Body, an Unanticipated Complication of COVID-19 Care: A Case Report.

BACKGROUND: Coronavirus disease 2019 (COVID-19) has changed the way we practice medicine. Standards of care are evolving in an effort to diagnose, manage, and treat the cause of this global pandemic, as well as to protect the health care workforce. These practices can have unexpected and potentially dangerous consequences, particularly for patient populations with confounding factors that put them at increased risk for complications and poor outcomes. CASE REPORT: A 52-year-old previously healthy woman presented with 4 days of nasal pain and discharge after using a home collection kit in an attempt to obtain a nasopharyngeal viral sample for COVID-19 testing. WHY SHOULD AN EMERGENCY PHYSICIAN BE AWARE OF THIS?: With treatments, policies, and procedures that are rapidly evolving and often deviating from established, evidence-based, usual care in response to the COVID-19 pandemic, emergency physicians must be cognizant of and monitor for poor outcomes and potential downstream complications, especially in underserved patient populations.

A denitrifying community associated with a major, marine nitrogen fixer.

The diazotrophic cyanobacterium, Trichodesmium, is an integral component of the marine nitrogen cycle and contributes significant amounts of new nitrogen to oligotrophic, tropical/subtropical ocean surface waters. Trichodesmium forms macroscopic, fusiform (tufts), spherical (puffs) and raft-like colonies that provide a pseudobenthic habitat for a host of other organisms including marine invertebrates, microeukaryotes and numerous other microbes. The diversity and activity of denitrifying bacteria found in association with the colonies was interrogated using a series of molecular-based methodologies targeting the gene encoding the terminal step in the denitrification pathway, nitrous oxide reductase (nosZ). Trichodesmium spp. sampled from geographically isolated ocean provinces (the Atlantic Ocean, the Red Sea and the Indian Ocean) were shown to harbor highly similar, taxonomically related communities of denitrifiers whose members are affiliated with the Roseobacter clade within the Rhodobacteraceae (Alphaproteobacteria). These organisms were actively expressing nosZ in samples taken from the mid-Atlantic Ocean and Red Sea implying that Trichodesmium colonies are potential sites of nitrous oxide consumption and perhaps earlier steps in the denitrification pathway also. It is proposed that coupled nitrification of newly fixed N is the most likely source of nitrogen oxides supporting nitrous oxide cycling within Trichodesmium colonies.

Use of Emergency Ultrasound in Arizona Community Emergency Departments.

OBJECTIVES: Despite the increased educational exposure to point-of-care ultrasound (US) at all levels of medical training, there are utilization gaps between academic and nonacademic emergency department (ED) settings. The purpose of this study was to assess the current practices and potential barriers to the use of point-of-care US in nonacademic EDs throughout the state of Arizona. METHODS: We conducted a cross-sectional study. An online questionnaire was electronically sent to all nonacademic EDs in Arizona. The survey consisted of questions regarding demographics, current practice patterns, policies, interdepartmental agreements, and perceptions regarding the use of point-of-care US. RESULTS: Seventy nonacademic EDs were identified for inclusion in our study, and 58 EDs completed the survey, which represented an 83% response rate. Seventy-eight percent (95% confidence interval [CI], 67%-89%) perform or interpret point-of-care US examinations for patient care. The 3 most common applications of point-of-care US reported by respondents were focused assessment with sonography for trauma, cardiac US examinations, and line placement, and 36% (95% CI, 22%-50%) bill for point-of-care US examinations. At 75% (95% CI, 62%-88%) of EDs, no one is specifically responsible for reviewing point-of-care US examinations for quality assurance, and at 50% (95% CI, 35%-65%), no mechanism exists to archive images. Eighty-three percent (95% CI, 72%-94%) of EDs think that their groups will benefit from the American College of Emergency Physicians Clinical Ultrasound Accreditation Program. CONCLUSIONS: Ultrasound equipment is available in nearly all nonacademic EDs in Arizona. However, it appears that most providers lack US training, credentialing, quality assurance, and reimbursement mechanisms.

