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Objective: Takotsubo syndrome (TTS) is an acute heart failure syndrome which resembles acute coronary syndrome (ACS) at presentation. Differentiation requires coronary angiography, but where this does not occur immediately, cardiac biomarkers may provide additional utility. We performed a meta-analysis to compare troponin and natriuretic peptides (NPs) in TTS and ACS to determine if differences in biomarker profile can aid diagnosis., Methods: We searched five literature databases for studies reporting NPs (Brain NP (BNP)/NT-pro-BNP) or troponin I/T in TTS and ACS, identifying 28 studies for troponin/NPs (5618 and 1145 patients, respectively)., Results: Troponin was significantly lower in TTS than ACS (standardised mean difference (SMD) -0.86; 95% CI, -1.08 to -0.64; p<0.00001), with an absolute difference of 75 times the upper limit of normal (×ULN) higher in ACS than TTS. Conversely, NPs were significantly higher in TTS (SMD 0.62; 95% CI, 0.44 to 0.80; p<0.00001) and 5.8×ULN greater absolutely. Area under the curve (AUC) for troponin in ACS versus TTS was 0.82 (95% CI, 0.70 to 0.93), and 0.92 (95% CI, 0.80 to 1.00) for ST-segment elevation myocardial infarction versus TTS. For NPs, AUC was 0.69 (95% CI, 0.48 to 0.89). Combination of troponin and NPs with logistic regression did not improve AUC. Recursive Partitioning and Regression Tree analysis calculated a troponin threshold ≥26×ULN that identified 95% cases as ACS where and specificity for ACS were 85.71% and 53.57%, respectively, with 94.32% positive predictive value and 29.40% negative predictive value., Conclusions: Troponin is lower and NPs higher in TTS versus ACS. Troponin had greater power than NPs at discriminating TTS and ACS, and with troponin ≥26×ULN patients are far more likely to have ACS., Competing Interests: Competing interests: ARL has received speaker, advisory board or consultancy fees and/or research grants from Janssens-Cilag Ltd, Astellas Pharma, Pfizer, Novartis, Servier, AstraZeneca, Bristol Myers Squibb, GSK, Amgen, Takeda, Roche, Clinigen Group, Eli Lilly, Eisai Ltd, Ferring Pharmaceuticals, Boehringer Ingelheim, Akcea Therapeutics, Myocardial Solutions, iOWNA Health and Heartfelt Technologies Ltd., (© Author(s) (or their employer(s)) 2024. Re-use permitted under CC BY-NC. No commercial re-use. See rights and permissions. Published by BMJ.)

Chronic total occlusions (CTOs) represent the most complex subset of coronary artery disease and therefore careful planning of CTO percutaneous coronary recanalization (PCI) strategy is of paramount importance aiming to achieve procedural success, and improve patient's safety and post CTO PCI outcomes. Intravascular imaging has an essential role in facilitating CTO PCΙ. First, intravascular ultrasound (IVUS), due to its higher penetration depth compared to optical coherence tomography (OCT), and the additional capacity of real-time imaging without need for contrast injection is considered the preferred imaging modality for CTO PCI. Secondly, IVUS can be used to resolve proximal cap ambiguity, facilitate wire re-entry when dissection and re-entry strategies are applied and most importantly to guide stent deployment and optimization post implantation. The role of OCT during CTO PCI is currently limited to stent sizing and optimization, however, due to its high spatial resolution, OCT is ideal for detecting stent edge dissections and strut malapposition. In this review, we describe the use of intravascular imaging for lesion crossing, plaque characterization and wire tracking, extra- or intra-plaque, and stent sizing and optimization during CTO PCI and summarize the findings of the major studies in this field., Competing Interests: EB has received consulting and speaker honoraria from Abbott Vascular, the American Heart Association (associate editor, Circulation), Amgen, Asahi Intecc, Biotronik, Boston Scientific, Cardiovascular Innovations Foundation (Board of Directors), ControlRad, Cardiovascular Systems, Inc, Elsevier, GE Healthcare, IMDS, InfraRedx, Medicure, Medtronic, Opsens, Siemens, and Teleflex; is an owner of Hippocrates; and is a shareholder in MHI Ventures and Cleerly Health. The remaining authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (© 2023 Xenogiannis, Pavlidis, Kaier, Rigopoulos, Karamasis, Triantafyllis, Vardas, Brilakis and Kalogeropoulos.)

