BACKGROUND: Randomized controlled trials have generated strong evidence on the efficacy of electrical device therapy in selected patients with heart failure (HF). The enrolment criteria of these three trials generated patient profiles that helped to shape current guidelines on chronic heart failure (CHF) treatment and sudden cardiac death (SCD) prevention. We investigated the prevalence of trial-generated profiles for implantable defibrillator or cardiac resynchronization therapy candidacy among HF outpatients; we explored differences between real-world and trial populations and we evaluated 1-year survival without device treatment. METHODS: We reviewed Italian Network on Congestive Heart Failure (IN-CHF) registry patients (n = 4977) enrolled in a period (1995-2000) roughly concurrent with the MADIT-II and SCD-HeFT trials. RESULTS: Regarding device eligibility, 14.5% IN-CHF patients at entry satisfied MADIT-II criteria, 6.8% satisfied CARE-HF criteria and as many as 47.9% fulfilled SCD-HeFT criteria. One-year overall mortality among non-implanted patients was 1.5 to 2-fold higher in each of these subgroups than in control arms of the corresponding trials. Among registry patients, different trial-profile combinations were associated with a wide range of 1-year outcomes (mortality, 8-35%; SCD/total mortality ratio, 0.35-0.57). Despite clear differences between registry and trial patients in pharmacological therapy (and clinical characteristics), none of the main drug classes independently predicted 1-year mortality in any of the IN-CHF subgroups. CONCLUSIONS: As many as half the IN-CHF outpatients fulfilled current criteria for device implantation. Various subgroups had higher 1-year mortality than patients in trial control arms - a finding that may not be entirely attributable to differences in drug therapy (especially beta blockers).