The Dutch String-of-Pearls Stroke Study: protocol of a large prospective multicenter genetic cohort study

Sex Differences in Risk Profile, Stroke Cause and Outcome in Ischemic Stroke Patients With and Without Migraine

Background: An increased risk of stroke in patients with migraine has been primarily found for women. The sex-dependent mechanisms underlying the migraine–stroke association, however, remain unknown. This study aims to explore these sex differences to improve our understanding of pathophysiological mechanisms behind the migraine–stroke association.

Methods: We included 2,492 patients with ischemic stroke from the prospective multicenter Dutch Parelsnoer Institute Initiative study, 425 (17%) of whom had a history of migraine. Cardiovascular risk profile, stroke cause (TOAST classification), and outcome [modified Rankin scale (mRS) at 3 months] were compared with both sexes between patients with and without migraine.

Results: A history of migraine was not associated with sex differences in the prevalence of conventional cardiovascular risk factors. Women with migraine had an increased risk of stroke at young age (onset < 50 years) compared with women without migraine (RR: 1.7; 95% CI: 1.3–2.3). Men with migraine tended to have more often stroke in the TOAST category other determined etiology (RR: 1.7; 95% CI: 1.0–2.7) in comparison with men without migraine, whereas this increase was not found in women with migraine. Stroke outcome was similar for women with or without migraine (mRS ≥ 3 RR 1.1; 95% CI 0.7–1.5), whereas men seemed to have a higher risk of poor outcome compared with their counterparts without migraine (mRS ≥ 3 RR: 1.5; 95% CI: 1.0–2.1).

Conclusion: Our results indicate possible sex differences in the pathophysiology underlying the migraine–stroke association, which are unrelated to conventional cardiovascular risk factors. Further research in larger cohorts is needed to validate these findings.

Smoking Does Not Alter Treatment Effect of Intravenous Thrombolysis in Mild to Moderate Acute Ischemic Stroke-A Dutch String-of-Pearls Institute (PSI) Stroke Study

Background: The smoking-thrombolysis paradox refers to a better outcome in smokers who suffer from acute ischemic stroke (AIS) following treatment with thrombolysis. However, studies on this subject have yielded contradictory results and an interaction analysis of exposure to smoking and thrombolysis in a large, multicenter database is lacking.

Methods: Consecutive AIS patients admitted within 12 h of symptom onset between 2009 and 2014 from the prospective, multicenter stroke registry (Dutch String-of-Pearls Stroke Study) were included for this analysis. We performed a generalized linear model for functional outcome 3 months post-stroke depending on risk of the exposure variables (smoking yes/no, thrombolysis yes/no). The following confounders were adjusted for: age, smoking, hypertension, atrial fibrillation, diabetes mellitus, stroke severity, and stroke etiology.

Results: Out of 468 patients, 30.6% (N = 143) were smokers and median baseline NIHSS was 3 (interquartile range 1–6). Smoking alone had a crude and adjusted relative risk (RR) of 0.99 (95% CI 0.89–1.10) and 0.96 (95% CI 0.86–1.01) for good outcome (modified Rankin Score ≤ 2), respectively. A combination of exposure variables (smoking and thrombolysis) did not change the results significantly [crude RR 0.87 (95% CI 0.74–1.03], adjusted RR 1.1 (95%CI 0.90–1.30)]. Smoking alone had an adjusted RR of 1.2 (95% CI 0.6–2.7) for recanalization following thrombolysis (N = 88).

Conclusions: In patients with mild to moderate AIS admitted within 12 h of symptom onset, smoking did not modify treatment effect of thrombolysis.

Design and protocol of a comprehensive multicentre biobank for abdominal aortic aneurysms

INTRODUCTION

The pathophysiology and natural course of abdominal aortic aneurysms (AAAs) are insufficiently understood. In order to improve our understanding, it is imperative to carry out longitudinal research that combines biomarkers with clinical and imaging data measured over multiple time points. Therefore, a multicentre biobank, databank and imagebank has been established in the Netherlands: the 'Pearl Abdominal Aortic Aneurysm' (AAA bank).

