Exposure to high concentrations of inspired oxygen does not worsen lung injury after cardiac arrest.

INTRODUCTION: Post-cardiac arrest patients are often exposed to 100% oxygen during cardiopulmonary resuscitation and the early post-arrest period. It is unclear whether this contributes to development of pulmonary dysfunction or other patient outcomes. METHODS: We performed a retrospective cohort study including post-arrest patients who survived and were mechanically ventilated at least 24 hours after return of spontaneous circulation. Our primary exposure of interest was inspired oxygen, which we operationalized by calculating the area under the curve of the fraction of inspired oxygen (FiO2AUC) for each patient over 24 hours. We collected baseline demographic, cardiovascular, pulmonary and cardiac arrest-specific covariates. Our main outcomes were change in the respiratory subscale of the Sequential Organ Failure Assessment score (SOFA-R) and change in dynamic pulmonary compliance from baseline to 48 hours. Secondary outcomes were survival to hospital discharge and Cerebral Performance Category at discharge. RESULTS: We included 170 patients. The first partial pressure of arterial oxygen (PaO2):FiO2 ratio was 241 ± 137, and 85% of patients had pulmonary failure and 55% had cardiovascular failure at presentation. Higher FiO2AUC was not associated with change in SOFA-R score or dynamic pulmonary compliance from baseline to 48 hours. However, higher FiO2AUC was associated with decreased survival to hospital discharge and worse neurological outcomes. This was driven by a 50% decrease in survival in the highest quartile of FiO2AUC compared to other quartiles (odds ratio for survival in the highest quartile compared to the lowest three quartiles 0.32 (95% confidence interval 0.13 to 0.79), P = 0.003). CONCLUSIONS: Higher exposure to inhaled oxygen in the first 24 hours after cardiac arrest was not associated with deterioration in gas exchange or pulmonary compliance after cardiac arrest, but was associated with decreased survival and worse neurological outcomes.

Risk of Stroke and Death in Atrial Fibrillation by Type of Anticoagulation: A Propensity-Matched Analysis.

BACKGROUND: We examined the effect of novel oral anticoagulants (NOACs) compared to warfarin on the risk of death or stroke in atrial fibrillation (AF) patients in every day clinical practice. METHODS: We examined a cohort of 2,836 AF patients, of whom 2,253 were prescribed warfarin and 583 were prescribed an NOAC. Patients with glomerular filtration rate < 30 mg/mL or history of significant valvular heart disease were excluded. Patients were followed to primary end points of death or stroke. Propensity matching was used to adjust for differences in baseline characteristics between the groups. RESULTS: Compared to patients in the NOAC group, patients on warfarin had more comorbidities and higher CHADS2 and CHA2 DS2 -VASc scores (1.7 vs 1.3 for CHADS2 , 2.8 vs 2.2 for CHA2 DS2 -VASc, P < 0.0001 for both). After adjusting for differences in baseline characteristics, NOAC use was associated with significant reduction in all-cause mortality compared to warfarin (hazard ratio [HR] = 0.47, 95% confidence interval [CI; 0.3-0.8], P = 0.006) but not stroke, over a median follow-up of 42.5 months. The difference in mortality persisted after propensity score matching (HR = 0.51, 95% CI [0.28-0.93], P = 0.03). CONCLUSIONS: Compared to warfarin, NOAC use is associated with decreased all-cause mortality but not stroke risk. These data from real-life clinical practice add to existing evidence for decreased mortality among patients prescribed NOACs compared to warfarin.

Failure-free survival of the Durata defibrillator lead.

AIMS: Given design similarities and a common manufacturer, there have been suspicions regarding the Durata™ defibrillator (ICD) lead, in the aftermath of the Riata™ class I recall. We therefore examined the failure-free survival rates of the Durata™ compared with the Riata™ and Sprint Quattro™ ICD leads. METHODS AND RESULTS: All patients (n = 2475) implanted with a Durata (n = 828), Riata [n = 627; 8 Fr. (n = 472) and 7 Fr. (n = 155)], or Sprint Quattro (n = 1020) leads at our institution were included and Kaplan-Meier failure-free survival curves were constructed for all leads. Lead failure was defined as electrical malfunction resulting in lead replacement, excluding dislodgements or perforations. Annual electrical failure rates were 0.3%, 1.7, and 0.3% for the Durata, Riata, and Sprint Quattro leads, respectively (P < 0.0001 for the comparison of Durata to Riata and P = 0.1.0 for the comparison of Durata to Sprint Quattro). The failure-free survival of the Durata lead was significantly better than that of the Riata lead (P < 0.0001) and similar to that of the Sprint Quattro (P = 0.94). The 7 Fr. Riata ST lead had better survival compared with the 8 Fr. Riata lead (P = 0.050) and comparable survival with the Durata lead (P = 0.12). CONCLUSION: The Durata lead failure-free survival is significantly better than the 8 Fr. Riata, albeit at a shorter follow-up time. Riata and comparable with that of the 7 Fr. Riata ST and the Sprint Quattro ICD leads. These data provide an insight into the mechanism of electrical failure of Riata leads and have implications for patient management.

