What Makes New Ischemic Lesions Symptomatic after Aortic Valve Replacement?

BACKGROUND: Acute cerebral infarctions on diffusion-weighted magnetic resonance imaging (MRI) are common after cardiothoracic surgery. However, most are asymptomatic and we aimed to identify features associated with clinical stroke symptoms. METHODS: Patients over 65 years of age undergoing surgical aortic valve replacement (AVR) for calcific stenosis were prospectively recruited (N = 196). All patients underwent neurological evaluation preoperatively and on postoperative days 1, 3, and 7, and MRI on planned postoperative day 5. Among those with new postoperative DWI lesions, we performed univariate and multivariable analyses to identify clinical, demographic, surgical, and imaging factors associated with clinical stroke symptoms. RESULTS: Of the 129 patients who completed a postsurgical MRI, 79 (61%) had DWI lesions and 17 (21.5%) of these had new stroke symptoms concordant with the infarct distribution. In an exploratory multivariable analysis, focal neurological symptoms were associated with increased age, a longer bypass duration, and a larger pre-existing lesion burden on fluid-attenuated inversion recovery. Limiting the analysis to the 61 patients with analyzable volume and location data, logistic regression failed to identify any location-related determinant of symptomatic lesions. CONCLUSIONS: New DWI lesions are common after AVR, but most are asymptomatic. Patients are more likely to have symptoms with longer bypass durations, increasing age, and larger pre-existing lesion burdens.

Pathogenesis and Risk Factors for Cerebral Infarct After Surgical Aortic Valve Replacement.

BACKGROUND AND PURPOSE: Stroke is a potentially devastating complication of cardiac surgery. Identifying predictors of radiographic infarct may lead to improved stroke prevention for surgical patients. METHODS: We reviewed 129 postoperative brain magnetic resonance imagings from a prospective study of patients undergoing surgical aortic valve replacement. Acute infarcts were classified as watershed or embolic using prespecified criteria. RESULTS: Acute infarct on magnetic resonance imaging was seen in 79 of 129 patients (61%), and interrater reliability for stroke pathogenesis was high (κ=0.93). Embolic infarcts only were identified in 60 patients (46%), watershed only in 2 (2%), and both in 17 (13%). In multivariable logistic regression, embolic infarct was associated with aortic arch atheroma (odds ratio [OR], 3.4; 95% confidence interval [CI], 1.0-12.0; P=0.055), old subcortical infarcts (OR, 5.5; 95% CI, 1.1-26.6; P=0.04), no history of percutaneous transluminal coronary angioplasty or coronary artery bypass graft (OR, 4.0; 95% CI, 1.2-13.7; P=0.03), and higher aortic valve gradient (OR, 1.3 per 5 mm Hg; 95% CI, 1.09-1.6; P=0.004). Watershed infarct was associated with internal carotid artery stenosis ≥70% (OR, 11.7; 95% CI, 1.8-76.8; P=0.01) and increased left ventricular ejection fraction (OR, 1.6 per 5% increase; 95% CI, 1.08-2.4; P=0.02). CONCLUSIONS: The principal mechanism of acute cerebral infarction after aortic valve replacement is embolism. There are distinct factors associated with watershed and embolic infarct, some of which may be modifiable.

Thromboelastography defines late hypercoagulability after TBI: a pilot study.

INTRODUCTION: Traumatic brain injury (TBI) is associated with a hypercoagulable state, the mechanism and duration of which remain unclear. We sought to determine whether thromboelastography (TEG) analysis could identify the hypercoagulable state after TBI, as defined by elevations in maximal amplitude (MA), thrombus generation (TG), G value (G), and alpha angle (αA). METHODS: Patients with moderate-severe TBI, defined primarily as a GCS <12, admitted between 1/2012 and 8/2013 were eligible for enrolment in this prospective cohort study. TEG profiles were obtained between 0-24 h (T1), 24-48 h (T2), 48-72 h (T3), 72-96 h (T4), and 96-120 h (T5) after admission. Early TEG was defined as 0-48 h, and late TEG was defined as >48 h. RESULTS: Twenty five patients (80 % men) and 7 age- and sex-matched control subjects were studied. Median age was 38 years (range 18-85). Early MA was [63.6 mm (60.5, 67.4)] versus late MA [69.9 mm (65.2,73.9); p = 0.02], early TG was [763.3 mm/min (712.8, 816.2)] versus late TG [835.9 mm/min (791.2,888.3); p = 0.02], and early G was [8.8 d/cm(2) (7.7,10.4)] versus late G [11.6 d/cm(2) (9.4,14.1); p = 0.02]. Study patients had higher MA (p = 0.02), TG (p = 0.03), and G (p = 0.02) values at T5 compared to controls. There was a linear increase per day of MA by 2.6 mm (p = 0.001), TG 31.9 mm/min (p ≤ 0.001), and G value by 1.3 d/cm(2) (p ≤ 0.001) when clustered by pairs in regression analysis. Lower MA values trended toward home discharge (p = 0.08). CONCLUSION: The data suggest a progressive and delayed hypercoagulable state observed days after initial TBI. The hypercoagulable state may reflect excess platelet activity.

