Heart News and Notes

Thirty percent of patients over 65 experience some type of dizziness, such as presyncope (a feeling that they’re about to faint) or vertigo (a sensation of motion when there isn’t any). Past studies suggested that the cause was usually a problem in the vestibular system in the inner ear, which regulates balance.

A recent study in Amsterdam (the Netherlands) evaluated 417 patients, 65 to 95 years old, who complained of persistent dizziness to their family physicians. The patients were diagnosed by a standard set of criteria and their cases were reviewed by an independent panel.

They found that the primary cause was cardiovascular disease in 57 percent of cases, inner ear problems in 14 percent, and psychiatric illness in 10 percent of cases. In most cases there were minor contributing causes, notably drug effects.

Reports at the recent International Society for Heart & Lung Transplantation 2010 Scientific Sessions looked into the history of heart transplant donors. One study of nearly 300 cases found that alcohol use had no effect. Whether the donors were abstainers, moderate users or heavy drinkers, there was no significant difference in short term survival or other complications.

The same author reported a study in which 73 out of 284 donors had previously had CPR (cardiopulmonary resuscitation). There was no significant difference in either 30 day survival or survival in a follow-up averaging 3 years.

Another study reported that survival is poorer if the donor was homeless. Three year mortality was about 50 percent if the donor was homeless, but only 15 percent (five out of ten) if not. Infection was involved in three of those five deaths, but in only one case could it be traced to the donor.

High-density lipoprotein (HDL, the “good cholesterol”) is involved in the process of removing cholesterol from the body. A high level of HDL in the blood usually means that there is less cholesterol going into arterial plaque and therefore less risk of coronary heart disease.

A study reported last month in Arteriosclerosis, Thrombosis, and Vascular Biology found that if the level of CRP (C-reactive protein) was also high, indicating the presence of inflammation, high levels of HDL increased the risk of cardiovascular disease instead of reducing it. The author suggests that the presence of inflammation reverses the function of HDL.

Red meat contains saturated fats and cholesterol, and U.S. dietary guidelines recommend eating less of it. Most studies found that red meat raises heart disease risk but did not distinguish between processed and unprocessed meats.

Last month the journal Circulation carried a report of the first study to look separately at the heart risks of processed and unprocessed red meat. Unprocessed red meat did not increase risk. But eating 50g of processed meat a day - one hot dog or two slices of deli meat - was associated with 42 percent higher risk of coronary artery disease and 19 percent higher risk of diabetes, perhaps due to its salt and nitrate content.

The authors point out that while red meats don’t increase risk, they don’t reduce it either, and we should eat more foods that reduce risk, like fish and plant foods.

Observational studies have shown that eating nuts is associated with reduced risk of heart disease, and packages of certain kinds of nuts are now allowed to claim that evidence suggests (but does not prove) that eating nuts as part of a healthy diet lowers the risk of coronary artery disease.

A study published last month analyzed combined data from 25 small interventional (not observational) trials. Eating nuts lowered LDL (“bad cholesterol”) and total cholesterol, and lowered triglycerides if they were too high to begin with, but had no effect on HDL (“good cholesterol”).

The changes were small compared with the gains from statin drugs, and the studies were too brief to look at end points such as mortality or occurrence of heart disease.

When heart patients in the U.S. have diagnostic catheterization, or are treated with PCI (stenting or angioplasty), a catheter is usually inserted into the femoral artery in the groin and passed up the aorta to the coronary arteries. The standard procedure in many other countries is to insert the catheter in the radial artery at the wrist.

According to a report last month at the Society for Cardiovascular Angiography and Interventions (SCAI) 2010 Scientific Sessions, radial access PCI allows the patient to be discharged the same day (compared with an overnight stay for femoral access PCI). The radial artery is smaller and the risk of bleeding is less (though the smaller artery requires smaller catheters).

A study in Italy, reported later last month at the EuroPCR 2010 meeting, fine-tuned the procedure. It found that PCI through the left wrist is somewhat faster than the right wrist, requiring less exposure to radiation. Left wrist access is less convenient for right-handed workers, but the author suggested moving the arm after opening the artery.