- Email: [email protected]
Myocardial Injury and Bacterial Pneumonia Contribute to the Pathogenesis of Fatal Influenza B Virus Infection
The Journal of Emergency Medicine months (HR 0.63, 95% CI 0.50–0.79), and there was no difference in epilepsy diagnosis later in life (HR 1.01, 95% CI 0.66– 1.56). The authors concluded that although there is a small increased risk of febrile seizures after the first and second vaccinations, there was no increased risk of epilepsy overall later in life. [Austin Johnson, MD Denver Health Medical Center, Denver, CO] Comments: Although this study does demonstrate a small increased risk of febrile seizures within the first day after vaccination, it seems that there is no long-term risk for seizure disorder. , MYOCARDIAL INJURY AND BACTERIAL PNEUMONIA CONTRIBUTE TO THE PATHOGENESIS OF FATAL INFLUENZA B VIRUS INFECTION. Paddock CD, Liu L, Denison AM, et al. J Infect Dis 2012;205:895–905. In this study of cadavers with fatal influenza B infections, Paddock et al. described the demographics of the disease, as well as associations with myocardial injury and bacterial pneumonia. Tissue samples were analyzed from 45 case patients with fatal influenza B infection, as confirmed at the Centers for Disease Control via polymerase chain reaction. Demographic data showed that the median age of death was 11 years, and 76% of the case patients were < 18 years old. Average time from symptom onset to death was 3 days. This is faster than any historic influenza A pandemic or seasonal infection. Tissue sample analysis revealed evidence of concomitant bacterial pneumonia in 38% of patients; 76% of these were infected with Staphylococcus aureus. Age > 18 years was the only variable that correlated significantly with the presence of histologically confirmed bacterial pneumonia (p < 0.001). Finally, the authors evaluated case patients for the presence of myocardial injury. Immunohistochemical assays detected C4d and C9 as evidence of myocardial injury in 69% of the 29 case patients from whom cardiac tissue was available. Ninety percent of individuals with evidence of myocardial injury were aged < 18 years. Importantly, no viral antigens were detected in the myocardium of any patient. [Mike Miller, MD Denver Health Medical Center, Denver, CO] Comments: From 2004–2008, influenza B accounted for 34% of influenza-associated deaths in children in the United States. This study emphasizes that fatal influenza B can progress rapidly, is often accompanied by evidence of myocardial injury in children, and is infrequently associated with bacterial pneumonia in that same age group. The clinical significance of this disease is often overshadowed by its more well-known counterpart, influenza A.
209 , INTRAVENOUS THROMBOLYSIS IN YOUNG STROKE PATIENTS: RESULTS FROM THE SITS-ISTR. Toni D, Ahmed N, Anzini A, et al. Neurology 2012; 78:880–7. Stroke in younger patients (18–50 years) can have important long-term outcomes. Aggressive treatment of this condition is important given the longer expected survival of this population when compared to those over 50 years of age. Conflicting data exist about the relative benefit of acute treatment with intravenous alteplase in younger patients, though all prior studies have been limited by small sample size. This study sought to evaluate the safety and efficacy of this medication in younger patients when compared to older patients. A post hoc analysis of data from the Safe Implementation of Thrombolysis in Stroke – International Stroke Thrombolysis Register (SITS-ISTR) was performed on data of patients aged 18–80 years that received intravenous alteplase within 4.5 h of stroke onset between 2002 and 2010. Primary outcomes were symptomatic intracerebral hemorrhage (SICH), mortality, and functional independence at 3 months. The SITS-ISTR contained data on 3246 patients aged 18–50 years and 24,425 patients aged 51–80 years. Multivariable logistic regression models were performed for each outcome variable. Regressions were also performed for subdivision of patients in deciles (under 30 years, 31–40 years, 41–50 years, and over 50 years). There was a significant difference in the baseline characteristics of the two groups, with increasing rates of comorbidities such as hypertension, diabetes mellitus, hyperlipidemia, and atrial fibrillation, among others. The authors found that SICH occurred in 0.6% of younger patients and 1.9% of older patients (adjusted odds ratio [OR] 0.53, p = 0.02). Three-month mortality was 4.9% and 14.4% in young vs. old patients (adjusted OR 0.49, p < 0.001). Functional independence was 72.1% vs. 54.5% for young vs. old patients (adjusted OR 1.61, p < 0.0001). Evaluation of the age deciles showed progressive rates of SICH, mortality, and lower functional independence with increasing age, with steepest change of rates after age 50 years. The authors concluded that treatment with intravenous alteplase is safe in young patients, with greater benefit than in older cohorts. [Peter Emiley, MD Denver Health Medical Center, Denver, CO] Comments: Although limited by its retrospective design, this study suggests greater benefit from the treatment of acute stroke in younger patients. This seems somewhat intuitive and is likely explained by less comorbidity and improved plasticity in the injured brain at a younger age.
209 , INTRAVENOUS THROMBOLYSIS IN YOUNG STROKE PATIENTS: RESULTS FROM THE SITS-ISTR. Toni D, Ahmed N, Anzini A, et al. Neurology 2012; 78:880–7. Stroke in younger patients (18–50 years) can have important long-term outcomes. Aggressive treatment of this condition is important given the longer expected survival of this population when compared to those over 50 years of age. Conflicting data exist about the relative benefit of acute treatment with intravenous alteplase in younger patients, though all prior studies have been limited by small sample size. This study sought to evaluate the safety and efficacy of this medication in younger patients when compared to older patients. A post hoc analysis of data from the Safe Implementation of Thrombolysis in Stroke – International Stroke Thrombolysis Register (SITS-ISTR) was performed on data of patients aged 18–80 years that received intravenous alteplase within 4.5 h of stroke onset between 2002 and 2010. Primary outcomes were symptomatic intracerebral hemorrhage (SICH), mortality, and functional independence at 3 months. The SITS-ISTR contained data on 3246 patients aged 18–50 years and 24,425 patients aged 51–80 years. Multivariable logistic regression models were performed for each outcome variable. Regressions were also performed for subdivision of patients in deciles (under 30 years, 31–40 years, 41–50 years, and over 50 years). There was a significant difference in the baseline characteristics of the two groups, with increasing rates of comorbidities such as hypertension, diabetes mellitus, hyperlipidemia, and atrial fibrillation, among others. The authors found that SICH occurred in 0.6% of younger patients and 1.9% of older patients (adjusted odds ratio [OR] 0.53, p = 0.02). Three-month mortality was 4.9% and 14.4% in young vs. old patients (adjusted OR 0.49, p < 0.001). Functional independence was 72.1% vs. 54.5% for young vs. old patients (adjusted OR 1.61, p < 0.0001). Evaluation of the age deciles showed progressive rates of SICH, mortality, and lower functional independence with increasing age, with steepest change of rates after age 50 years. The authors concluded that treatment with intravenous alteplase is safe in young patients, with greater benefit than in older cohorts. [Peter Emiley, MD Denver Health Medical Center, Denver, CO] Comments: Although limited by its retrospective design, this study suggests greater benefit from the treatment of acute stroke in younger patients. This seems somewhat intuitive and is likely explained by less comorbidity and improved plasticity in the injured brain at a younger age.