Oleg Merzeliak

Chronic Kidney Disease and Clinical Outcome in Patients With Acute Stroke

Background and Purpose— Chronic kidney disease (CKD) is increasingly recognized as an independent risk factor for cardiovascular disease and stroke. Our aim was to examine the association between estimated glomerular filtration rate (GFR) and stroke outcome and to assess whether CKD and its severity affect stroke outcome in a large cohort of unselected patients with acute stroke. Methods— We examined the association between baseline estimated GFR and CKD and 1-year outcomes in 821 consecutive patients with acute stroke (ischemic or hemorrhagic). GFR was estimated by 2 methods: the Modification of Diet in Renal Disease and the Mayo Clinic quadratic equation. An estimated GFR rate ≤60 mL/min/1.73 m2 defined CKD. Results— Odds ratios (95% CI) for death across levels of estimated GFR based on both equations were estimated. CKD was present in 36% (n=291) of patients based on the Modification of Diet in Renal Disease equation and 18% (n=147) based on the Mayo Clinic equation. The adjusted ORs for mortality after 1-year based on the Modification of Diet in Renal Disease equation were 0.7 (95% CI, 0.4 to 1.2) associated with GFR 45 to 60 and 3.2 (1.7 to 6.4) associated with GFR 15 to 44 as compared with GFR >60 mL/min/1.73 m2, whereas those based on the Mayo Clinic equation were 2.3 (1.1 to 4.7) and 3.3 (1.6 to 7.1), respectively. The adjusted ORs for Barthel Index ≤75 or death after 1 year were 0.8 (0.5 to 1.5) and 2.1 (0.9 to 4.8) by the Modification of Diet in Renal Disease equation and 1.9 (0.8 to 4.4) and 3.9 (1.5 to 11.0) by the Mayo Clinic equation, respectively. Conclusions— CKD is a strong independent predictor of mortality and poor outcome in patients with acute stroke. The estimation of the prevalence of CKD and of the GFR cutoffs associated with poor outcome depend on the equation used to estimate GFR.

Chronic Kidney Disease in Patients with Acute Intracerebral Hemorrhage: Association with Large Hematoma Volume and Poor Outcome

Background: Chronic kidney disease (CKD) is associated with both a risk of adverse vascular outcome and a risk of bleeding. We have tested the hypothesis that in the setting of an acute intracerebral hemorrhage (ICH), CKD is associated with poor outcome and with larger hematoma volume. Methods: We examined the association between CKD and ICH characteristics and outcome within a prospective cohort study of consecutive patients hospitalized with an acute stroke and followed for 1 year. CKD was categorized by the estimated baseline glomerular filtration rate into moderate/severe impairment (<45), mild impairment (45–60) and no impairment (>60 ml/min/1.73 m2). Results: Among 128 patients with an ICH (mean age = 71.7 ± 12.3 years, 41.4% women) 46.1% had CKD (23.4% mild and 22.7% moderate/severe). Patients with moderate/severe impairment had >4-fold adjusted hazard ratio for mortality over 1 year (4.29; 95% CI = 1.69–10.90) compared to patients with no impairment. The hematoma volumes [median (25–75%)] were 15.3 ml (5.4–37.5) in patients with no impairment, 16.6 (6.8–36.9) in mild impairment and 50.2 (10.4–109.1) in moderate/severe impairment (p = 0.009). The location of the hematoma was lobar in 12% with no impairment, 17% with mild impairment and 39% with moderate/severe impairment (p = 0.02). Patients with moderate/severe impairment exhibited a 2.3-fold higher hematoma volume (p = 0.04) and a >6-fold higher odds of lobar location (95% CI = 1.59–24.02) as compared to no impairment. Further adjustment for antiplatelet use and for presence of leukoaraiosis attenuated the association with hematoma volume (p = 0.15), while moderate/severe impairment was associated with an adjusted OR of 5.35 (95% CI = 1.18–24.14) for lobar location. Conclusions: Presence of moderate/severe CKD among patients with ICH is associated with larger, lobar hematomas and with poor outcome.

Anemia status, hemoglobin concentration and outcome after acute stroke: a cohort study

