Association of atrial fibrillation risk alleles and response to acute rate control therapy.

OBJECTIVES: Given the sparse evidence for selection of first-line therapy for acute atrial fibrillation (AF) based on clinical factors alone, incorporation of genotype data may improve the effectiveness of treatment algorithms and advance the understanding of interpatient heterogeneity. We tested whether candidate nucleotide polymorphisms (SNPs) related to AF physiologic responses are associated with ventricular rate control after intravenous diltiazem in the emergency department (ED). METHODS: We conducted an analysis within a prospective observational cohort of ED patients with acute symptomatic AF, ventricular rate >110 beats per minute within the first 2 hours, initially treated with intravenous diltiazem, and who had DNA available for analysis. We evaluated 24 candidate SNPs that were grouped into 3 categories based on their phenotype response (atrioventricular nodal [AVN] conduction, resting heart rate, disease susceptibility) and calculated 3 genetic scores for each patient. Our primary outcome was maximum heart rate reduction within 4 hours of diltiazem administration. Multivariable regression was used to identify associations with the outcome while adjusting for age, sex, baseline heart rate, and diltiazem dose. RESULTS: Of the 142 patients, 127 had complete data for the primary outcome. None of the genetic scores for AVN conduction, resting heart rate, or AF susceptibility showed a significant association with maximal heart rate response. CONCLUSION: Using a candidate SNP approach, screening for genetic variants associated with AVN conduction, resting heart rate, or AF susceptibility failed to provide significant data for predicting successful rate control response to intravenous diltiazem for treating acute AF in the ED.

Incidence of catheter-related bloodstream infections in neonates following removal of peripherally inserted central venous catheters.

OBJECTIVES: Catheter-associated bloodstream infections are a significant source of morbidity and healthcare cost in the neonatal ICU. Previous studies examining the prevalence of bloodstream infections after removal of peripherally inserted central venous catheters in neonates are equivocal. DESIGN: A retrospective cohort study. PATIENTS: All infants with peripherally inserted central venous catheters treated at the Vanderbilt neonatal ICU between 2007 and 2009. MEASUREMENTS AND MAIN RESULTS: We evaluated the following outcomes: 1) bloodstream infections, 2) culture-negative sepsis, 3) number of sepsis evaluations, and 4) number of significant apnea/bradycardia events comparing odds ratios between 72 hours before and 72 hours after peripherally inserted central venous catheter removal. We analyzed a total of 1,002 peripherally inserted central venous catheters in 856 individual infants with a median (interquartile range) gestational age of 31 weeks (28-37 wk) and a median birth weight of 1,469 g (960-2,690 g). Comparing 72 hours before with 72 hours after peripherally inserted central venous catheter removal did not show a difference in the prevalence of bloodstream infections (9 vs 3, p = 0.08), prevalence of culture-negative sepsis (37 vs 40, p = 0.73), number of sepsis evaluations (p = 0.42), or number of apnea/bradycardia events (p = 0.32). However, in peripherally inserted central venous catheter not used for delivery of antibiotics, there was a 3.83-fold increase in odds for culture-negative sepsis following peripherally inserted central venous catheter removal (95% confidence interval, 1.48-10.5; p = 0.001). For infants less than 1,500 g birth weight (very low birth weight), odds for culture-negative sepsis increased to 6.3-fold following removal of peripherally inserted central venous catheters not used for antibiotic delivery (95% confidence interval, 1.78-26.86; p < 0.01). CONCLUSIONS: Although these data do not support the routine use of antibiotics for sepsis prophylaxis prior to peripherally inserted central venous catheter removal, they suggests that very low birth weight infants not recently exposed to antibiotics are at increased odds for associated adverse events following discontinuation of their peripherally inserted central venous catheter.

The impact of a new CPR assist device on rate of return of spontaneous circulation in out-of-hospital cardiac arrest.

OBJECTIVE: The San Francisco Fire Department deployed an automated, load-distributing-band chest compression device (AutoPulse, Revivant Corporation) to evaluate its function in a large urban emergency medical services (EMS) service. A retrospective chart review was undertaken to determine whether the AutoPulse had altered short-term patient outcome, specifically, return of spontaneous circulation (ROSC). METHODS: AutoPulse cardiopulmonary resuscitation (A-CPR) was used by paramedic captains responding to adult cardiac arrests with an average +/-SD response time of 15 +/- 5 minutes. The primary endpoint was patient arrival to an emergency department with measurable spontaneous pulses. The manual CPR comparison group was case-matched for age, gender, initial presenting electrocardiogram rhythm, and the number of doses of Advanced Cardiac Life Support medications as a proxy for treatment time. Matching was performed by an investigator blinded to outcome and treatment group. RESULTS: Sixty-nine AutoPulse uses were matched to 93 manual-CPR-only cases. A-CPR showed improvement in the primary outcome when compared with manual CPR with any presenting rhythm (A-CPR 39%, manual 29%, p = 0.003). When patients were classified by first presenting rhythm, shockable rhythms showed no difference in outcome (A-CPR 44%, manual 50%, p = 0.340). Outcome was improved with A-CPR in initial presenting asystole and approached significance with pulseless electrical activity (PEA)(asystole: A-CPR 37%, manual 22%, p = 0.008; PEA: A-CPR 38%, manual 23%, p = 0.079). CONCLUSION: The AutoPulse may improve the overall likelihood of sustained ROSC and may particularly benefit patients with nonshockable rhythms. A prospective randomized trial comparing the AutoPulse with manual CPR in the setting of out-of-hospital sudden cardiac arrest is under way.