Health
Report:
Thrombus (Clot) Aspiration from Coronary Arteries
Intensive Management of Diabetes & Death
Possible Cure for Down's Syndrome
"A critical weekly review of important new research findings for health-conscious readers..."
Thrombus (Clot) Aspiration from Coronary Arteries
Intensive Management of Diabetes & Death
Possible Cure for Down's Syndrome
"A critical weekly review of important new research findings for health-conscious readers..."
By, Robert A. Wascher, MD, FACS
Last Updated: 2/10/2008
The
information in this column is intended for informational
purposes only, and does not constitute medical advice or
recommendations by the author. Please consult with your
physician
before making any lifestyle or medication changes, or if you have any
other concerns regarding your health.
THROMBUS (CLOT) ASPIRATION FROM THE CORONARY ARTERIES
Increasingly, patients with blocked arteries in their hearts are undergoing percutaneous transluminal coronary angioplasty, or PTCA, instead of the more invasive coronary artery bypass graft (CABG) surgery that was previously the only option before PTCA was developed. When the coronary arteries become severely narrowed or obstructed with plaque and tiny blood clots, precious oxygen can no longer be delivered to the heart’s muscle, resulting in severe chest pain (angina) or heart attack (myocardial infarction). In many cases, cardiologists can thread a special balloon-tipped catheter into a vein in the groin or arm, and use this balloon catheter to open up narrowed coronary arteries. After the artery is reopened, a tiny expandable metal tube (coronary artery stent) is then usually placed across the narrowed area of the artery in order to prevent rapid re-narrowing of the same coronary artery again. However, in many cases, when the balloon is expanded within the narrowed coronary artery, little chunks of fatty plaque and clotted blood (thrombus) are dislodged. These little bits of solid material can then flow downstream (embolization) within the coronary arteries, causing additional blockages of the smaller downstream coronary artery branches. In a landmark clinical research trial, just published in the New England Journal of Medicine, researchers added an additional procedure to PTCA. In addition to using the balloon to re-expand narrowed coronary arteries, and placing stents within the re-expanded arteries, researchers actually used specialized, tiny catheters to suck out the debris that broke away from the coronary arteries undergoing angioplasty.
A total of 1,071 volunteers undergoing PTCA for critical narrowing of their coronary arteries were randomized to either conventional PTCA or PTCA plus “thrombus aspiration.” (Smaller previous studies have suggested that thrombus aspiration, when added to PTCA, might improve restoration of blood flow to compromised heart muscle following PTCA.) This relatively large study appears to have confirmed the clinically beneficial effects of routine thrombus aspiration. Compared to patients who received standard PTCA therapy alone, the patients who additionally underwent thrombus aspiration were significantly less likely to have angiographic signs of continued poor blood flow to the affected heart muscle (26% vs. 17%, respectively) and abnormal EKG changes following PTCA (57% vs. 44%, respectively). Even more important was the finding that 30-day survival was significantly better, and complications were significantly fewer, in patients who achieved the greatest restoration of cardiac blood flow to the heart after PTCA. Death within 30 days of PTCA occurred in 5% of patients with no significant restoration of blood flow to their hearts, but only 1% of patients died during the same interval with when PTCA resulted in substantial restoration of cardiac blood flow.
This well-designed and well-executed prospective, randomized clinical research trial strongly suggests, as prior smaller studies have, that a significant number of patients undergoing PTCA could benefit from the addition of thrombus aspiration as a routine part of the minimally invasive management of acute heart attacks and severe angina. The study’s authors believe that the majority of patients undergoing PTCA are candidates for thrombus aspiration, suggesting that thrombus aspiration should now probably become “standard of care” for patients undergoing PTCA for blocked or severely narrowed coronary arteries.
INTENSIVE MANAGEMENT OF DIABETES & DEATH
Much of the diabetes research world has been shaken by the preliminary findings of a recently aborted clinical research trial that found a greater risk of death (mostly due to heart attacks) in diabetic patients who underwent ultra-intensive management of their blood sugar levels. This large national diabetes study, which was sponsored bythe National Heart, Lung and Blood Institute, and which was recently andprematurely halted, emphasized aggressive lowering of blood sugar levels, which virtually all diabetes researchers expected would result in fewer deaths due to known diabetes-related complications, including heart attacks. The completely unexpected finding that the patients who were most aggressively treated to reduce elevated blood sugar levels actually had a higher likelihood of dying than patients undergoing less rigorous blood glucose control has rocked the diabetes research community. Although an explanation for this counterintuitive result has not yet been found, this finding has challenged seminal research findings and decades-old assumptions that stringently reducing elevated blood sugar levels should improve survival in diabetics (some researchers have speculated that the multiple drugs used to achieve improved blood glucose levels in this controversial research study may have caused interactions that caused the unexpected deaths, although this is little more than an educated guess at this point). Now, yet another new diabetes clinical research study, also published in the New England Journal of Medicine, has just reported its results, and these results are more in keeping with what one would expect from rigid, aggressive control of blood sugar levels in diabetics.
