Predictors of the efficacy of His bundle pacing in patients with a prolonged PR interval: A stratified analysis of the HOPE-HF randomized controlled trial.

Aims: The randomized, double-blind, placebo-controlled HOPE-HF trial assessed the benefit of atrio-ventricular (AV) delay optimization delivered using His bundle pacing. It recruited patients with left ventricular ejection fraction ≤40%, PR interval ≥200 ms, and baseline QRS ≤140 ms or right bundle branch block. Overall, there was no significant increase in peak oxygen uptake (VOmax) but there was significant improvement in heart failure specific quality of life.

Comparing invasive hemodynamic responses in adenosine hyperemia versus physical exercise stress in chronic coronary syndromes.

Objectives: Adenosine hyperemia is an integral component of the physiological assessment of obstructive coronary artery disease in patients with chronic coronary syndrome (CCS). The aim of this study was to compare systemic, coronary and microcirculatory hemodynamics between intravenous (IV) adenosine hyperemia versus physical exercise stress in patients with CCS and coronary stenosis.

Methods: Twenty-three patients (mean age, 60.

COVID-19 and its impact on the cardiovascular system.

Objectives: The clinical impact of SARS-CoV-2 has varied across countries with varying cardiovascular manifestations. We review the cardiac presentations, in-hospital outcomes and development of cardiovascular complications in the initial cohort of SARS-CoV-2 positive patients at Imperial College Healthcare National Health Service Trust, UK.

Methods: We retrospectively analysed 498 COVID-19 positive adult admissions to our institute from 7 March to 7 April 2020.

Management of Acute Coronary Syndromes During the Coronavirus Disease 2019 Pandemic: Deviations from Guidelines and Pragmatic Considerations for Patients and Healthcare Workers.

Coronavirus disease 2019 (COVID-19) is forcing cardiology departments to rapidly adapt existing clinical guidelines to a new reality and this is especially the case for acute coronary syndrome pathways. In this focused review, the authors discuss how COVID-19 is affecting acute cardiology care and propose pragmatic guideline modifications for the diagnosis and management of acute coronary syndrome patients, particularly around the appropriateness of invasive strategies as well as length of hospital stay. The authors also discuss the use of personal protective equipment for healthcare workers in cardiology.

Relative clinical value of coronary computed tomography and stress echocardiography-guided management of stable chest pain patients: a propensity-matched analysis.

Aims: The European Society of Cardiology recommends coronary computed tomography (CCT) for the assessment of low-risk patients with suspected stable angina. We aimed to assess in a real-life setting the relative clinical value of stress echocardiography (SE)- and CCT-guided management in this population.

Methods And Results: Patients with stable chest pain and no prior history of coronary artery disease (CAD) who underwent CCT or SE as the initial investigative strategy were propensity-matched (990 patients each group-age: 59 ± 13.

Association Between Physiological Stenosis Severity and Angina-Limited Exercise Time in Patients With Stable Coronary Artery Disease.

Importance: Physiological stenosis assessment is recommended to guide percutaneous coronary intervention (PCI) in patients with stable angina.

Objective: To determine the association between all commonly used indices of physiological stenosis severity and angina-limited exercise time in patients with stable angina.

Design, Setting, And Participants: This cohort study included data (without follow-up) collected over 1 year from 2 cardiac hospitals.

Impact of Percutaneous Revascularization on Exercise Hemodynamics in Patients With Stable Coronary Disease.

Background: Recently, the therapeutic benefits of percutaneous coronary intervention (PCI) have been challenged in patients with stable coronary artery disease (SCD).

Objectives: The authors examined the impact of PCI on exercise responses in the coronary circulation, the microcirculation, and systemic hemodynamics in patients with SCD.

Methods: A total of 21 patients (mean age 60.

Resolving the paradox of randomised controlled trials and observational studies comparing multi-vessel angioplasty and culprit only angioplasty at the time of STEMI.

Background: Patients presenting with ST-elevation myocardial infarction commonly have multi-vessel coronary artery disease. After the culprit artery is treated, the optimal treatment strategy for the residual disease is not yet defined. Large observational studies suggest that treatment of residual disease should be deferred but smaller randomised controlled trials (RCTs) suggest multi-vessel primary percutaneous coronary intervention (MV-PPCI) at the time of STEMI is safe.

Estimation of coronary wave intensity analysis using noninvasive techniques and its application to exercise physiology.

Wave intensity analysis (WIA) has found particular applicability in the coronary circulation where it can quantify traveling waves that accelerate and decelerate blood flow. The most important wave for the regulation of flow is the backward-traveling decompression wave (BDW). Coronary WIA has hitherto always been calculated from invasive measures of pressure and flow.

The effects of angiotensin II signaling blockade on platelet activity in subjects with hypertension.

Background: To investigate the effects of Angiotensin II receptor blockade (ARB) and angiotensin converting enzyme (ACE) inhibition on platelet reactivity in patients with mild to moderate hypertension. PFA-100 evaluates platelet function (expressed in seconds as closure time, CT) in anti-coagulated whole blood in vitro at high shear rates. The test cartridge is impregnated with either collagen and epinephrine (Col/Epi) or collagen and ADP (Col/ADP).

A new method of applying randomised control study data to the individual patient: A novel quantitative patient-centred approach to interpreting composite end points.

