News: Part 1

Clear Heart, Clear Mind Another risk factor for age-related dementia may have been uncovered. New research reveals that people with cardiovascular disease have an increased risk of developing dementia. It’s exciting to me because I’ve been saying this for years, and they’ve done a nice clinical study, says Dr. Michael Freedman, director of the division of geriatrics at New York University Medical Center. This is sort of how everybody has been treating patients, and it’s confirming all that we knew. The incidence of dementia in the United States is increasing as the population lives longer, yet little is known about its causes. Alzheimer’s is the most common form of dementia in older people, followed by vascular dementia. Scientists already knew treatment of hypertension seems to delay the onset of Alzheimer’s. Homocysteine, an amino acid found in the blood, is also a risk factor, and there’s been some evidence that lowering cholesterol can delay the start of dementia. The current study, presented at the annual meeting of the American Geriatric Society in Washington, D.C., was part of the larger Cardiovascular Health Study, which examined almost 6,000 people. The researchers, led by Dr. Anne Newman, a geriatrician and associate professor of medicine and epidemiology at the University of Pittsburgh’s School of Medicine, looked at a subset of that group: 3,602 people who had undergone additional cognitive testing. As it turned out, those with cardiovascular disease had about a 30 percent increased risk of dementia, a result only partially explained by stroke. Those with peripheral artery disease had the highest risk of dementia. The study did not look at interventions, but the implications are clear: treating cardiovascular disease may help prevent or delay the onset of different dementias. Although the relative risk was moderate, the high prevalence of cardiovascular disease, coupled with the high risk of dementia, in older adults would suggest that prevention of cardiovascular disease may be the most effective preventive measure we have for the prevention of dementia, Newman says. I see this in my office every day. A perfectly healthy 75-year-old with high blood pressure and cholesterol walks into my office. Do you treat it? Freedman asks. Just thinking logically, they’re 75 and perfectly healthy, we’ll just leave you alone. But, on the other hand, all the data is beginning to show that if you take a perfectly healthy 75-year-old and don’t do anything, they have an increased risk of Alzheimer’s by the time they’re 85. If you treat them, you may push off the onset until they’re in their 90s, and by then most of us aren’t around. This is another bit of evidence that it makes a difference. Medrad Expands Product Line By Adding Cardiac Magnetic Resonance Imaging Device Medrad, Inc. has signed a two-year agreement with W.L. Gore & Associates, Inc. to be the exclusive worldwide distributor of the Cardiovascular Array surface coil, the first magnetic resonance (MR) coil to combine a dedicated cardiac coil and a dedicated abdominal coil in a single device. Extending from the chest down to the bifurcation of the aorta in the pelvic region, the Cardiovascular Array makes it possible to image vascular disease throughout the entire torso in a single scan for the first time. The coil has received Food and Drug Administration clearance and will be available in the U.S. in July, with worldwide distribution rolled out over the next year. Since there is often a correlation between vascular disease in the heart and other critical vessel systems, a clear image of the entire area is critical for accurate diagnosis. Until now this required two separate scans, using valuable scanner time and increasing the likelihood of patient discomfort. The Cardiovascular Array is compatible with all phased array versions of the GE Signa® 1.5 T MR systems, and can be upgraded to be compatible with the eight-receiver scanners of the future. Its phased array design, a collection of antennae elements imbedded in the device that work with the scanner to produce a clear image, provides a clear, expanded image area for enhanced image and diagnosis. The coils are housed in flexible front-and-back panels that conform to different body sizes, delivering increased ease in patient positioning. Proprietary technology from Gore incorporates a radio frequency trap into the cable, eliminating the cumbersome external housing box required in the past. This is the second time that Medrad and Gore have partnered on a coil product; the Torso Array surface coil was released in November 2000, and has exceeded estimated sales targets. Coils are a significant part of Medrad’s product portfolio for the MR environment, and the company currently manufactures or distributes over 30 models that accommodate different body parts and scanners. New Cardiac Care Technologies Showcased by St. Jude Medical at the 23rd Annual North American Society of Pacing and Electrophysiology Scientific Sessions St. Jude Medical, Inc. displayed its broad suite of cardiac care technologies at the 23rd Annual Scientific Sessions of the North American Society of Pacing and Electrophysiology (NASPE) which ran from May 8-11 at the San Diego Convention Center in San