Flushing: Preventing Heart Problems While Keeping a Cool Head

The reason for this is that treatment with nicotinic acid has an unpleasant but harmless side-effect: the drug makes patients turn quite red in the face. Scientists at the Max Planck Institute for Heart and Lung Research have now discovered the mechanism behind this effect, which is known as flushing. This will enable the development of flush inhibitors.

The treatment of lipid metabolic disorders is one of the important measures used in the prevention of cardio-vascular disease. Cholesterol is the key molecule here and LDL cholesterol is the type of cholesterol most widely discussed in this context. This "bad" cholesterol is one of the most important risk factors for the emergence of cardio-vascular diseases. The higher the blood-plasma concentration of LDL cholesterol, the higher an individual's risk of suffering cardiac arrest or peripheral vascular disease. The opposite applies to the "good" HDL cholesterol: the higher the level of HDL cholesterol, the lower the risk of contracting these diseases. For this reason, the strategy of increasing HDL plasma concentration through medication has become more prevalent of late.

"The main problem with treatment using nicotinic acid – which has nothing to do with the nicotine in tobacco, by the way – is flushing," says Stefan Offermanns, Director of the Department of Pharmacology at the Max Planck Institute. "Just a short time after taking nicotinic acid, the patient experiences strong flushing of the face and upper body for up to one and a half hours. This is caused by the dilation of blood vessels in the skin." The flushing symptoms are completely harmless. However, patients often abandon the treatment on account of these symptoms.

Offermanns and his colleagues had already succeeded in identifying a specific receptor for nicotinic acid that conveys the desired effects of nicotinic acid. Tests on mice showed, however, that the receptor is also responsible for the nicotinic-acid-induced flushing reaction. "We have now succeeded in demonstrating that the receptor exists both in the main cells of the top layer of the skin or epidermis, which are called keratinocytes, and the immune cells, known as Langerhans cells, also found in the epidermis," reports Offermanns.

By studying mouse strains in which the receptor in either the Langerhans cells or keratinocytes is blocked, the researchers were able to show that the first phase of the flushing reaction is triggered by the activation of Langerhans cells. In contrast, the second and longer phase results from the activation of the keratinocytes. In both phases, different prostaglandins are formed. "The flushing phenomenon can be prevented by inhibiting prostaglandin formation or blocking the prostaglandin receptors in the skin, while the desired effects of the nicotinic acid on lipid metabolism remain unaffected."

Source:MEDICA.de

Molecular Imaging: Identification of High-risk Patients

A study finds that molecular imaging—a non-invasive imaging procedure—can identify high-risk patients with potentially life-threatening cardiovascular conditions and help physicians determine which patients are best suited for implantable cardioverter defibrillator (ICD) therapy.

"If the molecular imaging techniques are used for appropriate selection of ICD candidates, not only overuse but also underuse of ICD could be avoided and the assessment may be shown to be more cost-effective," said Doctor Kimio Nishisato, a physician in the cardiology division of Muroram City General Hospital, Muroram, Japan, and corresponding author for the study.

According to researchers from Sapporo University, Sapporo, Japan, the study shows that molecular imaging can play an important role in diagnosing and guiding the treatment strategy for arrhythmia, coronary artery disease and heart failure.

"This research holds significant potential for the detection, diagnosis and treatment of many common cardiovascular conditions," said Doctor Tomoaki Nakata, an associate professor at the Sapporo Medical University. "With molecular imaging, physicians can improve patient care by pinpointing the precise location of the disease in order to eliminate the need for invasive medical devices and unnecessary surgical techniques." Nakata adds that molecular imaging can also reduce unnecessary medical costs by better targeting treatment for each individual patient.

In this study, researchers hypothesized that both the impairment of myocardial perfusion and/or cell viability and cardiac sympathetic innervations are responsible for heart arrhythmia and sudden cardiac death. However, there was no established reliable method, including a molecular imaging technique which is highly objective, reproducible and quantitative.

The researchers investigated prognostic implications of cardiac pre-synaptic sympathetic function quantified by cardiac MIBG activity and myocyte damage or viability quantified by cardiac tetrofosmin activity in patients treated with prophylactic use of ICD, by correlating with lethal arrhythmic events which would have been documented during a prospective follow-up. Based on these aspects, the study is the first to show the efficacies of the method for more accurate identification of patients at greater risk of lethal arrhythmias and sudden cardiac death (SCD).

"Sudden cardiac death due to lethal arrhythmia represents an important health care problem in many developed countries," said Doctor Ichiro Matsunari, director of the clinical research department at the Medical & Pharmacological Research Center Foundation, Hakui, Japan. "While implantable cardioverter defibrillator therapy is an effective option over anti-arrhythmic medications to prevent SCD, the balance of clinical benefits, efficacy and risks is still a matter of discussion."

Source:MEDICA.de