Daily Respiratory Research Analysis
Analyzed 87 papers and selected 3 impactful papers.
Summary
A randomized crossover trial suggests fixed-pressure CPAP may provide superior blood pressure control versus auto-adjusting CPAP in hypertensive obstructive sleep apnea. Two large prospective cohorts highlight pragmatic imaging and laboratory markers: centrilobular emphysema progression predicted coronary artery calcification progression over 18 years, and admission eosinopenia (≤10 cells/μL) signaled higher ICU use and mechanical ventilation in community-acquired pneumonia.
Research Themes
- Sleep-disordered breathing and cardiovascular risk modification
- Imaging phenotypes linking pulmonary and cardiovascular disease
- Inflammation-based triage markers in pneumonia
Selected Articles
1. Fixed-pressure versus auto-adjusting continuous positive airway pressure for blood pressure control in obstructive sleep apnoea: a double-blind, randomised, crossover trial (FIX PAP Trial ).
In a double-blind randomized crossover trial in hypertensive OSA, fixed-pressure CPAP had a high posterior probability of greater 24-hour and nighttime systolic BP reduction than auto-adjusting CPAP and increased the likelihood of nocturnal diastolic dipping. Adherence and satisfaction were similar across modes despite higher delivered pressures with fixed-pressure therapy.
Impact: This RCT challenges the common assumption of cardiovascular equivalence between APAP and fixed-pressure therapy and suggests manual titration to a fixed pressure may better control blood pressure in hypertensive OSA.
Clinical Implications: For hypertensive OSA patients prioritizing cardiovascular risk reduction, consider fixed-pressure CPAP guided by manual titration, especially when ambulatory BP control is suboptimal on APAP. Larger confirmatory trials are warranted before guideline changes.
Key Findings
- Fixed-pressure CPAP showed greater reduction in 24-hour SBP versus APAP (posterior median −4.41 mmHg; pd 91.2%).
- Nighttime SBP reduction favored fixed-pressure CPAP (posterior median −6.80 mmHg; pd 94.0%).
- Fixed-pressure increased odds of nocturnal diastolic BP dipping (posterior probability 94.3%; OR 4.09) with similar adherence and satisfaction.
Methodological Strengths
- Double-blind randomized crossover design with Bayesian hierarchical analysis.
- Use of ambulatory BP monitoring and autonomic testing to capture physiologic effects.
Limitations
- Modest sample size with 30 completing both arms; short 4-week treatment periods.
- No hard cardiovascular outcomes; generalizability beyond study setting uncertain.
Future Directions: Conduct multicenter, adequately powered RCTs comparing BP and cardiovascular outcomes over longer durations, and identify phenotypes most likely to benefit from fixed-pressure therapy.
BACKGROUND: Limited data exist concerning the impact of fixed-pressure PAP (FPAP) and auto-adjusting CPAP (APAP) on blood pressure (BP) in patients with obstructive sleep apnoea (OSA). RESEARCH QUESTION: In hypertensive patients with OSA, do FPAP and APAP lead to different effects on blood pressure? METHODS: In this double-blind, randomised crossover clinical trial, patients with OSA and hypertension were treated with both FPAP and APAP. Ambulatory blood pressure monitoring (ABPM) and autonomic function testing were performed before and after each treatment. The effect of PAP mode on the change from baseline (4-week value minus baseline value) was analysed using a Bayesian hierarchical linear model. RESULTS: Forty-six patients (mean age 48.8±11.2 years) with OSA (median AHI 59 [IQR: 34, 99] events/hour) were enrolled, with 30 patients completing both treatment arms. Median device use was 6.2 hours/night. In the primary Bayesian hierarchical analysis, FPAP showed a high probability of superior Systolic Blood Pressure (SBP) control compared to APAP. For 24-hour SBP, the posterior median treatment effect was -4.41 mmHg [95% CrI: -11.11, 2.00] with a Probability of Direction (pd) of 91.2%. This effect was more pronounced for nighttime SBP, with a posterior median change of -6.80 mmHg [95% CrI: -15.37, 1.76] and a pd of 94.0%. FPAP increased the likelihood of nocturnal diastolic BP dipping compared with APAP (posterior probability of benefit 94.3%; OR 4.09).Baseline characteristics, compliance, and satisfaction were similar between treatment sequences (pd typically < 75%). Mean FPAP pressure was higher than APAP (P95) pressures (12.51±4.55 vs. 10.33±2.66 cmH INTERPRETATION: Our analysis suggests a high probability that FPAP provides superior BP control compared to APAP in OSA patients with Hypertension. These findings challenge the assumption that APAP provides equivalent cardiovascular protection and suggest that fixed-pressure therapy, guided by manual titration, may be preferable for optimal blood pressure management in this population.
2. Admission Eosinophil Count Is Associated with Hospital Resource Utilization in Community-Acquired Pneumonia: A Prospective Multicenter Study.
In a prospective multicenter CAP cohort, lower admission eosinophil counts were independently associated with higher ICU admission, increased mechanical ventilation, and longer hospitalization. A pragmatic threshold of ≤10 cells/μL identified higher-risk patients, including those receiving systemic glucocorticoids.
Impact: Defines a simple, readily available biomarker threshold to aid triage and resource planning in CAP, extending eosinopenia from prognostic association to operational decision support.
Clinical Implications: Integrate admission eosinophil count (≤10/μL) into initial CAP risk assessment to flag patients for closer monitoring, earlier ICU consultation, or escalation planning, alongside established severity tools.