Diego, California. The Downsized Atlas ICD and Riata ICD Lead Systems The St. Jude Medical Atlas DR/VR ICD family coupled with the Riata defibrillation lead provides physicians an ultra-small defibrillation system without any of the compromises traditionally associated with downsized products. At 42 joules (J) stored/36 joules (J) delivered, Atlas ICDs are the world’s most powerful rate-adaptive ICDs. Atlas delivers this powerful energy in a compact, sub-40 cc package while offering fast charge times, strong device longevity, and advanced Photon® Micro-based features. With their advanced functionality, Atlas ICDs can be prescribed for patients who need standard ICD therapy as well as those with high defibrillation thresholds (DFTs) who require more energy to terminate an arrhythmia. An ideal complement to the Atlas DR/VR ICD family is the newly released Riata family of active and passive fixation defibrillation leads, the world’s thinnest defibrillation leads. Riata leads provide physicians the best of both worlds by combining an ultra-thin lead body (used with an 8F sheath) for improved handling and implantation characteristics with a multi-cable design for increased strength and durability. The Identity Pacemaker Featuring AF Management A significant percentage of pacemaker patients suffer from atrial fibrillation, a cardiac disorder that affects over 5 million people worldwide. The St. Jude Medical Identity pacemaker family helps address this patient population through AF Management, featuring the clinically proven AF Suppression algorithm, stored intracardiac electrograms, and numerous AF-related diagnostics. Housecall ICD Transtelephonic Monitoring (TTM) System Dr. Thomas J. Dresing of the Cleveland Clinic presented data in support of St. Jude Medical’s Housecall ICD transtelephonic monitoring (TTM) system, a system that allows ICD patients to transmit diagnostic data through a standard telephone line. According to the findings from the major, 124-patient, yearlong study, 93-99% of patients indicated they were satisfied with the system from the standpoint of ease of use, timesaving, and confidence in the system. Researchers concluded that the Housecall TTM provided for frequent and comprehensive monitoring and reduced the frequency of outpatient visits. Patients can be reassured by an operator that the transmission was successful and have their diagnostic information interpreted immediately by a trained technician rather than having downloaded diagnostic information evaluated at a later time. Catheter-Based Solutions St. Jude Medical displayed its catheter systems, including the Livewire TC Bi-directional ablation catheter, designed for the radio frequency (RF) ablation of selected cardiac arrhythmias, the latest addition to the company’s broad portfolio of electrophysiology (EP) catheters. The new bi-directional tip provides increased flexibility to enable physicians to reach difficult endocardial locations. Other features offer precise catheter tip control and improved tissue contact. The company also offers the Seal-Away CS introducer kit, which allows for easier access to the coronary sinus (CS) during permanent lead placement for resynchronization therapy. These long peel-away sheaths with specialty curves help a physician quickly gain access to the coronary sinus and perform a CS venogram-facilitating visualization of the left ventricular vasculature for optimal lead placement. First Patients Enrolled in Clinical Trial of GuardWire Plus in Patients With Acute Myocardial Infarction In a study intended to further demonstrate the safety and effectiveness of balloon occlusion distal protection during vascular interventions, Medtronic announced the start of its EMERALD (Enhanced Myocardial Efficacy and Recovery by Aspiration of Liberalized Debris) trial. The study is specifically designed to compare results in patients with acute myocardial infarction (AMI), half of whom will be randomized to the new generation .028 inch GuardWire Plus Temporary Occlusion and Aspiration System, while the other half will receive conventional percutaneous interventional therapy (PCI) without embolic protection. Medtronic’s GuardWire Plus system has been available in its .036 configuration in the U.S. since last year. It was the first product to be approved for protection against potentially catastrophic major adverse clinical events (MACE) in patients undergoing diseased saphenous vein graft stenting. Studies have shown that distal embolization can lead to increased long-term mortality in such patients. Preventing embolization through the use of the .036 GuardWire Plus system has been shown to reduce morbidity and mortality by 42 percent in these patients. The GuardWire Plus system being tested in the EMERALD study includes three components: the .028 inch GuardWire Plus Balloon catheter, the MicroSeal® Adapter with E-Z Flator, and the Export® Aspiration Catheter. The balloon catheter will be deployed at the onset of the interventional procedure after crossing the lesion and then inflated to occlude the vessel. This prevents migration of embolic and thrombotic material that may dislodge during treatment of the lesion. The angioplasty balloon and/or stent systems are then advanced to the treatment site, where