Greater than 10% change in EF
Using a >10% change in EF as a clinically meaningful cutoff, 446 patients (38%) had an increase, 683 (58%) were unchanged, and 49 (4%) had a decrease in EF at first follow-up (Figure 2). Of the 446 patients who experienced an increase in EF at first follow-up, 109 (24%) had a >10% decrease at the second follow-up (Figure 2). On the other hand, of the 49 patients who experienced a decrease in EF at first follow-up, 16 (33%) had an increase at second follow-up (Figure 2). While a fluctuation in EF was present in both the ischemic and non-ischemic cardiomyopathy subgroups (Appendix), a larger proportion of the patients with non-ischemic cardiomyopathy had an increase in EF at first follow-up than those with ischemic cardiomyopathy (44% vs. 32%, p<0.0001). The results were similar in sensitivity analysis using >5% change as the cut-off.