Risk Factors and Stroke Subtypes: Results of Five Consecutive Years of the Perugia Stroke Registry

A tool to identify patients with embolic stroke of undetermined source at high recurrence risk

OBJECTIVE

A tool to stratify the risk of stroke recurrence in patients with embolic stroke of undetermined source (ESUS) could be useful in research and clinical practice. We aimed to determine whether a score can be developed and externally validated for the identification of patients with ESUS at high risk for stroke recurrence.

METHODS

We pooled the data of all consecutive patients with ESUS from 11 prospective stroke registries. We performed multivariable Cox regression analysis to identify predictors of stroke recurrence. Based on the coefficient of each covariate of the fitted multivariable model, we generated an integer-based point scoring system. We validated the score externally assessing its discrimination and calibration.

RESULTS

In 3 registries (884 patients) that were used as the derivation cohort, age, leukoaraiosis, and multiterritorial infarct were identified as independent predictors of stroke recurrence and were included in the final score, which assigns 1 point per every decade after 35 years of age, 2 points for leukoaraiosis, and 3 points for multiterritorial infarcts (acute or old nonlacunar). The rate of stroke recurrence was 2.1 per 100 patient-years (95% confidence interval [CI] 1.44-3.06) in patients with a score of 0-4 (low risk), 3.74 (95% CI 2.77-5.04) in patients with a score of 5-6 (intermediate risk), and 8.23 (95% CI 5.99-11.3) in patients with a score of 7-12 (high risk). Compared to low-risk patients, the risk of stroke recurrence was significantly higher in intermediate-risk (hazard ratio [HR] 1.78, 95% CI 1.1-2.88) and high-risk patients (HR 4.67, 95% CI 2.83-7.7). The score was well-calibrated in both derivation and external validation cohorts (8 registries, 820 patients) (Hosmer-Lemeshow test χ²: 12.1 [p = 0.357] and χ²: 21.7 [p = 0.753], respectively). The area under the curve of the score was 0.63 (95% CI 0.58-0.68) and 0.60 (95% CI 0.54-0.66), respectively.

CONCLUSIONS

The proposed score can assist in the identification of patients with ESUS at high risk for stroke recurrence.

Renal Function and Risk Stratification of Patients With Embolic Stroke of Undetermined Source

Background and Purpose- We aimed to assess if renal function can aid in risk stratification for ischemic stroke or transient ischemic attack (TIA) recurrence and death in patients with embolic stroke of undetermined source (ESUS). Methods- We pooled 12 ESUS datasets from Europe and America. Renal function was evaluated using the estimated glomerular filtration rate (eGFR) and analyzed in continuous, binary, and categorical way. Cox-regression analyses assessed if renal function was independently associated with the risk for ischemic stroke/TIA recurrence and death. The Kaplan-Meier product limit method estimated the cumulative probability of ischemic stroke/TIA recurrence and death. Results- In 1530 patients with ESUS followed for 3260 patient-years, there were 237 recurrences (15.9%) and 201 deaths (13.4%), corresponding to 7.3 ischemic stroke/TIA recurrences and 5.6 deaths per 100 patient-years, respectively. Renal function was not associated with the risk for ischemic stroke/TIA recurrence when forced into the final multivariate model, regardless if it was analyzed as continuous (hazard ratio, 1.00; 95% CI, 0.99-1.00 for every 1 mL/min), binary (hazard ratio, 1.27; 95% CI, 0.87-1.73) or categorical covariate (likelihood-ratio test 2.59, P=0.63 for stroke recurrence). The probability of ischemic stroke/TIA recurrence across stages of renal function was 11.9% for eGFR ≥90, 16.6% for eGFR 60-89, 21.7% for eGFR 45-59, 19.2% for eGFR 30-44, and 24.9% for eGFR <30 (likelihood-ratio test 2.59, P=0.63). The results were similar for the outcome of death. Conclusions- The present study is the largest pooled individual patient-level ESUS dataset, and does not provide evidence that renal function can be used to stratify the risk of ischemic stroke/TIA recurrence or death in patients with ESUS.

