Relative Contribution of Atrial Fibrillation to Outcomes of Patients With Cardiomyopathy Based on Severity of Left Ventricular Dysfunction.

In patients with left ventricular (LV) dysfunction, the risk of death or heart failure hospitalizations (HFHs) increases with worsening ejection fraction (EF). Whether the relative contribution of atrial fibrillation (AF) to outcomes is more pronounced in patients with worse EF is not confirmed. The present study aimed to investigate the relative influence of AF on the outcome of cardiomyopathy patients by severity of LV dysfunction. In this observational study, data from 18,003 patients with EF ≤50% seen at a large academic institution between 2011 and 2017 were analyzed. Patients were stratified by EF quartiles (EF<25%, 25%≤EF<35%, 35%≤EF<40%, and EF≥40%, for quartiles 1, 2, 3, and 4, respectively). and followed to the end point of death or HFH. Outcomes of AF versus non-AF patients were compared within each EF quartile. During a median follow-up of 3.35 years, 8,037 patients (45%) died and 7,271 (40%) had at least 1 HFH. Rates of HFH and all-cause mortality increased as EF decreased. The hazard ratios (HRs) of death or HFH for AF versus non-AF patients increased steadily with increasing EF (HR of 1.22, 1.27, 1.45, 1.50 for quartiles 1, 2, 3, and 4, respectively, p = 0.045) driven primarily by the risk of HFH (HR of 1.26, 1.45, 1.59, 1.69 for quartiles 1, 2, 3, and 4, respectively, p = 0.045). In conclusion, in patients with LV dysfunction, the detrimental influence of AF on the risk of HFH is more pronounced in those with more preserved EF. Mitigation strategies for AF with the goal of decreasing HFH may be more impactful in patients with more preserved LV function.

Impact of a dedicated center for atrial fibrillation on resource utilization and costs.

BACKGROUND: Atrial fibrillation (AF) affects millions of Americans each year and can lead to high levels of resource utilization through emergency department (ED) visits and inpatient stays. HYPOTHESIS: We hypothesized that referral of patients to a dedicated Center for AF from the ED would reduce costs of care. METHODS: The University of Pittsburgh Center for AF serves as a rapid referral center for patients with AF to avoid unnecessary inpatient admissions and provide specialized care. Patients that presented to the ED with AF and met prespecified criteria were directed to rapid outpatient follow-up instead of inpatient admission. The primary outcome of interest was 30-day total costs. Secondary outcomes included outpatient costs, inpatient costs, 90-day costs, and inpatient stay characteristics. RESULTS: We identified 96 patients (median age 65, 38% women) referred to the center for AF for a new diagnosis of AF between October 2017 and December 2019 and matched 96 control patients. After 30 days of follow-up, patients referred to the center for AF had a lower average cost ($619 vs. $1252, p < 0.001) compared to controls, driven by lower costs of ED care tempered by slightly higher outpatient costs. Thirty-day admissions and lengths of stay were also lower. These differences were persistent at 90 days. CONCLUSION: Directing patients with AF that present to the ED to follow-up at a dedicated Center for AF significantly reduced overall costs, while reducing subsequent inpatient admissions and total lengths of stay in the hospital.

Comparison of Circadian Variation for In-Hospital Versus Out-of-Hospital Sudden Cardiac Arrest Survivors.

Several studies have reported circadian periodicity of sudden cardiac arrest (SCA). It remains unclear to what extent this circadian rhythm is influenced by variation in patients' activities. One way to elucidate this is to compare patients with out-of-hospital cardiac arrests (OHCAs) with those with in-hospital cardiac arrests (IHCAs). We therefore examined the presence of a circadian pattern of SCA in a large cohort of OHCA and IHCA survivors. A total of 1,433 consecutive survivors of SCA in the Pittsburgh area from 2002 to 2012 were included. Patient demographics, including clinical histories and details of SCA, were collected. The distribution of SCA throughout the day was tested for differences using the chi-square test. Of the 1,224 patients analyzed, 706 had IHCA and 518 OHCA. We observed a nadir of SCA in the nighttime hours between 12 a.m. and 6 a.m. in both IHCA and OHCA groups (p <0.001), although this pattern was more blunted in the IHCA group. Patients who had an SCA in the nighttime window had more co-morbidities (p = 0.01). The circadian pattern was noted to be absent in patients with higher co-morbidity burden in IHCA only. In conclusion, the typical pattern of nighttime nadir in SCA is observed in patients with both OHCA and IHCA but is blunted in the hospital and especially in sicker patients. This suggests a common mechanistic pathway of SCA transcending differences in physical activities of patients and a difference in how co-morbidities interact with the timing of SCA in the inpatient setting.

Development of a Chest Wall Protector Effective in Preventing Sudden Cardiac Death by Chest Wall Impact (Commotio Cordis).

OBJECTIVE: Commotio cordis, sudden death with chest impact, occurs clinically despite chest wall protectors worn in sports. In an experimental model of commotio cordis, commercially available chest wall protectors failed to prevent ventricular fibrillation (VF). The goal of the current investigation was to develop a chest wall protector effective in the prevention of commotio cordis. DESIGN: In the Tufts experimental model of commotio cordis the ability of chest protectors to prevent VF was assessed. Impacts were delivered with a 40-mph lacrosse ball, timed to the vulnerable period for VF. INTERVENTION: A chest wall protector or no chest wall protector (control) was randomly assigned to be placed over the chest. Four iterative series of 2 to 4 different chest wall material combinations were assessed. Materials included 3 different foams (Accelleron [Unequal Technologies, Glen Mills, PA], closed cell high density foam; Airilon [Unequal Technologies, Glen Mills, PA], closed cell low density soft foam; and an open cell memory foam) that were adhered to a layer of TriDur (Unequal Technologies, Glen Mills, PA), a flexible elastomeric coated aramid that was bonded to a semirigid polypropylene polymer (ImpacShield, Unequal Technologies, Glen Mills, PA). MAIN OUTCOME MEASURE: Induction of VF by chest wall impact was the primary outcome. RESULTS: Of 80 impacts without chest protectors, 43 (54%) resulted in VF. Ventricular fibrillation with chest protectors ranged from a high of 60% to a low of 5%. Of 12 chest protectors assessed, only 3 significantly lowered the risk of VF compared with impacts without chest protectors. These 3 chest protectors were combinations of Accelleron, Airilon, TriDur, and ImpacShield of different thicknesses. Protection increased linearly with the thicker combinations. CONCLUSIONS: Effective protection against VF with chest wall protection can be achieved in an experimental model of commotio cordis. CLINICAL RELEVANCE: Chest protector designs incorporating these novel materials will likely be effective in the prevention of commotio cordis on the playing field.