A Comparison of Two Methods for MRI Classification of At-Risk Tissue and Core Infarction

Objective: To compare how at-risk tissue and core infarction were defined in two major trials that tested the use of MRI in selecting acute stroke patients for endovascular recanalization therapy.Methods: MRIs from 12 patients evaluated for possible endovascular therapy were processed using the methods published from two major trials, MR RESCUE and DEFUSE 2. Specifically, volumes of at-risk tissue and core infarction were generated from each patient’s MRI. MRIs were then classified as to whether or not they met criteria for salvageable tissue: penumbral pattern for MR RESCUE and/or target profile for DEFUSE 2) as defined by each trial.Results: Volumes of at-risk tissue by the two definitions were correlated (p=0.017) while the volumes of core infarct were not (p=0.059). The volume of at-risk tissue was consistently larger when defined by the penumbral pattern than the target profile while the volume of core infarct was consistently larger when defined by the target profile than the penumbral pattern. When these volumes were used to classify the MRI scans, nine out of 12 patients (75%) were classified as having a penumbral pattern, while only 4 out of 12 patients (33%) were classified as having a target profile. Of the 9 patients classified as penumbral pattern, 5 (55%) were classified differently by the target profile.Interpretation: Our analysis found that the MR RESCUE trial defined salvageable tissue in a way which made it more likely for patients be labeled as favorable for treatment. For the cohort of patients examined in this study, had they been enrolled in both trials, most of the patients identified as having salvageable tissue by the MR RESCUE trial would not have been considered to have salvageable tissue in the DEFUSE 2 trial. Caution should be taken in concluding that MRI selection for endovascular therapy is not effective as imaging selection criteria were substantially different between trials

Ischemic stroke subtypes and migraine with visual aura in the ARIC study

OBJECTIVE: To investigate the association among migraine, ischemic stroke, and stroke subtypes in the Atherosclerosis Risk in Communities (ARIC) study. METHODS: In this ongoing, prospective, longitudinal community-based cohort study, participants were given an interview ascertaining migraine history in 1993-1995, and were followed for all vascular events, including stroke. All stroke events over the subsequent 20 years were adjudicated and classified into stroke subtypes by standard definitions. Cox proportional hazards models adjusted for stroke risk factors were used to study the relationship between migraine and ischemic stroke, overall, as well as stroke subtypes (cardioembolic, lacunar, or thrombotic). RESULTS: We identified 1,622 migraineurs among 12,758 participants. Mean age of the study population at the 3rd clinical visit was 59 years. When compared to nonheadache participants, there was a significant association between migraine with visual aura and ischemic stroke (hazard ratio [HR] 1.7, 95% confidence interval [CI] 1.2-2.6, p = 0.008). Migraine without visual aura was not significantly associated with ischemic stroke (HR 1.2, CI 1.0-1.8, p = 0.28) when compared to nonheadache participants. Among the 3 subtypes of ischemic stroke evaluated, migraine with visual aura was significantly associated only with cardioembolic stroke (HR 3.7, 95% CI 1.6-8.7, p = 0.003). CONCLUSION: In participants with migraine with visual aura in late middle age, increased risk of cardioembolic stroke was observed. Migraine with visual aura was linked to increased stroke risk, while migraine without visual aura was not, over the period of 20 years. These results are specific to older migraineurs

Hospitalized Infection as a Trigger for Acute Ischemic Stroke

Acute triggers for ischemic stroke, which may include infection, are understudied, as is whether background cardiovascular disease (CVD) risk modifies such triggering. We hypothesized that infection increases acute stroke risk, especially among those with low CVD risk

Cardiac Biomarkers and Subsequent Risk of Hospitalization With Bleeding in the Community: Atherosclerosis Risk in Communities Study