Background: Modern randomised controlled trials typically use composite endpoints. This is only valid if each endpoint is equally important to patients but few trials document patient preference and seek the relative importance of components of combined endpoints. If patients weigh endpoints differentially, our interpretation of trial data needs to be refined.

Change in coronary blood flow after percutaneous coronary intervention in relation to baseline lesion physiology: results of the JUSTIFY-PCI study.

Background: Percutaneous coronary intervention (PCI) aims to increase coronary blood flow by relieving epicardial obstruction. However, no study has objectively confirmed this and assessed changes in flow over different phases of the cardiac cycle. We quantified the change in resting and hyperemic flow velocity after PCI in stenoses defined physiologically by fractional flow reserve and other parameters.

Pre-angioplasty instantaneous wave-free ratio pullback provides virtual intervention and predicts hemodynamic outcome for serial lesions and diffuse coronary artery disease.

Objectives: The aim of this study was to perform hemodynamic mapping of the entire vessel using motorized pullback of a pressure guidewire with continuous instantaneous wave-free ratio (iFR) measurement.

Background: Serial stenoses or diffuse vessel narrowing hamper pressure wire-guided management of coronary stenoses. Characterization of functional relevance of individual stenoses or narrowed segments constitutes an unmet need in ischemia-driven percutaneous revascularization.

Improvement in coronary haemodynamics after percutaneous coronary intervention: assessment using instantaneous wave-free ratio.

Objective: To determine whether the instantaneous wave-free ratio (iFR) can detect improvement in stenosis significance after percutaneous coronary intervention (PCI) and compare this with fractional flow reserve (FFR) and whole cycle Pd/Pa.

Design: A prospective observational study was undertaken in elective patients scheduled for PCI with FFR ≤ 0.80.

Diagnostic classification of the instantaneous wave-free ratio is equivalent to fractional flow reserve and is not improved with adenosine administration. Results of CLARIFY (Classification Accuracy of Pressure-Only Ratios Against Indices Using Flow Study).

Objectives: This study sought to determine if adenosine administration is required for the pressure-only assessment of coronary stenoses.

Background: The instantaneous wave-free ratio (iFR) is a vasodilator-free pressure-only measure of the hemodynamic severity of a coronary stenosis comparable to fractional flow reserve (FFR) in diagnostic categorization. In this study, we used hyperemic stenosis resistance (HSR), a combined pressure-and-flow index, as an arbiter to determine when iFR and FFR disagree which index is most representative of the hemodynamic significance of the stenosis.

Hybrid iFR-FFR decision-making strategy: implications for enhancing universal adoption of physiology-guided coronary revascularisation.

Aims: Adoption of fractional flow reserve (FFR) remains low (6-8%), partly because of the time, cost and potential inconvenience associated with vasodilator administration. The instantaneous wave-Free Ratio (iFR) is a pressure-only index of stenosis severity calculated without vasodilator drugs. Before outcome trials test iFR as a sole guide to revascularisation, we evaluate the merits of a hybrid iFR-FFR decision-making strategy for universal physiological assessment.

Classification performance of instantaneous wave-free ratio (iFR) and fractional flow reserve in a clinical population of intermediate coronary stenoses: results of the ADVISE registry.

Aims: To evaluate the classification agreement between instantaneous wave-free ratio (iFR) and fractional flow reserve (FFR) in patients with angiographic intermediate coronary stenoses.

Methods And Results: Three hundred and twelve patients (339 stenoses) with angiographically intermediate stenoses were included in this international clinical registry. The iFR was calculated using fully automated algorithms.

Development and validation of a new adenosine-independent index of stenosis severity from coronary wave-intensity analysis: results of the ADVISE (ADenosine Vasodilator Independent Stenosis Evaluation) study.

Objectives: The purpose of this study was to develop an adenosine-independent, pressure-derived index of coronary stenosis severity.

Background: Assessment of stenosis severity with fractional flow reserve (FFR) requires that coronary resistance is stable and minimized. This is usually achieved by administration of pharmacological agents such as adenosine.

Tubercular myocarditis presenting with ventricular tachycardia.

Background: A previously fit and healthy 30-year-old man reported experiencing palpitations accompanied by nausea, sweating and presyncope. These symptoms were found to be associated with episodes of nonsustained ventricular tachycardia. He was a nonsmoker, did not drink excessively, denied illicit drug use and had no family history of structural cardiac disease or sudden death.

Homocysteine-induced endothelin-1 release is dependent on hyperglycaemia and reactive oxygen species production in bovine aortic endothelial cells.

Background: Elevated plasma homocysteine (Hcy) is a risk factor for coronary disease. The objective of this study was to investigate whether Hcy either alone or in high glucose conditions induces endothelin-1 (ET-1) synthesis via the production of reactive oxygen species (ROS).

Methods: Bovine aortic endothelial cells were grown in high (25 mmol/l) and low (5 mmol/l) glucose medium.

Factor VIIa stimulates endothelin-1 synthesis in TNF-primed endothelial cells by activation of protease-activated receptor 2.

The mechanisms linking prothrombotic changes to endothelial dysfunction and accelerated atheroma formation have yet to be fully defined. Expression of TF (tissue factor) on the endothelium is potentially an initiating event as binding and activation of FVII (factor VII) can result in thrombosis. Although PAR2 (protease-activated receptor-2) is expressed on vascular endothelium, its precise physiological significance and mechanism of activation have yet to be defined.