A Medical Device Daily
Survival among patients with implantable cardioverter-defibrillators (ICDs) treated only with anti-tachycardia pacing (ATP) was superior to patients who experienced at least one shock-treated episode, according to research Medtronic (Minneapolis) presented yesterday at the American Heart Association (AHA; Dallas) Scientific Sessions in New Orleans.
The med-tech giant is one of many companies presenting clinical trial results and showcasing new products at the AHA meeting, which kicked off Saturday and runs through Wednesday at the Morial Convention Center.
Medtronic also said the analysis evaluating more than 2,000 patients found no link between inappropriate therapy and mortality, nor a causal relationship between ICD therapy and mortality. ATP allows most patients with ICDs to receive painless pacing pulses to safely and effectively terminate dangerous ventricular tachyarrhythmias – those rapid, abnormal rhythms in the lower chambers of the heart that can result in sudden cardiac arrest.
The analysis included 3,630 treated tachyarrhythmia episodes, of which 97% were classified as either ventricular tachycardia (VT) or fast VT (FVT), irregular heart rhythms ranging from 100 to 300 beats a minute. Of these episodes for which therapy was delivered, 80.2% were treated with ATP. Of 2,176 treated VT episodes, 91.9% were terminated by ATP, without the need for a shock, according to Medtronic. Likewise, 68.2% of 1,339 treated FVT episodes were terminated by ATP, without the need for a shock.
"Today's highly advanced ICDs can delivery both painless ATP therapy as well as a high-energy shock, if needed, to terminate dangerous heart rhythms and safe lives," said Michael Sweeney, MD, director of cardiac pacing and implantable device therapies at Brigham and Women's Hospital (Boston), who led the analysis. "Previous studies of ATP technology have proven its ability to improve patients' quality of life by reducing discomfort sometimes associated with life-saving shocks."
Sweeney said the new data suggests that "aggressive use of ATP as part of a broad strategy to reduce shocks may not only improve patient tolerance of the therapy but also may further enhance the life-saving benefit" of the devices beyond what has been previously shown. "This analysis provides further evidence that ATP should be routinely programmed in all ICD patients, he said.
Medtronic says it was the first company to introduce ATP in an ICD in 1993. ATP is designed to send a short series of impulses to the heart to short-circuit dangerously accelerated rhythms, the company said.
The analysis was based on data from 2,135 patients in four Medtronic-supported trials: PainFREE Rx, PainFREE Rx II, EMPIRIC, and PREPARE. Each of the studies was designed to evaluate the benefits of using ATP before resorting to shocks to terminate irregular heart rhythms.
Medtronic also presented U.S. clinical trial data yesterday on the Melody transcatheter pulmonic heart valve. The company said it represents the first time U.S. trial data has been presented on the use of a transcatheter valve in a population with congenital heart disease.
In other AHA news:
• PGxHealth (Newton, Massachusetts) reported the launch of its new genetic test for arrhythmogenic right ventricular cardiomyopathy (ARVC), an inherited and often fatal heart condition. The addition of the Familion ARVC test expands the company's Familion family of genetic tests for inherited cardiac syndromes. According to PgxHealth, the Familion tests detect genetic mutations that can cause cardiac channelopathies, such as Long QT Syndrome, Brugada Syndrome and Catecholaminergic Polymorphic Ventricular Tachycardia, or cardiomyopathies such as Hypertrophic Cardiomyopathy and ARVC in individuals and their families. By detecting genetic mutations, the Familion tests can be used to recognize inherited forms of these syndromes, helping to guide treatment and reduce the incidence of deadly cardiac events associated with them, the company said. When a cardiac channelopathy or cardiomyopathy has been diagnosed, the test can help doctors and patients make more informed treatment decisions and aid in uncovering other family members that may be at risk, even if asymptomatic, PgxHealth noted.
• The past three decades have seen a dramatic increase in hospitalization rates for heart failure among older Americans, according to a new study presented Sunday at AHA. In 2006, an estimated 807,082 men and women older than 65 were hospitalized for heart failure, up from 348,866 in 1980 – a 131% increase.
The Drexel University (Philadelphia) study also found the increase in hospitalization rates has been more dramatic among women than men. The study suggests that medical advances have, ironically, led to more heart failure because patients are more likely to survive heart attacks than they did in the past but they are left with heart failure. The study examined hospital discharge data on more than 2.2 million people aged 65 and older from 1980 through 2006.
The study authors note that the heart failure epidemic is mirrored by a number of other epidemics, such as high blood pressure, obesity and diabetes, all of which are also risk factors for heart failure.
• GE Healthcare (Waukesha, Wisconsin) is showcasing new products, including three ultrasound devices: the Vivid E9, which it says is "making the promise of true 4-D heart imaging and opening the door to full cardiac studies in a completely 4-D environment"; Vivid q, which GE says adds "quantitative analysis to portable excellence, bringing even more diagnostic confidence into the equation while its intravascular ultrasound (ICE) imaging probe opens up an entirely new care area."
The company's diagnostic cardiology business also released new products at AHA, including the EMR Gateway, designed to deliver electrocardiogram (ECG) results and patient demographic data to virtually any Electronic Medical Records (EMR) system. GE said it would also announce a new electrocardiograph system in MAC 1600, Event Recording for advanced arrhythmia assessment and a new version of its ECG management system.
GE's ultrasound services team reported the availability of AcoustiCare, a package including as many as four, fully covered, transesophageal ultrasound probe repairs a year.
Last but not least, GE unveiled Proactive System Check-up & Patch Management coverage for facilities needing optimal efficiency & security. The system check-up can improve network performance, prevent workflow interruption and keep the system performing at optimal levels, the company noted.