Thirteen-year nationwide trends in use of implantable cardioverter-defibrillators and subsequent long-term survival.
BACKGROUND
Long-term trends in use of implantable cardioverter-defibrillators (ICDs) and outcomes are rare.


OBJECTIVE
We examined 13-year nationwide trends in ICD implantation and survival rates in Denmark.


METHODS
Using medical databases, we identified all first time ICD recipients in Denmark during 2000-2012 (N = 8460) and ascertained all-cause mortality. We computed standardized annual implantation rates and mortality rate ratios according to age, sex, comorbidity level, indication, and device type.


RESULTS
The standardized annual implantation rate increased from 42 per million persons in 2000 to 213 per million persons in 2012 (from 34 to 174 for men and from 8 to 39 for women). The increase was driven by secondary prophylactic ICDs until 2006 and primary prophylactic ICDs thereafter. The increase occurred particularly in older patients and those with a high level of comorbidity. Independent of indication, 76% of all patients with ICD were alive after 5 years. Men had a higher mortality rate compared with women (mortality rate ratio 1.28; 95% confidence interval 1.10-1.49). Compared with low comorbidity level, moderate, severe, and very severe comorbidity levels were associated with 1.6-, 2.5-, and 4.9-fold increased mortality rates, respectively. The most influential individual comorbidities were heart failure, diabetes, liver disease, and renal disease.


CONCLUSIONS
The annual implantation rate of ICDs increased 5-fold in Denmark between 2000 and 2012. The rate increase occurred for both men and women, but particularly in the elderly and patients with severe comorbidity. Five-year survival probability was high, but severe comorbidity and male sex were associated with shorter survival.
Departments of Clinical Epidemiology; Cardiology, Aarhus University Hospital, Aarhus, Denmark. Electronic address: morten.schmidt@clin.au.dk.
Morten
M
Schmidt
Cardiology, Aarhus University Hospital, Aarhus, Denmark.
Susanne Bendesgaard
SB
Pedersen
Departments of Clinical Epidemiology.
Dóra Körmendiné
DK
Farkas
Department of Cardiology, Aalborg University Hospital, Aalborg, Denmark.
Søren Pihlkjær
SP
Hjortshøj
Cardiology, Aarhus University Hospital, Aarhus, Denmark.
Hans Erik
HE
Bøtker
Cardiology, Aarhus University Hospital, Aarhus, Denmark.
Jens Cosedis
JC
Nielsen
Departments of Clinical Epidemiology.
Henrik Toft
HT
Sørensen
D000368:Aged; D016757:Death, Sudden, Cardiac / Q000453:epidemiology / Q000209:etiology / Q000517:prevention & control*; D017147:Defibrillators, Implantable / Q000706:statistics & numerical data*; D003718:Denmark / Q000453:epidemiology; D005260:Female; D005500:Follow-Up Studies; D005544:Forecasting; D006333:Heart Failure / Q000401:mortality / Q000628:therapy*; D006801:Humans; D008297:Male; D008875:Middle Aged; D011159:Population Surveillance / Q000379:methods*; D012042:Registries; D012189:Retrospective Studies; D012307:Risk Factors; D015996:Survival Rate / Q000639:trends; D013997:Time Factors; D016896:Treatment Outcome
Cohort study; Epidemiology; Implantable cardioverter-defibrillator; Implantation rate; Survival