Impact of Thrombolysis on Stroke Outcome at 12 Months in a Population

208 differences in patient outcomes would help in justifying or providing evidence against measures such as those proposed by CMS for head CT scans. , IMPACT OF THROMBOLYSIS ON STROKE OUTCOME AT 12 MONTHS IN A POPULATION. Fischer U, Mono ML, Zwahlen M, et al. Stroke 2012;43:1039–45. Multiple clinical trials have shown that thrombolytics improve short-term outcomes in individuals with acute ischemic stroke (AIS). Several similar studies show that thrombolytics also improve long-term outcomes. What is not clear, and what this article attempted to address, is whether these findings can be replicated in a single study population. Investigators prospectively assessed 807 patients with first-time AIS who were admitted to the hospital within 48 h of symptom onset in Bern, Switzerland over the course of 12 months. Of the 807 total patients, 13% (n = 107) received thrombolysis. Thirty-eight percent of patients (n = 41) received intra-arterial thrombolysis, 33% (n = 35) received intravenous thrombolysis, and 5% (n = 5) underwent mechanical thrombolysis. Median National Institute of Health Stroke Scale (NIHSS) at admission was 14 in the group that received thrombolytics (n = 107) and 4.3 in the group that did not receive thrombolytics (n = 700). Follow-up was then obtained at 3 and 12 months to assess for predictors of mortality as well as favorable outcomes. Favorable outcomes were defined as a modified Rankin Scale # 2. The authors found that the following variables were independent predictors of mortality at 3 months and 12 months: age $ 75 years, higher NIHSS, and higher Charlson comorbidity index. They found that the following variables were independent predictors of favorable outcomes at 3 and 12 months: age < 75 years, male gender, NIHSS < 4, lower Charlson comorbidity index, and thrombolysis. The authors emphasize that thrombolysis is the only modifiable variable that was shown to predict favorable outcomes at 3 months (relative risk [RR] 1.49; 95% confidence interval [CI] 1.18– 1.89) and 12 months (RR 1.59; 95% CI 1.24–2.04). [Mike Miller, MD Denver Health Medical Center, Denver, CO] Comments: Although numerous clinical trials have shown that thrombolytics improve outcomes in AIS, this is the first population-based study to do so. Although this is unlikely to significantly change the clinical practice of most physicians, it does provide one with more confidence when discussing the pros and cons of thrombolysis at the bedside. , SLEEP APNEA AND RISK OF DEEP VEIN THROMBOSIS: A NON-RANDOMIZED, PAIR-MATCHED COHORT STUDY. Chou KT, Huang CC, Chen YM, et al. Am J Med 2012;125:374–80. Sleep apnea is defined as apneic episodes during the sleeping hours, which may be due to either obstruction or temporary loss of central neurologic drive. The majority of patients with sleep apnea (90%) have obstructive sleep apnea (OSA). A growing body of research supports the association between OSA and a hypercoaguable state. This study from Taiwan sought to evaluate the association between OSA and deep vein thrombosis (DVT). The study was a nonrandomized pair-matched cohort model using the National Health Insurance Research Database in Taiwan

Abstracts to identify 5680 new diagnoses of DVT and their pair-matched controls between 2000 and 2007. Mean follow-up was 3.56 6 2.12 years. The primary outcome was new diagnosis of DVT. The secondary outcome was use of continuous positive airway pressure (CPAP) devices as a proxy measure of OSA severity and its association with increased risk of DVT. The authors found a significantly higher incidence of DVT development in patients with sleep apnea when compared to controls (hazard ratio [HR] 3.113, p < 0.002). The only other demographic factors of significance were female sex (HR 2.145, p < 0.017) and hypertension (HR 2.510, p < 0.034). In the subset of patients with OSA who used CPAP, there was significantly higher risk of DVT (HR 9.575, p < 0.001 vs. HR 2.751, p < 0.007; respectively). The authors’ final conclusion was that sleep apnea is an independent risk factor for future development of DVT. They also posited that, if use of CPAP can be used as a proxy for worse disease, increasing severity of OSA increases risk of DVT formation. [Peter Emiley, MD, Denver Health Medical Center, Denver, CO] Comments: This study provides some interesting information on the association between OSA and the development of DVT. Clearly, causality cannot be established by such an observational design, and confounders such as obesity and underlying medical disease were not controlled for. Nonetheless, it would be wise for Emergency Physicians to be wary of DVT in patients with OSA who present with the appropriate clinical symptoms. , RISK OF FEBRILE SEIZURES AND EPILEPSY AFTER VACCINATION WITH DIPHTHERIA, TETANUS, ACELLULAR PERTUSSIS, INACTIVATED POLIOVIRUS, AND HAEMOPHILUS INFLUENZAE TYPE B. Sun Y, Christensen J, Hviid A, Li J, Vedsted P, Olsen J, Vestergaard M. JAMA 2012;307:823–31. Prior studies have demonstrated an increased risk of febrile seizures with whole-cell pertussis vaccine, but no studies to date have clearly demonstrated a significant increase in febrile seizures with an acellular pertussis vaccine. In this large cohort study from Denmark, 378,834 children were followed after 3, 5, and 12-month vaccinations with an acellular-pertussis-containing combination vaccine. Outcome measures included febrile seizures within 7 days of receiving the vaccine as well as rates of epilepsy diagnosis. Children outside the 7-day time window were used as controls. Over a 5-year time period, 7811 children under the age of 18 months were diagnosed with febrile seizures. Of these children, 17 were diagnosed within the first 7 days after the first vaccine, 32 children after the second vaccine, and 201 children after the third vaccine. Calculated hazard ratios (HR) of febrile seizures within the first week after each vaccination were not statistically significant. The risk of seizure on the first day after each vaccination, however, was increased after the 3month vaccine (3-month vaccine HR 6.02, 95% confidence interval [CI] 2.86–12.65) and after the 5-month vaccine (HR 3.94, 95% CI 2.18–7.10), but not after the 12-month vaccine (HR 1.07, 95% CI 0.73–1.57). Patients were followed for 7 years after vaccination to monitor for the rate of epilepsy. There were 2117 children diagnosed with epilepsy, with 813 occurring between 3 and 15 months. When compared to children not vaccinated, vaccinated children had a lower risk of epilepsy between 3 and 15