Tu, Jack V.

Objectives: Limited information is available on the prevalence of cardiorespiratory arrest (CA) and its predisposing factors in patients with acute ischemic stroke. We analyzed/evaluated clinical characteristics, risk factors, access to care, and survival in stroke patients who developed a cardiac arrest. Methods: This is a multicenter cohort study including consecutive patients with acute ischemic stroke admitted to regional stroke centers participating in the Registry of the Canadian Stroke Network from July 2003 to March 2008. Patients with DNR order on admission were excluded. CA was defined as cardiac or respiratory arrest within 30 days of admission documented by a physician and identified from resuscitation records. The main outcome measures were the 30-day and 1-year survival among patients with CA vs. no CA. We also assessed the association between medical complications during hospitalization and CA. Results: Overall, 9,019 patients with acute ischemic stroke were included. Cardiac arrest was observed in 352 patients (3.9%). In patients with CA, 30-day survival (17.9% vs. 90.7%, P<0.001) and 1-year survival (4.5% vs. 80.1, p<0.001) were significantly lower. Less than 1% of stroke patients with CA were discharged home (vs. 47.3%; p<0.0001). Other outcome measures are summarized in Table 1. On multivariable analyses, older age, more severe stroke, previous history of myocardial infarction, congestive heart failure, atrial fibrillation, and diabetes were associated with CA. Conclusions: Cardiac arrest affects less than 5% of patients admitted with an acute ischemic stroke and is associated with poor outcomes. Less than 1% of patients were independent or discharged home.

Abstract Background: Recent data suggest that older men with detectable cardiac troponin I (cTnI) concentrations that remain below the 99th percentile concentration cutoff are at increased risk for subsequent cardiovascular events. We designed this study to extend this observation by examining risk prediction in both men and women presenting to an emergency department with chest discomfort. Methods: We obtained data for all-cause mortality and hospital discharges associated with either acute myocardial infarction (AMI) or congestive heart failure (CHF) for up to 8 years after the initial presentation in 448 patients who originally presented in 1996 with acute coronary syndrome (ACS). We performed retrospective analysis for cTnI (AccuTnI™; Beckman Coulter) in frozen plasma samples based on the patients’ reported time from onset of symptoms. Peak cTnI concentration was used for risk assessment. Results: Patients with cTnI concentrations ≥0.02 μg/L (i.e., limit of detection), including those whose peak values remained below the 99th percentile (0.04 μg/L), were at greater risk for death and AMI/CHF readmissions at 2, 5, and 8 years of follow-up compared with those with peak cTnI &lt;0.02 μg/L. All results were statistically significant (P &lt;0.05) except for death within 2 years among patients with normal but detectable cTnI (0.02 to 0.03 μg/L), relative to the group with values &lt;0.02 μg/L. Kaplan–Meier analyses indicated that both men and women with cTnI ≥0.02 μg/L had worse outcomes (P &lt;0.001). Conclusion: Both men and women who present with possible ACS with detectable cTnI concentrations that remain below the 99th percentile are at a greater risk for future adverse events.

Abstract Background: In a population originally classified for acute myocardial infarction (AMI) by the World Health Organization (WHO) definition, we compared the health outcomes after retrospectively reclassifying with the European Society of Cardiology and the American College of Cardiology (ESC/ACC) AMI definition, using the peak cardiac troponin I (cTnI) concentrations. The health outcomes were based on the WHO definition and occurred in an era that preceded the use of cardiac troponin biomarkers. Methods: For 448 patients who presented to the emergency department with symptoms suggestive of cardiac ischemia in 1996, we obtained data for all-cause mortality and recurrent AMI for up to 1 year after the initial presentation. We performed retrospective analysis of the patients’ frozen plasma samples to measure cTnI (AccuTnI®, Beckman Coulter). Results: At 30, 120, and 360 days, the risk for AMI/death in patients positive for AMI by only the ESC/ACC criteria was significantly lower than the risk in patients positive by both ESC/ACC and WHO criteria, and significantly higher than in patients negative according to both criteria. In a separate analysis, patients with a peak cTnI &gt;0.10 μg/L were at greater risk for AMI/death than patients with cTnI concentrations of 0.04–0.10 μg/L. Patients negative by both definitions or with peak cTnI concentrations &lt;0.04 μg/L had the highest event-free survival rates (92% and 94%, respectively) at 1 year. Conclusion: In a troponin-naïve population, patients classified as positive for AMI by only the ESC/ACC criteria have a prognosis that appears to be intermediate between those classified positive by both the WHO and ESC/ACC definitions and those who meet neither criteria.