BEDFORD, Mass.--(BW HealthWire)--Aug. 23, 1999--
Cambridge Heart Alternans Test Seen as Useful Diagnostic Tool
Cambridge Heart, Inc. (NASDAQ:CAMH) today announced that a study
published in the August Journal of the American College of Cardiology
(34(2); 374-380, 1999) found that the presence of microvolt T-wave
alternans (TWA), an alternating pattern in the heartbeat, was
correlated with that of ventricular tachyarrhythmia (VT) in patients
with non-ischemic dilated cardiomyopathy (DCM). The Cambridge Heart
Alternans Test is the only non-diagnostic test available that measures
T-wave alternans during routine exercise, pacing, or pharmacologic
stress. VT, a rapid heart beating in the ventricles, can give rise to
a life-threatening situation called ventricular fibrillation where the
lower chambers quiver and the heart cannot pump blood. Patients with
DCM suffer from a condition unrelated to coronary artery disease where
the heart becomes enlarged, weak and does not pump properly.
"These study findings are especially significant because invasive
electrophysiology study, the current gold standard in arrhythmia
diagnosis, is not considered useful in diagnosing patients with
non-ischemic DCM," said Jeffrey M. Arnold, Cambridge Heart Chairman,
President, and Chief Executive Officer. "Cambridge Heart's Alternans
Test gives physicians a non-invasive tool to help diagnose this
difficult-to-detect population in time to offer therapeutic
alternatives, such as drug therapy or cardioverter/defibrillator
implantation."
Cambridge Heart's Alternans Test is the only non-invasive test to
receive clearance by the Food and Drug Administration to identify
patients at risk of life threatening arrhythmias and subsequent sudden
cardiac death.
DCM, which often affects people in their forties and fifties, has
been considered a disease with a severe prognosis often leading to
either sudden cardiac death, or death from congestive heart failure.
DCM has a mortality rate of 25% to 50% in the first two years after
diagnosis, and approximately half of these deaths are sudden.
According to this study, T-wave alternans testing was the only
non-invasive test to reliably predict VT in this patient population.
Other tests, including invasive electrophysiology study and
non-invasive (1-8) signal-averaged ECG, QT dispersion, standard
exercise testing, heart rate variability, and echocardiography were
not useful in identifying DCM patients with life threatening
arrhythmias.
The study, titled "Determinant of Microvolt-Level T-Wave
Alternans in Patients With Dilated Cardiomyopathy," by Adachi et al,
included 58 consecutive patients with DCM. All patients underwent a
complete non-invasive and invasive evaluation, including T-wave
alternans testing. The sensitivity, specificity, and predictive
accuracy of T-wave alternans for VT were 88%, 72%, and 77%,
respectively.
About the Cambridge Heart Alternans Test
The Cambridge Heart Alternans Test measures extremely subtle
beat-to-beat fluctuations in a person's heartbeat called T-wave
alternans. T-wave alternans is not visible on electrocardiograms used
in conjunction with ordinary exercise stress tests. These tiny
heartbeat variations - measured at one millionth of a volt - are
detected during a typical treadmill or bicycle exercise stress test by
specially designed, high-resolution electrodes placed on a patient's
chest. Extensive clinical research has shown that patients with
symptoms of or at risk of life threatening arrhythmias who test
positive for T-wave alternans are at significant risk for subsequent
sudden cardiac events including sudden death.
About Cambridge Heart
Cambridge Heart is engaged in the research, development and
commercialization of products for the noninvasive diagnosis of cardiac
disease. Using innovative technologies, the Company is addressing such
key problems in cardiac diagnosis as the identification of those at
risk of sudden cardiac arrest, the early detection of coronary artery
disease and the prompt and accurate diagnosis of heart attack. The
Company, started in 1992, is based in Bedford, Mass., and is traded on
the NASDAQ/NMS under the symbol CAMH.
Statements made in this press release that are not historical
facts include forward-looking statements that involve risks and
uncertainties. Important factors that could cause actual results to
differ materially from those indicated by such forward-looking
statements include uncertainties associated with regulatory approval
processes and other factors that are included in Cambridge Heart's
Annual Report on Form 10-K for the year ending December 31, 1998.
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interval variability: novel evidence for repolarization lability in
ischemic and nonischemic dilated cardiomyopathy. Circulation
1997;96:1557-65.
(5) Grimm W, Hoffmann J, Knop U, et al. Value of time- and
frequency-domain analysis of signal-averaged electrocardiography for
arrhythmia risk prediction in idiopathic dilated cardiomyopathy. PACE
Pacing Clin Electrophysiol 1996;19:1923-7.
(6) Grimm W, Steder U, Menz V, et al. QT dispersion and
arrhythmic events in idiopathic dilated cardiomyopathy. Am J Cardiol
1996;78:458-61.
(7) Silverman ME, Pressel MD, Brackett JC, et al. Prognostic
value of the signal-averaged electrocardiogram and a prolonged QRS in
ischemic and nonischemic cardiomyopathy. Am J Cardiol 1995;75:460-4.
(8) Keeling PJ, Kulakowski P, Yi G, et al. Usefulness of
signal-averaged electrocardiogram in idiopathic dilated cardiomyopathy
for identifying patients with ventricular arrhythmias. Am J Cardiol
1993;72:78-84.
--30--kms/bos*
CONTACT: At Feinstein Kean Partners
Jeff Mooney, 617-577-8110
or
At Cambridge Heart
Robert Palardy, 781-271-1200 ext. 231
or
At Schwartz Communications
Helen Shik, 781-684-0770 ext. 6587
Lloyd Benson, 781-684-0770 ext. 6511
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