Although both ends of the hemoglobin range may negatively influence clinical outcomes in acute ischemic stroke, most studies have examined the linear relationship or focused on the lower end of the range. Furthermore, it is unclear whether hemoglobin concentrations at different time points during hospitalization correlate with clinical outcomes in the same manner.
We identified 2681 consecutive patients with acute ischemic stroke from a prospective stroke registry database and grouped them into hemoglobin concentration quintiles using the following 5 indices: initial, nadir, time-averaged, discharge hemoglobin, and hemoglobin drop. To examine the effect of both ends of hemoglobin range, the third quintile was selected as a reference category except for hemoglobin drop, for which the first quintile was used. As outcome variables, 3-month modified Rankin Scale as an ordinal scale and 3-month mortality were used.
With respect to higher modified Rankin Scale scores, the adjusted odds ratios and 95% confidence intervals of the first quintiles of initial, nadir, time-averaged, and discharge hemoglobin were 1.74 (1.31-2.31), 2.64 (2.09-3.33), 1.81 (1.42-2.30), and 1.65 (1.29-2.13), respectively. The opposite ends of these hemoglobin indices were not significantly associated. The adjusted odds ratio of the fifth quintile of hemoglobin drop (greatest hemoglobin drop) was 2.09 (1.51-2.89). The mortality analysis showed similar results except for initial hemoglobin.
In acute ischemic stroke, poor outcome was related to the lower but not the higher end of the hemoglobin range, regardless of when and how hemoglobin concentrations were measured.
[Show abstract][Hide abstract] ABSTRACT: Missing data are a pervasive problem in health investigations. We describe some background of missing data analysis and criticize ad hoc methods that are prone to serious problems. We then focus on multiple imputation, in which missing cases are first filled in by several sets of plausible values to create multiple completed datasets, then standard complete-data procedures are applied to each completed dataset, and finally the multiple sets of results are combined to yield a single inference. We introduce the basic concepts and general methodology and provide some guidance for application. For illustration, we use a study assessing the effect of cardiovascular diseases on hospice discussion for late stage lung cancer patients.
[Show abstract][Hide abstract] ABSTRACT: There is considerable debate regarding whether anemia qualifies as a prognostic factor for stroke. The purpose of this study was twofold: first, to assess the influence of anemia on vascular risk factors and clinical presentations in patients with first-ever atherosclerosis-related ischemic stroke and, second, to evaluate whether anemia may be of prognostic importance. A total of 774 consecutive patients with first-ever atherosclerosis-related ischemic stroke were prospectively investigated. Vascular risk factors, clinical presentations and outcomes were recorded and compared between those patients with and without anemia. Stroke recurrence and mortality were recorded at the 3-year follow-up. Of the study population, 168 (21.7%) were anemic. Multivariate analysis revealed that patients with anemia were more likely to be older than 70 years (p<0.001) and have chronic renal insufficiency (p<0.001). After a mean follow-up period of 958 days, 21 (12.5%) and 24 (4.0%) of the patients in the anemic and control groups, respectively, died. Within 3 years of initial onset, the mortality rate was significantly higher in patients with anemia (p=0.021). The Kaplan-Meier analysis for patients with and without anemia showed different survival curves (Log-rank test p<0.001). Within 3 years of the onset of first-ever atherosclerosis-related ischemic stroke, patients who had anemia at the time of the initial admission had an associated higher mortality rate. The stroke risk factors of being older than 70 years and having chronic renal insufficiency were more frequently observed in those patients with anemia.
[Show abstract][Hide abstract] ABSTRACT: Although conceivably relevant for penumbra oxygenation, the optimal levels of hemoglobin (Hb) and hematocrit (Hct) in patients with acute ischemic stroke are unknown.
We identified patients from our prospective local stroke database who received intravenous thrombolysis based on multimodal magnet resonance imaging during the years 1998 to 2009. A favorable outcome at 3 months was defined as a modified Rankin Scale score≤2 and a poor outcome as a modified Rankin Scale score≥3. The dynamics of Hemoglobin (Hb), Hematocrit (Hct), and other relevant laboratory parameters as well as cardiovascular risk factors were retrospectively assessed and analyzed between these 2 groups.
Of 217 patients, 114 had a favorable and 103 a poor outcome. In a multivariable regression model, anemia until day 5 after admission (odds ratio [OR]=2.61; 95% CI, 1.33 to 5.11; P=0.005), Hb nadir (OR=0.81; 95% CI, 0.67 to 0.99; P=0.038), and Hct nadir (OR=0.93; 95% CI, 0.87 to 0.99; P=0.038) remained independent predictors for poor outcome at 3 months. Mortality after 3 months was independently associated with Hb nadir (OR=0.80; 95% CI, 0.65 to 0.98; P=0.028) and Hb decrease (OR=1.34; 95% CI, 1.01 to 1.76; P=0.04) as well as Hct decrease (OR=1.12; 95% CI, 1.01 to 1.23; P=0.027).
Poor outcome and mortality after ischemic stroke are strongly associated with low and further decreasing Hb and Hct levels. This decrease of Hb and Hct levels after admission might be more relevant and accessible to treatment than are baseline levels.
Data provided are for informational purposes only. Although carefully collected, accuracy cannot be guaranteed. The impact factor represents a rough estimation of the journal's impact factor and does not reflect the actual current impact factor. Publisher conditions are provided by RoMEO. Differing provisions from the publisher's actual policy or licence agreement may be applicable.