Table 6 |
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Studies assessing the association between hemoglobin concentrations or anemia and subsequent clinical outcomes among patients with acute ischemic stroke |
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|
Study |
Patients |
Design and setting |
Exposure |
Outcome |
Main result |
Comment |
|
|
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|
Sacco and colleagues [174] |
3481 ischemic stroke |
Retrospective (prospective data-base) Multi-center |
Baseline hct (patients divided into quartiles) |
Death at 28 days |
Hct >46% associated with death, but only among women |
Hct ≤40% represented lowest quartile; effects of more extreme anemia not reported |
|
|
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Diamond and colleagues [175] |
1012 ischemic stroke |
Retrospective Single-center |
Baseline hct Median 41%; inter-quartile range 38 to 44% |
Discharge home (rather than nursing facility) |
High and low hct associated with worse outcome (U shaped curve) Optimal hct 45% |
Only 2% of patients had hct <30% at time of their stroke |
|
|
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|
Lowe and colleagues [177] |
270 ischemic stroke |
Retrospective Single-center |
Baseline hct |
Death in hospital |
Patients with high hct (≥50%) had higher mortality (66 to 71%) |
Elderly (≥75) with hct <40% also had higher mortality (65%) |
|
|
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Allport and colleagues [178] |
64 hemispheric ischemic stroke |
Prospective Single-center |
Baseline hct Median 42%; range 33 to 48% |
Reperfusion, infarct growth on serial MRI |
Higher hct associated with less reperfusion (OR = 0.53, P < 0.0001) and more infarct growth (OR = 1.26, P < 0.05) |
This was a study of the effects of high hct; few patients were anemic |
|
|
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†Huang and colleagues [179] |
774 ischemic stroke |
Prospective Single-center |
Anemia (Hb <13 g/dl for men, <12 g/dl for women) (21%) |
Death and mRS ≥3 at 3 years |
Anemic patients more likely to die (OR = 2.2, P = 0.02) and to have a poor neurological outcome (67% vs. 60%, P = 0.07) |
Numerous potential confounders not adjusted for; severity of anemia not well characterized |
|
|
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†Huang and colleagues [180] |
66 ischemic stroke (complicating ICA occlusion) |
Prospective Single center |
Anemia (Hb <13 for men, <12 for women) |
Death or recurrent stroke at 2 years |
Anemia associated with death or recurrent stroke at 2 years (OR = 5.1, P = 0.012) |
Numerous potential confounders not adjusted for; severity of anemia not well characterized |
|
|
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Nybo and colleagues [181] |
250 ischemic stroke |
Retrospective Single-center |
Anemia (Hb <13 g/dl for men, <12 g/dl for women) (15%) |
Death at 6 months |
Anemia associated with greater risk of death (OR = 3.6, CI = 1.4 to 9.3) |
Numerous potential confounders not adjusted for; severity of anemia not well characterized |
|
|
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Bhatia and colleagues [182] |
116 ischemic or hemorrhagic stroke |
Retrospective Single-center |
Baseline Hb |
Death at 30 days |
Hb not associated with risk of death |
Degree of anemia relatively mild |
|
|
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Wade and colleagues [183] |
1377 symptomatic cerebrovascular disease |
Retrospective (post hoc review of prospective RCT) Multi-center |
Hb >15 g/dl vs. ≥15 g/dl at study entry |
Stroke |
Patients with Hb ≥15 had similar outcomes to patients with Hb <15 g/dl |
This was a study of the effects of high Hb; few patients were anemic |
|
|
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|
LaRue and colleagues [184] |
2077 ischemic or hemorrhagic stroke |
Retrospective (prospective database) Multi-center |
Baseline hct (patients divided into quartiles) |
Death in hospital |
Hct not predictive of death (neither when high nor low) |
Neurologic outcomes (other than death) not reported |
|
|
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CI = confidence interval; Hb = hemoglobin; hct = hematocrit; ICA = internal carotid artery; MRI = magnetic resonance imaging; mRS = modified Rankin scale; OR = odds ratio; RCT = randomized controlled trial |
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Kramer and Zygun Critical Care 2009 13:R89 doi:10.1186/cc7916 |
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