Daily Cardiology Research Analysis
Three high-impact studies advance cardiovascular care across critical care, electrophysiology, and population health. Hyperoxia on VA-ECMO is strongly linked to higher mortality independent of end-organ complications, supporting tighter oxygen targets. Real-world LAAO in 34,975 Medicare patients shows durable low stroke rates, while 1.27 million retail-kiosk BP readings reveal persistently high hypertension prevalence, especially in older adults and non-Hispanic Black populations.
Summary
Three high-impact studies advance cardiovascular care across critical care, electrophysiology, and population health. Hyperoxia on VA-ECMO is strongly linked to higher mortality independent of end-organ complications, supporting tighter oxygen targets. Real-world LAAO in 34,975 Medicare patients shows durable low stroke rates, while 1.27 million retail-kiosk BP readings reveal persistently high hypertension prevalence, especially in older adults and non-Hispanic Black populations.
Research Themes
- Oxygen management strategies in VA-ECMO for cardiogenic shock
- Real-world effectiveness of left atrial appendage occlusion in atrial fibrillation
- Population-level blood pressure surveillance using retail health kiosks
Selected Articles
1. Hyperoxia and End-Organ Complications Among Cardiogenic Shock Patients Supported by Venoarterial Extracorporeal Membrane Oxygenation.
In a multinational registry of 10,541 VA-ECMO patients with cardiogenic shock, severe hyperoxia (PaO2 >300 mmHg at 24 h) was associated with markedly higher in-hospital mortality (71.7%; aOR 2.17 vs normoxia) and more end-organ complications. Mediation analysis showed that 86% of hyperoxia’s effect on mortality was direct, underscoring potential oxygen toxicity and the need for conservative oxygen targets.
Impact: This large, contemporary analysis identifies hyperoxia as a modifiable risk in VA-ECMO and quantifies its predominantly direct lethality, informing immediate bedside practice and future trials on oxygen targets.
Clinical Implications: Adopt conservative PaO2 targets and avoid severe hyperoxia in VA-ECMO. Implement continuous oxygen titration protocols and consider PaO2 at 24 h as a quality metric and trigger for intervention.
Key Findings
- Severe hyperoxia (PaO2 >300 mmHg at 24 h) had 71.7% in-hospital mortality (aOR 2.17 vs normoxia); mild hyperoxia had 63.8% (aOR 1.34).
- Hyperoxia was associated with more end-organ complications (aOR 1.42), but mediation analysis showed 86% of mortality effect was direct.
- Neurologic, hepatic, renal, and bleeding complications mediated small portions of the mortality effect (3.1%, 3.9%, 3.5%, and 2.3%, respectively).
Methodological Strengths
- Very large, multinational registry with standardized data elements
- Use of multivariable adjustment and causal mediation analysis to delineate direct vs indirect effects
Limitations
- Observational design with potential residual confounding and selection bias
- Single PaO2 timepoint at 24 h may not capture dynamic oxygen exposure
Future Directions: Randomized or adaptive trials testing oxygenation targets in VA-ECMO and mechanistic studies on hyperoxia-induced injury in this population.
OBJECTIVES: To investigate whether severe hyperoxia predisposes to end-organ complications and whether these complications contribute to in-hospital mortality among cardiogenic shock (CS) patients supported in venoarterial extracorporeal membrane oxygenation (VA-ECMO). DESIGN: Adult patients with CS from the Extracorporeal Life Support Organization Registry between 2010 and 2023 were categorized into normoxia (Pa o2 60-150 mm Hg), mild hyperoxia (Pa o2 151-300 mm Hg), and severe hyperoxia (Pa o2 > 300 mm Hg) based on their Pa o2 at 24 hours. The primary outcome was in-hospital mortality. End-organ complications were analyzed using multivariate logistic regression models, and causal mediation analysis was performed to estimate the direct and indirect effects of hyperoxia on mortality. SETTING: Multicenter, multinational prospective cohort study. PATIENTS: Adults with CS supported on VA-ECMO. INTERVENTIONS: Partial pressure of oxygen at 24 hours after VA-ECMO cannulation. MEASUREMENTS/MAIN RESULTS: A total of 10,541 patients were included (normoxia: 48.4%, mild hyperoxia: 30.0%, severe hyperoxia: 21.5%). There was higher in-hospital mortality in patients with severe hyperoxia (71.7%, adjusted OR [aOR]: 2.17; 95% CI, 1.19-2.50) and mild hyperoxia (63.8%, aOR: 1.34; 95% CI, 1.19-1.50) compared normoxia (52.7%; referent group). Severe hyperoxia was associated with more end-organ complications, which incrementally predicted higher mortality (aOR: 1.42; 95% CI, 1.25-1.61). Mediation analysis demonstrated that hyperoxia primary exerted a direct effect on mortality (86%), with contributions from neurologic (3.1%), hepatic (3.9%), renal (3.5%), and bleeding (2.3%) complications. CONCLUSIONS: Severe hyperoxia in patients with CS receiving VA-ECMO is associated with increased mortality and more end-organ complications. However, most of the effect of severe hyperoxia on mortality occurs via direct effects, independent of end-organ complications. These findings highlight the potential direct toxicity of hyperoxia and underscore the need for strategies to optimize oxygen delivery in this critically ill population.