Revisiting Anticoagulation in Spine Surgery: Balancing Venous Thromboembolic Events and Epidural Hematoma.

STUDY DESIGN: Retrospective Cohort Study. OBJECTIVE: Venous thromboembolic events (VTE) and post-operative epidural hematoma (EDH) are significant complications after spine surgery. Guidelines for chemoprophylaxis are controversial and variability amongst surgeons remains. The objective of this study was to establish the incidence of clinical VTE and EDH at our institution and evaluate the association of chemoprophylaxis with clinical VTE and EDH. METHODS: We conducted a retrospective cohort study of patients undergoing spine surgery at a high-volume tertiary care center in Seattle, WA between January 2016 and December 2019. The Premier Health Care Database and Agency for Healthcare Research and Quality (AHRQ) patient indicators PSI-9 (Perioperative hemorrhage and hematoma) and PSI-12(Perioperative PE or DVT) were used to identify patients experiencing VTE and/or post-operative EDH. The primary outcome was the incidence of clinical VTE and EDH in post-operative spine patients. Secondary outcomes included the association of chemoprophylaxis with clinical VTE and EDH. RESULTS: From 2016 to 2019, 4587 patients underwent spine surgery, totaling 4764 hospital stays. The incidence of clinical VTE was .21% (10/4764) and the incidence of EDH was .10% (5/4764). Most hemorrhages occurred prior to the initiation of chemoprophylaxis. One patient with EDH received chemoprophylaxis prior to hemorrhage. CONCLUSIONS: The rate of post-operative clinical VTE and EDH in spine surgery is low. Despite early initiation of chemoprophylaxis after major spine surgery we did not appreciate a high rate of EDH. We attribute our low rate of clinical VTE to multimodal prophylaxis with SCDs, early mobilization and chemoprophylaxis on post-operative day 1.

Palliative Care in Patients With High-Grade Gliomas in the Neurological Intensive Care Unit.

BACKGROUND: Palliative care improves quality of life in patients with malignancy; however, it may be underutilized in patients with high-grade gliomas (HGGs). We examined the practices regarding palliative care consultation (PCC) in treating patients with HGGs in the neurological intensive care unit (NICU) of an academic medical center. METHODS: We conducted a retrospective cohort study of patients admitted to the NICU from 2011 to 2016 with a previously confirmed histopathological diagnosis of HGG. The primary outcome was the incidence of an inpatient PCC. We also evaluated the impact of PCC on patient care by examining its association with prespecified secondary outcomes of code status amendment to do not resuscitate (DNR), discharge disposition, 30-day mortality, and 30-day readmission rate, length of stay, and place of death. RESULTS: Ninety (36% female) patients with HGGs were identified. Palliative care consultation was obtained in 16 (18%) patients. Palliative care consultation was associated with a greater odds of code status amendment to DNR (odds ratio [OR]: 18.15, 95% confidence interval [CI]: 5.01-65.73), which remained significant after adjustment for confounders (OR: 27.20, 95% CI: 5.49-134.84), a greater odds of discharge to hospice (OR: 24.93, 95% CI: 6.48-95.88), and 30-day mortality (OR: 6.40, 95% CI: 1.96-20.94). CONCLUSION: In this retrospective study of patients with HGGs admitted to a university-based NICU, PCC was seen in a minority of the sample. Palliative care consultation was associated with code status change to DNR and hospice utilization. Further study is required to determine whether these findings are generalizable and whether interventions that increase PCC utilization are associated with improved quality of life and resource allocation for patients with HGGs.