The relationship between particulate matter with a diameter of 2.5 micrometers or less (PM_2.5) and heart failure (HF) hospitalizations and mortality in the US is unclear. Prior studies are limited to studying the effects of daily PM_2.5exposure on HF hospitalizations in specific geographic regions. Because PM_2.5can vary by geography, this study examines the effects of annual ambient PM_2.5exposure on HF hospitalizations and mortality at a county-level across the US. A cross-sectional analysis of county-level ambient PM_2.5concentration, HF hospitalizations, and HF mortality across 3135 US counties nationwide was performed, adjusting for county-level demographics, socioeconomic factors, comorbidities, and healthcare-associated behaviors. There was a moderate correlation between county PM_2.5and HF hospitalization among Medicare beneficiaries (r = 0.41) and a weak correlation between county PM_2.5and HF mortality (r = 0.08) (p-values < 0.01). After adjustment for various county level covariates, every 1 ug/m³increase in annual PM_2.5concentration was associated with an increase of 0.51 HF Hospitalizations/1,000 Medicare Beneficiaries and 0.74 HF deaths/100,000 residents (p-values < 0.05). In addition, the relationship between PM_2.5and HF hospitalizations was similar when factoring in metropolitan status of the counties. In conclusion, increased ambient PM_2.5concentration level was associated with increased incidence of HF hospitalizations and mortality at the county level across the US. This calls for future studies exploring policies that reduce ambient particulate matter pollution and their downstream effects on potentially improving HF outcomes.

Background: There is a dearth of research examining geographic disparities in access to cardiac rehabilitation (CR). We evaluated whether disparities in geographic access to CR exist among socially vulnerable communities, using the Social Vulnerability Index (SVI). Methods: Among 3113 US counties, we investigated relationships between SVI and number of hospitals with CR per 100 000 adults, modeled with SVI as a linear variable, and SVI and distance to the nearest county with CR facilities, modeled using spline terms for SVI. We used multivariable zero‐inflated negative binomial regression modeling adjusted for county population, CR eligibility, percentage without health insurance, metropolitan status, and availability of existing health care infrastructure. We explored whether these relationships changed in the context of rurality. Results: After adjustment, as SVI increased by 1 percentile, number of hospitals with CR per 100 000 adults decreased by 1.2% ( P <0.001). For distance to CR, individual spline terms were not significant in our adjusted model; however, the overall predicted distance to CR increased as SVI increased. When stratified by metropolitan status, these relationships not only persisted but also intensified in rural counties. As SVI increased by 1 percentile, the odds of a county containing a CR facility decreased by 0.9% in metropolitan counties ( P =0.002) versus 2.2% in rural counties ( P <0.001). Conclusion: More socially vulnerable communities experienced worse geographic access to CR facilities. This access disparity intensified in rural communities. Our findings call for reducing barriers to CR access among socially vulnerable and rural communities, potentially through virtual or hybrid models of CR.

Left ventricular (LV) dysfunction is associated with poor clinical outcomes in acute respiratory failure (ARF). This study evaluates the efficacy of LV strain in detecting LV dysfunction in ARF patients requiring invasive mechanical ventilation (IMV) compared to conventionally measured left ventricular ejection fraction (LVEF). ARF patients requiring IMV who had echocardiography performed during MICU admission were included. LV global longitudinal strain (LVGLS) and LVEF were measured retrospectively using speckle tracking (STE) and traditional transthoracic echocardiography (TTE), respectively, by investigators blinded to the status of IMV and clinical data. The cohort was divided into three groups: TTE during IMV (TTE-IMV), before IMV (TTE-bIMV), and after IMV (TTE-aIMV). Multivariable regression models, adjusted for illness severity score, chronic cardiac disease, acute respiratory failure etiology, body mass index, chronic obstructive pulmonary disease, and obstructive sleep apnea, evaluated associations between LV function parameters and the presence of IMV. Among 376 patients, TTE-IMV, TTE-bIMV, and TTE-aIMV groups constituted 223, 68, and 85 patients, respectively. The median age was 65 years (IQR: 56–74), with 53.2% male participants. Adjusted models showed significantly higher LVGLS in groups not on IMV at the time of TTE (TTE-bIMV: β = 4.19, 95% CI 2.31 to 6.08, p < 0.001; TTE-aIMV: β = 3.79, 95% CI 2.03 to 5.55, p < 0.001), while no significant differences in LVEF were observed across groups. In a subgroup analysis of patients with LVEF ≥55%, the significant difference in LVGLS among the groups remained (TTE-bIMV: β = 4.18, 95% CI 2.22 to 6.15, p < 0.001; TTE-aIMV: β = 3.45, 95% CI 1.50 to 5.40, p < 0.001), but was no longer present in those with LVEF < 55%. This suggests an association between IMV and lower LVGLS in ARF patients requiring IMV, indicating that LVGLS may be a more sensitive marker for detecting subclinical LV dysfunction compared to LVEF in this population. Future studies should track and assess serial echocardiography data in the same cohort of patients pre-, during, and post-IMV in order to validate these findings and prognosticate STE-detected LV dysfunction in ARF patients requiring IMV.