Mexican-National Institute of Neurology and Neurosurgery-Stroke Registry: Results of a 25-Year Hospital-Based Study

Background and purpose

Stroke has been scarcely studied in Latin America (LA). The Mexican Institute of Neurology Stroke Registry was established in 1990 as a prospective computer-based database to register data obtained from patients admitted with stroke. Using this data, we attempted to define the profile of risk factors and outcomes.

Methods

The demographic data, stroke description, ancillary tests, vascular risk factors, and modified Rankin scale (mRs) were registered. Ischemic stroke subtyping was based on the Trial of Org 10,172 of the Acute Stroke Treatment classification. We followed-up patients using multiple overlapping methods. Primary outcomes included mRs, recurrence, and death at 30 days and at the end of follow-up.

Results

We included 4,481 patients with a median follow-up of 27 months, (17,281 person-years follow-up). The mean age was 52.8 ± 18 years. There were 2,229 males (50%) included in the study. CI was present in 64.9%, intracerebral hemorrhage (ICH) in 25.6%, and cerebral venous thrombosis (CVT) in 6.3%. Hypertension was the major risk factor (46.5%). The most common cause of CI was atherosclerosis (27%). ICH was mainly hypertensive (58%), and 60% of CVT were puerperal. Overall, the mortality rate was 24.5%. The recurrence rate was 16.9%. Poor outcome (mRs ≥ 3) was found in 56.2% of patients. The best outcomes were observed in CVT patients (74.5% mRs ≤ 2), whereas 72.1% ICH patients had mRs ≥3.

Conclusion

This is one of the largest hospital-based registries in LA and shows significant differences with other previously published registries, including a younger age, relatively less hypertension, and larger proportion of CVT. Poor functional outcome was common. This study adds to the understanding of geographic differences in stroke characteristics and outcomes.

Comparing Risk Factor Profiles between Intracerebral Hemorrhage and Ischemic Stroke in Chinese and White Populations: Systematic Review and Meta-Analysis

BACKGROUND

Chinese populations have a higher proportion of intracerebral hemorrhage (ICH) in total strokes. However, the reasons are not fully understood.

METHODS

To assess the differences in frequency of major risk factors between ICH and ischemic stroke (IS) in Chinese versus white populations of European descent, we systematically sought studies conducted since 1990 that compared frequency of risk factors between ICH and IS in Chinese or white populations. For each risk factor, in Chinese and Whites separately, we calculated study-specific and random effects pooled prevalence and odds ratios (ORs) for ICH versus IS.

RESULTS

Six studies among 36,190 Chinese, and seven among 52,100 white stroke patients studied hypertension, diabetes, atrial fibrillation (AF), ischemic heart disease (IHD), hypercholesterolemia, smoking and alcohol. Pooled prevalence of AF was significantly lower in Chinese. Pooled ORs for ICH versus IS were mostly similar in Chinese and Whites. However, in Chinese--but not Whites--mean age was lower (62 versus 69 years), while hypertension and alcohol were significantly more frequent in ICH than IS (ORs 1.38, 95% CI 1.18-1.62, and 1.46, 1.12-1.91). Hypercholesterolemia and smoking were significantly less frequent in ICH in Whites, but not Chinese, while IHD, AF and diabetes were less frequent in ICH in both.

CONCLUSIONS

Different risk factor distributions in ICH and IS raise interesting possibilities about variation in mechanisms underlying the different distributions of pathological types of stroke between Chinese and Whites. Further analyses in large, prospective studies, including adjustment for potential confounders, are needed to consolidate and extend these findings.

Risk Factors for Ischemic Stroke and its Subtypes in Chinese vs. Caucasians: Systematic Review and Meta-Analysis

Background

Chinese populations are reported to have a different distribution of ischemic stroke subtypes compared with Caucasians.

Aims

To understand this better, we aimed to evaluate the differences in prevalence of risk factors in ischemic stroke and their distributions among ischemic stroke subtypes in Chinese vs. Caucasians.

