Advances in the Post-coronary Artery Bypass Graft Management of Occlusive Coronary Artery Disease

Revascularisation of chronic total occlusion (CTO) represents one of the most challenging aspects of percutaneous coronary intervention, but advances in equipment and an understanding of CTO revascularisation techniques have resulted in considerable improvements in success rates. In patients with prior coronary artery bypass grafting (CABG) surgery, additional challenges are encountered. This article specifically explores these challenges, as well as antegrade methods of CTO crossing. Techniques, equipment that can be used and reference texts are highlighted with the aim of providing potential CTO operators adequate information to tackle additional complexities likely to be encountered in this cohort of patients. This review forms part of a wider series where additional aspects of patients with prior CABG should be factored into decisions and methods of revascularisation.

Invasive Haemodynamic Assessment Before and After Left Ventricular Assist Device Implantation: A Guide to Current Practice

Mechanical circulatory support for the management of advanced heart failure is a rapidly evolving field. The number of durable long-term left ventricular assist device (LVAD) implantations increases each year, either as a bridge to heart transplantation or as a stand-alone ‘destination therapy’ to improve quantity and quality of life for people with end-stage heart failure. Advances in cardiac imaging and non-invasive assessment of cardiac function have resulted in a diminished role for right heart catheterisation (RHC) in general cardiology practice; however, it remains an essential tool in the evaluation of potential LVAD recipients, and in their long-term management. In this review, the authors discuss practical aspects of performing RHC and potential complications. They describe the haemodynamic markers associated with a poor prognosis in patients with left ventricular systolic dysfunction and evaluate the measures of right ventricular (RV) function that predict risk of RV failure following LVAD implantation. They also discuss the value of RHC in the perioperative period; when monitoring for longer term complications; and in the assessment of potential left ventricular recovery.

What an Interventionalist Needs to Know About INOCA

Ischaemia with non-obstructed coronary artery disease (INOCA) remains a diagnostic and therapeutic challenge. An anatomical investigation-based approach to ischaemic heart disease fails to account for disorders of vasomotion. The main INOCA endotypes are microvascular angina, vasospastic angina, mixed (both) or non-cardiac symptoms. The interventional diagnostic procedure (IDP) enables differentiation between clinical endotypes, with linked stratified medical therapy leading to a reduced symptom burden and a better quality of life. Interventionists are therefore well placed to make a positive impact with more personalised care. Despite adjunctive tests of coronary function being supported by contemporary guidelines, IDP use in daily practice remains limited. More widespread adoption should be encouraged. This article reviews a stratified approach to INOCA, describes a streamlined approach to the IDP and highlights some practical and safety considerations.

Cardiovascular Imaging and Intervention Through the Lens of Artificial Intelligence

Artificial Intelligence (AI) is the simulation of human intelligence in machines so they can perform various actions and execute decision-making. Machine learning (ML), a branch of AI, can analyse information from data and discover novel patterns. AI and ML are rapidly gaining prominence in healthcare as data become increasingly complex. These algorithms can enhance the role of cardiovascular imaging by automating many tasks or calculations, find new patterns or phenotypes in data and provide alternative diagnoses. In interventional cardiology, AI can assist in intraprocedural guidance, intravascular imaging and provide additional information to the operator. AI is slowly expanding its boundaries into interventional cardiology and can fundamentally alter the field. In this review, the authors discuss how AI can enhance the role of cardiovascular imaging and imaging in interventional cardiology.

The Impact of Calcium on Chronic Total Occlusion Management

Coronary artery calcification is prevalent in chronic total occlusions (CTO), particularly in those of longer duration and post-coronary artery bypass. The presence of calcium predicts lower procedural success rates and a higher risk of complications of CTO percutaneous coronary intervention. Adjunctive imaging, including pre-procedural computed tomography and intracoronary imaging, are useful to understand the distribution and morphology of the calcium. Specialised guidewires and microcatheters, as well as penetration, subintimal entry and luminal re-entry techniques, are required to cross calcific CTOs. The use of both atherectomy devices and balloon-based calcium modification tools has been reported during CTO percutaneous coronary intervention, although they are limited by concerns regarding safety and efficacy in the subintimal space.

