Primary-prevention ICDs in NICM reduce all-cause mortality (HR 0.79) and sudden cardiac death (HR 0.44), with 5-year ARR 4.4%-5.9%; projected ARR with full GDMT is 2.31%.
Does prophylactic ICD implantation reduce all-cause mortality and sudden cardiac death in patients with non-ischemic cardiomyopathy and LVEF ≤35%?
While historical trials show ICDs reduce mortality in non-ischemic cardiomyopathy, scenario-based modeling suggests the absolute benefit is substantially attenuated (projected NNT 43) in the era of contemporary comprehensive guideline-directed medical therapy.
Absolute Event Rate: 0% vs 0%
Abstract Aims Implantable cardioverter–defibrillators (ICDs) reduce sudden cardiac death (SCD) in non-ischemic cardiomyopathy (NICM), but most evidence predates comprehensive guideline-directed medical therapy (GDMT). We quantified the relative and absolute survival benefit of primary-prevention ICDs in NICM across therapeutic eras and explored how contemporary GDMT modifies absolute benefit. Methods and results We searched MEDLINE, Embase, and CENTRAL through March 2025 and included randomized controlled trials comparing prophylactic ICD implantation versus control in NICM with LVEF ≤35%. Three trials (DEFINITE, SCD-HeFT NICM subgroup, and DANISH) contributed to the quantitative synthesis. ICD therapy reduced all-cause mortality (pooled HR 0.79, 95% CI 0.66–0.95) and sudden cardiac death (HR 0.44, 95% CI 0.28–0.70). Five-year absolute risk reduction (ARR) was 5.9% (NNT 17) in SCD-HeFT NICM and 4.4% (NNT 23) in DANISH. Under a full-GDMT scenario parameterized from pharmacological RCTs, projected baseline risk was ∼11%, yielding ARR 2.31% (NNT 43). Conclusions All contemporary “GDMT-era” absolute benefit estimates are scenario-based modeling outputs. No randomized trial has evaluated ICDs on top of full modern GDMT in NICM; therefore, these results represent illustrative ranges rather than empirical estimates.
Puljevic et al. (Fri,) reported a other. Primary-prevention ICDs in NICM reduce all-cause mortality (HR 0.79) and sudden cardiac death (HR 0.44), with 5-year ARR 4.4%-5.9%; projected ARR with full GDMT is 2.31%.