Objectives: End-stage renal disease is associated with a high risk of cardiovascular disease. We compared the concentration and prognostic ability of high sensitivity cardiac troponin T (hs-cTnT) and I (hs-cTnI) and cardiac myosin-binding protein C (cMyC) among stable hemodialysis patients., Methods: Patients were sampled before and after hemodialysis. We measured hs-cTnI, hs-cTnT and cMyC and used Cox regressions to assess the association between quartiles of concentrations and all-cause mortality and a combination of cardiovascular events and all-cause mortality during follow-up., Results: A total of 307 patients were included, 204 males, mean age 66 years (SD 14). Before dialysis, 299 (99 %) had a hs-cTnT concentration above the 99th percentile, compared to 188 (66 %) for cMyC and 35 (11 %) for hs-cTnI. Hs-cTnT (23 %, p<0.001) and hs-cTnI (15 %, p=0.049) but not cMyC (4 %, p=0.256) decreased during dialysis. Follow-up was a median of 924 days (492-957 days); patients in the 3rd and 4th quartiles of hs-cTnT (3rd:HR 3.0, 95 % CI 1.5-5.8, 4th:5.2, 2.7-9.8) and the 4th quartile of hs-cTnI (HR 3.8, 2.2-6.8) had an increased risk of mortality. Both were associated with an increased risk of the combined endpoint for patients in the 3rd and 4th quartiles. cMyC concentrations were not associated with risk of mortality or cardiovascular event., Conclusions: Hs-cTnT was above the 99th percentile in almost all patients. This was less frequent for hs-cTnI and cMyC. High cTn levels were associated with a 3-5-fold higher mortality. This association was not present for cMyC. These findings are important for management of hemodialysis patients., (© 2023 Walter de Gruyter GmbH, Berlin/Boston.)

Application of the hybrid algorithm for the treatment of coronary chronic total occlusions requires the operator to readily deploy complex techniques and advanced technologies to achieve successful revascularization. Patient-specific factors and limitations in torquability and material strength of low-profile equipment such as microcatheters can result in procedural complications due to device fracture. Using a mini-series of 2 cases to demonstrate the successful application of antegrade dissection re-entry techniques to overcome such challenges, we highlight procedural complexities and risk, and review prior approaches and literature.

Background: Guidelines endorse a heart team (HT) approach to standardize the decision-making process for patients with complex coronary artery disease (CAD). With percutaneous treatment options for complex CAD increasing, we hypothesized that practice had changed over the past decade-and that more individuals, previously deemed too high risk for intervention, would now be referred for either surgical or percutaneous revascularization., Methods: This observational study was conducted at St Thomas' Hospital (London, United Kingdom). All patients discussed at HT meetings were recorded and treatment recommendations audited. A subset of historic cases was selected for blinded, repeat discussion., Results: From April 2018 to 2019, a total of 52 HT meetings discussing 375 cases were held. Patients tended to be male, with a majority demonstrating multivessel CAD in the context of preserved left ventricular function. SYNTAX scores were balanced across the tertiles. Thirty-five percent of patients had at least 1 chronic total occlusion (mean J-CTO, 3 [interquartile range, 2-3]), affecting the right coronary artery in 60%. Fifteen historic patients with isolated CTOs were re-presented an average of 8 years later; only 3 patients received the same outcome, with 80% now receiving a recommendation for revascularization over medical therapy., Conclusions: A dedicated program supporting complex coronary intervention is associated with a change in treatment recommendations issued by the local HT. In line with international guidelines, this might indicate that any complex or multivessel CAD should be discussed at HT meetings with, ideally, the presence of CTO operators.

