Stroke in patients with sickle cell disease

Figures & data

Figure 1. Transcranial Doppler screening recommendations.

^†Consider repeating TCD more frequently in those with additional risk factors such as silent infarcts, family history of stroke or abnormal TCD or abnormal MRA.

MRA: Magnetic resonance angiography; SCD-SS: Homozygous sickle-cell disease; TCD: Transcranial Doppler ultrasound.

Table 1. Risk factors for cerebrovascular events.

Ischemic stroke	Hemorrhagic stroke	Silent infarcts
Prior TIA	Low hemoglobin	Low hemoglobin
Frequent/recent ACS	High white blood count	High white blood count
Increased SBP	History of hypertension	Increased SBP
Prior silent infarct	Older age	History of seizures
Nocturnal hypoxemia (<90%)	Recent PRBC transfusion	Male gender
High velocity blood flow on TCD	Frequent admissions for VOERecent treatment with steroids or NSAIDs	SEN haplotype

ACS: Acute chest syndrome; PRBC: Packed red blood cell; SBP: Systolic blood pressure; TCD: Transcranial Doppler; TIA: Transient ischemic attack; VOE: Vaso-occlusive events.

Table 2. Rates of stroke recurrence with hydroxyurea.

Study (year)	Type of study	Use of HU	Individuals (n)	Mean age (years)	Duration of CTT prior to HU (months)	Maximum tolerated dose of HU (mg/kg/day)	Rate of stroke recurrence	Ref.
Sumoza et al. (2002)	Prospective study	HU alone or after CTT	5	Range: 3–16	2 subjects received CTT prior to HU for 31 and 33 months	38	No recurrent events after 42–112 months of observation	[108]
Lefèvre et al. (2008)	Retrospective case series	HU alone	4	NR	NA	NR	2.9 per 100 person-years	[109]
Ali et al. (2011)	Prospective study	HU alone	10	7.7 ± 2.7	NA	25.4 ± 3.4	2 per 100 person-years	[104]
Ware et al. (1999)	Prospective study	HU after CTT	16	12.1 ± 4.9	56 ± 36	24.9 ± 4.2	6.8 per 100 person-years	[107]
Ware et al. (2004)	Prospective study	HU after CTT	15	13.1 ± 4.9	50 ± 33^†	26.0 ± 4.3	7.4 per 100 person-years	[105]
Ware et al. (2004)	Prospective study	HU after CTT with transfusion overlap	20	11.1 ± 2.9	50 ± 33^†	27.2 ± 5.1	3.6 per 100 person-years	[105]
Ware et al. (2012)	Randomized clinical trial	HU after CTT with transfusion overlap	67	13.0 ± 4.0	88.8 ± 45.6	26.2 ± 4.9	5.6 per 100 person-years	[106]

^†All subjects in the study included. Duration of chronic transfusion therapy for each of the two cohorts of subjects not reported.

CTT: Chronic transfusion therapy; HU: Hydroxyurea; NA: Not applicable; NR: Not reported.

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