ST Segment Detection Study

• ICD (Device): Subjects implanted with an ICD.

Primary outcomes

• Number of Participants With ST Segment Changes During Myocardial Infarction [Implant to 2 years]: The primary objective of the study was to observe if there are any detectable ST segment changes on an electrogram (EGM) signal from an implanted cardiac defibrillator (ICD) during myocardial infarctions among study participants.

Secondary outcomes

• Occurrence of Spontaneous Coronary Event [Implant to 2 years]: During the study, spontaneous coronary ischemic events were categorized as STEMI, Non-ST elevated myocardial infarction (NSTEMI), or Unstable Angina. This objective was to provide estimates of rates per patient year for the study population. Rates are presented as: Average number of events per patient year (95% Confidence Interval)
• ST Segment Changes Measured by an ICD in Subjects Who Test Positive for Ischemia During an Exercise Stress Test [One-month follow-up visit]: Patients underwent an exercise stress test at their one month study visit. This objective was to summarize the magnitude of the hearts electrical activity signal measured by the implanted ICD during a positive exercise stress test for ischemia.
• Number of Years of Stored Data in a Database of the Hearts Electrical Activity in This Specific Patient Population to be Used for Future Research. [Implant to 2 years]: The device in this study included an additional capacity to collect and store information about the hearts electrical activity specific to ischemic heart disease. This additional capacity of the device is not currently available in market release ICDs. There is no measure to this objective, other than reporting the number of follow-up years of data accrued, which can be used by Medtronic for additional research.
• Participants That Consented to Wear a Holter Monitor for a Period of 24 Hours to Collect Heart Sounds Data. [Six-month follow-up visit]: When study subjects completed their six-month follow-up visit, they were asked if they would consent to wear a Holter monitor for a period of 24 hours to collect Heart Sounds data. The study subject would have to return to the center the following day to return the Holter monitor and have their ICD EGM vectors reprogrammed.

Sex: All, ages: 18 Years to any

Inclusion Criteria:

* Subject is indicated for an ICD implantation
* AND subject must meet ONE of the following:

  * Prior acute coronary event
  * Previously underwent Percutaneous Coronary Intervention (PCI) or stent procedure
  * Multivessel disease
  * Positive stress test completed with evidence of ischemic heart disease, as determined by physician, and no subsequent successful revascularization

Exclusion Criteria:

* Subject is currently dependent on ventricular pacing
* Subject has Left Bundle Brunch Block (LBBB) and/or wide QRS
* Subject has chronic Atrial Fibrillation (AF)
* Subject has dementia
* Subject is indicated for a single chamber device
* Subject requires a right sided or abdominal ICD implant
* Subject is pregnant or in fertile age without secure birth control
* Subject has New York Heart Association (NYHA) class IV or refractory heart failure
* Subject is not expected to survive greater than 12 months
* Subject is participating in other confounding research studies

Participant flow

Outcome results

• Number of Participants With ST Segment Changes During Myocardial Infarction (Primary)
• Occurrence of Spontaneous Coronary Event (Secondary), Number, Events per patient year: ICD Indicated 0 (0 to 2.1)
• ST Segment Changes Measured by an ICD in Subjects Who Test Positive for Ischemia During an Exercise Stress Test (Secondary), Mean, millivolts: ICD Indicated 1.23 +/- 0.91
• Number of Years of Stored Data in a Database of the Hearts Electrical Activity in This Specific Patient Population to be Used for Future Research. (Secondary), Number, Years: ICD Indicated 164.1
• Participants That Consented to Wear a Holter Monitor for a Period of 24 Hours to Collect Heart Sounds Data. (Secondary), Number, Participants: ICD Indicated 11

Adverse events

Time frame: Baseline through 2 years.

Serious adverse events by term

46 more terms not shown.

Other adverse events by term

• George Crossley, MD, Principal investigator, St. Thomas Research Institute and University of Tennessee College of Medicine Nashville, TN
• Timothy Henry, MD, Principal investigator, Minneapolis Heart Institute Foundation Minneapolis, MN