Plasma potassium concentration and cardiac repolarisation markers, Tpeak-Tend and Tpeak-Tend/QT, during and after exercise in healthy participants and in end-stage renal disease.

PURPOSE: The cardiac T-wave peak-to-end interval (Tpe) is thought to reflect dispersion in ventricular repolarisation, with abnormalities in Tpe associated with increased risk of arrhythmia. Extracellular K+ modulates cardiac repolarisation, and since arterial plasma K+ concentration ([K+]) rapidly increases during and declines following exercise, we investigated the relationship between [K+] and Tpe with exercise. METHODS: Serial ECGs (Tpe, Tpe/QT ratio) and [K+] were obtained from 8 healthy, normokalaemic volunteers and 22 patients with end-stage renal disease (ESRD), at rest, during, and after exhaustive exercise. RESULTS: Post-exercise [K+] nadir was 3.1 ± 0.1, 5.0 ± 0.2 and 4.0 ± 0.1 mmol.L-1 (mean ± SEM) for healthy participants and ESRD patients before and after haemodialysis, respectively. In healthy participants, compared to pre-exercise, recovery-induced low [K+] was associated with a prolongation of Tpe (110 ± 8 vs. 87 ± 5 ms, respectively, p = 0.03) and an increase in Tpe/QT ratio (0.28 ± 0.01 vs. 0.23 ± 0.01, respectively, p = 0.01). Analyses of serial data revealed [K+] as a predictor of Tpe in healthy participants (ß = -0.54 ±0.05, p < 0.0001), in ESRD patients (ß = -0.75 ± 0.06, p < 0.0001) and for all data pooled (ß = -0.61 ± 0.04, p < 0.0001). The [K+] was also a predictor of Tpe/QT ratio in healthy participants and ESRD patients. CONCLUSIONS: Tpe and Tpe/QT ratio are predicted by [K+] during exercise. Low [K+] during recovery from exercise was associated with increased Tpe and Tpe/QT, indicating accentuated dispersion of ventricular repolarisation. The findings suggest that variations in [K+] with physical exertion may unmask electrophysiological vulnerabilities to arrhythmia.

Potassium homoeostasis and pathophysiology of hyperkalaemia.

Determination of potassium level is one of the most frequent laboratory tests in clinical medicine. Hyperkalaemia is defined as a potassium level >5.0 mmol/L and is one of the most clinically important electrolyte abnormalities, because it may cause dangerous cardiac arrhythmia and sudden cardiac death. Here, we review methodological challenges in the determination of potassium levels, important clinical aspects of the potassium homoeostasis as well as of the pathophysiology of hyperkalaemia.

CardioScape mapping the cardiovascular funding landscape in Europe.

Aims: The burden of cardiovascular disease is increasing worldwide, which has to be reflected by cardiovascular (CV) research in Europe. CardioScape, a FP7 funded project initiated by the European Society of Cardiology (ESC), identified where CV research is performed, how it is funded and by whom. It could be transformed into an on-line and up-to-date resource of great relevance for researchers, funding bodies and policymakers and could be a role model for mapping CV research funding in Europe and beyond. Methods and results: Relevant funding bodies in 28 European Union (EU) countries were identified by a multistep process involving experts in each country. Projects above a funding threshold of 100 k€ during the period 2010-2012 were included using a standard questionnaire. Results were classified by experts and an adaptive text analysis software to a CV-research taxonomy, integrating existing schemes from ESC journals and congresses. An on-line query portal was set up to allow different users to interrogate the database according to their specific viewpoints. Conclusion: CV-research funding varies strongly between different nations with the EU providing 37% of total available project funding and clear geographical gradients exist. Data allow in depth comparison of funding for different research areas and led to a number of recommendations by the consortium. CardioScape can support CV research by aiding researchers, funding agencies and policy makers in their strategic decisions thus improving research quality if CardioScape strategy and technology becomes the basis of a continuously updated and expanded European wide publicly accessible database.

Facing the challenge of polypharmacy when prescribing for older people with cardiovascular disease. A review by the European Society of Cardiology Working Group on Cardiovascular Pharmacotherapy.

