Results
Baseline demographics and treatment plans for the 29 patients with
sickle cell CNS vasculopathy prior to implementation of the MRA scanning
protocol in May 2016 are listed in Table 1. Indications for chronic
transfusion therapy included primary stroke prevention for 7 patients,
secondary stroke prevention for 17 patients, and chronic pain for 2
patients.
MRAs were performed for routine screening, symptoms including headache,
or focal neurologic findings. Pre- May 2016, 16/29 patient studies used
TE <5msec whereas post May 2016, 26/29 patient studies used TE
<5msec.
For 12 of the 29 patients (41%), some or all stenosis that was
previously seen on pre- May 2016 MRA imaging was not identified on MRA
imaging done post- May 2016. Figures 2 and 3 show examples of MRAs in
two patients in whom vasculopathy was no longer visualized. In six
patients, there was a decrease in the classification of CNS
vasculopathy, however, their treatment was not impacted. These patients
were not on disease modifying therapy, already had significant stenosis
requiring transfusions, or had undergone curative bone marrow
transplant.
In six patients (21%) there was complete resolution of previously seen
CNS vasculopathy that lead to a change in treatment plan; all six
patients were on chronic transfusion therapy for primary stroke
prevention and after review of newer imaging showing no vasculopathy,
this therapy was discontinued. Two patients had an increase in the
degree of classification of stenosis, suggestive of the commonly seen
progression of sickle cell CNS vasculopathy, without change in their
treatment plan.
As seen in Figure 4, 24 patients (83%) were on chronic transfusion
therapy prior to May 2016, while this number decreased to 18 (62%)
after May 2016. For the McNemar analysis (Table 2), clinical treatment
plans were categorized as “Transfusions” or “Not transfusions” both
pre- and post- implementation of the scanning protocol. 18 patients
remained in the same category of requiring transfusion therapy pre- and
post- implementation. While six patients on chronic transfusion therapy
were able to discontinue transfusion therapy, 0 patients required
escalation in treatment plan (starting chronic transfusion therapy).
Five patients with CNS vasculopathy remained off chronic transfusion
therapy. The proportion of patients with change in treatment plan after
the implementation of scanning protocol with TE < 5msec was
found to be statistically significant (p = 0.0412).