Unusual presentation of listerial myocarditis and the diagnostic value of cardiac magnetic resonance.

Listeria monocytogenes is an infrequent cause of bacterial myocarditis. Myocarditis without evidence of endocarditis is even rarer. Management in such cases involves early diagnosis, antibiotic therapy, and emergency treatment of arrhythmias. We report the case of a 47-year-old man who presented with features of acute ST-segment-elevation myocardial infarction complicated by ventricular tachycardia that necessitated urgent electrical cardioversion. Contrast-enhanced cardiac magnetic resonance images revealed hypertrophy, necrosis, and a mass that was determined to be an abscess caused by L. monocytogenes. Antibiotic treatment led to resolution of the listerial myocarditis. In addition to reporting our patient's case, we discuss the comparative advantages of cardiac magnetic resonance versus transthoracic echocardiography in characterizing myocarditis, upon presentation and in follow-up evaluation.

The association between hyperoxia and patient outcomes after cardiac arrest: analysis of a high-resolution database.

PURPOSE: Previous observational studies have inconsistently associated early hyperoxia with worse outcomes after cardiac arrest, and have methodological limitations. We tested this association using a high-resolution database controlling for multiple disease-specific markers of severity of illness and care processes. METHODS: This was a retrospective analysis of a single-center, prospective registry of consecutive cardiac arrest patients. We included patients who survived and were mechanically ventilated ≥24 h after arrest. Our main exposure was arterial oxygen tension (PaO2), which we categorized hourly for 24 h as severe hyperoxia (>300 mmHg), moderate or probable hyperoxia (101-299 mmHg), normoxia (60-100 mmHg) or hypoxia (<60 mmHg). We controlled for Utstein-style covariates, markers of disease severity and markers of care responsiveness. We performed unadjusted and multiple logistic regression to test the association between oxygen exposure and survival to discharge, and used ordered logistic regression to test the association of oxygen exposure with neurological outcome and Sequential Organ Failure Assessment (SOFA) score at 24 h. RESULTS: Of 184 patients, 36 % were exposed to severe hyperoxia and overall mortality was 54 %. Severe hyperoxia, but not moderate or probable hyperoxia, was associated with decreased survival in both unadjusted and adjusted analysis [adjusted odds ratio (OR) for survival 0.83 per hour exposure, P = 0.04]. Moderate or probable hyperoxia was not associated with survival but was associated with improved SOFA score 24 h (OR 0.92, P < 0.01). CONCLUSION: Severe hyperoxia was independently associated with decreased survival to hospital discharge. Moderate or probable hyperoxia was not associated with decreased survival and was associated with improved organ function at 24 h.

Patient outcomes according to adherence to treatment guidelines for rhythm control of atrial fibrillation.

BACKGROUND: Although guidelines for antiarrhythmic drug therapy in atrial fibrillation (AF) were published in 2006, it remains uncertain whether adherence to these guidelines affects patient outcomes. METHODS AND RESULTS: We retrospectively evaluated the records of 5976 consecutive AF patients who were prescribed at least 1 antiarrhythmic drug between 2006 and 2013. Patients with 1 or more prescribed antiarrhythmic drugs that did not comply with guideline recommendations comprised the non-guideline-directed group (=2920); the remainder constituted the guideline-directed group (=3056). Time to events was assessed using the survival analysis method and adjusted for covariates using Cox regression. Rates of adherence to the guidelines increased significantly with a higher degree of prescriber specialization in arrhythmias (49%, 55%, and 60% for primary care physicians, general cardiologists, and cardiac electrophysiologists, respectively, P=0.001) for the first prescribed antiarrhythmic drug. Compared to the non-guideline-directed group, the guideline-directed group had higher rates of heart failure, but lower baseline CHADS2-VASc scores (P<0.001) and lower rates of coronary artery disease, valvular disease, hypertension, hyperlipidemia, pulmonary disease, and renal insufficiency (P<0.05 for all). During 45 ± 26 months follow-up, the guideline-directed group had a lower risk of AF recurrence (hazard ratio=0.86, 95% CI=0.80 to 0.93), fewer hospital admissions for AF (hazard ratio=0.87, 95% CI=0.79 to 0.97), and fewer procedures for recurrent AF, including electrical cardioversion, pacemaker implantation, and atrioventricular nodal ablation (P<0.01 for all). The mortality and stroke risks were similar between the groups. CONCLUSIONS: Adherence to published guidelines in the antiarrhythmic management of AF is associated with improved patient outcomes.