Quantitative PCR Profiling of Escherichia coli in Livestock Feces Reveals Increased Population Resilience Relative to Culturable Counts under Temperature Extremes.

The relationship between culturable counts (CFU) and quantitative PCR (qPCR) cell equivalent counts of Escherichia coli in dairy feces exposed to different environmental conditions and temperature extremes was investigated. Fecal samples were collected in summer and winter from dairy cowpats held under two treatments: field-exposed versus polytunnel-protected. A significant correlation in quantified E. coli was recorded between the qPCR and culture-based methods (r = 0.82). Evaluation of the persistence profiles of E. coli over time revealed no significant difference in the E. coli numbers determined as either CFU or gene copies during the summer for the field-exposed cowpats, whereas significantly higher counts were observed by qPCR for the polytunnel-protected cowpats, which were exposed to higher ambient temperatures. In winter, the qPCR returned significantly higher counts of E. coli for the field-exposed cowpats, thus representing a reversal of the findings from the summer sampling campaign. Results from this study suggest that with increasing time post-defecation and with the onset of challenging environmental conditions, such as extremes in temperature, culture-based counts begin to underestimate the true resilience of viable E. coli populations in livestock feces. This is important not only in the long term as the Earth changes in response to climate-change drivers but also in the short term during spells of extremely cold or hot weather.

Transradial approach for coronary chronic total occlusion interventions: Insights from a contemporary multicenter registry.

OBJECTIVES: To examine the impact of transradial access on the procedural outcomes of chronic total occlusion (CTO) percutaneous coronary interventions (PCI). BACKGROUND: The efficacy and safety of transradial access in CTO PCI has received limited study. METHODS: We compared the technique and outcomes of transradial vs. transfemoral access among 650 CTO PCI cases performed between January 2012 and March 2014 at 6 US centers. RESULTS: Most patients were men (87%) with high frequency of diabetes mellitus (42%) and prior coronary artery bypass graft surgery (36%). The CTO target vessel was the right coronary (59%), left anterior descending (20%), or circumflex (17%) artery. TR access was used in 110 (17%) of the 650 cases, as follows: bilateral radial access (63%); bilateral radial access plus unilateral or bilateral femoral access (7%); unilateral radial access plus unilateral or bilateral femoral access (26%); and unilateral radial access (4%). Six and eight French guide catheters were used through the radial and femoral artery, respectively. Compared to transfemoral, transradial cases had similar technical (92.6% vs. 93.0%, P = 0.87) and procedural (91.1% vs. 90.0%, P = 0.95) success and major complication rates (1.7% vs 1.8%, P = 0.99). However, transradial access was associated with higher mean procedure (142 ± 83 vs. 120 ± 60 min, P = 0.008) and fluoroscopy (58 ± 40 vs. 49 ± 31 min, P <0.026) time, and number of crossing approach changes (0.7 ± 1.0 vs. 0.5 ± 0.7, P = 0.008). CONCLUSION: Transradial CTO PCI can be performed with similar success and complication rates with transfemoral CTO PCI, but is associated with longer procedural and fluoroscopy times. © 2015 Wiley Periodicals, Inc.

A putative link between phagocytosis-induced apoptosis and hemocyanin-derived phenoloxidase activation.