Is This the Prime Time for Transradial Access Left Ventricular Endomyocardial Biopsy?

Left ventricular endomyocardial biopsy (EMB) is an essential tool in the management of myocarditis and is conventionally performed via transfemoral access (TFA). Transradial access EMB (TRA-EMB) is a novel alternative and the authors sought to determine its safety and feasibility by conducting a systematic review of the literature. Medline was searched in 2020, and cohort demographics, procedural details and complications were extracted from selected studies. Four observational studies with a combined total of 496 procedures were included. TRA-EMB was most frequently performed with a sheathless MP1 guide catheter via the right radial artery. The most common complication was pericardial effusion (up to 11% in one study), but pericardial drainage for tamponade was rare (one reported case). Death and mitral valve damage have not been reported. TRA-EMB was successful in obtaining samples in 99% of reported procedures. The authors concluded that TRA-EMB is a safe and feasible alternative to TFA-EMB and the most common complication is uncomplicated pericardial effusion.

Pre-dilation and Post-dilation in Transcatheter Aortic Valve Replacement: Indications, Benefits and Risks

Transcatheter aortic valve replacement (TAVR) is an established treatment for patients with symptomatic severe aortic stenosis. In recent years, an emphasis has been placed on simplification of the procedure. Balloon predilation was initially considered a mandatory step to cross and prepare the stenotic aortic valve, but several studies demonstrated the feasibility of performing TAVR without balloon valvuloplasty. Balloon postdilation of the implanted valve is sometimes required to optimise results, although many patients do not require this step. Contemporary consensus advocates an individualised approach to TAVR procedures and so balloon pre- and post-dilation are performed selectively. This review aims to outline the advantages and disadvantages of balloon pre- and post-dilation and to identify the scenarios in which they are required during TAVR procedures.

Factors Influencing Stent Failure in Chronic Total Occlusion Coronary Intervention

Stent failure remains one of the greatest challenges for interventional cardiologists. Despite the evolution to superior second- and third-generation drug-eluting stent designs, increasing use of intracoronary imaging and the adoption of more potent antiplatelet regimens, registries continue to demonstrate a prevalence of stent failure or target lesion revascularisation of 15–20%. Predisposition to stent failure is consistent across both chronic total occlusion (CTO) and non-CTO populations and includes patient-, lesion- and procedure-related factors. However, histological and pathophysiological properties specific to CTOs, alongside complex strategies to treat these lesions, may potentially render percutaneous coronary interventions in this cohort more vulnerable to failure. Prevention requires recognition and mitigation of the precipitants of stent failure, optimisation of interventional techniques, including image-guided precision percutaneous coronary intervention, and aggressive modification of a patient’s cardiovascular risk factors. Management of stent failure in the CTO population is technically challenging and itself begets recurrence. We aim to provide a comprehensive review of factors influencing stent failure in the CTO population and strategies to attenuate these.

Patient-specific Computer Simulation: An Emerging Technology for Guiding the Transcatheter Treatment of Patients with Bicuspid Aortic Valve

Transcatheter aortic valve implantation (TAVI) is increasingly being used to treat younger, lower-risk patients, many of whom have bicuspid aortic valve (BAV). As TAVI begins to enter these younger patient cohorts, it is critical that clinical outcomes from TAVI in BAV are matched to those achieved by surgery. Therefore, the identification of patients who, on an anatomical basis, may not be suitable for TAVI, would be desirable. Furthermore, clinical outcomes of TAVI in BAV might be improved through improved transcatheter heart valve sizing and positioning. One potential solution to these challenges is patient-specific computer simulation. This review presents the methodology and clinical evidence surrounding patient-specific computer simulation of TAVI in BAV.