A Systematic Literature Review of Patients With Carotid Web and Acute Ischemic Stroke.

Background and Purpose- Carotid web (CW) is a rare form of focal fibromuscular dysplasia defined as an abnormal shelf-like projection of intimal fibrous tissue into the carotid bulb. It is theorized that CW leads to ischemic stroke secondary to blood flow stasis and subsequent embolization. The natural history and optimal management of CW are unclear. To address this knowledge gap, we performed a systematic literature review (SLR) of CW. Methods- Our librarians performed a SLR for CW and related terminology. Patient-level demographics, stroke risk factors, neuroimaging findings, stroke recurrence or stroke free-duration, and treatment modality were extracted. We used descriptive statistics to characterize our results. When specific patient-level metrics were not reported, the denominators for reporting percentage calculations were adjusted accordingly. Results- Our literature search produced 1150 articles. Thirty-seven articles including 158 patients (median age 46 years [range 16-85], 68% women, 76% symptomatic) met entry criteria and were included in our SLR. Of the symptomatic CW patients: 57% did not have stroke risk factors, 56% who received medical therapy had recurrent stroke (median 12 months, range 0-97), and 72% were ultimately treated with carotid revascularization (50% carotid stenting, 50% carotid endarterectomy). There were no periprocedural complications or recurrent strokes in carotid revascularization patients. Conclusions- CW leads to ischemic stroke in younger patients without conventional stroke risk factors. We found a high stroke recurrence rate in medically managed symptomatic CW patients, whereas carotid revascularization effectively prevented recurrent stroke. Our findings should be interpreted with caution because of risk of publication and reporting bias.

Readmission after spinal cord injury: analysis of an institutional cohort of 795 patients.

BACKGROUND: Recent studies in other fields have suggested that healthcare on the weekend may have worse outcomes. In particular, patients with stroke and acute cardiovascular events have shown worse outcomes with weekend treatment. It is unclear whether this extends to patients with spinal cord injury. This study was designed to evaluate factors for readmission after index hospitalization for spinal cord injury. METHODS: A total of 795 consecutive patients over an 11-year period were analyzed. After excluding patients with chronic spinal cord injury and surgical care at an outside hospital, 745 patients remained. The primary outcome measure evaluated was 30-day readmission. Secondary measures include perioperative complications, readmission rate when discharged on the weekend, and the effect of race and insurance status on readmission rate. Univariate and multivariate analysis were utilized to evaluate the covariates collected. The χ2 test, Fisher's exact test, and linear and logistic regression methods were utilized for statistical analysis. RESULTS: A total of 745 patients were analyzed after exclusions. Payer status did not affect length of stay, ICU length of stay, or perioperative complications. Neither weekend admission nor weekend operation affected length of stay, ICU length of stay, or readmission by 30 days. Patients undergoing weekend surgical treatment had lower perioperative complication rates (2.2% vs. 6.5% on weekday, P<0.01). Discharge on the weekend was associated with a significantly lower rate of readmission by 30 days (OR=0.07, 95% CI: 0.009-0.525, P<0.005). Payer status was associated with 30-day readmission (P<0.005). Patients with Medicare (20.8%) and Medicaid (20.1%) showed higher rates of readmission than patients with other payers. 21.1% of African-American patients were readmitted, versus 10.2% of other patients (Odds ratio: 2.2, 95% confidence interval 1.36-3.27, P<0.001). Correcting for payer status lessened but did not eliminate the effect of race on readmission. CONCLUSIONS: Weekend admission did not increase perioperative complications or hospital length of stay. After discharge, patients with Medicaid and Medicare show higher rates of 30-day readmission, as do African-American patients. The effect of race on readmission is multifactorial, and may partially explained by the increased rate of Medicaid coverage in African-Americans in our institutions catchment area.

The Electrophysiologic Effects of Acute Mitral Regurgitation in a Canine Model.

BACKGROUND: Atrial fibrillation (AF) occurs in 30% of patients with mitral regurgitation referred for surgical intervention. However, the underlying mechanisms in this population are poorly understood. This study examined the effects of acute left atrial volume overload on atrial electrophysiology and the inducibility of AF. METHODS: Ten canines underwent insertion of an atrioventricular shunt between the left ventricle and left atrium. Shunt and aortic flows were calculated, and the shunt was titrated to a shunt fraction to 40% to 50% of cardiac output. An epicardial plaque with 250 bipolar electrodes was used to determine activation and refractory periods. Biatrial pressures and volumes, conduction times, and atrial fibrillation inducibility were recorded. Data were collected at baseline and 20 minutes after shunt opening and closure. RESULTS: Mean shunt flow was 1.3 ± 0.5 L/min with a shunt fraction of 43% ± 6% simulating moderate to severe mitral regurgitation. Compared with baseline, left atrial volumes and maximum pressures increased by 27% and 29%, respectively, after shunt opening. Biatrial effective refractory periods did not change significantly after shunt opening or closure. Conduction times increased by 9% with shunt opening and returned to baseline after closure. AF duration or inducibility did not change with shunt opening. CONCLUSIONS: This canine model of mitral regurgitation demonstrated that acute left atrial volume overload did not increase the inducibility of atrial arrhythmias in contrast with experimental and clinical findings of chronic left atrial volume overload. This suggests that the substrates for AF in patients with mitral regurgitation are a result of chronic remodeling.