Apoptosis and phagocytosis are crucial processes required for developmental morphogenesis, pathogen deterrence and immunomodulation in metazoans. We present data showing that amebocytes of the chelicerate, Limulus polyphemus, undergo phagocytosis-induced cell death after ingesting spores of the fungus, Beauveria bassiana, in vitro. The observed biochemical and morphological modifications associated with dying amebocytes are congruent with the hallmarks of apoptosis, including: extracellularisation of phosphatidylserine, intranucleosomal DNA fragmentation and an increase in caspase 3/7-like activities. Previous studies have demonstrated that phosphatidylserine is a putative endogenous activator of hemocyanin-derived phenoloxidase, inducing conformational changes that permit phenolic substrate access to the active site. Here, we observed extracellular hemocyanin-derived phenoloxidase activity levels increase in the presence of apoptotic amebocytes. Enzyme activity induced by phosphatidylserine or apoptotic amebocytes was reduced completely upon incubation with the phosphatidylserine binding protein, annexin V. We propose that phosphatidylserine redistributed to the outer plasma membrane of amebocytes undergoing phagocytosis-induced apoptosis could interact with hemocyanin, thus facilitating its conversion into a phenoloxidase-like enzyme, during immune challenge.

Denitrifying alphaproteobacteria from the Arabian Sea that express nosZ, the gene encoding nitrous oxide reductase, in oxic and suboxic waters.

Marine ecosystems are significant sources of the powerful greenhouse gas nitrous oxide (N2O). A by-product of nitrification and an intermediate in the denitrification pathway, N2O is formed primarily in oxygen-deficient waters and sediments. We describe the isolation of a group of alphaproteobacteria from the suboxic waters of the Arabian Sea that are phylogenetically affiliated with Labrenzia spp. and other denitrifiers. Quantitative PCR assays revealed that these organisms were very broadly distributed in this semienclosed ocean basin. Their biogeographical range extended from the productive, upwelling region off the Omani shelf to the clear, oligotrophic waters that are found much further south and also included the mesotrophic waters overlying the oxygen minimum zone (OMZ) in the northeastern sector of the Arabian Sea. These organisms actively expressed NosZ (N2O reductase, the terminal step in the denitrification pathway) within the OMZ, an established region of pelagic denitrification. They were found in greatest numbers outside the OMZ, however, and nosZ mRNAs were also readily detected near the base of the upper mixed layer in nutrient-poor, oxic regions. Our findings provide firm molecular evidence of a potential sink for N2O within well-ventilated, oceanic surface waters in this biogeochemically important region. We show that the Labrenzia-like denitrifiers and their close relatives are habitual colonizers of the pseudobenthic environment provided by Trichodesmium spp. We develop the conjecture that the O2-depleted microzones that occur within the colonies of these filamentous, diazotrophic cyanobacteria might provide unexpected niches for the reduction of nitrogen oxides in tropical and subtropical surface waters.

Temporal orchestration of glycogen synthase (GlgA) gene expression and glycogen accumulation in the oceanic picoplanktonic cyanobacterium Synechococcus sp. strain WH8103.

Glycogen is accumulated during the latter half of the diel cycle in Synechococcus sp. strain WH8103 following a midday maximum in glgA (encoding glycogen synthase) mRNA abundance. This temporal pattern is quite distinct from that of Prochlorococcus and may highlight divergent regulatory control of carbon/nitrogen metabolism in these closely related picocyanobacteria.

Mechanical Circulatory Support in Chronic Total Occlusion Percutaneous Coronary Intervention: Insights From a Multicenter U.S. Registry.

OBJECTIVE: To study outcomes with use of percutaneous mechanical circulatory support (MCS) devices in chronic total occlusion (CTO) percutaneous coronary intervention (PCI). METHODS: We examined characteristics and outcomes of 1598 CTO-PCIs performed from 2012-2017 at 12 high-volume centers. RESULTS: Patient age was 66 ± 10 years; 86% were men. An MCS device was used electively in 69 procedures (4%) and urgently in 22 procedures (1%). The most commonly used elective MCS device was Impella 2.5 or CP (62%). Compared to patients without elective MCS, patients with elective MCS had higher prevalence of prior heart failure (55% vs 29%; P<.001), prior coronary artery bypass graft surgery (49% vs 35%; P=.02), and lower left ventricular ejection fraction (34 ± 14% vs 50 ± 14%; P<.001). MCS patients had a higher prevalence of moderate/ severe calcification (88% vs 55%; P<.001) and higher J-CTO scores (3.1 ± 1.2 vs 2.6 ± 1.2; P<.01), and a greater proportion underwent retrograde crossing attempts (55% vs 39%; P<.01). Despite more complex characteristics in MCS patients, technical success rates (88% vs 87%; P=.70) and procedural success rates (83% vs 87%; P=.32) were similar in the two groups. Use of elective MCS was associated with longer procedure and fluoroscopy times, and higher incidences of in-hospital major adverse cardiovascular events (8.7% vs 2.5%; P<.01) and bleeding (7.3% vs 1.0%; P<.001). CONCLUSION: Elective MCS was used in 4% of patients undergoing CTO-PCI. Despite more complex clinical and angiographic characteristics, elective use of MCS in high-risk patients is associated with similar technical and procedural success rates, but higher risk of complications, compared to cases without elective MCS.