Background hs-cTnT (high-sensitivity cardiac troponin T), but not NT-proBNP (N-terminal pro-B natriuretic peptide), has been shown to predict bleeding in patients with atrial fibrillation. Whether these biomarkers are independently associated with bleeding in the general population is unknown. Methods and Results We used Cox proportional hazards models to examine the association of hs‐cTnT and NT‐proBNP with incident bleeding (defined by International Classification of Diseases, Ninth Revision [ICD‐9] codes) among 9550 middle‐aged men and women without a history of cardiovascular disease or bleeding. There were 847 hospitalizations with bleeding (92% from gastrointestinal bleeding) during a median follow‐up of 9.0 years. Serum levels of hs‐cTnT were associated with bleeding in a graded fashion, with a hazard ratio of 1.28 (95% CI, 1.06–1.59) for 6 to \u3c 9 ng/L, 1.52 (1.21–1.91) for 9 to \u3c 14, and 2.05 (1.56–2.69) for ≥14 versus \u3c 3 ng/L. For NT‐proBNP, the highest category (≥264 versus \u3c 42 pg/mL) showed a hazard ratio of 2.00 (1.59–2.61), and the remaining 3 categories had hazard ratios ranging from 1.2 to 1.3. Individuals in the highest category of both hs‐cTnT and NT‐proBNP had a hazard ratio of 3.03 (1.97–4.68) compared with those in the lowest categories. Conclusions In a community‐based population, elevated hs‐cTnT and NT‐proBNP were associated with bleeding‐related hospitalizations. These biomarkers may have a high utility in identifying people at high risk for bleeding. There is a need for research on the underlying mechanisms linking subclinical cardiac abnormalities and bleeding

Associations between atrial cardiopathy and cerebral amyloid: The ARIC-PET study

Background Atrial fibrillation (AF) is a risk factor for cognitive decline, possibly from silent brain infarction. Left atrial changes in structure or function (atrial cardiopathy) can lead to AF but may impact cognition independently. It is unknown if AF or atrial cardiopathy also acts on Alzheimer disease-specific mechanisms, such as deposition of β-amyloid. Methods and Results A total of 316 dementia-free participants from the ARIC (Atherosclerosis Risk in Communities) study underwent florbetapir positron emission tomography, electrocardiography, and 2-dimensional echocardiography. Atrial cardiopathy was defined as ≥1: (1) left atrial volume index \u3e34 mL/

Postural Changes in Blood Pressure and Incidence of Ischemic Stroke Subtypes: The ARIC Study

The relation of orthostatic blood pressure decrease, or increase, with occurrence of ischemic stroke subtypes has not been examined. We investigated the association of orthostatic blood pressure change (within 2 minutes after supine to standing) obtained at baseline (1987–89) in the Atherosclerosis Risk in Communities Study with incidence of ischemic stroke subtypes through 2007. Among 12,817 black and white individuals without a history of stroke at baseline, 680 ischemic strokes (153 lacunar, 383 nonlacunar thrombotic, and 144 cardioembolic strokes) occurred during a median follow-up of 18.7 years. There was a U-shaped association between orthostatic systolic blood pressure change and lacunar stroke incidence (quadratic p=0.004). In contrast, orthostatic systolic blood pressure decrease of 20 mmHg or more was associated with increased occurrence of nonlacunar thrombotic and cardioembolic strokes independent of sitting systolic blood pressure, antihypertensive medication use, diabetes, and other lifestyle, physiological, biochemical, and medical conditions at baseline (hazard ratio: 2.02, 95% confidence interval: 1.43–2.84 for nonlacunar thrombotic, hazard ratio: 1.85, 95% confidence interval: 1.01–3.39 for cardioembolic). Orthostatic diastolic blood pressure decrease was associated with increased risk of nonlacunar thrombotic and cardioembolic strokes; the hazard ratios (95% confidence interval) associated with 10 mmHg lower orthostatic diastolic blood pressure (continuous) were 1.26 (1.06–1.50) and 1.41 (1.06–1.88), respectively, in fully-adjusted models. In conclusion, the present study found that nonlacunar ischemic stroke incidence was positively associated with an orthostatic decrease of systolic and diastolic blood pressure whereas greater lacunar stroke incidence was associated with both orthostatic increases and decreases in systolic blood pressure