Summary or review

We systematically sought studies conducted since 1990 with data on frequency of risk factors among ischemic stroke subtypes in Chinese or Caucasians. For each risk factor, we calculated study-specific and random effects pooled estimates in Chinese and Caucasians separately for: prevalence among ischemic stroke; odds ratios, comparing prevalence for each ischemic stroke subtype vs. all others. We included seven studies among 16 199 Chinese, and eleven among 16 189 Caucasian ischemic stroke patients. Risk factors studied were hypertension, diabetes, atrial fibrillation, ischemic heart disease, hypercholesterolemia, smoking and alcohol. Chinese ischemic stroke patients had younger onset of stroke than Caucasians, similar prevalence of hypertension, diabetes, smoking and alcohol, and significantly lower prevalence of atrial fibrillation, ischemic heart disease and hypercholesterolemia. Risk factor associations with ischemic stroke subtypes were mostly similar among Chinese and Caucasian ischemic stroke patients. Compared with all other ischemic subtypes, diabetes was more common in large artery stroke, atrial fibrillation and ischemic heart disease in cardioembolic stroke, and hypertension and diabetes in lacunar stroke.

Conclusion

Our study showed a lower prevalence of atrial fibrillation, ischemic heart disease and hypercholesterolemia in Chinese, and mostly similar risk factor associations in Chinese and Caucasian ischemic stroke patients. Further analyses of individual patient data to allow adjustment for confounders are needed to confirm and extend these findings.

Stroke incidence and 30-day and six-month case fatality rates in Udine, Italy: a population-based prospective study

BACKGROUND

Stroke incidence in high-income countries is reported to decrease, and new data on stroke incidence and outcome are needed to design stroke services and to ameliorate stroke management.

METHODS

This study is part of a two-year prospective community-based registry of all cerebrovascular events in the district of Udine (153,312 inhabitants), Friuli-Venezia Giulia region, northeast of Italy, between 1 April 2007 and 31 March 2009. Overlapping sources for case finding were used, combining hot and cold pursuit.

RESULTS

We identified 784 stroke cases, 640 (81.6%) incident. The crude overall annual incidence rate per 100,000 residents was 256 (95% confidence interval 241-271) for all strokes and 209 (95% confidence interval 195-223) for first-ever strokes. Incidence rate for first-ever strokes was 181 (95% confidence interval 155-211) after adjustment to the 2007 Italian population and 104 (95% confidence interval 88-122) compared with the European standard population. Incidence rates for first-ever strokes was 215 (196-235) for women, 202 (183-223) for men. Crude annual incidence rates per 100,000 population were 167 (153-178) for ischemic stroke, 31 (26-37) for intracerebral hemorrhage, 8.1 (5.7-11.4) for sub-arachnoid hemorrhage, and 4.6 (2.8-7.1) for undetermined stroke. Overall case fatality rates for first-ever stroke were 20.6% at 28 days and 30.2% at 180 days.

CONCLUSIONS

Our study shows incidence rates higher than previously reported in our region but not supporting the view of higher incidence rates in Northern than in Southern Italy. Results contribute to time-trends analysis on epidemiology, useful for dimensioning services in Italy and show the persistence of a gap between the outcome of stroke in Italy and that of the best performing European countries, urging to adopt better stroke management plans.

The Lombardia Stroke Unit Registry: 1-year experience of a web-based hospital stroke registry

This paper presents methodological aspects of the Lombardia Stroke Registry. At the registry start-up, 36 recruiting centres were identified according to a regional survey. The registry recruits consecutive patients with acute stroke or transient ischaemic attacks (TIAs). A 3-month follow-up was planned to correlate acute care with outcomes. On 31st December 2007, data concerning 6,181 patients discharged alive were available. The registry aims at measuring performance parameters, identifying guidelines non-compliance and analysing care processes. In this first phase, 30% of the Lombardia acute stroke and 10% of TIA patients have been enrolled, thus the sample can be considered informative for the disease care in the region. The proportion of completed data items is very high with very small differences among items. The following critical points were highlighted: (1) lack of data input staff for 30% of centres, and (2) difficulty of obtaining the informed consent for post-discharge follow-up.