Appraising stroke risk in maintenance hemodialysis patients: a large single-center cohort study

Abstract

Background: Stroke incidence in hemodialysis patients is up to 10 times greater than in the general population and is associated with a worse prognosis. Factors influencing stroke risk by subtype and subsequent prognosis are poorly described in the literature.

Study design: Retrospective single-center cohort study.

Setting & participants: 2,384 established maintenance hemodialysis patients at a single center from January 1, 2002, to June 1, 2009.

Predictor: Patient demographics, comorbid conditions.

Outcomes: Incidence of acute stroke (International Classification of Diseases, 9th Revision codes 430, 431, 432.9, 433.1, and 434.1 with evidence of compatible neuroimaging), patient survival.

Measurements: Cumulative patient survival, incidence of acute fatal and nonfatal stroke.

Results: 127 strokes occurred during 9,541 total patient-years of follow-up. First (incident) stroke occurred at a rate of 14.9/1,000 patient years (95% CI, 12.2-17.9) with a predominance of ischemic compared with hemorrhagic subtypes (11.2 vs 3.7/1,000 patient-years). 54% of hemorrhagic strokes occurred in patients of South Asian ethnicity compared with ischemic strokes, which occurred predominantly in white patients (45% of events). Diabetes mellitus (HR, 1.92; 95% CI, 1.29-2.85; P = 0.001) and prior cerebrovascular disease (HR, 4.54; 95% CI, 3.07-6.72; P < 0.001) were independently associated with incident cerebrovascular accident on multivariate analysis. Acute stroke was associated with worse patient survival (HR, 3.26; 95% CI, 2.47-4.30; P < 0.001) and overall 1-year mortality of 24%, which was significantly worse in patients with hemorrhagic events (39% vs 19% mortality for ischemic subtypes). Serum albumin level >3.5 g/L (HR, 0.38; 95% CI, 0.19-0.76; P = 0.007) and C-reactive protein level >3.0 mg/l (HR, 1.36; 95% CI, 1.12-1.64; P = 0.002) influenced survival after stroke on multivariate analysis.

Limitations: Retrospective analysis of data cannot prove causality.

Conclusions: The high incidence of stroke in hemodialysis patients is associated with high mortality, especially hemorrhagic subtypes. Strict management of hypertension, better appreciation of hemodialysis anticoagulation, and large-scale interventional studies are urgently required to direct prevention and treatment of this significant disease.