Implantable cardioverter defibrillator therapy in patients with ischemic or non-ischemic cardiomyopathy and nonsustained ventricular tachycardia.
BACKGROUND
Mortality benefit from implantable cardioverter defibrillator (ICD) therapy in ischemic cardiomyopathy (ICM) with non-sustained ventricular tachycardia (NS-VT) and inducible VT is well defined. Although NS-VT may suggest an increased risk of sudden cardiac death (SCD) in non-ischemic cardiomyopathy (NICM), the role of ICD therapy is unclear. This retrospective study compares follow-up data in these two groups after ICD implantation.


METHODS
153 consecutive patients with ICD implantation for NS-VT were analyzed. ICM patients received an ICD if they had inducible VT at electrophysiology study (EPS). NICM patients did not routinely undergo EPS before ICD implantation.


RESULTS
There were 48 patients (33 males) in NICM group and 105 patients (89 males) in the ICM group. Baseline characteristics including mean ejection fraction (EF), distribution in various New York Heart Association (NYHA) classes, and the mean duration of follow up in the two groups were similar. 50% of the patients in the NICM group and 36% in the ICM group received appropriate therapies (p = 0.106). The mean number of appropriate therapies in the two groups were similar (23.3 +/- 56.7 and 22.5 +/- 59.5 respectively, p = NS). The percentage of patients with inappropriate therapies in the two groups were 27% and 23% respectively (p = NS). Patients in the NICM group received appropriate ICD discharges at a greater rate (p = 0.02).


CONCLUSIONS
Patients undergoing ICD implantation for NICM and NS-VT receive appropriate ICD therapy at a greater rate than those implanted for ICM, NS-VT, and a positive EPS. Although these data do not prove survival benefit in NICM, they suggest a beneficial effect.
Thoracic and Cardiovascular Institute, Department of Epidemiology, Michigan State University, Lansing, Michigan 48912, USA.
Rudolph F
RF
Evonich
Alok
A
Maheshwari
Joseph C
JC
Gardiner
Atul
A
Khasnis
Sricharan
S
Kantipudi
John H
JH
Ip
Denise
D
Grimes
Gregory
G
Hayter
Ranjan K
RK
Thakur
D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D009202:Cardiomyopathies / Q000503:physiopathology / Q000628:therapy*; D017147:Defibrillators, Implantable; D022062:Electrophysiologic Techniques, Cardiac; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008297:Male; D008824:Michigan; D008875:Middle Aged; D017202:Myocardial Ischemia / Q000503:physiopathology / Q000628:therapy*; D012189:Retrospective Studies; D013318:Stroke Volume; D016019:Survival Analysis; D017180:Tachycardia, Ventricular / Q000503:physiopathology / Q000628:therapy*; D016896:Treatment Outcome