Anomalous origins of the coronary arteries: current knowledge and future perspectives Purpose of review The purpose of this review is to survey the contemporary literature surrounding congenital anomalies of origin of the coronary arteries and to identify remaining gaps in knowledge. Recent findings In recent years, lineage tracing analyses and mechanistic studies in model organisms have enhanced our understanding of the normal embryologic development of the coronary arteries, and how disruption of this intricate process can lead to congenital coronary anomalies. The true incidence of these anomalies remains unknown. Although a majority of cases are believed to be clinically silent, clinical presentation varies widely, from asymptomatic to sudden cardiac death. Cardiac computed tomography angiography and/or magnetic resonance angiography are the mainstay diagnostic modalities. Management of anomalous coronary arteries depends on the morphology and clinical presentation. Surgery is the gold-standard treatment for anomalous left coronary artery arising from the pulmonary artery and anomalous aortic origin of a coronary artery with intramural or interarterial course. Summary Several large multicenter initiatives are currently underway and should help address some of the numerous knowledge gaps surrounding the evaluation and management of anomalous coronary arteries. Correspondence to Edward J. Hickey, MD, The Hospital for Sick Children, 555 University Ave., Toronto, ON, Canada M5G 1X8. E-mail: edward.hickey@sickkids.ca Copyright © 2019 Wolters Kluwer Health, Inc. All rights reserved.

Assessment of myocardial viability by myocardial contrast echocardiography: current perspectives Purpose of review The current guidelines recommend the use of myocardial contrast echocardiography (MCE) to assess myocardial viability. There are two clinical scenarios where detection of myocardial viability has clinical significance: in ischemic cardiomyopathy and following acute myocardial infarction with significant left ventricular dysfunction. Myocardial contrast echocardiography (MCE), which utilizes microbubbles can assess the integrity of the microvasculature, which sustains myocardial viability in real time and can hence rapidly provide information on myocardial viability at the bedside without ionizing radiation. Recent findings We discuss the value of MCE to predict myocardial viability through the detection of the integrity of myocardial microvasculature, the newer evidences behind the MCE-derived coronary flow reserve and use of MCE postmyocardial infarction to detect no-reflow. Newer studies have also demonstrated the comparable sensitivities and specificities of MCE to single photon-emission computed tomography (SPECT), cardiac myocardial resonance imaging and PET for the detection of myocardial viability. Summary Ample evidence now exist that supports the routine use of MCE for the detection of viability as laid down in recent guidelines. Correspondence to Professor Roxy Senior, MD, DM, FRCP, FESC, FACC, Royal Brompton Hospital & National Heart and Lung Institute, Imperial College, London, UK. E-mail: roxysenior@cardiac-research.org Copyright © 2019 Wolters Kluwer Health, Inc. All rights reserved.

Revascularization in left ventricular dysfunction: an update Purpose of review The purpose of this article is to provide an overview of revascularization in patients with coronary artery disease (CAD) and left ventricular dysfunction (LVD). Recent findings Patients with significant CAD and LVD are a high-risk patient population. They make up a minority of the cases from the largest, prospective coronary revascularization trials. The Surgical Treatment for Ischemic Heart Failure (STICH) Trial and its substudies are the most important and well cited in this field. The 10-year data from STICH showed that surgical revascularization was associated with lower all-cause mortality compared with medical therapy. Several smaller studies have confirmed that surgical revascularization carries a significant risk of short-term mortality but overall improved long-term outcomes in patients with LVD. Data from multiple observational studies further confirm that coronary artery bypass graft (CABG) is superior to percutaneous coronary revascularization for long-term survival and freedom from repeat revascularization in patients with LVD. We suggest that patients with LVD undergoing CABG should be considered for multiarterial grafting and that some patients may benefit from an off-pump procedure. Summary Surgical revascularization confers a long-term survival benefit in patients with significant CAD and LVD. Further studies will be needed to precisely determine the ideal candidate for surgical versus percutaneous revascularization. Correspondence to Bobby Yanagawa, MD, PhD, FRCSC, Program Director, Division of Cardiac Surgery, University of Toronto, Assistant Professor, Division of Cardiac Surgery, St Michael's Hospital, 30 Bond Street, 8th Floor, Bond Wing, Toronto, ON, Canada M5B 1W8. Tel: +1 416 864 5706; fax: +1 416 864 5031; e-mail: yanagawab@smh.ca Copyright © 2019 Wolters Kluwer Health, Inc. All rights reserved.

