Discussion
long-term stroke, death, diabetes, coronary heart disease, artery disease co-morbidity, stroke, decompensated heart failure, smoking,
RECURRENCES, DECOMPENSATED HEART FAILURE, RECURRENCE, STROKE, DIABETES MELLITUS, ACUTE STROKE, CARDIAC DISEASE, EVENTS, ARTERY DISEASE
The results of the extended follow-up evaluation of the DEVT trial showed that EVT alone was noninferior to intravenous alteplase combined with EVT regarding to functional outcome at 18 months, which was similar to the originally reported results at 90 days. The between-group difference of the percentage of patients who were functionally independent (i.e., a mRS score of 0 to 2) at 18 months (4.3%) was lower than the results at 90 days (7.7%), and the lower boundary of the CI (− 8.4%) was greater than the prespecified noninferiority margin of − 10%.The percentage of patients with independent functional outcome at 18 months was lower than the percentages at 90 days in the EVT alone group, although this difference was not statistically significant, whereas in the combined treatment group, the percentage was slightly higher at 18 months than the percentage at 90 days. This may have contributed to the differences across the original trial and extended follow-up study. A possible explanation for the lower rate of functional independence at 18 months in the EVT alone group included the higher proportion of both stroke recurrence (10.3% vs 3.4%) and decompensated heart failure (5.2% vs 2.5%) over the combined treatment group during the extended follow-up period, because both these factors appeared to be associated with worse functional outcomes after endovascular treatment in long-term studies [In addition to the above results, notable differences were observed between the two time points. First, the mortality rate at 18 months was higher than the risk of death at 90 days in both groups. Second, the percentage of patients with excellent outcome at 18 months was higher than the percentages at 90 days in the combined treatment group, although this difference was not statistically significant. Third, the utility index of EQ-5D-5L was slightly lower at 18 months in the EVT alone group but did not differ substantially between the two time points.We observed more major vascular events in the endovascular treatment alone group but did not differ substantially between the two groups during the extended follow-up period. This observation may be attributed to a higher proportion of patients with diabetes, coronary heart disease and large artery disease co-morbidity in the EVT alone group than in the combined treatment group, although there was no significant difference. A recent meta-analysis showed that predictors of long-term stroke recurrences were both modifiable and nonmodifiable. Increasing age, male sex, diabetes mellitus, smoking, cardiac disease, and stroke etiology (large artery disease) were all associated with increased risk of late recurrences. Moreover, many of the nonmodifiable and modifiable risk factors which contribute to stroke recurrences were also important predictors of cardiovascular events.Acute stroke studies typically reported the primary outcome measure at 90 days. Longer follow-up assessments were prone to result in patients being lost to follow-up, which carried a substantial risk of bias. In that regard, our study was unique in that data for the primary outcome were available for all enrolled patients at all follow-up times, with the exception of three patients at 18 months, conferring strong internal validity to our findings.