Efficacy Results
Results of the efficacy analysis for the ITT population are shown
in Table 4. For the first primary end points (4-point NIHSS
improvement), a higher percentage of rtPA patients had a
4-point improvement at 24 hours (placebo 21%, rtPA 40%;
P50.02); however, this early effect was reversed by 30 days,
with more placebo patients having a 4-point improvement (75%)
compared with patients treated with rtPA (60%, P50.05). No
difference was seen on CT lesion volume at day 30, with both
groups showing large variations: placebo 64674 cm3 versus
rtPA 45654 cm3 (P50.17). There were also no treatment
benefits seen on any of the planned secondary functional
outcomes at 30 and 90 days with placebo patients actually
having a lower (better) median Rankin score (see Table 4).
In order to provide a direct comparison with the NINDS
rtPA study results several “excellent recovery ” (scores of 0
and 1) post hoc analyses were conducted.1 In these tests a
higher percentage of rtPA patients had an excellent outcome
on the NIHSS at day 30 (placebo 20%, rtPA 36%; P50.04 by
uncorrected post hoc test) but not day 90. This, along with the
24-hour 4-point NIHSS findings, suggests that rtPA treatment
produces a higher number of cases with early, dramatic
neurological recoveries. In contrast, no benefit was seen on
the “excellent recovery” post hoc functional outcome assessments
using the Barthel Index. However, because the trial
was not powered to detect differences on these “excellent
recovery” variables, these results may reflect a type II error.
SAE s for the ITT population are shown in Table 4. The
occurrence of ICH was determined by a CT scan at 2466
hours, although any ICH detected by repeat CT within the
first 10 days was also included. Determination of whether the
ICH was asymptomatic or symptomatic was made by the
local principal investigator, who was blinded to treatment
group. Treatment with rtPA increased the rate of both
asymptomatic and symptomatic ICH: asymptomatic 4.3%
versus 12.7, symptomatic 0.0% versus 11.3%. The mortality
rate at 30 and 90 days was significantly higher in the rtPA
group: 30 days, 4.2% with placebo, 18.3% with rtPA
(P50.008); 90 days, 7.0% with placebo, 22.5% with rtPA
(P50.009; see Table 4).
The trial was stopped by the DMSB because of safety concerns
in the 5- to 6-hour group. Table 5 provides the results for the 5- to
6-hour subgroup of patients. The rate of symptomatic ICH and the
30- and 90-day mortality rates were higher with rtPA treatment than
with placebo, and the rates in the 5- to 6-hour rtPA group were
higher than the corresponding rtPA rates in the study overall.
However these increased SAE results in the 5- to 6-hour rtPA group
may have been confounded by a baseline imbalance in the number
of patients with severe strokes. In the 5- to 6-hour group, only 8%
(2/24) of the placebo patients had an NIHSS .20 at baseline
compared with 23% (5/22) of the rtPA patients (P,0.05). In the
study overall, patients with an NIHSS of .20 had increased ICH
rates and very poor outcomes (see Table 6). In patients with an
NIHSS .20, there was a 38% rate of symptomatic ICH and a
100% 90-day mortality rate with rtPA treatment. If the 5- to 6-hour
patients are excluded, the symptomatic ICH rate in the remaining 0-
to 5-hour patients is 8.2%