Paclitaxel-Eluting Stents Come out Winners Again
Paclitaxel-eluting stents in both a slow-release and moderate-release formulation reduced in-stent neointimal formation and restenosis and improved the 12-month outcomes of subjects with single, newly diagnosed lesions, when compared to those with similar lesions who received bare-metal stents, according to a report that went online in Circulation this week (Circulation. 2003;108:r36–r42OpenUrlCrossRef). This report of TAXUS II was led by Antonio Colombo, MD, of Ospedale San Raffaele in Milan, Italy.
Investigators from 38 medical centers enrolled 536 patients in a randomized, double-blind trial that evaluated the slow-release and moderate-release paclitaxel-eluting stents (TAXUS) against bare-metal stents. The primary end point was the percent in-stent volume obstruction measured by intravascular ultrasound. The trial also evaluated 6-month angiographically proven stenosis and the 6- and 12-month incidence of major cardiac events, including death from heart-related causes, myocardial infarction, and the performance of repeat revascularization.
After 6 months, the researchers found significantly less in-stent obstruction in the patients with the TAXUS stents than in the bare-stented controls. They also found less angiographically proven restenosis in the TAXUS stent groups. The incidence of major adverse heart-related events was much less in both TAXUS groups than in the controls. For the most part, the difference occurred because the TAXUS stent groups required fewer repeat revascularizations.
The researchers wrote: “TAXUS II suggests that TAXUS-SR is the minimum effective paclitaxel formulation for standard-risk, de novo lesions. The slow- and moderate-release formulations studied in TAXUS II are loaded with the same dose density of paclitaxel (85 g per 15-mm stent). The major distinction between the 2 formulations is the 8-fold greater amount of drug released from the TAXUS-MR stent over 10 days, even though the total loaded dose is the same. This pharmacological difference did not translate into differences in IVUS [intravascular ultrasound], angiographic, or clinical outcomes, given that the study was not designed to detect differences between formulations. The similar efficacy profiles of the 2 formulations may indicate that the dosing threshold to interrupt the restenotic cascade in low-risk lesions had been reached with the slow-release formulation.”
Exercise for Vasodilation
Moderate aerobic exercise increases endothelium-dependent vasodilation in healthy young people, according to Japanese researchers in this week’s issue of the journal Circulation (Circulation. 2003;108:530–535OpenUrl).
In a study led by researchers from the Hiroshima University Graduate School of Biomedical Sciences, the response of blood flow in the forearm to acetylcholine, an endothelium-dependent vasodilator, and isosorbide dinitrate, an endothelium-independent vasodilator, was measured before and after different intensities of exercise performed by 26 healthy young men. The men rode bicycle ergometer for 30 minutes 5 to 7 times each week for 12 weeks.
The researchers found that 12 weeks of moderate exercise (measured as 50% Vo2max, or the maximum amount of oxygen a person can take in and use) significantly increased vasodilation induced by acetylcholine. However, the augmentation was induced by either high-intensity or low-intensity exercise. Exercise had no effect on isosorbide dinitrate–induced vasodilation. When a chemical that inhibited nitric oxide was given to the subjects, the moderate exercise effect on acetylcholine-induced vasodilation disappeared.
The researchers found that high-intensity exercise (100% Vo2max) increased the levels of chemicals that indicate high oxidative stress, whereas moderate exercise tended to decrease the indicators.
PLAC Test Gets FDA Nod
The PLAC test that measures the levels of lipoprotein-associated phospholipase A2 (Lp-PLA2), an enzyme shown to be an independent risk factor for heart disease, has received marketing clearance by the US Food and Drug Administration.
Diadexus, the company that makes the test, received word that it had received clearance on July 18, 2003. The test is believed to identify some of the individuals who are at risk for heart attack but have been diagnosed with none of the usual risk factors. Studies have demonstrated that high levels of the enzyme correlate with a high risk of heart attack.
New Retirees Less Likely to Receive Supplemental Health or Drug Benefits From Employers Than Their Elders
A study published online by the journal Health Affairs at www.healthaffairs.org/WebExclusives/Stuart_Web_Excl_072303. htm shows that between 1996 and 2000, the percentage of Medicare enrollees aged 65 to 69 who received employee-sponsored health benefits dropped from 46% to 39%. The percentage of those in the same group who received drug benefits dropped from 40% in 1996 to 35% in the year 2000.
“All indications are that employer-sponsored benefits available to new retirees are going to erode,” says lead study author Bruce Start, PhD, Professor and Director of the Peter Lamy Center at the University of Maryland School of Pharmacy. “This is especially alarming since any new prescription drug benefit sponsored by Congress won’t be available for several more years, and even those proposed benefits are likely to be far less than the benefits most retirees already receive.”
Coverage for older retirees has remained fairly stable during the same time, but people who are now facing retirement will likely find themselves without the supplemental coverage. The report notes that men were more likely to lose benefits than women. In fact, they said, the erosion in coverage in this group would have been even greater had not men sought coverage under their wives’ employee-sponsored policies. They also note that prescription drug benefits have been singled out as a rapidly rising cost and are likely to be cut even more severely in the future.
“The future of employer-sponsored health insurance looks bleak,” said Stuart. “In the face of continued rising prescription drug costs, employers may choose to abandon providing any coverage at all. At least a properly structured Medicare drug benefit would provide employers with an incentive to maintain coverage for critical medical benefits.”
The other authors on the paper included Puneet Singhal, Cheryl Fahlman, Jalpa Doshi, and Becky Briesacher of the University of Maryland School of Pharmacy.