Bypass surgery done on a beating heart is just as effective as the conventional operation performed with a heart-lung machine, and is less expensive, according to a study reported last month. Results of the SMART (Surgical Management of Arterial Revascularization) trial, published in the April 21 issue of the Journal of the American Medical Association (JAMA), provide compelling evidence of the benefits of performing coronary artery bypass graft (CABG) surgery while the patient's heart continues to beat. In traditional CABG surgery, the patient's heart is stopped and a heart-lung machine maintains circulation during the procedure.
While the results were positive, it is not clear if they offer definitive proof of efficacy, as previous research produced conflicting conclusions on the benefits of the beating-heart technique, with one study published in the January issue of the New England Journal of Medicine finding that the newly grafted blood vessels are far more likely to become clogged three months after surgery in those who undergo the procedure. Additionally, longer-term data will be required by cardiovascular surgeons, who perform the majority of CABG procedures. This largely conservative group may require five to 10 years of positive data showing that these off-pump grafts are as durable as their on-pump counterparts before they begin large scale adoption of a technique that is known to be more technically demanding.
The prospective, randomized, blinded study of 197 patients who were treated by cardiac surgeon John Puskas, MD, of Emory Crawford Long Hospital (Atlanta, Georgia) revealed that grafts performed during beating-heart procedures are as effective as conventional CABG surgery in restoring blood flow to the heart muscle and maintaining complete revascularization over time. Moreover, the number of grafts performed per patient during beating-heart procedures was virtually identical to the number performed in the conventional CABG operation, demonstrating that completeness of revascularization was similar between groups.
In his beating-heart procedures, Puskas, a pioneer of the off-pump technique, used the two most recent generations of Medtronic's (Minneapolis, Minnesota) Octopus Tissue Stabilizer, which holds the beating heart's surface tissue nearly stationary as the bypass graft is sutured in place. The Octopus device was the original suction-based stabilizer, and Medtronic has used feedback from its customers to develop seven generations of the device. The Octopus has been used in more than 345,000 procedures worldwide, the company said. Guidant (Indianapolis, Indiana), St. Jude Medical (St. Paul, Minnesota) and Johnson & Johnson (New Brunswick, New Jersey) also are working on products in the off-pump field.
The study found that restoration of blood flow to the heart was demonstrated in angiograms prior to discharge from the hospital, and graft durability and patency (freedom from blockage) was confirmed in angiograms one year later. In addition, there were no significant differences between the groups in the incidence of death, heart attack, stroke, recurrent angina, hospital readmissions or percutaneous intervention 30 days and one year after surgery. As of January, none of the patients had required surgical reintervention.
The study also found some benefits for beating-heart patients over traditional CABG patients. The study found that participants who underwent the less-invasive beating-heart surgery lost less blood during surgery, had less damage to their hearts during surgery and recovered more quickly than those who underwent traditional CABG procedures. Some 26% of beating-heart patients needed blood transfusions compared with 49% of conventional CABG patients. Beating-heart patients in the study also were able to breathe on their own sooner after surgery, spent less time in intensive care and left the hospital one day sooner, on average, than conventional CABG patients.
About 350,000 patients undergo CABG operations every year in the U.S., and an estimated 25% of the procedures are performed on beating hearts, or "off-pump." In the Medicare population, beating-heart procedures comprise 30% of all CABG surgeries, a still largely untapped market.
According to Puskas, the primary question that the study answered was whether the bypass grafts in the off-pump procedures were holding up as well as those in a traditional CABG surgery. "Are you sacrificing long-term benefit for short-term gain? The answer is 'no,'" he told The BBI Newsletter. "The quality and durability of the bypass grafts is the same in both groups."
Puskas said, "This is important information for physicians, who until now haven't had good prospective data comparing revascularization and other efficacy measures," he said. "I expect these results will be replicated as more surgeons adopt and become comfortable with the off-pump procedure."
Puskas pointed out that since he began doing the off-pump procedure in the late 1990s, the technology used for the surgery has improved vastly, and he predicts a significant increase in the use of the beating-heart CABG in the near future with the addition of more positive data. "In 1997, less than 3% of all coronary bypasses were done off-pump. Last year, it was about 22%," he said, adding that in five years the rate of adoption could rise to around 50% nationwide.