Percutaneous transluminal coronary angioplasty balloon fracture, retention, and embolization are rare complications of percutaneous coronary intervention. The incidence has historically been estimated at <0.8%, which is likely an underestimate given the increasing quantity and complexity of percutaneous procedures. We demonstrate how to avoid emergency surgery by using basic balloon trapping techniques and a snare in the more distal arterial bed.

Aims: To evaluate the clinical feasibility of implementing the 2020 ESC 0/1 hr algorithm for rapid rule-out/rule-in of acute coronary syndrome (ACS)., Methods and Results: Data were collected retrospectively from 5496 patients in 2020 and 7363 patients in 2021 who received cardiac troponin measurements through the ACS algorithm in acute care settings within a large tertiary cardiac centre in the United Kingdom. This period overlapped the introduction of the 2020 ESC 0/1 hr algorithm. After exclusion of haemolysis, 1905 patients underwent repeat troponin measurement within the study period in 2020 and 2658 in 2021. Median time to repeat was significantly reduced from 3 h 14 min for intermediate low risk patients (5-12 ng/L) in 2020 to 1 h 22 min in 2021, and from 3 h 30 min to 1 h 59 min in intermediate high-risk patients (12-51 ng/L). Less than 15% of patients requiring repeat testing had dynamic changes in troponin of sufficient magnitude to change their initial risk category. Of all patients, 58.1% of patients in 2020 were ultimately classified as 'low risk', 19.2% deemed 'ACS likely', and 22.7% as 'ACS possible', with similar distributions in 2021., Conclusion: Whilst an efficient algorithm, our study demonstrates multi-faceted, practical limitations of achieving the 1 h target for the triage of patients with suspected ACS. Despite challenges predominantly of logistic nature, the algorithm enables rapid, streamlined, and efficient triage of large patient cohorts. Further work is required to streamline this process and achieve the targeted 1 h repeat in a resource-constrained healthcare environment, which would invariably require second blood draw before the result of first, as recommended by the ESC., (© The Author(s) 2022. Published by Oxford University Press on behalf of the European Society of Cardiology.)

Aims: Cardiac myosin-binding protein C (cMyC) demonstrated high diagnostic accuracy for the early detection of non-ST-elevation myocardial infarction (NSTEMI). Its dynamic release kinetics may enable a 0/1h-decision algorithm that is even more effective than the ESC hs-cTnT/I 0/1 h rule-in/rule-out algorithm., Methods and Results: In a prospective international diagnostic study enrolling patients presenting with suspected NSTEMI to the emergency department, cMyC was measured at presentation and after 1 h in a blinded fashion. Modelled on the ESC hs-cTnT/I 0/1h-algorithms, we derived a 0/1h-cMyC-algorithm. Final diagnosis of NSTEMI was centrally adjudicated according to the 4th Universal Definition of Myocardial Infarction. Among 1495 patients, the prevalence of NSTEMI was 17%. The optimal derived 0/1h-algorithm ruled-out NSTEMI with cMyC 0 h concentration below 10 ng/L (irrespective of chest pain onset) or 0 h cMyC concentrations below 18 ng/L and 0/1 h increase <4 ng/L. Rule-in occurred with 0 h cMyC concentrations of at least 140 ng/L or 0/1 h increase ≥15 ng/L. In the validation cohort (n = 663), the 0/1h-cMyC-algorithm classified 347 patients (52.3%) as 'rule-out', 122 (18.4%) as 'rule-in', and 194 (29.3%) as 'observe'. Negative predictive value for NSTEMI was 99.6% [95% confidence interval (CI) 98.9-100%]; positive predictive value 71.1% (95% CI 63.1-79%). Direct comparison with the ESC hs-cTnT/I 0/1h-algorithms demonstrated comparable safety and even higher triage efficacy using the 0h-sample alone (48.1% vs. 21.2% for ESC hs-cTnT-0/1 h and 29.9% for ESC hs-cTnI-0/1 h; P < 0.001)., Conclusion: The cMyC 0/1h-algorithm provided excellent safety and identified a greater proportion of patients suitable for direct rule-out or rule-in based on a single measurement than the ESC 0/1h-algorithm using hs-cTnT/I., Trial Registration: ClinicalTrials.gov number, NCT00470587., (© The Author(s) 2022. Published by Oxford University Press on behalf of the European Society of Cardiology.)