This relatively small study, involving only 160 diabetic patients, all of whom had laboratory evidence of early kidney damage from their diabetes, were included in this research study. The patients were randomly divided into two groups. The “control group” received standard medical therapy for their diabetes and diabetes-related conditions. The “experimental group” received intensive therapy that included aggressive reduction of their blood sugar levels, heart-protective high blood pressure medications (renin-angiotensin inhibitors), aspirin, and cholesterol-lowering drugs. The average duration of treatment in these two groups of patients was nearly 8 years, and they were then subsequently followed for an average of almost 6 additional years.
The results of this long-term study were strikingly different from the previous study mentioned above. Intensive management of diabetic patients, in this study, was associated with a whopping 46% reduction in the risk of death from any cause, and a 57% reduction in the risk of death due, specifically, to cardiovascular causes (including heart attacks). Similarly, progression of kidney disease was significantly lower in the group receiving intensive management, when compared to the control group receiving only standard medical treatment. Finally, the risk of diabetes-associated retinal disease, which is the most common cause of blindness in our society, was reduced by 55% among the intensively managed patients.
The results of this study are exactly what one would have expected from a more rigorous management of diabetes and diabetes-associated illnesses. It will now fall to the diabetes experts to look at these two pivotal studies, and previous studies, in an effort to explain the surprising and disturbing results of the recently aborted the National Heart, Lung and Blood Institute study. Despite the controversial findings of the National Heart, Lung and Blood Institute study, my recommendation to all patients with diabetes is that you should notmake any changes in your current diabetes treatment plan without first discussing your concerns with your physician. For now, anyway, most diabetes experts are not recommending any major changes in our current approach to managing diabetes.
CURE FOR DOWN’S SYNDROME?
Down’s syndrome, or trisomy 21, results when an extra copy of chromosome #21 is inherited, leaving affected individuals with three copies of this gene instead of the normal two copies. Down’s syndrome occurs in approximately 1 out of every 800 births, resulting in approximately 5,000 new cases in the United States each year, and becomes more common with increasing maternal age at the time of conception. Generally, in addition to the characteristic physical appearance associated with this genetic abnormality, mild-to-severe mental retardation, congenital heart disease, Alzheimer’s disease, hearing problems, and a predisposition to certain cancers, among other conditions, are strongly associated with Down’s syndrome.
New research recently presented at the annual Society for Maternal –Fetal Medicine meeting, and reported by Medpage Today, suggests the possibility that the severe learning deficits associated with Down’s syndrome might actually be reversible, at least in mice bred with three copies of Chromosome #21.
This study, which was sponsored by the National Institutes of Health, treated a group of trisomy 21 mice with the “neuron-protective” proteins NAP and SAL, and then subjected these mice, as well as untreated trisomy 21 mice and mice without trisomy 21, to standardized rodent learning tests. Following 9 days of treatment with NAP and SAL, trisomy 21 mice were then subjected to a water maze learning tests, along with the other two groups of mice. Incredibly, the NAP- and SAL-treated trisomy 21 mice were able to learn how to navigate the water maze as easily as the mice without trisomy 21, while the trisomy 21 mice that did not receive the neuron-protective peptides learned to navigate the maze much more slowly than either of the other two groups of mice.
While, as I have emphasized in previous columns, treatments that work in mice and rats do not always have the same effects in humans, this research is, nonetheless, dramatic, and offers at least the possibility that some—or perhaps all—of the severe cognitive disabilities associated with Down’s syndrome might actually be reversible, something never thought to be possible before.
It is estimated that 90-95% of couples who learn that their unborn child has Down’s syndrome, though prenatal testing, choose not to continue with the pregnancy. Perhaps, if the results of this trisomy 21 mouse research study can be confirmed in humans with Down’s syndrome, both those living with Down’s syndrome and fetuses with trisomy 21 might actually someday have the heretofore impossible opportunity of living without the serious and often disabling cognitive deficits caused by this genetic illness.
Disclaimer: As always, my advice to readers is to seek the advice of your physician before making any significant changes in medications, diet, or level of physical activity.
Dr. Wascher is an oncologic surgeon, professor of surgery, a widely published author, and the Director of the Division of Surgical Oncology at Newark Beth Israel Medical Center
http://www.sbhcs.com/hospitals/newark_beth_israel/mservices/oncology/surgical.html
Send your feedback to Dr. Wascher at
rwascher@doctorwascher.net
Copyright 2008. Robert A. Wascher, MD, FACS. All rights reserved.
Dr. Wascher's Archives:
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1-12-2008: Statins,
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