Predictors of Excess Patient Radiation Exposure During Chronic Total Occlusion Coronary Intervention: Insights From a Contemporary Multicentre Registry.

BACKGROUND: High patient radiation dose during chronic total occlusion (CTO) percutaneous coronary intervention (PCI) might lead to procedural failure and radiation skin injury. METHODS: We examined the association between several clinical and angiographic variables on patient air kerma (AK) radiation dose among 748 consecutive CTO PCIs performed at 9 experienced US centres between May 2012 and May 2015. RESULTS: The mean age was 65 ± 10 years, 87% of patients were men, and 35% had previous coronary artery bypass graft surgery (CABG). Technical and procedural success was 92% and 90%, respectively. The median patient AK dose was 3.40 (interquartile range, 2.00-5.40) Gy and 34% of the patients received > 4.8 Gy (high radiation exposure). In univariable analysis male sex (P = 0.016), high body mass index (P < 0.001), history of hyperlipidemia (P = 0.023), previous CABG (P < 0.001), moderate or severe calcification (P < 0.001), tortuosity (P < 0.001), proximal cap ambiguity (P = 0.001), distal cap at a bifurcation (P = 0.006), longer CTO occlusion length (P < 0.001), blunt/no blunt stump (P < 0.001), and centre (P < 0.001) were associated with higher patient AK dose. In multivariable analysis high body mass index (P < 0.001), previous CABG (P = 0.005), moderate or severe calcification (P = 0.005), longer CTO occlusion length (P < 0.001), and centre (P < 0.001) were independently associated with higher patient AK dose. CONCLUSIONS: Approximately 1 in 3 patients who undergo CTO PCI receive high AK radiation dose (> 4.8 Gy). Several baseline clinical and angiographic characteristics can help predict the likelihood of high radiation dose and assist with intensifying efforts to reduce radiation exposure for the patient and the operator.

Impact of Calcium on Chronic Total Occlusion Percutaneous Coronary Interventions.

We sought to examine the impact of calcific deposits on the outcomes of chronic total occlusion (CTO) percutaneous coronary intervention (PCI). The outcomes of 1,476 consecutive CTO PCIs performed in 1,453 patients (65.5 ± 10 years, 85% male) between 2012 and 2016 at 11 US centers were evaluated. Moderate or severe quantity of calcium was present in 58% of target lesions. Calcified lesions were more tortuous and more likely to have proximal cap ambiguity and interventional collaterals. PCI of moderately/severely calcified CTOs more often required use of the retrograde approach (54% vs 30%, p <0.001) and was associated with longer procedure and fluoroscopy time and higher air kerma radiation dose and contrast volume. Moderate/severe quantity of calcium was associated with lower technical (86.6% vs 93.8%, p <0.001) and procedural (84.4% vs 92.7%, p <0.001) success rates and higher incidence of major adverse cardiac events (3.7% vs 1.8%, p = 0.033). On multivariate analysis, the presence of moderate/severe quantity of calcium was not independently associated with technical success. Balloon angioplasty was the most common lesion preparation technique for calcified lesions, followed by rotational atherectomy and laser. To conclude, in a contemporary, multicenter registry, moderate/severe calcific deposits were present in 58% of attempted CTO lesions and were associated with higher use of the retrograde approach, lower success, and higher complication rates. However, on multivariable analysis, the amount of calcium was not independently associated with technical success.