BackgroundIn the setting of an acute stroke, anemia has the potential to worsen brain ischemia, however, the relationship between the entire range of hemoglobin to long-term outcome is not well understood.MethodsWe examined the association between World Health Organization-defined admission anemia status (hemoglobin<13 in males, <12 g/dl in women) and hemoglobin concentration and 1-year outcome among 859 consecutive patients with acute stroke (ischemic or intracerebral hemorrhage).ResultsThe mean baseline hemoglobin concentration was 13.8 ± 1.7 g/dl (range 8.1 - 18.7). WHO-defined anemia was present in 19% of patients among both women and men. After adjustment for differences in baseline characteristics, patients with admission anemia had an adjusted OR for all-cause death at 1-month of 1.90 (95% CI, 1.05 to 3.43) and at 1-year of 1.72 (95% CI, 1.00 to 2.93) and for the combined end-point of disability, nursing facility care or death of 2.09 (95% CI, 1.13 to 3.84) and 1.83 (95% CI, 1.02 to 3.27) respectively. The relationship between hemoglobin quartiles and all-cause death revealed a non-linear association with increased risk at extremes of both low and high concentrations. In logistic regression models developed to estimate the linear and quadratic relation between hemoglobin and outcomes of interest, each unit increment in hemoglobin squared was associated with increased adjusted odds of all-cause death [at 1-month 1.06 (1.01 to 1.12; p = 0.03); at 1-year 1.09 (1.04 to 1.15; p < 0.01)], confirming that extremes of both low and high levels of hemoglobin were associated with increased mortality.ConclusionsWHO-defined anemia was common in both men and women among patients with acute stroke and predicted poor outcome. Moreover, the association between admission hemoglobin and mortality was not linear; risk for death increased at both extremes of hemoglobin.

Cerebral leukoaraiosis in patients with stroke or TIA: clinical correlates and 1-year outcome.

Background and purpose:  Cerebral leukoaraiosis is frequently observed in patients with acute stroke, but its clinical consequences on functional recovery remain incompletely defined. We evaluated the clinical correlates of leukoaraiosis, and its association with stroke‐outcome in a cohort of consecutively hospitalized patients.

Interleukin-6 and soluble intercellular adhesion molecule-1 in acute brain ischaemia

Inflammation plays a critical role in the pathogenesis of atherothrombosis. Our aim was to examine the association between plasma concentrations of inflammatory biomarkers and severity and outcome of acute brain ischaemia. Plasma samples were collected within 36 h of symptom onset in patients with acute brain ischaemia, and assessed by conventional ELISA kits for concentration of interleukin‐6 (IL‐6) and soluble intercellular adhesion molecule‐1 (sICAM‐1). Patients were assessed serially for stroke severity (National Institute of Health stroke scale) and outcome during follow‐up (modified Rankin Scale, mRS; and Stroke Impact Scale‐16, SIS). Patients (n = 113, 65% men, mean age 64 ± 12 years) had a mean IL‐6 concentrations of 5.1 ± 5.0 pg/ml and sICAM‐1 of 377 ± 145 ng/ml. IL‐6, but not sICAM‐1, concentrations were strongly associated with stroke severity (P < 0.01 at all serial assessments). Ln‐transformed IL‐6 levels (per 1 SD) were associated with disability (mRS ≥2, OR = 1.7; 95% CI 1.1–3.0) and poor physical function (SIS ≤85, OR = 1.7; 95% CI 1.0–2.8). Further adjustment for baseline stroke severity, however, eliminated these associations. Our results suggest that high plasma concentrations of the inflammatory biomarker IL‐6 but not sICAM‐1 are associated with stroke severity and poorer functional outcome. IL‐6 does not add, however, additional prognostic information for stroke outcome beyond that conveyed by the stroke severity.

Cerebral artery calcification in patients with acute cerebrovascular diseases: determinants and long‐term clinical outcome

Background and purpose:  Coronary artery calcium is an independent predictor of all‐cause mortality. We sought to examine the determinants of intracranial cerebral artery calcification (CAC) and its association with long‐term outcome in a large prospective cohort of stroke patients.

Serum calcium levels and long-term mortality in patients with acute stroke.

Background: Calcium concentrations in serum are maintained within an exquisitely narrow range. Our aim was to examine the association between serum calcium and albumin-adjusted calcium (calciumadj) levels and stroke outcome in a cohort of unselected patients with acute stroke. Methods: Consecutive patients hospitalized due to acute stroke (ischemic or intracerebral hemorrhage) throughout a large medical center were systematically assessed and followed for 1 year. Baseline total calcium and calciumadj levels were collapsed into groups of low (<8.6 mg/dl), normal (8.7–9.9 mg/dl) and high (>10 mg/dl) levels and linear and quadratic relations with outcome were examined. Result: Among 784 patients (mean age 70.7 ± 12.5 years, 42.5% females), the mean ± SD total calcium level was 9.3 ± 0.6 mg/dl. For total calcium, the adjusted hazard ratio (HR) for all-cause death over 1 year was 1.83 [95% confidence interval (CI) 1.22–2.75] among patients with low versus normal levels. For calciumadj, the adjusted HR for all-cause death among women was over 3-fold higher among patients with high calciumadj levels versus those with normal levels (3.31; 95% CI 1.70–6.46), while no such associations were observed among men. In models developed to estimate the linear and quadratic relations, each unit increment in total calcium squared was associated with an increased adjusted HR of all-cause death over 1 year (p = 0.02) confirming nonlinear associations, and each unit increment in calciumadj squared was associated with an increased adjusted HR of all-cause death over 1 year among women (p < 0.001) but not among men (p = 0.70). Conclusions: Serum calcium concentrations are a marker of mortality in acute stroke patients, but the associations are not linear, increasing at both extremes of calcium levels. Our findings suggest that long-term survival is optimal in a distinct range of serum calcium levels.