News | March 04, 2011

Study: ICD Therapy Beneficial Regardless of Time From Heart Attack

March 4, 2011 – According to a retrospective sub-study of the Sudden Cardiac Death in Heart Failure Trial (SCD-HeFT), there is no evidence that implantable cardioverter defibrillator (ICD) benefit varies with time from myocardial infarction (MI) to device implantation. Accordingly, single lead ICD benefit is not restricted to patients with a remote MI (more than 18 months).

The study, published in HeartRhythm, the official journal of the Heart Rhythm Society, suggests that ICD therapy post-MI decreases the chances of SCD starting immediately after the post-infarct period of up to 40 days.

In SCD-HeFT, 2,521 patients across the United States, Canada and New Zealand were randomly assigned to single lead, shock-only ICD therapy, amiodarone or placebo (double blind). The trial analyzed the use of ICDs in patients who experienced MI, yet had no previous life-threatening arrhythmia. The purpose was to determine the efficacy of ICDs as a primary prevention therapy for patients with moderate heart failure. It found that ICD therapy significantly decreased the relative risk of mortality by 23 percent.

The retrospective sub-study, led by Jonathan Piccini, M.D., MHS, analyzed the outcomes of ICD therapy in post-MI patients to determine whether mortality benefit varied as a function of time. Data from 712 patients were analyzed and divided into tertiles based on the amount of time that had passed between MI and the implantation of a single-lead ICD.

Analysis revealed that patients randomized to ICD therapy (vs. placebo) were less likely to experience SCD in all three groups: 6.2 percent versus 14.2 percent within the first 2.11 years, 5.8 percent versus 10.3 percent between 2.11 and 7.31 years, and 2.5 percent versus 17.4 percent over 7.31 years. A sensitivity analysis was also conducted and revealed that there was no evidence that ICD benefit varied between implantation within the first 18 months or after.

“It is widely known that the risk of SCD is most common in people immediately following a heart attack, yet some evidence suggests that the benefits of ICD therapy may be restricted to those patients who are more than a year after their MI,” Piccini said. “However, the SCD-HeFT results show that the benefit of single lead, conservatively programmed ICD therapy is not limited to those patients remote from a myocardial infarction. Ensuring that eligible patients receive primary prevention defibrillator therapy is likely to be more important than when the device is implanted, outside of 40 days.”

Although future, prospective trials are needed, the analysis has shown there is no evidence that ICD benefit varied with time from MI to implantation. Therefore, ICD implantation, at least as implemented in SCD-HeFT, should not be restricted to patients with remote MI (more than 18 months), as previously suggested. The differences in outcome between SCD-HeFT and prior studies are not clear but the use of a simpler more conservatively programmed ICD may be responsible.

There are also some important limitations to the SCD-HeFT analysis. Patients with MI, unstable angina, or coronary revascularization within the last 30 days were not eligible for enrollment in SCD-HeFT. Additionally, only 10 percent of the patients in the SCD-HeFT analysis were within six months of their most recent MI.

For more information:

Related Content

Smartphone Apps Help Patients and Providers Manage Atrial Fibrillation
News | Patient Engagement| October 19, 2017
October 19, 2017 — Novel smartphone and tablet applications for atrial fibrillation patients and healthcare professio
Pregnancy-Related Heart Failure Strikes Black Women Twice as Often as Other Races
News | Womens Healthcare| October 19, 2017
African American women were found to be twice as likely to be diagnosed with peripartum cardiomyopathy as compared to...
The Respicardia Remede System is a pacemaker-like device designed to improve cardiovascular health by restoring natural breathing during sleep in patients with Central sleep apnea.
Technology | Heart Failure| October 18, 2017
October 18, 2017 — The U.S.
MRI May Predict Neurological Outcomes for Cardiac Arrest Survivors
News | Sudden Cardiac Arrest| October 18, 2017
Magnetic resonance imaging (MRI)-based measurements of the functional connections in the brain can help predict long-...
Xarelto Significantly Reduces Major Cardioavascular Events in Stable CAD and PAD Patients
News | Pharmaceuticals| October 18, 2017
October 18, 2017 — Results from the pivotal Phase 3 COMPASS study found that the...
Baylis Medical and Siemens Co-Sponsor Transseptal Access Training Course
News | EP Lab| October 18, 2017
Baylis Medical Co. Inc. and Siemens Healthineers are co-sponsoring a first-of-its kind training program aimed at...
First Patient Enrolled in U.S. Arm of ALIVE Pivotal Heart Failure Trial
News | Heart Failure| October 17, 2017
October 17, 2017 — BioVentrix Inc. recently announced enrollment of the first patient in the U.S.
Low Mortality and Stroke Risks Displayed for Minimally Invasive Aortic Valve Replacements
News | Heart Valve Technology| October 11, 2017
An analysis of more than 1,000 minimally invasive aortic valve replacements and more than 400 additional associated...
CardioFocus Announces European CE Mark Approval of HeartLight Excalibur Balloon
Technology | Ablation Systems| October 10, 2017
October 10, 2017 — CardioFocus Inc. recently announced the European CE Mark approval of the HeartLight Excalibur Ball
New Evaluation Sends Low-Risk ER Chest Pain Patients Home Sooner
News | Cardiac Diagnostics| October 10, 2017
A new evaluation to determine whether emergency room patients with chest pain can go home and follow up with their...
Overlay Init