The Impact of Proximal Vessel Tortuosity on the Outcomes of Chronic Total Occlusion Percutaneous Coronary Intervention: Insights From a Contemporary Multicenter Registry.

INTRODUCTION: We examined the impact of proximal vessel tortuosity on the outcomes of chronic total occlusion (CTO) percutaneous coronary intervention (PCI). METHODS: The baseline clinical and angiographic characteristics and procedural outcomes of 1618 consecutive CTO-PCIs performed between 2012 and 2016 at 14 United States centers in 1589 patients were reviewed. RESULTS: Mean patient age was 65.3 ± 10.0 years and 85% were men. Moderate/severe proximal vessel tortuosity was present in 35.7% of target lesions. Compared with non-tortuous lesions, tortuous lesions had longer length (30 mm [interquartile range, 20-50 mm] vs 28 mm [interquartile range, 16-40 mm]; P<.001), more proximal cap ambiguity (36% vs 28%; P<.01), and more frequent utilization of the retrograde approach (52% vs 37%; P<.001). Moderate/severe proximal vessel tortuosity was associated with lower technical success rates (84.1% vs 91.3%; P<.001) and procedural success rates (82.3% vs 89.9%; P<.001), but similar incidence of major cardiac adverse events (3.0% vs 2.5%; P=.59). Moderate/severe tortuosity was associated with longer procedure time and fluoroscopy time, higher air kerma radiation dose, and larger contrast volume. CONCLUSION: In a contemporary multicenter registry, moderate/severe proximal vessel tortuosity was present in approximately one-third of target CTO lesions and was associated with more frequent use of the retrograde approach and lower success rates, but similar complication rates.

Development and Validation of a Novel Scoring System for Predicting Technical Success of Chronic Total Occlusion Percutaneous Coronary Interventions: The PROGRESS CTO (Prospective Global Registry for the Study of Chronic Total Occlusion Intervention) Score.

OBJECTIVES: This study sought to develop a novel parsimonious score for predicting technical success of chronic total occlusion (CTO) percutaneous coronary intervention (PCI) performed using the hybrid approach. BACKGROUND: Predicting technical success of CTO PCI can facilitate clinical decision making and procedural planning. METHODS: We analyzed clinical and angiographic parameters from 781 CTO PCIs included in PROGRESS CTO (Prospective Global Registry for the Study of Chronic Total Occlusion Intervention) using a derivation and validation cohort (2:1 sampling ratio). Variables with strong association with technical success in multivariable analysis were assigned 1 point, and a 4-point score was developed from summing all points. The PROGRESS CTO score was subsequently compared with the J-CTO (Multicenter Chronic Total Occlusion Registry in Japan) score in the validation cohort. RESULTS: Technical success was 92.9%. On multivariable analysis, factors associated with technical success included proximal cap ambiguity (beta coefficient [b] = 0.88), moderate/severe tortuosity (b = 1.18), circumflex artery CTO (b = 0.99), and absence of "interventional" collaterals (b = 0.88). The resulting score demonstrated good calibration and discriminatory capacity in the derivation (Hosmer-Lemeshow chi-square = 2.633; p = 0.268, and receiver-operator characteristic [ROC] area = 0.778) and validation (Hosmer-Lemeshow chi-square = 5.333; p = 0.070, and ROC area = 0.720) subset. In the validation cohort, the PROGRESS CTO and J-CTO scores performed similarly in predicting technical success (ROC area 0.720 vs. 0.746, area under the curve difference = 0.026, 95% confidence interval = -0.093 to 0.144). CONCLUSIONS: The PROGRESS CTO score is a novel useful tool for estimating technical success in CTO PCI performed using the hybrid approach.