Right ventricular (RV) dysfunction is associated with poor prognosis in acute respiratory failure (ARF). Our study evaluates the efficacy of RV strain in detecting RV dysfunction in ARF patients requiring invasive mechanical ventilation (IMV) compared to tricuspid annular plane systolic excursion (TAPSE). In this retrospective study involving 376 patients diagnosed with ARF and requiring IMV, we extracted clinical and outcome data from patient records. RV global longitudinal strain (RVGLS), free wall longitudinal strain (FWLS), and TAPSE were measured retrospectively using speckle tracking echocardiography (STE) and traditional echocardiography, respectively. We divided the cohort into three groups: TTE during IMV (TTE-IMV, 223 patients), before IMV (TTE-bIMV, 68 patients), and after IMV (TTE-aIMV, 85 patients). Multivariable regression analysis, adjusted for covariates, revealed significantly higher RVGLS and FWLS in the groups not on IMV at the time of TTE compared to the TTE-IMV group. Specifically, the TTE-bIMV group showed higher RVGLS (β = 7.28, 95% CI 5.07, 9.48) and FWLS (β = 5.83, 95% CI 3.36, 8.31), while the TTE-aIMV group exhibited higher RVGLS (β = 9.39, 95% CI 6.10, 12.69) and FWLS (β = 7.54, 95% CI 4.83, 10.24). TAPSE did not reveal any significant differences across the groups. Our study suggests an association between IMV and lower RVGLS and FWLS in ARF patients, indicating that IMV itself may contribute to RV dysfunction. RVGLS and FWLS appear to be more sensitive than TAPSE in detecting changes in RV function that were previously subclinical in patients on IMV. Prospective studies with TTE before, during, and after IMV are necessary to assess the primary driver of RV dysfunction and to prognosticate STE-detected RV dysfunction in this population.

Background/Objectives: Left ventricular diastolic dysfunction (LVDD) and elevated left ventricular filling pressure (LVFP) are strong predictors of clinical outcomes across various populations. However, their diagnostic utility in embolic stroke of undetermined source (ESUS) remains unclear. We hypothesized that LVDD with elevated LVFP (based on echocardiography) was more likely to be prevalent in ESUS compared to non-cardioembolic stroke (NCE) and to be associated with atrial fibrillation (AF) on follow-up monitoring. Methods: This is a single-center retrospective study that included adult patients with a diagnosis of acute ischemic stroke between January 2016 and June 2017. LV function was assessed by inpatient transthoracic echocardiogram (TTE), and stroke etiology was adjudicated by the neurologist per the consensus criteria. Patients with cardioembolic stroke and those with indeterminate diastolic function on TTE were excluded. Baseline patient characteristics and clinical variables were compared among patients with and without LVDD and elevated LVFP. Multivariable regression models were used to assess the associations between diastolic dysfunction, ESUS, and AF detection in ESUS patients. Results: We identified 509 patients with ESUS and NCE stroke who had reported diastolic function. The mean age was 64.19 years, 45.19% were female, and 146 had LVDD with available LVFP data. LVDD was not associated with ESUS (adjusted OR: 1.43, 95% CI: 0.90–2.27, p = 0.130) or atrial fibrillation (AF) detection on cardiac monitoring (adjusted OR: 1.88, 95% CI: 0.75–4.72, p = 0.179). However, LVDD with elevated LVFP was borderline associated with ESUS (adjusted OR: 2.17, 95% CI: 0.99–4.77, p = 0.054) and significantly associated with AF detection (adjusted OR: 3.59, 95% CI: 1.07–12.06, p = 0.038). Conclusions: Our data suggest that LVDD with elevated LVFP is borderline associated with ESUS and significantly associated with AF detection on follow-up cardiac monitoring. Therefore, the presence of LVDD with an increased probability of elevated LVFP may help identify a subset of stroke patients more likely to have ESUS, potentially due to atrial cardiopathy with underlying occult AF. Further studies are needed to confirm our findings and to evaluate the safety and efficacy of anticoagulation in patients with ESUS and LVDD with elevated LVFP.