Mortality and appropriate therapies in patients with HFrEF undergoing EPS before ICD implantation

Background

Current guidelines recommend ICD implantation for primary prevention in patients with LVEF ≤35% of both ischemic and nonischemic etiology, regardless of the results of the electrophysiological study. Recent evidence calls for modification of this policy, at least in nonischemic patients. We accessed the predictors of mortality and appropriate therapies in patients with reduced EF (≤35%) who underwent EPS and ICD implantation.

Methods

Patients with HFrEF who underwent EPS in our institution before ICD implantation between 2007 and 2023 were included. We compared the risk for all-cause mortality in patients with positive and negative EPS with and without ICD implantation and compared the risk for appropriate therapyaccording to the results of the EP study of patients who underwent ICD implantation in our institution. The median follow-up was 87 months.

Results

Of 475 patients who underwent EPS, 75 (15.8% were women), 383 (80.6%) had ischemic CMP and 217 (45.7%) had diabetes; 233 patients (49.1%) had negative EPS result (noninducible to VT). These patients were more likely to be female (22.3% vs 9.5%, p<0.001) and have nonischemic etiology (28.8% vs 10.3%, p<0.001) than patients with positive EPS. Patients did not differ in age, presence of diabetes, atrial fibrillation, ejection fraction or mortality.

A total of 367 patients underwent ICD implantation. Kaplan-Meier survival analysis showed that there was no difference in mortality between ICD recipients and non-recipients in both EPS negative (46.7% vs 52.1%, p=0.105) and EPS positive (43.0% vs 41.7%, p=0.822) patients. This was also true in both ischemic (45.3% vs 54.2%, p=0.163) and nonischemic (39.3% vs 44.4%, p=0.974) patients. Of 367patients who underwent ICD implantation, 137 had negative EPS. Kaplan-Meier survival analysis showed that these patients were significantly less likely to receive appropriate therapy (8.8% vs 22.6%, p<0.001) and appropriate shock (2.2% vs 10.4%, p=0.002. The time to first appropriate ICD therapy was significantly longer in EPS negative patients (70.8 vs 59.7months, p=0.018). The incidence of inappropriate therapies was similar in both groups (10.9% vs 10.9%, p=0.981). Age, gender, ischemic etiology, coronary disease risk factors, EF and NYHA class were not significantly associated with appropriate ICD therapy.

Conclusion

ICD implantation does not reduce mortality in patients with reduced EF and either positive or negative EPS. Patients with negative EPS and implanted ICD had much lower incidence of appropriate ICD therapies (less than inappropriate therapies) and cery low incidence of appropriate shocks. EP study can be useful to guide decisions about ICD implantation in patients with EF≤35%.KM2