the dislodged particles should remain suspended in the occluded vessel. Upon completion of the stent placement or other interventional procedure, the Export Aspiration Catheter will be introduced, and the atherosclerotic particles removed. The GuardWire Plus balloon is then deflated and withdrawn. The EMERALD trial marks the first time a distal protection system will be evaluated for use during percutaneous intervention in patients who have experienced AMI. The EMERALD trial will be a multicenter, prospective, randomized study and will enroll a total of 500 patients. The .028 inch GuardWire Plus system is designed with a low profile and is designed to be small enough to accommodate vessel diameters from 2.0 mm to 5.0 mm. In addition, its smaller size may allow physicians to use the Export catheter for thrombus aspiration prior to, as well as after PTCA or stent deployment. Gregg W. Stone, MD, Lenox Hill Hospital, New York and the primary investigator for the EMERALD study, said the GuardWire Plus system may be beneficial for use in thrombus-laden lesions in vessels that are already occluded, such as those commonly found in AMI patients. The system is designed to provide enhanced protection of the distal myocardial bed and aspiration of all embolic debris. We believe this study will demonstrate that percutaneous intervention with the GuardWire Plus will significantly improve clinical outcomes in patients with AMI. Radiation Helps Keep Arteries Clear Long-Term Zapping the heart arteries with a dose of radiation after angioplasty seems to help keep them clear for up to 5 years, according to results of a new study. While previous studies indicated that radiation therapy results in early benefits, it was unclear if these effects would last, note Dr. Paul S. Teirstein from the Scripps Clinic in La Jolla, California and colleagues. In the study, patients who were given a dose of radiation inside their blood vessels during angioplasty were less likely to have their arteries narrow again 5 years later than those given angioplasty alone. In the longest follow-up of patients given radiation during angioplasty, the researchers compared outcomes over 5 years between 26 patients given radiation and 29 given angioplasty alone to treat restenosis. Teirstein’s team found that patients given radiation were 74% less likely to experience restenosis than those in the placebo group 6 months after the procedure, and were 48% less likely to have restenosis 5 years later. Teirstein noted that previous studies have shown that patients treated with radiation are at risk of a potentially life-threatening blood clot. However, in this study, nine people in the placebo group died compared with only five in the irradiated group, showing that irradiated patients may have no increased long-term risk of blood clots. Blood Pressure Medication is Not Administered to Best Protect Against MI, Stroke A majority of physicians tell patients to take their antihypertensive medication at a time of day that may not adequately protect them against potentially dangerous surges in blood pressure. According to a new survey by The Gallup Organization, little more than half of primary care physicians (PCPs) consider the body’s natural rhythms when prescribing treatments for high blood pressure, although more than 90 percent recognize these factors may put patients at a higher risk for heart attack and stroke during certain periods of the day. A growing body of evidence illustrates that the early-morning rise in blood pressure or a.m. surge experienced by most people may increase the risk of heart attack and stroke, particularly in individuals who suffer from hypertension. In fact, researchers have identified a 49 percent higher risk of stroke, a 40 percent higher risk of heart attack, and a 29 percent higher risk of cardiac death in the hours between 6 a.m. and noon. In the Gallup survey, slightly more than 80 percent of PCPs surveyed acknowledged that circadian rhythms put patients at the greatest risk for heart attack and stroke immediately upon awakening or in the morning. Yet, of the 88 percent who said they advise patients to take their antihypertensive medication at a certain time of day, more than two-thirds (68 percent) recommend in the morning or upon awakening as the optimal time. That dosing schedule does little to shield patients from morning circadian risks because blood pressure medication can take hours to reach peak concentrations. Nighttime dosing should be strongly considered because it allows blood pressure medication to reach peak concentrations as morning circadian variations begin to appear. But the survey showed only 21 percent of physicians are recommending evening or bedtime administration. A separate arm of the survey, which studied 600 randomly selected antihypertensive patients ages 50 and over, confirmed, and in some instances compounded, the findings of the physician poll. Chronotherapy, a relatively new approach to drug design and administration, may provide additional help to people with hypertension and other disorders. Chronotherapy coordinates medical treatment with the body’s circadian rhythms, and ensures the timing and amount of drug delivered optimizes the desired effects while minimizing adverse events.