The 4th Universal Definition of Myocardial Infarction has stimulated considerable debate since its publication in 2018. The intention was to define the types of myocardial injury through the lens of their underpinning pathophysiology. In this review, we discuss how the 4th Universal Definition of Myocardial Infarction defines infarction and injury and the necessary pragmatic adjustments that appear in clinical guidelines to maximize triage of real-world patients., (© The Author(s) 2021. Published by Oxford University Press on behalf of the European Society of Cardiology.)

Importance: Rapid and accurate noninvasive discrimination of type 2 myocardial infarction (T2MI), which is because of a supply-demand mismatch, from type 1 myocardial infarction (T1MI), which arises via plaque rupture, is essential, because treatment differs substantially. Unfortunately, this is a major unmet clinical need, because even high-sensitivity cardiac troponin (hs-cTn) measurement provides only modest accuracy., Objective: To test the hypothesis that novel cardiovascular biomarkers quantifying different pathophysiological pathways involved in T2MI and/or T1MI may aid physicians in the rapid discrimination of T2MI vs T1MI., Design, Setting, and Participants: This international, multicenter prospective diagnostic study was conducted in 12 emergency departments in 5 countries (Switzerland, Spain, Italy, Poland, and the Czech Republic) with patients presenting with acute chest discomfort to the emergency departments. The study quantified the discrimination of hs-cTn T, hs-cTn I, and 17 novel cardiovascular biomarkers measured in subsets of consecutively enrolled patients against a reference standard (final diagnosis), centrally adjudicated by 2 independent cardiologists according to the fourth universal definition of MI, using all information, including cardiac imaging and serial measurements of hs-cTnT or hs-cTnI., Results: Among 5887 patients, 1106 (18.8%) had an adjudicated final diagnosis of MI; of these, 860 patients (77.8%) had T1MI, and 246 patients (22.2%) had T2MI. Patients with T2MI vs those with T1MI had lower concentrations of biomarkers quantifying cardiomyocyte injury hs-cTnT (median [interquartile range (IQR)], 30 (17-55) ng/L vs 58 (28-150) ng/L), hs-cTnI (median [IQR], 23 [10-83] ng/L vs 115 [28-576] ng/L; P < .001), and cardiac myosin-binding protein C (at presentation: median [IQR], 76 [38-189] ng/L vs 257 [75-876] ng/L; P < .001) but higher concentrations of biomarkers quantifying endothelial dysfunction, microvascular dysfunction, and/or hemodynamic stress (median [IQR] values: C-terminal proendothelin 1, 97 [75-134] pmol/L vs 68 [55-91] pmol/L; midregional proadrenomedullin, 0.97 [0.67-1.51] pmol/L vs 0.72 [0.53-0.99] pmol/L; midregional pro-A-type natriuretic peptide, 378 [207-491] pmol/L vs 152 [90-247] pmol/L; and growth differentiation factor 15, 2.26 [1.44-4.35] vs 1.56 [1.02-2.19] ng/L; all P < .001). Discrimination for these biomarkers, as quantified by the area under the receiver operating characteristics curve, was modest (hs-cTnT, 0.67 [95% CI, 0.64-0.71]; hs-cTn I, 0.71 [95% CI, 0.67-0.74]; cardiac myosin-binding protein C, 0.67 [95% CI, 0.61-0.73]; C-terminal proendothelin 1, 0.73 [95% CI, 0.63-0.83]; midregional proadrenomedullin, 0.66 [95% CI, 0.60-0.73]; midregional pro-A-type natriuretic peptide, 0.77 [95% CI, 0.68-0.87]; and growth differentiation factor 15, 0.68 [95% CI, 0.58-0.79])., Conclusions and Relevance: In this study, biomarkers quantifying myocardial injury, endothelial dysfunction, microvascular dysfunction, and/or hemodynamic stress provided modest discrimination in early, noninvasive diagnosis of T2MI.

