The CHADS2 Components Are Associated with Stroke-Related In-hospital Mortality in Patients with Atrial Fibrillation.

BACKGROUND: The CHADS2 score predicts stroke risk in patients with atrial fibrillation. Although strokes caused by atrial fibrillation carry the highest mortality when compared with other etiologies, it is not known whether the CHADS2 score predicts stroke-related mortality in patients with atrial fibrillation. We hypothesized that higher CHADS2 scores would be associated with higher stroke-related in-hospital mortality. METHODS: Data were obtained from administrative claims data from all emergency department encounters and hospitalizations at California's nonfederal acute care hospitals between 2008 and 2011. Patients with atrial fibrillation and an admission for acute stroke were identified using appropriate International Classification of Diseases, Ninth Revision (ICD-9), Clinical Modification codes. Age and ICD-9 codes for hypertension, diabetes, congestive heart failure, and prior stroke were used to calculate the CHADS2 score of patients with atrial fibrillation. The primary outcome was in-hospital stroke mortality and the primary predictor was CHADS2 score. A multivariate logistic regression model adjusted for sex and race was used to determine the odds ratio (OR) and 95% confidence interval (CI) for the association between CHADS2 and mortality. RESULTS: Between January 1, 2008, and December 31, 2011, 25,599 patients with atrial fibrillation were hospitalized with a stroke. The odds of in-hospital mortality was significantly higher with a CHADS2 score of 2 more versus less than 2 (OR, 1.15; 95% CI, 1.08-1.23); however, there was no dose-response association between the CHADS2 score and in-hospital mortality. Among the individual CHADS2 score items, factors associated with increased in-hospital mortality were congestive heart failure (OR, 1.61; 95% CI, 1.53-1.70), age 75 years or older (OR, 1.27; 95% CI, 1.19-1.35), and diabetes (OR, 1.24; 95% CI, 1.14-1.35). CONCLUSIONS: Unlike prior studies, our studies show that the prestroke CHADS2 score is of limited use in predicting in-hospital mortality in ischemic stroke hospitalizations in patients with atrial fibrillation.

The Impact of Therapeutic Hypothermia Used to Treat Anoxic Brain Injury After Cardiopulmonary Resuscitation on Organ Donation Outcomes.

Therapeutic hypothermia (TH) is clinically used to improve neurologic outcomes in patients with anoxic brain injury after cardiopulmonary resuscitation (CPR). For patients that regress and become organ donors after neurologic determination of death (DNDDs), the impact of TH received before determination of death on organ donation outcomes remains unknown. A prospective observational study of all adult DNDDs that received CPR and had anoxia as a cause of death from March 2013 to December 2014 was conducted across 20 organ procurement organizations (OPOs) in the United States. Main outcome measures included organs transplanted per donor (OTPD), specific organ transplantation rates, and recipient graft outcomes. One thousand ninety eight DNDDs met inclusion criteria, with 46% having received TH before determination of death. DNDDs with hypothermia before death had a similar number of OTPD (2.74 vs. 2.69, p = 0.61) and similar transplantation rates of individual organs. With regards to recipients, there was significantly less delayed graft function (DGF) in kidney grafts from donors who received TH before death (24% vs. 30%, p = 0.02). After adjusting for donor, recipient, and graft related factors, the protective effect of TH on DGF persisted (OR 0.75, 95%CI [0.56-0.995], p = 0.046). TH before death in the donor is independently associated with a 25% decrease in DGF among kidney recipients. This should be considered a protective donor selection factor in guiding the decision to accept or reject an organ for transplantation.

Ischemic Stroke Risk After Acute Coronary Syndrome.

BACKGROUND: Prior studies show an increased risk of ischemic stroke (IS) after myocardial infarction; however, there is limited evidence on long-term risk and whether it is directly related to cardiac injury. We hypothesized that the risk of IS after acute coronary syndrome is significantly higher if there is evidence of cardiac injury, such as ST-segment elevation myocardial infarction (STEMI) or non-STEMI, than when there is no evidence of cardiac injury, such as in unstable angina. METHODS AND RESULTS: Administrative claims data were obtained from all emergency department encounters and hospitalizations at California's nonfederal acute care hospitals between 2008 and 2011. Patients with STEMI, non-STEMI, and unstable angina were identified using appropriate International Classification of Diseases, Ninth Revision, Clinical Modification codes. The primary outcome was IS during 2 years of follow-up. Unadjusted and adjusted Cox proportional hazards models were used to determine the association between acute coronary syndrome subtype and IS risk. We identified 73 059 patients with a diagnosis of STEMI (n=26 427), non-STEMI (n=39 833), or unstable angina (n=6819) during the study period. In the fully adjusted models that included potential confounders such as atrial fibrillation and congestive heart failure, the risk of IS was higher with STEMI (hazard ratio 4.17, 95% CI 3.00-5.83; P<0.001) and non-STEMI (hazard ratio 3.73, 95% CI 2.68-5.19, P<0.001) compared with unstable angina. CONCLUSIONS: Non-STEMI and STEMI confer an equally increased risk of IS. Studies exploring IS mechanisms in cardiac patients are needed to improve and tailor stroke prevention strategies.