CABG SURGERY vs. PCI IN DIABETICS WITH CORONARY ARTERY DISEASE
Two weeks ago, I reported on a prospective randomized clinical trial that compared coronary artery bypass surgery (CABG) with coronary artery angioplasty and stent placement (percutaneous coronary intervention, or PCI). I noted that, based upon the early results of this clinical study, the jury may still be out regarding which of these two treatment approaches to coronary artery narrowing (stenosis) offers the best risk-to-benefit equation for most patients. Now, a new report, just published in The Lancet, has analyzed the results of 10 different prospective randomized clinical research trials comparing CABG with PCI in the treatment of coronary artery disease affecting multiple coronary arteries.
Altogether, the 10 clinical trials evaluated in this report included 7,812 patient volunteers. After an average of 6 years of clinical follow-up, 575 of the 3,889 (15 percent) patients who underwent CABG died, while 628 of the 3,923 (16 percent) patients who underwent PCI died. Therefore, overall, there was no difference in survival between the two treatment groups within 6 years of coronary artery intervention. However, when the researchers analyzed certain groups of patients undergoing coronary artery interventions, they discovered that diabetic patients appeared to do much better following CABG, rather than PCI. Among the patients with diabetes, survival at 6 years after treatment was 30 percent greater among those diabetic patients who underwent CABG when compared to the diabetic patients who underwent PCI. Similarly, patients over the age of 65 also appeared to do better with CABG. Among patients over the age of 65, survival at 6 years was 18 percent better in the CABG group when compared to the PCI group. For all other patients, however, there was no statistically significant difference in survival at 6 years between those patients who underwent PCI and those who underwent the far more invasive CABG surgery.
Approximately 1.5 million coronary artery interventions (CABG and PCI) are performed in the United States each year, and an estimated 25 percent of these patients have diabetes. So, a significant number of patients undergoing CABG and PCI also have diabetes. The results of this analysis are in keeping with the findings of previous studies showing that the coronary arteries of diabetic patients are more likely than those of non-diabetic patients to narrow again following PCI using balloon angioplasty, with or without the insertion of bare metal stents. However, recent advances in the development of drug-eluting stents and newer anti-clotting drugs have shown considerable promise in diabetic patients undergoing PCI with stent placement (among the 10 clinical studies included in this analysis, all patients receiving PCI underwent balloon angioplasty with or without bare metal stent placement, and no drug-eluting stents were utilized). Fortunately, there are several ongoing prospective randomized clinical research trials that will, hopefully, shed more light on the coronary artery restenosis rate in diabetic patients using the newer drug-eluting stents and glycoprotein IIb/IIIa inhibiting drugs. Unfortunately, we will have to await the publication of the findings of these ongoing clinical trials before PCI can truly be declared equal to CABG in diabetic patients. Therefore, at the present time, patients with diabetes, and especially diabetic patients with more advanced multi-vessel coronary artery disease (as well as diabetic patients with abnormal function of the primary pumping chamber of the heart, the left ventricle) are more likely to be advised to undergo CABG instead of PCI; although an increasing number of favorable-risk diabetic patients with complicated coronary artery disease are now being offered PCI with the newer drug-eluting stents and anti-clotting drugs.
As I concluded 2 weeks ago, the ongoing improvements in minimally-invasive PCI have definitely narrowed the gap in clinical outcomes between PCI and CABG over the past 10 to 15 years, and it is no longer clear that CABG (which is much more invasive than PCI, and more likely to cause stroke than PCI) offers any significant survival benefit over PCI, although CABG does appear to still provide a longer duration of improvement in blood flow to the heart than PCI (however, PCI can often be repeated, when necessary), and CABG may still be more appropriate for patients with more advanced cases of multi-vessel coronary artery disease.
Stay tuned, as I will continue to track the results of this very important area of clinical research, and I will keep readers updated as the ongoing “CABG vs. PCI” clinical research trials begin to report their results.
SWEETENED BEVERAGES AND CORONARY ARTERY DISEASE
We all know that we are in the midst of an epidemic of obesity in this country. Not only are adults heavier than ever before, but the incidence of overweight and obesity among our children has skyrocketed, and with this rising incidence of childhood and adolescent obesity, the incidence of other obesity-related diseases has also increased.
Multiple prior studies have linked the regular consumption of sweetened sodas and juices with excessive weight gain in both children and adults, and with a rising incidence of diabetes among both the young and old. Now, a new Harvard University clinical study of female nurses, just published in the American Journal of Clinical Nutrition, suggests that the regular consumption of sugary beverages may also significantly increase the risk of coronary artery disease as well.
In this prospective clinical study, nearly 90,000 women (ages 34 to 59) participating in the enormous Nurses’ Health Study were followed from 1980 through 2004. None of these women had any clinical signs or history of heart disease, stroke, or diabetes when they entered into this clinical research study. All of these women completed repeated and detailed dietary surveys during the 24-year follow-up period in this study.
Among these 88,520 female nurses, 3,105 developed coronary artery disease during the 24-year follow-up period. When the researchers analyzed intake levels of sugary drinks, they discovered that the increasing consumption of sweetened beverages was associated with an increased risk of coronary artery disease. When compared to women who consumed less than one sugary drink per month, consuming one sugary drink per day increased the relative risk of coronary artery disease by 23 percent, while the consumption of 2 or more sugary drinks per day increased the relative risk of developing coronary artery disease by 35 percent. When the researchers then accounted for differences in body weight, overall dietary caloric intake, and the presence or absence of diabetes among these women volunteers, the risk of coronary artery disease associated with the consumption of sweetened beverages was diminished somewhat, but still remained significant. At the same time, artificially sweetened beverages were not associated, at all, with coronary artery disease risk.
In summary, this enormous and ongoing clinical research trial, with nearly 90,000 women participating, found that, over a 24-year observation period, increasing levels of sugary drink consumption were associated with increasing levels of risk for coronary artery disease. At the same time, beverages that were sweetened with non-caloric artificial sweeteners appeared to carry no associated risk of coronary artery disease. So, next time you reach for a bottle of sugar- or fructose-sweetened juice or soda pop, give it another thought before you pop the top!
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
is an oncologic surgeon, a professor
of surgery, a widely published author, and the
Physician-in-Chief for Surgical
Oncology at the Kaiser Permanente healthcare system in Orange County,
Robert A. Wascher, MD, FACS.
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