|
Presentation
Start/End Time:
|
Monday,
Mar 07, 2005, 1:30 PM - 2:30 PM
|
|
Author
Block:
|
Theodore
Chow, Richard
Cohen, Cheryl Bartone, Edward J. Schloss, Theodore Waller, Terri Booth,
Eugene Chung, Santosh Menon, Dean Kereiakes, Ohio Heart Health Center,
Cincinnati, OH
|
|
Background:
Since defibrillator (ICD) therapy is associated with some risk, including
worsened heart failure and inappropriate shocks, prophylactic implantation in
low risk patients could potentially increase mortality. Microvolt T-wave
alternans (MTWA) is a test with excellent negative predictive value for
sudden death risk. We evaluated the hypothesis that ICD therapy would
increase mortality in MTWA negative patients.
Methods:
Cardiology outpatients with LVEF≤ 40% within a large practice
underwhent MTWA testing (primarily by treadmill exercise). MTWA tests were
interpreted according to published criteria. Treatment strategy and ICD
programming were per physician discretion. All patients were maintained in a
prospective registry with follow-up by telephone contact and chart review. Subgroup
analysis on patients with coronary diseasae (CAD) and LVEF ≤ 30% was
performed.
Results:
413 patients with CAD and LVEF ≤ 30% (average = 25%±5%) were followed
for a mean of 362 days; 40/160 MTWA negative patients received ICDs. Kaplain-Meier
analysis for freedom from death according to ICD treatment status in MTWA
negative patients was performed (Figure). Survival at 300 days was 0.866 for
ICD patients and 0.966 for non-ICD patients (relative risk=4.0, p=0.035).
Conclusions:
Prophylactic ICD treatment of MTWA negative patients with CAD and
EF≤30% is associated with worse survival. Whether bradycardia pacing
contributes to this outcome requires further study. 
|
