A Novel Quantification Method for Determining Previously Undetected Silent Infarcts on MR-perfusion in Patients Following Carotid Endarterectomy

The purpose of this paper is to evaluate the post-operative Magnetic Resonance Perfusion (MRP) scans of patients undergoing carotid endarterectomy (CEA), using a novel image-analysis algorithm, to determine if post-operative neurocognitive decline is associated with cerebral blood flow changes. CEA procedure reduces the risk of stroke in appropriately selected patients with significant carotid artery stenosis. However, 25% of patients experience subtle cognitive deficits after CEA compared to a control group. It was hypothesized that abnormalities in cerebral blood flow (CBF) are responsible for these cognitive deficits. A novel algorithm for analyzing MRperfusion (MRP) scans to identify and quantify the amount of CBF asymmetry in each hemisphere was developed and to quantify the degree of relative difference between three corresponding vascular regions in the ipsilateral and contralateral hemispheres, the Relative Difference Map (RDM). Patients undergoing CEA and spine surgery (controls) were examined preoperatively, and one day postoperatively with a battery of neuropsychometric (NPM) tests, and labeled “injured” patients with significant cognitive deficits, and “normal” if they demonstrated no decline in neurocognitive function. There are apparently significant RDM differences with MRP scans between the two hemispheres in patients with cognitive deficits which can be used to guide expert reviews of the imagery. The proposed methodology aids in the analysis of MRP parameters in patients with cognitive impairment

Psychological stress and 30-day all-cause hospital readmission in acute coronary syndrome patients: an observational cohort study.

Many acute coronary syndrome (ACS; myocardial infarction and unstable angina) patients are rehospitalized within 30 days of discharge, and recent US health policy initiatives have tied hospital Medicare reimbursement to 30-day readmission rates. Patient-perceived psychological stress is thought to impact prognosis after ACS. A recently offered "posthospital syndrome" model of 30-day readmissions posits that the stress level at the time of the index hospitalization itself may increase 30-day risk for readmission in ACS patients. We tested whether self-reported stress in the days surrounding the ACS hospitalization was associated with increased risk for readmission within 30 days.A mean of 8.5 days after discharge, 342 consecutively hospitalized ACS patients reported on how often they felt stress during the past two weeks. Readmission within 30 days of hospital discharge for any cause was determined by follow-up telephone calls to patients and confirmed by hospital records.Overall, 40 (11.7%) participants were readmitted within 30 days, and 22 (6.4%) reported high stress. Readmission within 30 days was more common in patients with high stress (5 admissions, 23%) than in patients with low stress (35 admissions, 11%). After adjustment for demographic and clinical factors, as well as depression, high stress was associated with a 3-fold increased risk of 30-day readmission (HR = 3.21, 95% CI = 1.13, 9.10).Previous research has shown that stress in the days surrounding a hospitalization can mark long-term cardiovascular risk, but this is the first study to test a hypothesis of the posthospital syndrome model of early readmission. Further research is needed to confirm the association between stress and readmission risk, and to identify the processes of hospitalization that could be modified to both reduce the stress experienced and that would also be effective for reducing readmissions

Cox proportional hazards regression analysis predicted survival curves for acute coronary syndrome (ACS) patients by stress category, adjusted for age, sex, race, ethnicity, type of ACS, Charlson comorbidity index score, Global Registry of Acute Coronary Events risk score, and left ventricular ejection fraction.

<p>Cox proportional hazards regression analysis predicted survival curves for acute coronary syndrome (ACS) patients by stress category, adjusted for age, sex, race, ethnicity, type of ACS, Charlson comorbidity index score, Global Registry of Acute Coronary Events risk score, and left ventricular ejection fraction.</p

Participant characteristics by stress category.

<p>Note: * <i>p</i><.05, *** <i>p</i><.001. Abbreviations: GRACE, Global Registry of Acute Coronary Events; LVEF, Left ventricular ejection fraction; MI, myocardial infarction;</p><p>Note: Values are mean ± SD unless indicated otherwise.</p