Current Opinion in Cardiology最新文献

Purpose of review: To provide a summary of the current evidence and highlight future directions regarding coronary artery calcium (CAC) and risk of sudden cardiac death (SCD).

Recent findings: Although up to 80% of all SCD is attributed to coronary heart disease (CHD), the subclinical atherosclerosis markers that help to improve SCD risk prediction are largely unknown. Recent observational data have demonstrated that, after adjustment for traditional risk factors, there is a stepwise higher risk for SCD across increasing CAC burden such that asymptomatic patients without overt atherosclerotic cardiovascular disease (ASCVD) experience a three-fold to five-fold higher SCD risk beginning at CAC at least 100 when compared with CAC = 0. Although the mechanisms underlying increasing CAC and SCD risk have yet to be fully elucidated, risk for myocardial infarction and scar, and/or exercise-induced ischemia may be potential mediators.

Summary: High CAC burden is an important risk factor for SCD in asymptomatic middle-aged adults, suggesting that SCD risk stratification can begin in the early stages of CHD via measurement of calcific plaque on noncontrast computed tomography. Despite the clinical inertia for downstream functional cardiac testing after detecting high CAC, comprehensive ASCVD prevention strategies should be the primary focus for SCD risk reduction.

Purpose of review: The optimal antiplatelet strategy in patients after coronary artery bypass graft (CABG) surgery is unclear. We review the evidence on the efficacy and safety of DAPT after CABG and discuss potential novel antiplatelet strategies that reduce the risk of bleeding without loss of efficacy.

Recent findings: Adding the potent P2Y12 inhibitor ticagrelor to aspirin for 1 year after CABG is associated with a reduction in the risk of vein graft failure, at the expense of an increased risk of clinically important bleeding. Ticagrelor monotherapy is not associated with better efficacy than aspirin alone, but is not associated with increased bleeding risk.

Summary: Dual antiplatelet therapy (DAPT) is recommended after acute coronary syndrome events, but aspirin as single antiplatelet therapy remains the cornerstone of antithrombotic therapy in stable ischemic heart disease because of a lack of solid evidence on the benefit of DAPT on clinical outcomes. Shorter duration DAPT, based on the pathophysiology of vein graft failure, may be a promising strategy that requires testing in adequately powered randomized trials.

Purpose of review: Whilst abnormally increased left ventricular wall thickness is the hallmark feature of hypertrophic cardiomyopathy (HCM), anomalies of the mitral valve and supporting apparatus are well documented. This review addresses the clinical importance of mitral valve abnormalities in HCM, their mechanistic associations with symptoms, and therapeutic strategies targeting mitral valve and apparatus abnormalities.

Recent findings: The normal mitral valve possesses anatomical features facilitating unrestricted blood flow during LV filling, preventing regurgitation during LV systole, and avoiding obstruction of LV ejection. In HCM, a variety of structural and functional abnormalities can conspire to cause deranged mitral valve function, with implications for management strategy. Identification and characterization of these abnormalities is facilitated by multimodality imaging. Alcohol septal ablation (ASA) cannot address primary mitral valve abnormalities, and so is not preferred to surgical intervention if mitral valve abnormalities are present and are judged to make dominant contributions to LV outflow tract obstruction (LVOTO). Two broadly opposing surgical intervention strategies exist, one advocating isolated septal myectomy and the other including adjuvant mitral apparatus modification. Newer, less invasive surgical and transcatheter techniques will expand interventional options.

Summary: Mitral valve abnormalities are a central pathological feature of HCM. Multimodality imaging is crucial for their identification and characterization prior to therapeutic intervention.

Purpose of review: The aim of this study was to review imaging of myocardial hypertrophy in hypertrophic cardiomyopathy (HCM) and its phenocopies. The introduction of cardiac myosin inhibitors in HCM has emphasized the need for careful evaluation of the underlying cause of myocardial hypertrophy.

Recent findings: Advances in imaging of myocardial hypertrophy have focused on improving precision, diagnosis, and predicting prognosis. From improved assessment of myocardial mass and function, to assessing myocardial fibrosis without the use of gadolinium, imaging continues to be the primary tool in understanding myocardial hypertrophy and its downstream effects. Advances in differentiating athlete's heart from HCM are noted, and the increasing rate of diagnosis in cardiac amyloidosis using noninvasive approaches is especially highlighted due to the implications on treatment approach. Finally, recent data on Fabry disease are shared as well as differentiating other phenocopies from HCM.

Summary: Imaging hypertrophy in HCM and ruling out other phenocopies is central to the care of patients with HCM. This space will continue to rapidly evolve, as disease-modifying therapies are under investigation and being advanced to the clinic.

Purpose of review: The current article reviews obstructive forms of hypertrophic cardiomyopathy and associated morphologic cardiac abnormalities. It focuses on echocardiographic imaging of the left ventricular (LV) outflow tract obstruction, its evaluation, prognostication, and differentiation from other conditions mimicking obstructive hypertrophic cardiomyopathy.