Objectives: Cardiac myosin-binding protein C (cMyC) is a novel biomarker of myocardial injury, with a promising role in the triage and risk stratification of patients presenting with acute cardiac disease. In this study, we assess the weekly biological variation of cMyC, to examine its potential in monitoring chronic myocardial injury, and to suggest analytical quality specification for routine use of the test in clinical practice., Methods: Thirty healthy volunteers were included. Non-fasting samples were obtained once a week for ten consecutive weeks. Samples were tested in duplicate on the Erenna ® platform by EMD Millipore Corporation. Outlying measurements and subjects were identified and excluded systematically, and homogeneity of analytical and within-subject variances was achieved before calculating the biological variability (CV I and CV G ), reference change values (RCV) and index of individuality (II)., Results: Mean age was 38 (range, 21-64) years, and 16 participants were women (53%). The biological variation, RCV and II with 95% confidence interval (CI) were: CV A (%) 19.5 (17.8-21.6), CV I (%) 17.8 (14.8-21.0), CV G (%) 66.9 (50.4-109.9), RCV (%) 106.7 (96.6-120.1)/-51.6 (-54.6 to -49.1) and II 0.42 (0.29-0.56). There was a trend for women to have lower CV G. The calculated RCVs were comparable between genders., Conclusions: cMyC exhibits acceptable RCV and low II suggesting that it could be suitable for disease monitoring, risk stratification and prognostication if measured serially. Analytical quality specifications based on biological variation are similar to those for cardiac troponin and should be achievable at clinically relevant concentrations., (© 2021 Walter de Gruyter GmbH, Berlin/Boston.)

Competing Interests: Funding Support and Author Disclosures The authors have reported that they have no relationships relevant to the contents of this paper to disclose.

Treatment of chronic total occlusions poses a specific set of challenges above and beyond those encountered in conventional percutaneous coronary intervention. Antegrade dissection and re-entry (ADR) is an established and safe technique with high success rates in experienced centers. CTO techniques frequently require greater-than-usual guide-catheter support and rapid-exchange technologies. Either can be achieved with separate guide extension and a trapping balloon; in this case series of guide-extension facilitated ADR, we highlight the technical advantages gleaned from the use of combined devices such as the TrapLiner guide-extension catheter (Teleflex).

Background Early triage is essential to improve outcomes in patients with suspected acute myocardial infarction (AMI). This study investigated whether cMyC (cardiac myosin-binding protein), a novel biomarker of myocardial necrosis, can aid early diagnosis of AMI and risk stratification. Methods and Results cMyC and high-sensitivity cardiac troponin T were retrospectively quantified in blood samples obtained by ambulance-based paramedics in a prospective, diagnostic cohort study. Patients with ongoing or prolonged periods of chest discomfort, acute dyspnoea in the absence of known pulmonary disease, or clinical suspicion of AMI were recruited. Discrimination power was evaluated by calculating the area under the receiver operating characteristics curve; diagnostic performance was assessed at predefined thresholds. Diagnostic nomograms were derived and validated using bootstrap resampling in logistic regression models. Seven hundred seventy-six patients with median age 68 [58;78] were recruited. AMI was the final adjudicated diagnosis in 22%. Median symptom to sampling time was 70 minutes. cMyC concentration in patients with AMI was significantly higher than with other diagnoses: 98 [43;855] versus 17 [9;42] ng/L. Discrimination power for AMI was better with cMyC than with high-sensitivity cardiac troponin T (area under the curve, 0.839 versus 0.813; P=0.005). At a previously published rule-out threshold (10 ng/L), cMyC reaches 100% sensitivity and negative predictive value in patients after 2 hours of symptoms. In logistic regression analysis, cMyC is superior to high-sensitivity cardiac troponin T and was used to derive diagnostic and prognostic nomograms to evaluate risk of AMI and death. Conclusions In patients undergoing blood draws very early after symptom onset, cMyC demonstrates improved diagnostic discrimination of AMI and could significantly improve the early triage of patients with suspected AMI.