Assessment of myocardial viability by cardiac MRI Purpose of review Left ventricular systolic dysfunction because of coronary artery disease is common, and ascertaining which patients will benefit from revascularization can be challenging. Viability testing is an accepted means by which to base this decision, with multiple noninvasive imaging modalities available for this purpose. This review aims to highlight the key role of cardiac magnetic resonance in myocardial viability assessment, with a focus on its unique strengths over other imaging modalities. Recent findings Transmural extent of hyperenhancement with late gadolinium imaging has been shown to be greater acutely in ST elevation myocardial infarction patients undergoing primary percutaneous coronary intervention and regress at follow-up studies. An explanation for this reported phenomenon and an argument against redefining CMR viability criteria in the acute setting will be offered. Summary Although not universally available, cardiac magnetic resonance is an exceptionally powerful and well tolerated imaging modality that should be considered when viability testing will influence patient management. Although observational outcomes data suggest a promising prognostic role for viability, randomized studies in this area are needed. Correspondence to Dipan J. Shah, MD, Division of Cardiovascular Imaging, Department of Cardiology, Houston Methodist DeBakey Heart and Vascular Center, 6550 Fannin Street, Smith Tower, Suite #1801, Houston, TX 77030, USA. Tel: +1 713 441 3625; e-mail: djshah@houstonmethodist.org Copyright © 2019 Wolters Kluwer Health, Inc. All rights reserved.

See one, simulate many, do one, teach one: cardiac surgical simulation Purpose of review To review the cardiac surgical simulation experience with a focus on data supporting its use. Recent findings Simulators have been used to improve trainee performance across multiple surgical domains. Few cardiac surgery residency programs have incorporated the use of simulation individually and Boot Camp programs in the United States and Canada have also introduced surgical simulation early in cardiac surgical training. Simulation curricula have some common elements: component tasks, deliberate practice, progressive operative responsibility, and coaching by an experienced surgeon. Cardiac surgical simulators can range from inexpensive, low-fidelity models for the practice of isolated skills to high-fidelity, operating room-scenarios. Multiple small studies have consistently demonstrated that the use of simulation improves qualitative and quantitative performance measures as well as overall resident confidence in clinical settings. To our knowledge, no study has demonstrated that use of simulation has led to improved quantitative performance measures in the operating room or patient outcomes. The barriers to wider use of surgical simulators include perceived lack of time and resources, the need for sustained practice and the lack of high-quality data to demonstrate clinical benefit. Summary Incorporation of cardiac surgery simulation has been slow in most residency programs. There is consistent data demonstrating that simulation improves resident performance measures of simulation-based tasks but whether this will lead to improved patient outcomes remains an open question. Correspondence to Bobby Yanagawa, MD, PhD, FRCSC, Program Director, Division of Cardiac Surgery, University of Toronto, Toronto, Ontario, Canada; Assistant Professor, Division of Cardiac Surgery, St. Michael's Hospital, 30 Bond Street, 8th Floor, Bond Wing, Toronto, ON, Canada M5B 1W8. Tel: +1 416 864 5706; fax: +1 416 864 5031; e-mail: yanagawab@smh.ca Copyright © 2019 Wolters Kluwer Health, Inc. All rights reserved.