Recent findings: Symptomatic patients with LV outflow tract (LVOT) gradients at least 50 mmHg on maximally tolerated medical therapy are candidates for advanced therapies. Resting echocardiography may only identify 30% of patients with obstructive physiology. Provocative maneuvers are essential for symptomatic patients with hypertrophic cardiomyopathy (HCM). Exercise echocardiography is recommended if they fail to provoke a gradient. Although dynamic LV tract obstruction is seen with obstructive HCM, it is not specific to this condition and exists in other physiologic and pathophysiologic states. Careful clinical evaluation and imaging techniques aid in the differentiation of HCM from these conditions.

Summary: Imaging plays an integral role in the diagnosis, prognosis, and risk stratification of HCM patients. Newer imaging technologies, including 3D transthoracic echocardiography, 3D transesophageal, speckle-derived 2D strain, and cardiac MRI, allow for a better hemodynamic understanding of systolic anterior motion and LV tract obstruction. Evolving techniques, that is, artificial intelligence, will undoubtedly further increase diagnostic capabilities. Newer medical therapies are available with the hope that this will lead to better patient management.

Purpose of review: In-stent restenosis (ISR) is the most common cause of stent failure. Although the rate of ISR is significantly lower with contemporary drug-eluting stents (DES), it remains a challenging clinical entity to treat.

Recent findings: In this review, we focus on a practical approach to management of DES ISR with intravascular imaging at its core, as supported by several recently published articles. This facilitates assessment of the underlying mechanism(s) essential to the successful treatment of ISR allowing for a tailored selection of treatment modalities.

Summary: The successful treatment of DES ISR requires identification of the causative mechanism(s). Individualized treatment may include high-pressure balloon angioplasty alone, cutting or scoring balloons, intravascular lithotripsy, atheroablative therapies and a selection of either repeat DES implantation or drug-coated balloon treatment.

Purpose of review: Obstructive sleep apnea (OSA) is associated with several cardiovascular risk predictors that have only recently begun to be studied in detail. The strong association between OSA and hypertension, coronary artery disease, congestive heart failure, and sudden cardiac death underscores its significant impact on cardiovascular health. This brief review considers the links between OSA and cardiovascular risk.

Recent findings: OSA is an important contributor to endothelial dysfunction and damage, while repetitive hypoxia and hypercarbia contribute to autonomic dysfunction and sympathetic stimulation. In turn, these derangements have deleterious hematologic effects, including hypercoagulability and abnormal platelet aggregability, which are important in the pathogenesis of atherothrombotic disease.

Summary: The varied deleterious effects of OSA on cardiovascular health stem from a unique 'perfect storm' of hypoxic oxidative stress, autonomic dysregulation, endothelial damage, and inflammation occurring at the microvascular level. Further research may disentangle these multiple etiologic threads and provide a better understanding of the underlying pathophysiological relationship between OSA and cardiovascular disease.

Purpose of review: To describe the relationship between three pandemics: hypertension, obesity, and heart failure. From pathophysiology to treatment, understanding how these disease entities are linked can lead to breakthroughs in their prevention and treatment. The relevance of this review lies in its discussion of novel pharmacological and surgical treatment strategies for obesity and hypertension, and their role in the prevention and treatment of heart failure.

Recent findings: Novel medications such as GLP-1 agonists have demonstrated sustained weight loss in patients with obesity, and concurrent improvements in their cardiometabolic profile, and possibly also reductions in hypertension-related comorbidities including heart failure. Surgical therapies including laparoscopic bariatric surgery represent an important treatment strategy in obese patients, and recent studies describe their use even in patients with advanced heart failure, including those with ventricular assist devices.

Summary: These developments have deep implications on our efforts to understand, mitigate, and ultimately prevent the three pandemics, and offer promising improvements to quality of life, survival, and the cost burden of these diseases.

Purpose of review: Cardiac myosin inhibitors (CMIs) represent a major milestone in the treatment of patients with symptomatic obstructive hypertrophic cardiomyopathy. The objective of this review is to discuss the mechanisms of action, clinical trial evidence, safety profile and monitoring of CMIs, which are important to the implementation of these drugs in clinical practice.

Recent findings: Mavacamten and aficamten have both been shown to substantially improve left ventricular outflow tract gradients, biomarkers and symptoms in patients with obstructive hypertrophic cardiomyopathy. Both agents are well tolerated with few adverse events in clinical trial follow up. Transient reductions in left ventricular ejection fraction may be associated with both mavacamten and aficamten but respond to dose reduction.

Summary: There is now robust clinical trial evidence base to support the use of mavacamten for patients with symptomatic obstructive hypertrophic cardiomyopathy. Generation of long-term safety and efficacy data and exploring applications of CMI to nonobstructive cardiomyopathy and heart failure with preserved ejection fraction represent important next steps.