Incidence of adequate ICD interventions in patients with hypertrophic cardiomyopathy supposed to be at high risk for sudden cardiac death.
BACKGROUND
Although the incidence of sudden cardiac death (SCD) is as low as 1%/year in un-selected patients (pts) with hypertrophic cardiomyopathy (HCM), higher-risk populations may benefit from prophylactic implantation of an ICD. Risk assessment in HCM is thus important and currently based on the presence or absence of different risk markers (RM).


OBJECTIVE
The objective of this study is to correlate the incidence of adequate ICD interventions in HCM with the presence of different RM.


METHODS
Fifty pts with HCM had ICD implantation, either for secondary (n = 2/4%), or primary prophylaxis of SCD (n = 48/96%). ICD for primary prophylaxis pts had more than 1 (2-4) RM. Outflow obstruction was present in 25 pts, the other 25, including I patient each after septal ablation and myectomy, were non-obstructive. ICD memories were read out and interpreted in accordance with established guidelines.


RESULTS
The number of RM per patient was 1.7 +/- 0.8. During follow-up of 2.0 +/- 0.5 [0.2-6.3] years, adequate ICD interventions (11 episodes) were documented in 5, inadequate ICD interventions in 3 pts.Thirteen pts had at least I episode of atrial fibrillation. Pts with versus without events had a longer follow-up (3.2 +/- 4.3 vs. 1.8 +/- 2.6 years, P < 0.05), and were more frequently nonobstructive (all 5; P = 0.05).Within the time period observed no single RM was predictive for arrhythmic events.


CONCLUSIONS
Incidence of appropriate ICD discharges was 4-5%/patient-year, supporting the proposed risk stratification. No single RM was predictive for future arrhythmic events.
Dept. of Cardiology, Heart and Diabetes Centre North-Rhine Westphalia, Ruhr University Bochum, Bad Oeynhausen, Germany. akleemeyer@hdz-nrw.de
Christian
C
Prinz
Jürgen
J
Vogt
Thomas
T
Bitter
Bogdan G
BG
Muntean
Detlef
D
Hering
Dieter
D
Horstkotte
Lothar
L
Faber
D000328:Adult; D002312:Cardiomyopathy, Hypertrophic / Q000628:therapy*; D016757:Death, Sudden, Cardiac / Q000453:epidemiology / Q000517:prevention & control*; D017147:Defibrillators, Implantable; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D011379:Prognosis; D018570:Risk Assessment