Dobutamine echocardiography for assessment of viability in the current era Purpose of review Studies from the 1990s and early 2000s documented the utility of dobutamine echocardiography for the prediction of functional recovery and prognosis with revascularization. The results of The Surgical Treatment of Ischemic Heart Failure (STICH) trial called into question the value of viability assessment using dobutamine echocardiography. The purpose of this review is to re-examine the literature on dobutamine echocardiography, put into context the STICH results, and provide insight into the current role of dobutamine echocardiography viability testing. Recent findings In contrast to the results of previous nonrandomized trials, the STICH trial showed that patients with viability defined by nuclear perfusion imaging or dobutamine echocardiography did not have improved survival with CABG compared with optimal medical therapy. Viability by dobutamine echocardiography was defined as the presence of contractile reserve in at least five segments with baseline dysfunction. The results of dobutamine echocardiography studies published before and after initiation of the STICH trial suggest that the definition of viability utilized in that trial may be suboptimal for assessment of improvement in global function and prognosis in patients undergoing revascularization. Assessment of global contractile reserve using wall motion score (WMS) or ejection fraction may be superior to utilization of a binary definition of viability confined to assessment of contractile reserve in a fixed number of segments because these indices provide information on both the magnitude and extent of contractile reserve of the entire left ventricle (LV). Summary Assessment of WMS or ejection fraction with dobutamine echocardiography may be the optimal means of evaluating the impact of viability on prognosis. Video abstract http://links.lww.com/HCO/A56 Correspondence to Abhishek Khemka, MD, MBA, 1800 N Capitol Avenue, Noyes Building, Suite E371, Indianapolis, IN 46202, USA. Tel: +1 317 274 0992; fax: +1 317 963 3340; e-mail: akhemka@iu.edu Supplemental digital content is available for this article. Direct URL citations appear in the printed text and are provided in the HTML and PDF versions of this article on the journal's Website (www.co-cardiology.com). Copyright © 2019 Wolters Kluwer Health, Inc. All rights reserved.

Current and future role of lipoprotein(a) in preventive cardiology Purpose of review The purpose of this review is to highlight our emerging understanding of lipoprotein(a) [Lp(a)]'s role in atherosclerotic cardiovascular disease (ASCVD), its structure–function relationship, and promising developments within the therapeutic pipeline. Recent findings Elevated levels of Lp(a) are strongly associated with an increased risk of coronary heart disease, calcific aortic valve stenosis, and ischemic stroke. With circulating levels almost exclusively genetically mediated, increased levels of Lp(a) contribute significantly to the residual cardiovascular disease risk in individuals with otherwise well controlled risk factors. The unique structure of Lp(a) – comprised of a genetically heterogeneous apolipoprotein(a) molecule bound to an LDL-like moiety – provides insight into its pathogenic role in cardiovascular disease and also complicates its accurate measurement. Emerging therapies targeting the apolipoprotein(a) component of Lp(a) have the potential to revolutionize the management of individuals with elevated Lp(a). Summary With promising therapies on the horizon, there has been a renewed focus on the role of Lp(a) in ASCVD. Given Lp(a)'s strong and independent association with key cardiovascular outcomes, it is hopeful that these promising targeted therapies will add another therapeutic option for the prevention of cardiovascular disease. Correspondence to Ron Blankstein, MD, FACC, Cardiovascular Division, Department of Medicine; Department of Radiology, Brigham and Women's Hospital, Harvard Medical School, 75 Francis Street, Boston, MA 02115, USA. E-mail: rblankstein@bwh.harvard.edu Copyright © 2019 Wolters Kluwer Health, Inc. All rights reserved.

Percutaneous coronary intervention for the management of stable ischemic heart disease Purpose of review The purpose of this review is to summarize landmark studies and recent evidence in support for and against benefits of routine percutaneous coronary intervention (PCI) in the management of patients with stable ischemic heart disease (SIHD). Recent findings Randomized controlled trials have raised uncertainty regarding the prognostic benefits of routine PCI in patients with SIHD. The benefits of PCI to improve symptoms and quality of life (QOL), thought to be more established, was brought into question recently by the ORBITA trial. Two hundred participants with single vessel SIHD optimized first on antianginal therapy were randomized to PCI or sham PCI procedure. At 6 weeks, there was no significant difference in the primary endpoint of exercise time increment (PCI minus sham PCI 16.6 s, 95% confidence interval –8.9 to 42.0 s, P = 0.20), or secondary endpoints of change in angina or QOL scores between the groups. Summary Findings from this first placebo-controlled trial of PCI in patients with single vessel SIHD suggest that PCI need not necessarily be the first line or default strategy for symptomatic improvement. Results from the ongoing ISCHEMIA (International Study of Comparative Health Effectiveness with Medical and Invasive Approaches) trial will provide further guidance regarding symptomatic and prognostic benefits of early angiography and revascularization for higher risk SIHD patients with moderate-severe ischemia. Correspondence to Akshay Bagai, MD, MHS, Terrence Donnelly Heart Center, St. Michael's Hospital, University of Toronto, ON M5B1W8, Canada. Tel: 1 (416) 864-6060, ext. 5783; fax: 1 (416) 864-5989; e-mail: bagaia@smh.ca Copyright © 2019 Wolters Kluwer Health, Inc. All rights reserved.

