Update From the Medical Journals: April 2011
April 29, 2011
By Mary Pickett, M.D.
What's the latest news in the medical journals this month? Find out what your doctor is reading.
Your triglyceride level the blood fat that is measured along with cholesterol doesn't get as much attention as the LDL and HDL cholesterols. But a high triglyceride level can contribute to your heart disease risk. The American Heart Association (AHA) has revised its recommendation for how low this number needs to be for ideal heart health. The new guideline says people should aim for a level below 100mg/dL. The recommendation, along with a review of research, was published April 18 in the journal Circulation.
About one third of Americans have triglyceride levels that are above 150 milligrams per deciliter (mg/dL). The new guideline does not recommend medicines to help you lower your triglycerides except in severe cases. Instead, it advises lifestyle changes. We know from past research that diet and exercise can lower triglycerides by 50% or more.
To lower your triglyceride level:
Heart attacks are common during and after any type of surgery. Post-surgery heart attacks are more common because the body shifts its balance of blood clotting proteins in order to heal wounds. The body's reaction to stress and anesthesia may contribute to the risk for heart attack, too. Some patients have a "silent" heart attack where they don't notice any symptoms.
Researchers studied the records for 8,351 patients in 23 countries to see how often heart attacks occur after surgery and if there are ways to identify which patients are at risk. The Annals of Internal Medicine published the results April 19.
Five percent of patients who had surgery had a heart attack as a complication of surgery; 74% of the heart attacks occurred in the first 48 hours after surgery. Sixty-five percent of patients had a "silent" heart attack. Silent heart attacks did as much heart muscle damage as heart attacks with symptoms.
The researchers monitored patients for heart attacks after surgery using blood tests. In the first days after surgery, researchers measured a heart protein named troponin. The level of this protein goes up in the first day of a heart attack. Troponin levels are routinely checked when a person is having chest-pain symptoms. However, it is not the standard to check this test in a person who is recovering from surgery if there are no chest-pain symptoms. The researchers suggest that it should be standard practice to check patients' troponin levels one or more times in the first days after surgery. This would allow better treatment for silent heart attacks. It is a worthwhile suggestion.
Some people have high blood pressure readings only when they are in a doctor's office. This is called "white coat" hypertension. It is very common. Most people think being nervous causes white coat hypertension.
Findings from a new study show that more than one third of 8,295 patients being treated for resistant hypertension actually had white coat hypertension. (Resistant hypertension means that a person has high blood pressure readings in the doctor's office despite being on three blood pressure medications.) The study first appeared online March 28. It will be published in the May issue of Hypertension: Journal of the American Heart Association.
Researchers had people check their blood pressure at home every 20 minutes for 24 hours. This is called "ambulatory blood pressure monitoring." Thirty-seven percent had normal readings.
Doctors disagree about whether white coat hypertension should be treated with medicines. Studies don't always show that treatment for white coat hypertension improves health. People with white coat hypertension have a lower risk for heart disease and kidney damage from high blood pressure compared with people who have true resistant hypertension. It may be worthwhile to use ambulatory blood pressure monitoring more often to better advise patients about their heart risk.
Mary Pickett, M.D. is an Associate professor at Oregon Health & Science University where she is a primary care doctor for adults. She supervises and educates residents in the field of Internal Medicine, for outpatient and hospital care. She is a Lecturer for Harvard Medical School and a Senior Medical Editor for Harvard Health Publications.