Study Supports Effectiveness of Laser Therapy on Heart Blockage
Punching little-bitty holes in the heart with a laser is an effective way to fight blocked arteries in patients who do not respond to other therapies, according to a major new study.
Previous studies of the technique, called transmyocardial revascularization, or TMR, suggested that it was beneficial, but critics charged that those studies had serious flaws. The new study, named ATLANTIC (Angina Treatments--Lasers and Normal Therapies in Comparison), was designed to overcome those flaws.
The study enrolled 337 patients at 16 U.S. medical centers. Most were not eligible for angioplasty or bypass surgery because the blockages in their arteries were too widespread. All suffered severe chest pains when exercising or during everyday activities. Half received TMR and half continued on conventional drug therapy.
In TMR, a small incision in the chest is made to expose the heart. A laser is then used to punch microscopic holes in the heart in regions that are not getting enough blood flow. Scientists do not agree how the procedure works. The original idea was that the holes would allow blood to flow into the heart, but some researchers have suggested that the punctures stimulate the formation of new blood vessels.
The ATLANTIC team reported in Saturday’s Lancet that, after one year, the patients who received TMR had an average 65-second increase in exercise tolerance on a treadmill test, while those on medical therapy had a 45-second decrease. The TMR patients also reported significant improvements in their quality of life.
The Culprit Behind Chronic Sinusitis
As many as 37 million Americans suffer from chronic sinusitis, a persistent inflammation of the membranes of the nose and sinus cavity. Common symptoms include a runny nose, nasal congestion, headaches and loss of the sense of smell. Sometimes it leads to the growth of small polyps, which must be removed surgically.
Most short-term sinusitis, lasting less than three months, is caused by bacterial infections, but the cause of the chronic form has been a mystery. New results from a team at the Mayo Clinic in Rochester, Minn., however, indicate that it is probably caused by fungal infections. The findings suggest that it should be possible to cure chronic sinusitis with antifungal medications.
The researchers studied 210 patients with chronic sinusitis, using new techniques for collecting and testing mucus from the nose. They reported in the September issue of the Mayo Clinic Proceedings that they found fungus in 96% of the patients. At least 40 kinds of fungi were found, with an average of 2.7 kinds in each patient. Related studies also showed that the sinusitis symptoms were caused by an immune reaction to the fungi, not by an allergic reaction.
Lessening the Side Effects of Radiation
Research in mice suggests that deactivating a gene that normally protects against cancer may help minimize the side effects of radiation therapy for the disease. The gene is called p53, and its normal function is to tell the cell carrying it to die when it has been severely damaged, a process called apoptosis. In about 60% of cancers, the p53 gene is damaged, allowing cells with other genetic damage to continue proliferating indefinitely--the defining characteristic of cancer.
When radiation is used to kill cancer cells, it also damages nearby healthy cells, especially in the blood-forming system and the intestinal tract. The good p53 gene in these cells triggers apoptosis, and the widespread cell death causes nausea, diarrhea and other problems.
Geneticist Andrei Gudkov of the University of Illinois at Chicago reasoned that blocking the effects of p53 might prevent those side effects. After screening more than 10,000 chemicals, he and his colleagues found one that blocked the activity of p53 without adverse effects. They called it pifithrin.
Gudkov’s team reported in Friday’s Science that an injection of pifithrin would protect mice from a radiation dose that normally killed 60% of the animals. Some mice receiving it survived even higher doses of radiation. Mice receiving the drug also lost less weight than the survivors who did not receive the drug. Further animal studies are necessary before pifithrin can be tested in humans, however.
Tonsil, Adenoid Removal Questioned
Surgical removal of the adenoids, tonsils or both is not an effective treatment for recurrent ear infections, even though that is the most common reason the surgery is performed, according to a new study from the Children’s Hospital of Pittsburgh. An estimated 420,000 children younger than 15 undergo such surgery every year, making it the most commonly performed procedure in children.
Dr. Jack L. Paradise and his colleagues enrolled 461 children between the ages of 3 and 15 who had recurrent ear infections. The children who also had recurrent throat infections received either an adenotonsillectomy (removal of both adenoids and tonsils) or no surgical treatment, while those with ear infections only received either an adenoidectomy, a tonsillectomy or no treatment. One year later, the team reported in Wednesday’s Journal of the American Medical Society, those children who received no treatment had an average of 2.1 ear infections, while those undergoing any type of surgery were only slightly better, with an average of 1.4 infections. The difference disappeared after the first year.
Drug Cuts Instances of Blood Clots
Patients hospitalized for surgery are at risk of developing blood clots in their veins that can lead to strokes.
A new study suggests that those hospitalized for other reasons are also at risk, and that the risk can be reduced by administering a new blood-thinning agent called enoxaparin.
An international team headed by Dr. Meyer-Michel Samama of Ho^tel Dieu in Paris enrolled 1,102 patients who were bedridden and suffering from heart failure, acute respiratory failure or one of several other severe conditions. Two-thirds received enoxaparin in one of two doses, while the remainder received a placebo.
The team reported in Thursday’s New England Journal of Medicine that 14.9% of those receiving the placebo suffered a blood clot, compared to 5.5% of those receiving the high dose of the drug--a 63% reduction in risk.
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Medical writer Thomas H. Maugh II can be reached at thomas.maugh@latimes.com.