Future role of proprotein convertase subtilisin/kexin type 9 inhibitors in preventive cardiology Purpose of review The use of therapeutic monoclonal antibodies to target proprotein convertase subtilisin/kexin type 9 (PCSK9) represents a novel approach to the management of hypercholesteremia and prevention of atherosclerotic cardiovascular disease. We review the most recent literature relevant to PCSK9 inhibition with emphasis on how recent results and ongoing trials have and will continue to shape the use of this new therapeutic class in preventive cardiology. Recent findings PCSK9 inhibitors reduce plasma lipoprotein(a) concentrations but a mechanistic understanding remains elusive. Evaluation of evolocumab for use in patients without prior myocardial infarction or stroke is underway (NCT03872401). Concerns regarding the cost-effectiveness of PCSK9 inhibitors have continued to thwart access to these drugs, though innovative models of care delivery and price reductions have improved this situation. Inclisiran, a small interfering ribonucleic acid (siRNA), reduces translation of PCSK9 and demonstrates more durable reductions in low-density lipoprotein-cholesterol (LDL-C). It is currently evaluated in the context of a phase III cardiovascular outcome trial in patients with established vascular disease (NCT03705234). Summary The current scope of PCSK9 inhibitor therapy in preventive cardiology is limited to patients with familial hypercholesterolemia and/or established atherosclerotic cardiovascular disease. Future cardiovascular outcome trial results with PCSK9 blocking antibodies in primary prevention and with siRNA to PCSK9 in secondary prevention, improved understanding of the drivers of lipoprotein(a) reduction with PCSK9 inhibition, and cost-effectiveness will determine the future role of this therapeutic class. Correspondence to Michael D. Shapiro, DO, MCR, FACC, Section of Cardiovascular Medicine, Center for Preventive Cardiology, Wake Forest Baptist Medical Center, 1 Medical Center Boulevard, Winston-Salem, North Carolina, USA. E-mail: shapiromi@gmail.com Copyright © 2019 Wolters Kluwer Health, Inc. All rights reserved.

Myocardial viability: heart failure perspective Purpose of review This review highlights the different imaging modalities available to assess myocardial viability in patients with heart failure and coronary artery disease (CAD) being considered for revascularization. Recent findings Myocardial viability can be determined by a variety of cardiac imaging modalities. Recent studies have confirmed the use of cardiovascular magnetic resonance imaging (CMR) in patients with heart failure and CAD, suggesting that those who undergo revascularization but have evidence of residual viable or ‘jeopardized’ myocardium have increased mortality compared with those who achieve complete revascularization. The PET and Recovery Following Revascularization (PARR)-2 trial assessed whether viability noted on PET imaging in patients with severe LV dysfunction correlated with recovery of LV function and response to revascularization. The 5-year extension of the PARR-2 study noted a significant decrease in the composite outcome of cardiac death, myocardial infarction, or cardiac hospitalization in patient assessments adherent to PET-guided viability recommendations. Summary On the basis of the current available data, viability testing is reasonable in individuals with ICM, as identified by coronary angiography in whom complete revascularization can be achieved. Whenever available, the use of CMR or PET is preferred because of better resolution and increased sensitivity to detect myocardial viability. Correspondence to Jerry D. Estep, MD, Cleveland Clinic Foundation, 9500 Euclid Avenue J3-4, Cleveland, OH 44195, USA. Tel: +1 216 444 7646; fax: +1 216 636 6974; iPhone: +1 216 314 1711; e-mail: estepj@ccf.org Copyright © 2019 Wolters Kluwer Health, Inc. All rights reserved.