Hot Line 3: REFINE-ICD
31 Aug 2025
Hot Line ESC Congress 2025 ICDs in patients with severe LV systolic dysfunction: REFINE-ICD
Professor Derek Exner (Libin Cardiovascular Institute - Calgary, Canada) explained why the REFINE-ICD trial was conducted: “From earlier studies we knew that the risk of death was high after a myocardial infarction (MI), notably among patients with persistent, moderate LV systolic dysfunction and ECG markers associated with ventricular arrhythmia risk. We tested the hypothesis that an ICD may help these patients live longer than those who receive optimal medical therapy alone.”
The investigator-initiated international REFINE-ICD trial included nearly 2,000 patients with a prior MI (≥2 months) who underwent ambulatory ECG testing to assess two markers of ventricular arrhythmia risk: heart rate turbulence and T wave alternans. Of these, 597 patients with LVEF 36–50%, impaired heart rate turbulence and abnormal T wave alternans were randomised to an ICD added to medical therapy or medical therapy alone.
Overall mortality was higher in patients with both abnormal ECG markers vs. those without (hazard ratio [HR] 2.59; 95% CI 1.97 to 3.40; p<0.001).
During mean follow-up of around 5.7 years in randomised patients with abnormal ECG markers, total mortality was not reduced with ICDs: 24.5% of patients died in the ICD group and 21.3% died in the control group (HR 1.07; 95% CI 0.77 to 1.50; p=0.69). Almost half of deaths (47.4%) were adjudicated as non-cardiac deaths. Cardiac mortality was not reduced in the ICD group vs. controls (8.8% vs. 7.6%, respectively; HR 1.11; 95% CI 0.63 to 1.945). Sudden cardiac death occurred in 2.6% of patients in the ICD group and 3.8% in the control group (HR 0.66; 95% CI 0.27 to 1.62).
Summing up, Prof. Exner said: “In this trial, patients with ECG markers of ventricular arrhythmia risk had twice the incidence of death as similar patients without these risk markers, although overall, the risk of death was lower than expected and half of all deaths were non-cardiac. Importantly, ICD therapy did not reduce total mortality or cardiac death and further research efforts are needed to better manage these patients.”