Population ageing has resulted in an increasing number of older people living with chronic diseases (multimorbidity) requiring five or more medications daily (polypharmacy). Ageing produces important changes in the cardiovascular system and represents the most potent single cardiovascular risk factor. Cardiovascular diseases (CVDs) constitute the greatest burden for older people, their caregivers, and healthcare systems. Cardiovascular pharmacotherapy in older people is complex because age-related changes in body composition, organ function, homeostatic mechanisms, and comorbidities modify the pharmacokinetic and pharmacodynamic properties of many commonly used cardiovascular and non-cardiovascular drugs. Additionally, polypharmacy increases the risk of adverse drug reactions and drug interactions, which in turn can lead to increased morbi-mortality and healthcare costs. Unfortunately, evidence of drug efficacy and safety in older people with multimorbidity and polypharmacy is limited because these individuals are frequently underrepresented/excluded from clinical trials. Moreover, clinical guidelines are largely written with a single-disease focus and only occasionally address the issue of coordination of care, when and how to discontinue treatments, if required, or how to prioritize recommendations for patients with multimorbidity and polypharmacy. This review analyses the main challenges confronting healthcare professionals when prescribing in older people with CVD, multimorbidity, and polypharmacy. Our goal is to provide information that can contribute to improving drug prescribing, efficacy, and safety, as well as drug adherence and clinical outcomes.

The role of pharmacogenomics in contemporary cardiovascular therapy: a position statement from the European Society of Cardiology Working Group on Cardiovascular Pharmacotherapy.

There is a strong and ever-growing body of evidence regarding the use of pharmacogenomics to inform cardiovascular pharmacology. However, there is no common position taken by international cardiovascular societies to unite diverse availability, interpretation, and application of such data, nor is there recognition of the challenges of variation in clinical practice between countries within Europe. Aside from the considerable barriers to implementing pharmacogenomic testing and the complexities of clinically actioning results, there are differences in the availability of resources and expertise internationally within Europe. Diverse legal and ethical approaches to genomic testing and clinical therapeutic application also require serious thought. As direct-to-consumer genomic testing becomes more common, it can be anticipated that data may be brought in by patients themselves, which will require critical assessment by the clinical cardiovascular prescriber. In a modern, pluralistic and multi-ethnic Europe, self-identified race/ethnicity may not be concordant with genetically detected ancestry and thus may not accurately convey polymorphism prevalence. Given the broad relevance of pharmacogenomics to areas, such as thrombosis and coagulation, interventional cardiology, heart failure, arrhythmias, clinical trials, and policy/regulatory activity within cardiovascular medicine, as well as to genomic and pharmacology subspecialists, this position statement attempts to address these issues at a wide-ranging level.

Challenges in cardiovascular pharmacogenomics implementation: a viewpoint from the European Society of Cardiology Working Group on Cardiovascular Pharmacotherapy.

Pharmacogenomics promises to advance cardiovascular therapy, but there remain pragmatic barriers to implementation. These are particularly important to explore within Europe, as there are differences in the populations, availability of resources, and expertise, as well as in ethico-legal frameworks. Differences in healthcare delivery across Europe present a challenge, but also opportunities to collaborate on pharmacogenomics implementation. Clinical workforce upskilling is already in progress but will require substantial input. Digital infrastructure and clinical support tools are likely to prove crucial. It is important that widespread implementation serves to narrow rather than widen any existing gaps in health equality between populations. This viewpoint supplements the working group position paper on cardiovascular pharmacogenomics to address these important themes.

The age of randomized clinical trials: three important aspects of randomized clinical trials in cardiovascular pharmacotherapy with examples from lipid, diabetes, and antithrombotic trials.

This review article aims to explain the important issues that data safety monitoring boards (DSMB) face when considering early termination of a trial and is specifically addressed to the needs of clinical and research cardiologists. We give an insight into the overall background and then focus on the three principal reasons for stopping trials, i.e. efficacy, futility, and harm. The statistical essentials are also addressed to familiarize clinicians with the key principles. The topic is further highlighted by numerous examples from lipid trials and antithrombotic trials. This is followed by an overview of regulatory aspects, including an insight into industry-investigator interactions. To conclude, we summarize the key elements that are the basis for a decision to stop a randomized clinical trial (RCT).

Update on management of hypokalaemia and goals for the lower potassium level in patients with cardiovascular disease: a review in collaboration with the European Society of Cardiology Working Group on Cardiovascular Pharmacotherapy.

Hypokalaemia is common in patients with cardiovascular disease. In this review, we emphasize the importance of tight potassium regulation in patients with cardiovascular disease based on findings from observational studies. To enhance the understanding, we also describe the mechanisms of potassium homeostasis maintenance, the most common causes of hypokalaemia and present strategies for monitoring and management of low potassium levels. We propose elevation of potassium in asymptomatic patients with lower normal concentrations and concurrent cardiovascular disease. These proposals are intended to assist clinicians until more evidence is available.