Aims: In 2015, the European Society of Cardiology introduced new guidelines for the diagnosis of acute coronary syndromes in patients presenting without persistent ST-segment elevation. These guidelines included the use of high-sensitivity troponin assays for 'rule-in' and 'rule-out' of acute myocardial injury at presentation (using a '0 hour' blood test). Whilst these algorithms have been extensively validated in prospective diagnostic studies, the outcome of their implementation in routine clinical practice has not been described. The present study describes the change in the patient journey resulting from implementation of such an algorithm in a busy innercity Emergency Department., Methods and Results: Data were prospectively collected from electronic records at a large Central London hospital over seven months spanning the periods before, during and after the introduction of a new high-sensitivity troponin rapid diagnostic algorithm modelled on the European Society of Cardiology guideline. Over 213 days, 4644 patients had high-sensitivity troponin T measured in the Emergency Department. Of these patients, 40.4% could be 'ruled-out' based on the high-sensitivity troponin T concentration at presentation, whilst 7.6% could be 'ruled-in'. Adoption of the algorithm into clinical practice was associated with a 37.5% increase of repeat high-sensitivity troponin T measurements within 1.5 h for those patients classified as 'intermediate risk' on presentation., Conclusions: Introduction of a 0 hour 'rule-in' and 'rule-out' algorithm in routine clinical practice enables rapid triage of 48% of patients, and is associated with more rapid repeat testing in intermediate risk patients.

Chest pain is responsible for 6-10% of all presentations to acute healthcare providers. Triage is inherently difficult and heavily reliant on the quantification of cardiac Troponin (cTn), as a minority of patients with an ultimate diagnosis of acute myocardial infarction (AMI) present with clear diagnostic features such as ST-elevation on the electrocardiogram. Owing to slow release and disappearance of cTn, many patients require repeat blood testing or present with stable but elevated concentrations of the best available biomarker and are thus caught at the interplay of sensitivity and specificity.We identified cardiac myosin-binding protein C (cMyC) in coronary venous effluent and developed a high-sensitivity assay by producing an array of monoclonal antibodies and choosing an ideal pair based on affinity and epitope maps. Compared to high-sensitivity cardiac Troponin (hs-cTn), we demonstrated that cMyC appears earlier and rises faster following myocardial necrosis. In this review, we discuss discovery and structure of cMyC, as well as the migration from a comparably insensitive to a high-sensitivity assay facilitating first clinical studies. This assay was subsequently used to describe relative abundance of the protein, compare sensitivity to two high-sensitivity cTn assays and test diagnostic performance in over 1900 patients presenting with chest pain and suspected AMI. A standout feature was cMyC's ability to more effectively triage patients. This distinction is likely related to the documented greater abundance and more rapid release profile, which could significantly improve the early triage of patients with suspected AMI.