METHODS AND ANALYSIS

The AAA bank is a prospective multicentre observational biobank, databank and imagebank of patients with an AAA. It is embedded within the framework of the Parelsnoer Institute, which facilitates uniform biobanking in all university medical centres (UMCs) in the Netherlands. The AAA bank has been initiated by the two UMCs of Amsterdam UMC and by Leiden University Medical Center. Participants will be followed during AAA follow-up. Clinical data are collected every patient contact. Three types of biomaterials are collected at baseline and during follow-up: blood (including DNA and RNA), urine and AAA tissue if open surgical repair is performed. Imaging data that are obtained as part of clinical care are stored in the imagebank. All data and biomaterials are processed and stored in a standardised manner. AAA growth will be based on multiple measurements and will be analysed with a repeated measures analysis. Potential associations between AAA growth and risk factors that are also measured on multiple time points can be assessed with multivariable mixed-effects models, while potential associations between AAA rupture and risk factors can be tested with a conditional dynamic prediction model with landmarking or with joint models in which linear mixed-effects models are combined with Cox regression.

ETHICS AND DISSEMINATION

The AAA bank is approved by the Medical Ethics Board of the Amsterdam UMC (University of Amsterdam).

TRIAL REGISTRATION NUMBER

NCT03320408.

Cancer prevalence higher in stroke patients than in the general population: the Dutch String-of-Pearls Institute (PSI) Stroke study

Background and purpose

The aim of this study was to assess the prevalence of cancer and its characteristics in patients with ischemic stroke and to compare this with cancer prevalence in the general population.

Methods

This was a multicenter cohort study with 2736 patients presenting with ischemic stroke or transient ischemic attack. The prevalence of cancer was assessed by interview and verified by reviewing all medical records. In stroke patients with a history of cancer, we studied the subtype of cancer and its treatment characteristics. We used the national database of The Netherlands Cancer Registry to calculate population‐based age and sex cancer standardized prevalence ratios (SPRs) for patients with ischemic stroke.

Results

Cancer prevalence in ischemic stroke patients was 12%, corresponding to an SPR of 1.2 [95% confidence interval (CI), 1.0–1.3]. Increased SPRs were observed for cancer of the central nervous system (SPR, 18.2; 95% CI, 9.0–27.4), head and neck (SPR, 3.4; 95% CI, 2.3–4.6), lower respiratory tract (SPR, 2.4; 95% CI, 1.5–3.3) and urinary tract (SPR, 2.1; 95% CI, 1.4–2.9), but not for other cancer types. Cardiovascular risk factors, stroke etiology, treatment and outcome were not different between patients with or without a history of cancer.

Conclusions

In stroke patients, the prevalence of cancer, most prominently cancer of the central nervous system, head and neck, lower respiratory and urinary tract, was higher than in the general population. Medical treatment for the prevention of stroke in cancer survivors deserves further study.

The Dutch Pancreas Biobank Within the Parelsnoer Institute: A Nationwide Biobank of Pancreatic and Periampullary Diseases

OBJECTIVES

Large biobanks with uniform collection of biomaterials and associated clinical data are essential for translational research. The Netherlands has traditionally been well organized in multicenter clinical research on pancreatic diseases, including the nationwide multidisciplinary Dutch Pancreatic Cancer Group and Dutch Pancreatitis Study Group. To enable high-quality translational research on pancreatic and periampullary diseases, these groups established the Dutch Pancreas Biobank.

METHODS

The Dutch Pancreas Biobank is part of the Parelsnoer Institute and involves all 8 Dutch university medical centers and 5 nonacademic hospitals. Adult patients undergoing pancreatic surgery (all indications) are eligible for inclusion. Preoperative blood samples, tumor tissue from resected specimens, pancreatic cyst fluid, and follow-up blood samples are collected. Clinical parameters are collected in conjunction with the mandatory Dutch Pancreatic Cancer Audit.