While Puskas noted that 95% of the CABG procedures he does now are off-pump, he said that the traditional procedure still has a place in the surgeon's arsenal, noting that the heart-lung machine is still preferred for people with irregular heart rhythm or blood pressure, or those suffering a cardiac crisis, such as a heart attack at the time of surgery.
Airliners required to have AEDs
Beginning in mid-April, all large commercial jets must carry an automated external defibrillator (AED) on board. The mandated equipment is part of a rule promulgated four years ago by the Federal Aviation Administration (FAA; Washington), requiring that the large airliners carry kits containing advanced medical equipment, including the AEDs. Commuter planes are exempt from the rule.
Having the equipment on board makes an airliner one of the safest places to have the type of heart attack resulting from an electrical short-circuit of the heart. Such an attack is likely to be readily observed in-flight, and the AED is close at hand. Without an on-board AED, survival is unlikely, since a shock from an AED must be delivered within 10 minutes following onset in order for the individual to survive and hopefully much sooner to maximize the chance of survival and lessen collateral damage to other systems of the body.
At the time the FAA rule was first promulgated, at least nine airlines already had installed the AEDs. The FAA projected that it would cost the airline industry about $16 million to meet the equipment requirements. Besides AEDs, other equipment required in the mandated medical kits include a variety of simple drugs such as oral antihistamines, non-narcotic analgesics, and aspirin plus a bronchodilator inhaler, an IV administration kit with connectors, a system to assist respiration following defibrillation and CPR masks. The list was intended to be basic rather than comprehensive, the FAA said, while also allowing for the addition of other materials at the airline's discretion.
The airline industry American Airlines (Fort Worth, Texas) was the first to begin AED installations in the mid-1990s was the first to initiate AED placements, and it was followed by casinos, shopping malls and sports stadiums. American Airlines has reported that more than 40 people have been saved by the in-flight use of AEDs since the devices were installed on its planes. Last year, a report in the Medical Journal of Australia said that people suffering cardiac arrest had a better chance of surviving if they suffered the incident on a Qantas (Sydney, Australia) airliner than in an Australian hospital.
In 2000, the AED effort received more impetus from Congress, which passed the Cardiac Arrest Survival Act, requiring the Secretary of Health and Human Services to develop guidelines for AED placement and use in federal buildings and promoting the expansion of "Good Samaritan" legislation, providing protection for lay users of the devices. Since then, a variety of states and state organizations have launched public-access defibrillator programs.
Overall, the extension of AED programs also has been driven by the development of AEDs so easy to use that they can be operated by lay persons, those without training, and even by young children.
Among the latest facilities to install AEDs have been many health clubs and fitness centers. The International Health, Racquet & Sportsclub Association (IHRSA; Boston, Massachusetts) has issued a policy saying that fitness centers and health clubs are too varied in operation and function to mandate AEDs in all such venues. But the association has encouraged operators of these facilities "to consider the advantages" of installing them. And it has developed an AED purchase and training program with Philips Medical Systems North America (Milford, Connecticut), called the IHRSA Health Heart AED program for the association's 3,600 members.
Even more recently, national used car retailer CarMax (Richmond, Virginia), reported that it was leasing 100 AED units and training its associates in their use. It said that it will install AEDs in its 50 used car superstores, 12 new car franchises, corporate headquarters and a CarMax Auto Finance office. Those AEDs will be supplied by Medtronic Physio-Control (Redmond, Washington).
Proposed law expands SBIR grant access
Life sciences firms that have been unable to win Small Business Incentive Research (SBIR) grants due to a technicality in the law might be in the game again if legislation introduced in the House of Representatives last month makes it to the president's desk. Rep. Samuel Graves (R-Missouri) introduced legislation designed to amend Internal Revenue Code language that limits Small Business Incentive Research (SBIR) grants to firms that are 51% owned by "individuals" who are citizens or permanent residents of the U.S.
Steve Lawton, vice president and general counsel at the Biotechnology Industry Organization (BIO; Washington), said the problem cropped up about two years ago when the term "individuals" was interpreted to exclude venture capital funds, which often heavily fund emerging life science firms. "That means a lot of our companies were not eligible for the SBIR program," Lawton said, adding that the Graves legislation resolves that issue.