The definition of a high-sensitivity cardiac Troponin (cTn) assay describes the ability to quantify a cardiac biomarker level in at least 50% of healthy individuals. This advance in analytic sensitivity has come with a perceived loss of specificity in the most classic application - chest pain triage and the diagnosis of acute myocardial infarction (AMI). As cardiac Troponin can no longer be used as a dichotomous test, the medical field is increasingly moving towards a more granular interpretation. However, rapid rule-out/rule-in algorithms for AMI still rely on concrete thresholds for efficient triage, irrespective of the patient's comorbidities. Owing to a slightly elevated cTn value, evermore patients appear to fall into an indeterminate risk zone of diagnostic uncertainty. The reasons are manifold, spanning biological variation, analytical issues, increased plasma membrane permeability and the potential cytosolic release of cTn. This review provides a contemporary overview of the literature concerning the use of cardiac Troponin in chronic and acute cardiovascular care. Key messages High-sensitivity cardiac Troponin assays have transformed the assessment of cardiovascular disease. Rapid rule-out algorithms for chest pain triage have become increasingly complicated, but enable safe rule-out. Cardiac Troponin tracks mid- to long-term risk in patients with hyperlipidaemia, heart failure and renal dysfunction.

Background: Cardiac myosin-binding protein C (cMyC) is a cardiac-restricted protein that is more abundant than cardiac troponins (cTn) and is released more rapidly after acute myocardial infarction (AMI). We evaluated cMyC as an adjunct or alternative to cTn in the early diagnosis of AMI., Methods: Unselected patients (N=1954) presenting to the emergency department with symptoms suggestive of AMI, concentrations of cMyC, and high-sensitivity (hs) and standard-sensitivity cTn were measured at presentation. The final diagnosis of AMI was independently adjudicated using all available clinical and biochemical information without knowledge of cMyC. The prognostic end point was long-term mortality., Results: Final diagnosis was AMI in 340 patients (17%). Concentrations of cMyC at presentation were significantly higher in those with versus without AMI (median, 237 ng/L versus 13 ng/L, P <0.001). Discriminatory power for AMI, as quantified by the area under the receiver-operating characteristic curve (AUC), was comparable for cMyC (AUC, 0.924), hs-cTnT (AUC, 0.927), and hs-cTnI (AUC, 0.922) and superior to cTnI measured by a contemporary sensitivity assay (AUC, 0.909). The combination of cMyC with hs-cTnT or standard-sensitivity cTnI (but not hs-cTnI) led to an increase in AUC to 0.931 ( P <0.0001) and 0.926 ( P =0.003), respectively. Use of cMyC more accurately classified patients with a single blood test into rule-out or rule-in categories: Net Reclassification Improvement +0.149 versus hs-cTnT, +0.235 versus hs-cTnI ( P <0.001). In early presenters (chest pain <3 h), the improvement in rule-in/rule-out classification with cMyC was larger compared with hs-cTnT (Net Reclassification Improvement +0.256) and hs-cTnI (Net Reclassification Improvement +0.308; both P <0.001). Comparing the C statistics, cMyC was superior to hs-cTnI and standard sensitivity cTnI ( P <0.05 for both) and similar to hs-cTnT at predicting death at 3 years., Conclusions: cMyC at presentation provides discriminatory power comparable to hs-cTnT and hs-cTnI in the diagnosis of AMI and may perform favorably in patients presenting early after symptom onset., Clinical Trial Registration: URL: https://www.clinicaltrials.gov. Unique identifier: NCT00470587., (© 2017 The Authors.)