RESULTS

Between January 2015 and May 2017, 488 patients were included in the first 5 participating centers: 4 university medical centers and 1 nonacademic hospital. Over 2500 samples were collected: 1308 preoperative blood samples, 864 tissue samples, and 366 follow-up blood samples.

CONCLUSIONS

Prospective collection of biomaterials and associated clinical data has started in the Dutch Pancreas Biobank. Subsequent translational research will aim to improve treatment decisions based on disease characteristics.

A replication study of genetic risk loci for ischemic stroke in a Dutch population: a case-control study

We aimed to replicate reported associations of 10 SNPs at eight distinct loci with overall ischemic stroke (IS) and its subtypes in an independent cohort of Dutch IS patients. We included 1,375 IS patients enrolled in a prospective multicenter hospital-based cohort in the Netherlands, and 1,533 population-level controls of Dutch descent. We tested these SNPs for association with overall IS and its subtypes (large artery atherosclerosis, small vessel disease and cardioembolic stroke (CE), as classified by TOAST) using an additive multivariable logistic regression model, adjusting for age and sex. We obtained odds ratios (OR) with 95% confidence intervals (95% CI) for the risk allele of each SNP analyzed and exact p-values by permutation. We confirmed the association at 4q25 (PITX2) (OR 1.43; 95% CI, 1.13-1.81, p = 0.029) and 16q22 (ZFHX3) (OR 1.62; 95% CI, 1.26-2.07, p = 0.001) as risk loci for CE. Locus 16q22 was also associated with overall IS (OR 1.24; 95% CI, 1.08-1.42, p = 0.016). Other loci previously associated with IS and/or its subtypes were not confirmed. In conclusion, we validated two loci (4q25, 16q22) associated with CE. In addition, our study may suggest that the association of locus 16q22 may not be limited to CE, but also includes overall IS.

Age-Specific Vascular Risk Factor Profiles According to Stroke Subtype

BACKGROUND

Ischemic and hemorrhagic stroke are increasingly recognized as heterogeneous diseases with distinct subtypes and etiologies. Information on variation in distribution of vascular risk factors according to age in stroke subtypes is limited. We investigated the prevalence of vascular risk factors in stroke subtypes in relation to age.

METHODS AND RESULTS

We studied a prospective multicenter university hospital-based cohort of 4033 patients. For patients with ischemic stroke caused by large artery atherosclerosis, small vessel disease, or cardioembolism and for patients with spontaneous intracerebral hemorrhage or aneurysmal subarachnoid hemorrhage, we calculated prevalences of vascular risk factors in 4 age groups: <55, 55 to 65, 65 to 75, and ≥75 years, and mean differences with 95% CIs in relation to the reference age group. Patients aged <55 years were significantly more often of non-white origin (in particular in spontaneous intracerebral hemorrhage and aneurysmal subarachnoid hemorrhage patients) and most often smoked (most prominent for aneurysmal subarachnoid hemorrhage patients). Patients aged <55 years with ischemic stroke caused by large artery atherosclerosis or small vessel disease more often had hypertension, hyperlipidemia, and diabetes mellitus than patients with ischemic stroke of cardiac origin. Overall, the frequency of hypertension, hyperlipidemia, and diabetes mellitus increased with age among all stroke subtypes, whereas smoking decreased with age. Regardless of age, accumulation of potentially modifiable risk factors was most pronounced in patients with ischemic stroke caused by large artery atherosclerosis or small vessel disease.

CONCLUSIONS

The prevalence of common cardiovascular risk factors shows different age-specific patterns among various stroke subtypes. Recognition of these patterns may guide tailored stroke prevention efforts aimed at specific risk groups.