Development and Validation of a Scoring System for Predicting Periprocedural Complications During Percutaneous Coronary Interventions of Chronic Total Occlusions: The Prospective Global Registry for the Study of Chronic Total Occlusion Intervention (PROGRESS CTO) Complications Score.

BACKGROUND: High success rates are achievable for chronic total occlusion (CTO) percutaneous coronary intervention (PCI) using the hybrid approach, but periprocedural complications remain of concern. Although scores estimating success and efficiency in CTO PCI have been developed, there is currently no available score for estimation of the risk for periprocedural complications. We sought to develop a scoring tool for prediction of periprocedural complications during CTO PCI. METHODS AND RESULTS: We analyzed data from 1569 CTO PCIs in the Prospective Global Registry for the Study of Chronic Total Occlusion Intervention (PROGRESS CTO) using a derivation and validation sampling ratio of 2:1. Variables independently associated with periprocedural complications in multivariable analysis in the derivation set were assigned points based on their respective odds ratios. Forty-four (2.8%) patients experienced complications. Three factors were independent predictors of complications and were included in the score: patient age >65 years, +3 points (odds ratio, OR=4.85, CI 1.82-16.77); lesion length ≥23 mm, +2 points (OR=3.22, CI 1.08-13.89); and use of the retrograde approach +1 point (OR=2.41, CI 1.04-6.05). The resulting score showed good calibration and discriminatory capacity in the derivation (Hosmer-Lemeshow χ2 6.271, P=0.281, receiver-operating characteristic [ROC] area=0.758) and validation (Hosmer-Lemeshow χ2 4.551, P=0.473, ROC area=0.793) sets. Score values of 0 to 2, 3 to 4, and ≥5 were defined as low, intermediate, and high risk of complications (derivation cohort 0.4%, 1.8%, 6.5%, P<0.001; validation cohort 0.0%, 2.5%, 6.8%, P<0.001). CONCLUSIONS: The PROGRESS CTO complication score is a useful tool for prediction of periprocedural complications in CTO PCI. CLINICAL TRIAL REGISTRATION: URL: http://www.clinicaltrials.gov. Unique identifier: NCT02061436.

Effect of Previous Failure on Subsequent Procedural Outcomes of Chronic Total Occlusion Percutaneous Coronary Intervention (from a Contemporary Multicenter Registry).

We sought to examine the impact of previous failure on the outcomes of chronic total occlusion (CTO) percutaneous coronary intervention (PCI). We examined the clinical and angiographic characteristics and procedural outcomes of 1,213 consecutive patients who underwent 1,232 CTO PCIs from 2012 to 2015 at 12 US centers. Mean age was 65 ± 10 years, and 84.8% of patients were men. A previously failed attempt had been performed in 215 patients (17.5%). As compared with patients without previous CTO PCI failure, patients with previous failure had higher Multicenter CTO Registry in Japan CTO score (2.40 ± 1.13 vs 3.28 ± 1.29, p <0.0001) and were more likely to have in-stent restenosis (10.5% vs 28.4%, p <0.0001) and to undergo recanalization attempts using the retrograde approach (41% vs 50%, p = 0.011). Technical (90% vs 88%, p = 0.390) and procedural (89% vs 86%, p = 0.184) success were similar in the 2 study groups; however, median procedure time (125 vs 142 minutes, p = 0.026) and fluoroscopy time (45 vs 55 minutes, p = 0.015) were longer in the previous failure group. In conclusion, a previously failed CTO PCI attempt is associated with higher angiographic complexity, longer procedural duration, and fluoroscopy time, but not with the success and complication rates of subsequent CTO PCI attempts.

Use of antegrade dissection re-entry in coronary chronic total occlusion percutaneous coronary intervention in a contemporary multicenter registry.

