DANISH Trial Non-ischaemic ICD — EECC MCQ

Correct answer: D — DANISH showed that primary prevention ICD in non-ischaemic DCM did not significantly reduce all-cause mortality (though it reduced SCD); the benefit was most pronounced in younger patients (<59 years) — contributing to a weaker ICD recommendation (Class IIa) compared with ischaemic cardiomyopathy (Class I)

The DANISH trial (2016) randomised 1,116 non-ischaemic DCM patients (LVEF ≤35%) to ICD vs no ICD (all on GDMT, 58% with CRT). Results: ICD significantly reduced SCD (hazard ratio 0.50) but did NOT significantly reduce all-cause mortality (the primary endpoint). Subgroup analysis showed the mortality benefit was most pronounced in younger patients (<59 years at enrolment). This trial, combined with updated meta-analyses, contributed to the ESC 2022 VA/SCD Guidelines giving a weaker recommendation for primary prevention ICD in non-ischaemic DCM (Class IIa) compared with ischaemic cardiomyopathy (Class I). Additional risk stratifiers (LGE on CMR, genetic testing for arrhythmogenic genotypes) help identify non-ischaemic patients who may benefit most from ICD.

Reference: ESC (2022): VA/SCD Guidelines; DANISH Trial