2. Long-Term Outcomes Following Left Atrial Appendage Occlusion in Medicare Beneficiaries: Outcomes From the National Cardiovascular Data Registry.
Linking the NCDR LAAO registry to Medicare claims, this study evaluated 34,975 adults ≥65 years receiving WATCHMAN devices and found low and durable stroke rates over long-term follow-up despite high thromboembolic risk. Mortality was high, reflecting the elderly population and comorbidity burden, emphasizing shared decision-making when selecting LAAO.
Impact: Provides the largest real-world, nationally representative long-term outcomes for LAAO, supporting its stroke-preventive effectiveness while contextualizing mortality in elderly AF populations.
Clinical Implications: LAAO offers sustained stroke reduction for older AF patients unsuitable for long-term anticoagulation. Counseling should incorporate the high background mortality and align expectations and goals of care.
Key Findings
- Cohort of 34,975 Medicare beneficiaries ≥65 years undergoing WATCHMAN LAAO.
- Long-term stroke rates were low and remained consistent despite high thromboembolic risk.
- All-cause mortality was high in this elderly population, underscoring the need for individualized decision-making.
Methodological Strengths
- Large national registry linked to Medicare claims enabling comprehensive long-term outcomes
- Probabilistic matching and real-world representativeness of elderly AF population
Limitations
- Retrospective observational design with potential residual confounding
- Abstract lacks granular event rates and detailed follow-up duration metrics
Future Directions: Comparative effectiveness across devices and antithrombotic regimens, and identification of subgroups maximizing net clinical benefit.
BACKGROUND: Percutaneous left atrial appendage occlusion (LAAO) is an alternative to long-term anticoagulation for preventing ischemic stroke in patients with atrial fibrillation. There are limited long-term outcomes data for "real-world" patients undergoing LAAO. METHODS: We performed a retrospective cohort study using the National Cardiovascular Data Registry LAAO registry from January 1, 2016, through December 31, 2019. We linked LAAO data to inpatient Medicare fee-for-service claims data using probabilistic matching to establish a cohort of patients 65 years and older undergoing LAAO with a WATCHMAN device. The primary outcomes were any stroke and all-cause mortality. RESULTS: A total of 34 975 patients with a mean±SD CHA CONCLUSIONS: Long-term stroke rates in a large nationally representative cohort of Medicare patients following LAAO were low and durably consistent during long-term follow-up despite a high thromboembolic risk. High mortality rates in this elderly population underscore the importance of incorporating patient values and preferences when considering LAAO.
3. Blood Pressure Measurements From Self-Service Health Kiosks in US Retail Stores, 2017-2024.
Among 1,270,485 retail kiosk users (2017–2024), high BP prevalence remained high (50.0% to 47.6%), with the highest rates in non-Hispanic Black adults, those >65 years, and rural residents. Despite slight improvements in BP among those with a diagnosis, nearly 28% remained ≥140/90 mmHg in 2023–2024, highlighting surveillance and equity opportunities.
Impact: Provides real-time, large-scale BP distribution data capturing underrepresented populations, complementing traditional surveys and informing targeted hypertension control strategies.
Clinical Implications: Health systems can leverage kiosk data to identify hotspots and disparities, integrate outreach and confirmatory pathways, and tailor community-based BP control interventions.
