วันพุธที่ 21 เมษายน พ.ศ. 2553

Outcomes Of Patients Dismissed From The Hospital With Noncardiac Chest Pain

The growing number of Americans with cardiovascular disease has caused a heightened sensitivity in the evaluation of chest pain. In a study published in the April issue of Mayo Clinic Proceedings researchers reported that patients dismissed from the hospital with noncardiac chest pain continue to experience cardiac events, which may highlight a need for more aggressive cardiovascular risk factor management in this population.

Noncardiac chest pain is defined as a substernal chest pain in the absence of significant epicardial coronary artery stenoses. Noncardiac chest pain is attributed to a variety of disorders, including gastroesophageal reflux disease (GERD ) and esophageal hypersensitivity, panic attack, musculoskeletal pain and microvascular disease (cardiac syndrome).

Researchers identified 320 patients with a diagnosis of noncardiac chest pain to determine the frequency of gastrointestinal (GI) consultations and testing, and to identify the frequency of cardiac death. All patients had a hospital admission diagnosis of unstable angina, subsequent inpatient cardiac evaluation and a dismissal diagnosis of noncardiac chest pain.

The first aim of this study was to determine the frequency of GI consultation and testing. After the initial diagnosis of noncardiac chest pain, 49 percent of patients were re-evaluated in the Emergency Department and 42 percent underwent repeated cardiology evaluations; only 15 percent had GI consultations. In regards to GI testing, 38 percent underwent esophagogastroduodenoscopy, 4 percent underwent manometry (13 tests), and 2 percent had pH probes (six probes).

"Patients in this study received few GI consultations and underwent even fewer GI tests. Further study is needed to determine whether patients with noncardiac chest pain would benefit from more frequent GI consultations and more diverse use of GI testing modalities," says Michael Leise, M.D., co-investigator in the Department of Gastroenterology , Mayo Clinic.

The study's second aim was to report on overall mortality, specifically, cardiac death in patients with noncardiac chest pain. Although prognosis for patients with noncardiac chest pain is thought to be favorable, researchers found that previous data to support this view were limited. The total sample in this study did not display a significantly increased frequency of death compared with what would be expected in this community, but a substantial number of cardiac deaths occurred in an noncardiac chest pain population. "We speculate that cardiac death in patients with noncardiac chest pain may relate to overlapping risk factors for GERD and coronary artery disease, including obesity, obstructive sleep apnea, diabetes mellitus and smoking," says Dr. Leise. Until cardiac death in this population is better understood, it is important to screen for cardiac risk factors such as hypertension, hypercholesterolemia, and diabetes mellitus and aggressively manage these comorbid conditions.

วันเสาร์ที่ 10 เมษายน พ.ศ. 2553

Stomach-Friendly Coffee

With stomach irritation preventing almost 2 out of every 10 people from enjoying coffee, scientists reported discovery of several substances that may be among the culprits responsible for brewing up heartburn and stomach pain in every cup.

Their report, presented here at the 239th National Meeting of the American Chemical Society, included the counter-intuitive finding that espresso, French roast, and other dark-roasted coffee may be easier on the tummy because these roasts contain a substance that tells the stomach to reduce production of acid.

The research could lead to a new generation of stomach-friendly brews with the rich taste and aroma of regular coffee, the scientists said.

"This discovery is going to help a lot of people who suffer from coffee sensitivity," say Veronika Somoza, Ph.D. from the University of Vienna in Austria, and Thomas Hofmann, Ph.D. from the Technische Universität München in Germany, who conducted the study. "As coffee-lovers, we're very excited about this research."

Estimates suggest that up to 40 million people in the United States alone either avoid coffee, or cannot drink as much as they like, due to stomach irritation. Doctors think that chemicals in coffee cause the stomach to overproduce acid. Some coffee drinkers take antacids or drink decaffeinated coffee in an effort to reduce this effect. Others turn to a small but growing number of specialty coffee brews marketed as stomach friendly.

"The problem is that studies have not verified the stomach irritating potential of coffee or its components, until now," Somoza said. "Manufacturers currently make 'stomach friendly' coffees by processing raw coffee beans with steam or solvents intended to reduce levels of the irritants. But their effectiveness is unclear."

The processes used to produce stomach-friendly coffee also can reduce the amount of healthful substances in the coffee, including some that scientists have linked to benefits such as protection against diabetes and heart disease, Somoza said. In addition, the processing can affect the robust taste and smell of coffee.

To study the irritants in coffee, the scientists exposed cultures of human stomach cells to a variety of different coffee preparations, including regular, dark-roast, mild, decaffeinated, and stomach-friendly. They identified several substances that appeared to trigger chemical changes associated with increased acid production. These substances include caffeine, catechols, and other ingredients.

"Our data show, for the first time, that caffeine, catechols and N-alkanoly-5-hydroxytryptamides are those coffee components that stimulate molecular mechanisms of stomach acid secretion in human stomach cells," Somoza said. Most of them are indeed removed by steam or solvent treatment of the raw coffee bean. We found out there's no single, key irritant. It is a mixture of compounds that seem to cause the irritant effect of coffee."

The scientists unexpectedly found that one of the coffee components, N-methylpyridium (NMP), seems to block the ability of the stomach cells to produce hydrochloric acid and could provide a way to reduce or avoid stomach irritation. Since NMP is generated only upon roasting and not found in raw coffee beans, darker-roasted coffees contain higher amounts of this stomach-friendly coffee ingredient. Dark- roasted coffee can potentially contain up to twice as much of the ingredient as light-roasted coffees, but its levels can vary widely depending on the variety of coffee bean and the roasting method, Somoza noted.

"Since NMP is generated upon roasting, dark-roast coffees contain high amounts of this stomach friendly coffee ingredient," Hofmann and Somoza said. "Now, there is hope for a good morning start with a freshly brewed cup of optimized stomach friendly coffee."

The scientists are testing different varieties of raw coffee beans and different roasting methods in an effort to boost NMP levels to make a better stomach-friendly coffee. They hope to test the new brew in human volunteers later in 2010.