BACKGROUND: We assessed efficacy and safety of chronic total occlusion (CTO) percutaneous coronary intervention (PCI) using antegrade dissection re-entry (ADR). METHODS: We examined outcomes of ADR among 1313 CTO PCIs performed at 11 US centers between 2012-2015. RESULTS: 84.1% of patients were men. Prevalence of prior coronary artery bypass graft surgery was 34.3%. Overall technical and procedural success were 90.1% and 88.7%, respectively. In-hospital major adverse cardiovascular events (MACE) occurred in 31 patients (2.4%). ADR was used in 458 cases (34.9%), and was the first strategy in 169 cases (12.9%). ADR cases were angiographically more complex than non-ADR cases (mean J-CTO score: 2.8±1.2 vs. 2.4±1.2, p<0.001). ADR was performed using the CrossBoss catheter in 246 of 458 (53.7%) and the Stingray system in 251 ADR cases (54.8%). Compared with non-ADR cases, ADR cases had lower technical (86.9% vs. 91.8%, p=0.005) and procedural success (85.0% vs. 90.7%, p=0.002), but similar risk for MACE (2.9% vs. 2.2%, p=0.42). ADR was associated with longer procedure and fluoroscopy time, and higher patient air kerma dose and contrast volume (all p<0.001). After excluding retrograde cases, ADR and antegrade wire escalation (AWE) had similar technical success (92.7% vs. 94.2%, p=0.43), procedural success (91.8% vs. 94.1%, p=0.23), and MACE (2.1% vs. 0.6%, p=0.12). CONCLUSIONS: ADR is used relatively frequently in contemporary CTO PCI, especially for challenging lesions and after failure of other strategies. ADR is associated with similar success rates and risk for complications as compared with AWE, and is important for achieving high procedural success.

Use of Intravascular Imaging During Chronic Total Occlusion Percutaneous Coronary Intervention: Insights From a Contemporary Multicenter Registry.

BACKGROUND: Intravascular imaging can facilitate chronic total occlusion (CTO) percutaneous coronary intervention. METHODS AND RESULTS: We examined the frequency of use and outcomes of intravascular imaging among 619 CTO percutaneous coronary interventions performed between 2012 and 2015 at 7 US centers. Mean age was 65.4±10 years and 85% of the patients were men. Intravascular imaging was used in 38%: intravascular ultrasound in 36%, optical coherence tomography in 3%, and both in 1.45%. Intravascular imaging was used for stent sizing (26.3%), stent optimization (38.0%), and CTO crossing (35.7%, antegrade in 27.9%, and retrograde in 7.8%). Intravascular imaging to facilitate crossing was used more frequently in lesions with proximal cap ambiguity (49% versus 26%, P<0.0001) and with retrograde as compared with antegrade-only cases (67% versus 31%, P<0.0001). Despite higher complexity (Japanese CTO score: 2.86±1.19 versus 2.43±1.19, P=0.001), cases in which imaging was used for crossing had similar technical and procedural success (92.8% versus 89.6%, P=0.302 and 90.1% versus 88.3%, P=0.588, respectively) and similar incidence of major cardiac adverse events (2.7% versus 3.2%, P=0.772). Use of intravascular imaging was associated with longer procedure (192 minutes [interquartile range 130, 255] versus 131 minutes [90, 192], P<0.0001) and fluoroscopy (71 minutes [44, 93] versus 39 minutes [25, 69], P<0.0001) time. CONCLUSIONS: Intravascular imaging is frequently performed during CTO percutaneous coronary intervention both for crossing and for stent selection/optimization. Despite its use in more complex lesion subsets, intravascular imaging was associated with similar rates of technical and procedural success for CTO percutaneous coronary intervention. CLINICAL TRIAL REGISTRATION: URL: http://www.clinicaltrials.gov. Unique identifier: NCT02061436.

Percutaneous intervention of circumflex chronic total occlusions is associated with worse procedural outcomes: insights from a Multicentre US Registry.