Incident Heart Failure and Cognitive Decline: The Atherosclerosis Risk in Communities Study

Cognitive impairment is found in a significant proportion of patients with heart failure (HF). While cognitive impairment may be a consequence of HF, early signs of cognitive impairment may also indicate subclinical vascular disease, and thus a risk factor for future cardiovascular events

Validity of hospital discharge diagnosis codes for stroke: The atherosclerosis risk in communities study

BACKGROUND AND PURPOSE: Characterizing International Classification of Disease 9th Revision, Clinical Modification (ICD-9-CM) code validity is essential given widespread use of hospital discharge databases in research. Using the Atherosclerosis Risk in Communities (ARIC) Study, we estimated the accuracy of ICD-9-CM stroke codes. METHODS: Hospitalizations with ICD-9-CM codes 430 to 438 or stroke keywords in the discharge summary were abstracted for ARIC cohort members (1987-2010). A computer algorithm and physician reviewer classified definite and probable ischemic stroke, intracerebral hemorrhage, and subarachnoid hemorrhage. Using ARIC classification as a gold standard, we calculated the positive predictive value (PPV) and sensitivity of ICD-9-CM codes grouped according to the American Heart Association/American Stroke Association (AHA/ASA) 2013 categories and an alternative code grouping for comparison. RESULTS: Thirty-three percent of 4260 hospitalizations were validated as strokes (1251 ischemic, 120 intracerebral hemorrhage, 46 subarachnoid hemorrhage). The AHA/ASA code groups had PPV 76% and 68% sensitivity compared with PPV 72% and 83% sensitivity for the alternative code groups. The PPV of the AHA/ASA code group for ischemic stroke was slightly higher among blacks, individuals <65 years, and at teaching hospitals. Sensitivity was higher among older individuals and increased over time. The PPV of the AHA/ASA code group for intracerebral hemorrhage was higher among blacks, women, and younger individuals. PPV and sensitivity varied across study sites. CONCLUSIONS: A new AHA/ASA discharge code grouping to identify stroke had similar PPV and lower sensitivity compared with an alternative code grouping. Accuracy varied by patient characteristics and study sites

Obstructive Sleep Apnea and 15-Year Cognitive Decline: The Atherosclerosis Risk in Communities (ARIC) Study

Prospective data evaluating abnormal sleep quality and quantity with cognitive decline are limited because most studies used subjective data and/or had short follow-up. We hypothesized that, over 15 y of follow-up, participants with objectively measured obstructive sleep apnea (OSA) and other indices of poor sleep quantity and quality would experience greater decline in cognitive functioning than participants with normal sleep patterns

The Association of Long-Term Exposure to Particulate Matter Air Pollution with Brain MRI Findings: The ARIC Study.

BACKGROUND: Increasing evidence links higher particulate matter (PM) air pollution exposure to late-life cognitive impairment. However, few studies have considered associations between direct estimates of long-term past exposures and brain MRI findings indicative of neurodegeneration or cerebrovascular disease. OBJECTIVE: Our objective was to quantify the association between brain MRI findings and PM exposures approximately 5 to 20 y prior to MRI in the Atherosclerosis Risk in Communities (ARIC) study. METHODS: ARIC is based in four U.S. sites: Washington County, Maryland; Minneapolis suburbs, Minnesota; Forsyth County, North Carolina; and Jackson, Mississippi. A subset of ARIC participants underwent 3T brain MRI in 2011-2013 (n=1,753). We estimated mean exposures to PM with an aerodynamic diameter less than 10 or 2.5μm (PM RESULTS: In pooled analyses, higher mean PM CONCLUSIONS: Long-term past PM exposure in was not associated with markers of cerebrovascular disease. Higher long-term past PM exposures were associated with smaller deep-gray volumes overall, and higher P