Abstract
Defibrillation testing has been an integral part of implantable cardioverter defibrillator
(ICD) placement for many years, however, data from randomised trials evaluating the
need for it have not been available until recently. In the SIMPLE-study, 2,500 patients
were randomised to either receive or not to receive defibrillation testing during
de-novo ICD implantation and were followed for a mean of 3.1 years. The primary endpoint
of arrhythmic death or ineffective adequate shock was reached in similar proportions
in both groups satisfying the liberally set margins of non-inferiority in favour of
a non-testing strategy. All cause mortality did not differ significantly between the
groups. Similar results concerning first shock efficacy and mortality have been obtained
from the NORDIC Study.
The SIMPLE study provides evidence that defibrillation testing during ICD implantation
can be abandoned in patients receiving transvenous, left pectoral ICD for primary
or secondary prevention of sudden cardiac death. This is notably true for patients
with coronary artery disease or dilated cardiomyopathy as underlying cardiac diseases.
Other entities are not well represented in the study and the continuation of defibrillation
testing in these patients may be warranted. Patients with planned right sided ICD
placement or supplied with an entirely subcutaneous ICD were not included in the SIMPLE-study
and defibrillation testing should be upheld in these until data on the safety of a
non-testing strategy becomes available.
The SIMPLE-study has significantly influenced the recently published HRS/EHRA/APHRS/SOLAECE
consensus statement on optimal ICD programming and testing.