Key Findings
- Analytic sample: 1,270,485 adults across 49 states/DC; mean age 42 years; 52.1% men; 17.2% rural.
- High BP prevalence: 50.0% (2017–2018) vs 47.6% (2023–2024); highest in non-Hispanic Black adults (55.6% in 2023–2024).
- Among diagnosed hypertension, uncontrolled BP ≥140/90 mmHg decreased from 32.1% to 28.1% across study periods.
Methodological Strengths
- Very large, multi-year, multi-state dataset enabling subgroup analyses
- Standardized BP categorization with repeated two-year periods
Limitations
- Convenience sample with self-selection and potential measurement variability of kiosk devices
- Cross-sectional design precludes causal inference and clinical confirmation
Future Directions: Link kiosk data to clinical follow-up for confirmation and outcomes, and test targeted community interventions to reduce disparities revealed by kiosk surveillance.
IMPORTANCE: Hypertension is the leading risk factor for mortality in the US. Current national estimates of the prevalence of high blood pressure (BP) are derived from lagged averages based on complex, multistage, probability sampling designs to be representative of the US population. OBJECTIVE: To describe the distribution of BP readings among a convenience sample of individuals aged 18 to 99 years. DESIGN, SETTING, AND PARTICIPANTS: This was a serial cross-sectional analysis conducted from November 2017 to September 2024. The setting included Pursuant Health kiosk data at retail locations from 1892 counties in 49 US states (except Massachusetts) and the District of Columbia. Included were adult users of health kiosks. EXPOSURES: Two-year periods (2017-2018 to 2023-2024), age, gender, race, and ethnicity. MAIN OUTCOMES AND MEASURES: Users of health kiosks were self-selected visitors at retail locations. High BP was defined as either self-report of a diagnosis of hypertension or elevated BP measurement (systolic ≥140 mm Hg or diastolic ≥90 mm Hg). Among respondents with and without self-reported hypertension, proportions of individuals were estimated according to their systolic and diastolic BP (<120 and <80 mm Hg; 120-129 and <80 mm Hg; 130-139 or 80-89; and ≥140 mm Hg or ≥90 mm Hg). RESULTS: The analytic sample of 1 270 485 individuals had a mean (SD) age of 42.0 (15.6) years, 661 947 (52.1%) were men, and 219 086 (17.2%) were rural residents. Participants self-reported the following races and ethnicities: 87 553 non-Hispanic Asian (6.9%), 232 050 non-Hispanic Black (18.3%), 336 503 Hispanic (26.5%), 532 561 non-Hispanic White (41.9%), and 81 818 other race or ethnicity (6.4%). The prevalence of high BP was 50.0% (95% CI, 49.7%-50.2%) in 2017 to 2018 and 47.6% (95% CI, 47.4%-47.8%) in 2023 to 2024. Prevalence was highest among non-Hispanic Black populations across all time periods. In 2023 to 2024, prevalence was 55.6% (95% CI, 55.1%-56.0%) among non-Hispanic Black and 50.4% (95% CI, 50.1%-50.7%) and 41.0% (95% CI, 40.7%-41.4%) among non-Hispanic White and Hispanic adults, respectively. Higher prevalence was observed among those older than 65 years (eg, 2017-2018: 71.9%; 95% CI, 71.3%-72.6%) and adults in rural settings (eg, 2017-2018: 51.2%; 95% CI, 50.6%-51.8%) across all periods. Self-report of a hypertension diagnosis was 34.7% (95% CI, 34.4%-34.9%) in 2017 to 2018 and 35.9% (95% CI, 35.7%-36.1%) in 2023 to 2024. Among those who reported a hypertension diagnosis, the proportions of individuals with systolic BP greater than or equal to 140 mm Hg or diastolic BP greater than or equal to 90 mm Hg were 32.1% (95% CI, 31.7%-32.5%) in 2017 to 2018 and 28.1% (95% CI, 27.8%-28.3%) in 2023 to 2024. CONCLUSIONS AND RELEVANCE: In this cross-sectional analysis of a convenience sample of US adults who measured their BP at self-service kiosks at national retail stores, results reveal that frequency of self-report of hypertension and elevated BP measurements was high. Usage of health kiosks is more common among populations traditionally underrepresented in national surveys.