BACKGROUND: We sought to determine whether outcomes of chronic total occlusion (CTO) percutaneous coronary intervention (PCI) vary according to CTO target vessel: left anterior descending artery (LAD), left circumflex artery (LCX), and right coronary artery (RCA). METHODS: We evaluated the clinical and angiographic characteristics and procedural outcomes of 636 patients who underwent CTO PCI at 6 high-volume centres in the United States between January 2012 and March 2014. RESULTS: The CTO target vessel was the RCA in 387 cases (61%), LAD in 132 (21%), and LCX in 117 (18%). LCX lesions were more tortuous and RCA lesions had greater occlusion length and Japanese Chronic Total Occlusion (J-CTO) score, but were less likely to have a side branch at the proximal cap and had more developed collateral circulation. The rate of procedural success was lower in LCX CTOs (84.6%), followed by RCA (91.7%), and LAD (94.7%) CTOs (P = 0.016). Major complications tended to occur more frequently in LCX PCI (4.3% vs 1.0% for RCA vs 2.3% for LAD; P = 0.07). LCX and RCA CTO PCI required longer fluoroscopy times (45 [interquartile range (IQR), 30-74] minutes vs 45 [IQR, 21-69] minutes for RCA vs 34 [IQR, 20-60] minutes for LAD; P = 0.018) and LCX CTOs required more contrast administration (280 [IQR, 210-370] mL vs 250 [IQR, 184-350] mL for RCA and 280 [IQR, 200-400] mL for LAD). CONCLUSIONS: In a contemporary, multicentre CTO PCI registry, LCX was the least common target vessel. Compared with LAD and RCA, PCI of LCX CTOs was associated with a lower rate of procedural success, less efficiency, and a nonsignificant trend for higher rates of complications.

Transcriptionally active heterotrophic diazotrophs are widespread in the upper water column of the Arabian Sea.

Pelagic nitrogen fixation makes an important contribution to the fixed nitrogen budget of the world's oceans. Filamentous and unicellular cyanobacteria are significant players in this process but less is known of the potential activity of heterotrophic diazotrophs, although they are present and can be quite numerous in the nitrogen-deplete surface waters of the tropical and sub-tropical oceans. In this study we focused on the potential activity of several clades of heterotrophic nitrogen-fixers identified by phylogenetic analysis of 44 non-Trichodesmium-related, nifH (encoding the Fe-subunit of nitrogenase) clones from the Arabian Sea. Specific Northern slot blot protocols were developed to quantify nifH mRNAs from each clade and showed that two groups of Gammaproteobacteria, including the previously characterized UMB clade, and a third, novel phylotype affiliated with cluster III anaerobes, were actively expressing nitrogenase in the equatorial waters of this region. Transcripts (nifH mRNAs) from the latter clade were particularly abundant and were also detected in the suboxic waters of the oxygen minimum zone further north. Like the gammaproteobacterial groups, nifH expression by these organisms appeared to be insensitive to combined nitrogen concentrations and was readily detected in the nutrient-replete waters below the upper mixed layer as well as at shallower depths.

Rapid shifts in picoeukaryote community structure in response to ocean acidification.

Rapid shifts in picoeukaryote community structure were observed during a CO(2) perturbation experiment in which we followed the development of phytoplankton blooms in nutrient-amended mesocosms under the present day or predicted future atmospheric pCO(2) (750 µatm, seawater pH 7.8). Analysis of rbcL clone libraries (encoding the large subunit of RubisCO) and specific quantitative PCR assays showed that two prasinophytes closely related to Micromonas pusilla and Bathycoccus prasinos were present, but responded very differently to high CO(2)/acidification. We found that the abundance of Micromonas-like phylotypes was significantly higher (>20-fold) under elevated CO(2)/low pH, whereas the Bathycoccus-like phylotypes were more evenly distributed between treatments and dominated the prasinophyte community under ambient conditions.