Abstract Aims Current guidelines recommend ICD implantation for primary prevention in patients with ischaemic heart disease and LVEF ≤35%. We aimed to access the value of the EP study in prediction of the arrhythmic events in ischaemic patients with reduced EF (≤35%) who underwent EPS and ICD implantation and do address the impact of ICD implantation on the all-cause mortality. Methods We compared the risk for all-cause mortality in ischaemic patients with negative and positive EPS with and without ICD implantation and compared the risk for appropriate therapy according to the results of the EP study of patients who underwent ICD implantation in our institution. The median follow-up was 84 months. Results Of 235 patients, who underwent EPS, 115 were negative (noninducible to VT). These patients were more likely to be female and did not differ in age, presence of diabetes, hypertension, atrial fibrillation or ejection fraction. Kaplan-Meier survival analysis showed that there was no difference in mortality between the 2 groups (49.6% vs 44.2%, p=0.419). ICD was implanted in 168 patients: there was no difference in mortality between them (47%) and patients without implanted ICD (46.6%), p=0.861. This was true for patients with negative and positive EPS (p=0.136 and p=0.554, respectively) Of 167 patients who underwent ICD implantation, 66 had negative EPS. Kaplan-Meier analysis showed that these patients were significantly less likely to receive appropriate therapy (7.6% vs 25.7%, p=0.003) and appropriate shock (0% vs 10.9%, p=0.004. The time to first appropriate ICD therapy was significantly longer in EPS negative patients (112 vs 93 months, p<0.001). The incidence of inappropriate therapies was similar in both groups (2.6% vs 5.8%, p=0.221). Conclusion ICD implantation does not reduce mortality in ischaemic patients with reduced EF and both positive and negative EPS. Patients with negative EPS and implanted ICD had much lower incidence of appropriate ICD therapies and no appropriate shocks. The policy of implanting ICDs to all ischaemic patients with EF<35% should be reconsidered.ICD shocks according to the EPS resultsMortality with and without ICD