Abstract
BACKGROUND: Appropriate time for ejection fraction (EF) reassessment after revascularization in patients with left ventricular dysfunction has not been investigated comprehensively, although 3 months after revascularization is recommended to stratify the risk of sudden cardiac death (SCD). HYPOTHESIS: EF reassessed within different timeframe after revascularization may have incosistent contribution for risk stratification of SCD. METHODS: Patients who had EF ≤ 40% before revascularization and had EF reassessment at least once during follow-up were included. The role of early (<3 months) versus late (3-12 months) EF measurements in prediction of all-cause mortality and SCD were compared. RESULTS: A total of 1589 patients were identified. EF reassessed <3 months was lower than EF reassessed within 3-12 months (42.1 ± 9.7% vs. 45.8 ± 10.8%; p < .01). Among 1069 patients who had EF reassessed <3 months, EF ≤ 35% was associated with a higher risk of all-cause mortality (hazard ratio [HR], 1.67; 95% confidence interval [CI], 1.22-2.29; p < .01), but had no association with the risk of SCD (HR, 1.44; 95% CI, 0.84-2.48; p = .18). By contrast, among 595 patients who had EF reassessed within 3-12 months, EF ≤ 35% was associated with higher risks of both all-cause death (HR, 1.81; 95% CI, 1.06-3.10; p = .03) and SCD (HR, 2.71; 95% CI, 1.31-5.61; p < .01). The relative contribution of SCD to all-cause death was higher in patients with EF ≤ 35% than patients with EF > 35% when EF was reassessed within 3-12 months (p = .04). However, when EF was reassessed <3 months, the mode of death was similar in patients with EF ≤ 35% versus >35% (p = .85). CONCLUSIONS: 3 to 12 months after revascularization may be appropriate for cardiac function reassessment and SCD risk stratification.