Revealing Risk of Cardiac Death
With more than 300,000 cases reported annually in the U.S. alone, cardiac death is among the country’s leading killers. More than 12 million Americans are believed to be at high enough risk of cardiac death to be candidates for an implantable cardioverter defibrillator (ICD), a small device which detects heart rhythm disturbances and corrects them with electrical shocks.
Yet only a small fraction of those who need an ICD will get one. And even among those who do get one, more than 70 percent of those with an ICD will never receive an appropriate firing. In other words, patients will have been exposed to the discomfort, risk, and expense of surgery for nothing.
Of greater concern, nearly 80 percent of those who die of cardiac death — who may well have been saved by an ICD — don’t meet the criteria for implantation. In this large, unfortunate second group, death is their first and only symptom. Fully 95 percent will die before they reach the hospital.
Clearly, current methods do not provide adequate guidance for selecting ICD candidates. It’s no wonder many cardiologists believe that cardiac death risk-stratification — the science of determining who would benefit from an ICD — is in chaos.
Simple, Inexpensive Risk-Stratification…
Unprecedented Accuracy
Vicor Technologies’ PD2i CA™ is poised to solve the problem of inaccurate identification of those needing an ICD. In about 15 minutes, the PD2i CA™ may be able to identify patients at high risk of cardiac death from arrhythmia or pump failure within the upcoming six to 12 months. In clinical trials to date, the PD2i CA™ has reported virtually no false negatives — in other words, of those whom the test said would live, no one died.
The PD2i® nonlinear algorithm also demonstrated a very high specificity of 83 percent, which would dramatically reduce over implantation, compared with other triage methods, and result in an immense savings in health care costs. And, unlike competing diagnostics, the PD2i CA™ test is inexpensive, non-invasive, requires no active patient participation, is not derailed by irregular or ectopic heartbeats, and can be performed on patients taking beta blockers commonly prescribed for coronary artery disease. (These studies have not been reviewed by the Food and Drug Administration.)
The PD2i CA™ at Work
The charts below provide a typical example of the ability of the PD2i CA™ to detect risk of cardiac death. While both patients presented at the ER with the identical complaint of chest pains, the disparity between their PD2i® traces taken upon admission suggests that these patients would have very different prognoses.
Patient A (left) was safely discharged from the hospital after 24 hours, and did not die of cardiac death during the year of follow-up. Patient B (right) experienced cardiac death less than 24 hours after admission.
Patient B’s PD2i® trace shows a sustained low-dimension (red underline) followed by a transient low-dimensional excursion (red arrow.) The PD2i® patterns indicated by the red graphics show PD2i® values of ≤1.4 and are typical of what constitutes an abnormal PD2i® test, possibly indicating high risk of cardiac death.
What the PD2i CA™ Measures
Research by Vicor Technologies’ scientists established that cardiac death is the result of a breakdown in communication between the brain and heart.
There are several sensory-motor loops that normally work in competition to regulate heart rhythm. By analyzing 15 minutes of ECG data, the PD2i CA™ can detect whether these sensory-motor loops are being overly coordinated. Excessive coordination of these sensory-motor loops, reflected by a reduced PD2i® value, appears to be a clear indication of imminent risk of cardiac death.
(For a more in-depth explanation of Vicor’s PD2i® technology, please see the PD2i® Technology and Clinicians Overview pages, or read the underlying research.)
PD2i CA™ Clinical Trials
Under a collaborative research agreement — “Prognostic Significance of Point Correlation Dimension Algorithm (PD2i®) in Chronic Heart Failure” –with the University of Rochester and the Catalan Institute of Cardiovascular Sciences in Barcelona, the PD2i CA™ was used to retrospectively identify which of the patients enrolled in the Muerte Subita en Insuficiencia Cardiaca (MUSIC) Trial experienced cardiac death. MUSIC Trial participants were followed for an average period of 44 months. Of the 537 patients enrolled in the MUSIC Trial, 52 actually experienced cardiac death. The conclusion of the University of Rochester researchers who conducted the study is that the PD2i® nonlinear algorithm is predictive of total mortality, cardiac death, and heart failure death in patients with left ventricular ejection fraction of less than or equal to 35%. With a P value of 0.004 the study results are highly statistically significant.
FDA 510(k) Clearance Expected in 2011
Vicor believes the data obtained from analysis of the MUSIC Trial results will be sufficient to support FDA 510(k) marketing clearance for an application for cardiac death resulting from arrythmia or pump failure in the first half of 2011, with marketing to commence shortly thereafter.
Learn More About Vicor’s PD2i CA™
To learn more about Vicor’s PD2i CA™ and how you can add it to your practice, contact Vicor at 877.528.PD2i (7324) or refer to our Contact page.
