Reviews & Analysis

On the basis of high-quality observational data, Goyal et al. have found that serum potassium levels <3.5 mmol/l or ≥4.5 mmol/l are associated with increased in-hospital mortality in patients with acute myocardial infarction. We discuss whether target potassium levels in clinical practice and guidelines should be changed to 3.5–4.5 mmol/l.

Echocardiographic screening for rheumatic heart disease (RHD) over the past 5 years has revealed a higher RHD disease burden than previously imagined and, globally, at least 15 million people are estimated to be affected by this disease. In this article, an international advisory group of experts in RHD screening and echocardiographic manifestations of RHD present the 2012 World Heart Federation criteria for echocardiographic diagnosis of RHD.

Oral direct factor Xa inhibitors, particularly apixaban and rivaroxaban, are novel and promising alternatives to warfarin for stroke prevention in patients with atrial fibrillation. Drs Cabral and Ansell review the data from clinical trials of these drugs, and also discuss the challenges of reversing their anticoagulant effects, interactions with other medications, patient compliance, and therapeutic monitoring.

Novel, oral, direct inhibitors of factor Xa are valuable additions to anticoagulation therapy in patients with various thrombotic disorders, but have shown mixed results in trials for secondary prevention in patients with an acute coronary syndrome. Drs Wisler and Becker review the available data, with particular emphasis on the phase III APPRAISE 2 and ATLAS ACS 2–TIMI 51 trials of apixaban and rivaroxaban.

Observational data from the Women's Health Initiative show a 48% increased risk of developing diabetes mellitus with statins. Results from two meta-analyses of randomized trials of statins with 120,000 participants have indicated a dose-dependent, but more-modest, relationship between statins and new-onset diabetes. Careful interpretation of pharmacoepidemiological data is required.

Dr. Moss and colleagues review data from randomized clinical trials which suggest that important sex-specific differences in the epidemiology and clinical characteristics of patients with heart failure can affect their response to both medical and device therapies.

Multimodality and hybrid imaging combine various imaging modalities to enhance diagnostic accuracy and improve clinical outcomes. Dr. Delgado and colleagues review the use of multiple novel imaging techniques to evaluate plaque burden and stability in patients with coronary artery disease, target cardiac resynchronization therapy in patients with heart failure, and guide transcatheter procedures in patients with valvular heart disease.

Clinical trials of antihypertensive drugs typically last up to 5 years, but lifelong therapy for patients with hypertension is recommended in all treatment guidelines. To address this discrepancy, investigators from the Systolic Hypertension in the Elderly Program have published data from a 22-year follow-up showing sustained benefits of antihypertensive treatment.

Stroke after transcatheter aortic valve implantation (TAVI) is of major concern, with half of all events occurring days after the procedure. Amat-Santos and colleagues have reported a correlation between new-onset atrial fibrillation (NOAF) and 'delayed' cerebrovascular events in these patients and identified risk factors for this phenomenon, highlighting the need to rigorously address NOAF after TAVI.

Glucagon-like peptide 1 (GLP)-based therapies reduce blood glucose levels in patients with type 2 diabetes mellitus. Interestingly, GLP 1 receptor agonists can also have beneficial effects on cardiovascular risk. Dr. Sivertsen and colleagues provide an overview of the cardiovascular mechanisms targeted by GLP 1-based therapies and discuss clinical data for long-term management of cardiovascular risk in patients treated with these agents.

The primary objective of invasive treatment strategies for multivessel coronary artery disease is complete anatomical revascularization. As objective evidence of ischemia can be provided by a functional assessment based on fractional flow reserve, the focus of contemporary treatment could shift from anatomical to functional revascularization. In this Perspectives article, the authors summarize the data that supports contemporary functional revascularization and its applicability to real-world practice.

Particular mutations in cardiac potassium channels are known to be arrhythmogenic. In this Review, the authors discuss the genetic basis, diagnosis, risk stratification, and management of patients with various potassium channelopathies, including long and short QT syndromes, Brugada syndrome, and familial atrial fibrillation.

Studies published in 2011 in the field of heart failure have reinforced the benefit of cardiac resynchronization therapy in patients with mild symptoms and confirmed the value of left ventricular assist devices and CABG surgery in selected patients. Conversely, the efficacy of nesiritide in acute heart failure has been questioned.

Systems biology harnesses experimental and computational high-throughput techniques to unravel complex biological interactions, such as those between genetic and environmental factors. Drs MacLellan, Wang, and Lusis provide an overview of system-based approaches to cardiovascular diseases and discuss the translational implications of such studies.

The second of the two Reviews on cardiogenic shock in acute coronary syndromes focuses by Westaby et al. focuses on the use of mechanical circulatory support systems, from intra-aortic balloon pumps, extracorporeal membrane oxygenation, and ventricular assist devices, to the total artificial heart. The authors highlight the importance of multidisciplinary care teams, and discuss some of the ethical and economic issues that impact the use of these devices.