Cerebrovascular disease incidence, characteristics, and outcomes in patients initiating dialysis: the choices for healthy outcomes in caring for ESRD (CHOICE) study

Abstract

Background: Stroke is the third most common cause of cardiovascular disease death in patients on dialysis therapy; however, characteristics of cerebrovascular disease, including clinical subtypes and subsequent consequences, have not been well described.

Study design: Prospective national cohort study, the Choices for Healthy Outcomes in Caring for End-Stage Renal Disease (CHOICE) Study.

Settings & participants: 1,041 incident dialysis patients treated in 81 clinics enrolled from October 1995 to July 1998, followed up until December 31, 2004.

Predictor: Time from dialysis therapy initiation.

Outcomes & measurements: Cerebrovascular disease events were defined as nonfatal (hospitalized stroke and carotid endarterectomy) and fatal (stroke death) events after dialysis therapy initiation. Stroke subtypes were classified by using standardized criteria from the Trial of ORG 10172 in Acute Stroke Treatment (TOAST) system. The incidence of cerebrovascular event subtypes was analyzed by using time-to-event analyses accounting for competing risk of death. Clinical outcomes after stroke were abstracted from medical records.

Results: 165 participants experienced a cerebrovascular event with an overall incidence of 4.9 events/100 person-years. Ischemic stroke was the most common (76% of all 200 events), with cardioembolism subtype accounting for 28% of the 95 abstracted ischemic events. Median time from onset of symptoms to first stroke evaluation was 8.5 hours (25th and 75th percentiles, 1 and 42), with only 56% of patients successfully escaping death, nursing home, or skilled nursing facility.

Limitations: Relatively small sample size limits power to determine risk factors.

Conclusions: Cerebrovascular disease is common in dialysis patients, is identified late, and carries a significant risk of morbidity and mortality. Stroke etiologic subtypes on dialysis therapy are multifactorial, suggesting risk factors may change the longer one has end-stage renal disease. Additional studies are needed to address the poor prognosis through prevention, early identification, and treatment.

Figure 1. Cerebrovascular Event Classification in 1,041 Incident Dialysis Patients

The numbers of each cerebrovascular event, including recurrent events, are shown. Event types were determined from ICD-9 codes and chart abstraction. Ischemic stroke subtypes were defined using the Trial of ORG 10172 in Acute Stroke Treatment (TOAST) classification system by two abstractors. CEA: Carotid endarterectomy USRDS: U.S. Renal Data System *for 165 patients; 35 had repeated events †No statistically significant differences from non-abstracted patients with regard to demographics, comorbid conditions, or baseline laboratory results

Figure 2. Cumulative Incidence of Cerebrovascular Events in Incident Dialysis Patients

The cumulative incidence accounts for the competing risk of death from causes other than stroke. CEA: Carotid Endarterectomy