Background: Myocardial infarction is diagnosed when biomarkers of cardiac necrosis exceed the 99th centile, although guidelines advocate even lower concentrations for early rule-out. We examined how many myocytes and how much myocardium these concentrations represent. We also examined if dietary troponin can confound the rule-out algorithm., Methods: Individual rat cardiac myocytes, rat myocardium, ovine myocardium, or human myocardium were spiked into 400-μL aliquots of human serum. Blood was drawn from a volunteer after ingestion of ovine myocardium. High-sensitivity assays were used to measure cardiac troponin T (cTnT; Roche, Elecsys), cTnI (Abbott, Architect), and cardiac myosin-binding protein C (cMyC; EMD Millipore, Erenna ® )., Results: The cMyC assay could only detect the human protein. For each rat cardiac myocyte added to 400 μL of human serum, cTnT and cTnI increased by 19.0 ng/L (95% CI, 16.8-21.2) and 18.9 ng/L (95% CI, 14.7-23.1), respectively. Under identical conditions cTnT, cTnI, and cMyC increased by 3.9 ng/L (95% CI, 3.6-4.3), 4.3 ng/L (95% CI, 3.8-4.7), and 41.0 ng/L (95% CI, 38.0-44.0) per μg of human myocardium. There was no detectable change in cTnI or cTnT concentration after ingestion of sufficient ovine myocardium to increase cTnT and cTnI to approximately 1 × 10 8 times their lower limits of quantification., Conclusions: Based on pragmatic assumptions regarding cTn and cMyC release efficiency, circulating species, and volume of distribution, 99th centile concentrations may be exceeded by necrosis of 40 mg of myocardium. This volume is much too small to detect by noninvasive imaging., (© 2017 American Association for Clinical Chemistry.)

Aims: The aim of the study was to examine ventricular remodelling in patients free of cardiac risk factors, before, and 6 months post-bariatric surgery with the new imaging modality of three-dimensional (3D) strain and the comparison of two surgical techniques: sleeve gastrectomy vs. gastric bypass., Methods and Results: Fifty-two consecutive patients referred to the Bariatric Services of Imperial College NHS Trust were examined with conventional 2D and 3D strain echocardiography, prior to and 6 months after bariatric surgery. They were all free from cardiac disease. The study cohort's mean age was 44.2 ± 8.7 years and body mass index of 42.4 ± 4.6 g/m(2) prior to surgery. Eighteen patients (34.6%) underwent laparoscopic sleeve gastrectomy, and 34 laparoscopic gastric bypass. On 3D speckle tracking, there was significant reverse remodelling post-bariatric surgery [left ventricular (LV) ejection fraction (EF): pre-surgery: 59 ± 8% vs. post-surgery: 67 ± 7%, P < 0.001 and right ventricular (RV) EF: pre-surgery: 60 ± 9% vs. post-surgery: 68 ± 8.2%, P = 0.0001]. Furthermore, there was significant regression of mass (LV mass: pre-surgery: 111 ± 23.5 g vs. post-surgery: 92.8 ± 15.5 g and RV mass: pre-surgery: 95.2 ± 19.8 vs. post-surgery: 67.3 ± 16.3, P < 0.001). RV and LV global strain improved 6 months post-bariatric surgery: global RV strain: pre-surgery -11.7 ± 4 vs. post-surgery -17.52 ± 3.7, P < 0.001; global LV strain: pre-surgery: -20.2 ± 1.7 vs. post-surgery: -26.5 ± 1.86, P < 0.001. Sleeve gastrectomy and gastric bypass had comparable effects., Conclusion: Bariatric surgery has an important effect in reverse LV and RV remodelling and it substantially improves RV longitudinal strain., (Published on behalf of the European Society of Cardiology. All rights reserved. © The Author 2014. For permissions please email: journals.permissions@oup.com.)

Pulmonary embolism (PE) is a common finding in patients with underlying malignancy and is the commonest cause of acute cor pulmonale. A 65-year-old woman with a background of non-small-cell lung cancer presented to the emergency department with nausea and vomiting after starting erlotinib; she was pyrexial and had raised C-reactive protein. Despite aggressive fluid resuscitation and antibiotics the patient remained tachycardic, hypotensive, profoundly hypoxic and had a persistent raised jugular venous pulse. Massive PE was therefore suspected. A bedside echocardiogram demonstrated a dilated right ventricle and evidence of pulmonary hypertension. A CT pulmonary angiogram excluded a PE but revealed progression of the right hilar tumour causing complete obstruction of the right upper and middle lobe pulmonary arteries. This case highlights an important differential diagnosis when assessing patients with an underlying intrathoracic tumour with findings suggestive of PE and the importance of obtaining further imaging before considering thrombolysis.