Key Findings
- Lower eosinophil counts at admission correlated with higher ICU admission (p<0.001) across steroid-treated and untreated subgroups.
- Lower eosinophils associated with increased mechanical ventilation (p=0.014) and longer length of stay (p=0.024).
- A threshold of ≤10 cells/μL best stratified risk; eosinopenia increased ICU admission (14.2% vs 8.5%, adjusted OR 1.78) and ventilation (9.1% vs 5.2%, adjusted OR 1.82).
Methodological Strengths
- Prospective multicenter cohort with standardized data collection (CAPNETZ).
- Robust multivariable modeling and data-driven threshold identification with subgroup analyses.
Limitations
- Observational design with potential residual confounding and need for external validation.
- Did not compare eosinopenia head-to-head against comprehensive severity scores or biomarker panels.
Future Directions: Externally validate the ≤10/μL cutoff across healthcare systems and integrate eosinophils into predictive tools with clinical variables and biomarkers to guide escalation pathways.
BACKGROUND: Eosinopenia has been associated with adverse outcomes in community-acquired pneumonia (CAP). However, its relationship with hospital resource utilization remains unclear. RESEARCH QUESTION: What is the association between admission eosinophil counts and hospital resource utilization among adults with CAP? STUDY DESIGN AND METHODS: This prospective multicenter cohort study (CAPNETZ; project number 2024-07-11-CHV6) has enrolled patients aged ≥18 years with CAP in university hospitals in Germany since 2017. Associations between admission blood eosinophil counts and hospital resource utilization-including intensive care unit (ICU) admission, mechanical ventilation, and length of stay-were assessed using multivariable regression models. The optimal eosinophil count threshold for stratifying patients by ICU admission and mechanical ventilation rates was identified, and outcomes were compared between patients above and below this threshold. RESULTS: Lower eosinophil counts at admission were associated with increased ICU admission (n=1,639; P < .001), including among patients treated with systemic glucocorticoids (P = .002) and those not receiving glucocorticoids (P = .047). Lower eosinophil counts were also associated with higher rates of mechanical ventilation (P = .014) and longer hospital stays (P = .024). An eosinophil count threshold of 10 cells/μL was identified as the cut-off that best distinguished patients with higher versus lower risk of ICU admission and mechanical ventilation. Patients with eosinopenia (≤10 cells/μL) had higher ICU admission rates (14.2% vs. 8.5%; P < .001; adjusted odds ratio [OR], 1.78), increased mechanical ventilation rates (9.1% vs. 5.2%; P = .003; adjusted OR, 1.82), and longer hospitalization (mean 10.2 vs. 9.0 days; P = .013). INTERPRETATION: Admission eosinopenia (≤10 cells/μL) was associated with greater hospital resource utilization and may serve as a practical biomarker for healthcare resource planning.
3. Linking lungs and heart: centrilobular emphysema progression predicts coronary artery calcification progression during 18 years of follow-up.
Among 256 high-risk individuals followed a median of 18.3 years, progression of centrilobular emphysema—but not paraseptal emphysema—was independently associated with coronary artery calcification progression after adjustment for age and smoking. Baseline and follow-up CLE scores were higher in those with CAC progression.
Impact: Links a specific CT emphysema phenotype trajectory to coronary calcification progression over nearly two decades, supporting integrated cardio-pulmonary risk assessment in screening programs.
Clinical Implications: Detailed emphysema subtyping on LDCT, particularly CLE scoring and its progression, may refine cardiovascular risk stratification and prompt targeted prevention strategies in smokers and former smokers.
Key Findings
- Over 18.3 years median follow-up, 71.7% had CAC progression and 56.6% had emphysema progression.
- CLE progression independently predicted CAC progression (adjusted OR 3.32; 95% CI 1.75–6.63; p<0.001).
- PSE showed no significant association with CAC progression (OR 1.17; 95% CI 0.32–5.64; p=0.83).
Methodological Strengths
- Very long-term prospective follow-up with standardized visual scoring of emphysema and validated ordinal CAC scoring.
- Adjusted analyses accounting for age, smoking status, and pack-years.
Limitations
- Sample size was modest compared with the parent cohort, with potential selection bias.
- Use of ordinal CAC scoring without direct linkage to clinical cardiovascular events.
Future Directions: Link emphysema subtype progression to clinical cardiovascular events and test whether targeted cardio-pulmonary interventions mitigate CAC progression in those with advancing CLE.
BACKGROUND: Low-dose chest computed tomography(LDCT) for lung cancer screening provides an opportunity to evaluate smoking-related comorbidities such as emphysema and coronary artery calcification(CAC). Although cross-sectional associations exist, the long-term relationship between emphysema subtypes and CAC progression remains undefined. RESEARCH QUESTION: Is any emphysema subtype associated with long-term CAC progression? STUDY DESIGN AND METHODS: All total 256 participants with ≥15 years of follow-up were used from a prospective cohort of 9,047 asymptomatic, high-risk individuals enrolled in the Mount Sinai Early Lung and Cardiac Action Program(New York, June2000-August2004). Emphysema and its two subtypes-centrilobular(CLE) and paraseptal(PSE)-were visually assessed and graded using an enhanced Fleischner Society classification. CAC was scored using a validated ordinal method. Progression was defined as any increase in total score from baseline to follow-up. Logistic regression was used to identify predictors of CAC progression, including CLE and PSE progression, adjusted for age, smoking status, and pack-years. RESULTS: Among 256 participants(50%women, 50%men;median age, 58 years[IQR,52-63]), most (69.1%) were former smokers at enrollment, with a median of 31.1 pack-years[IQR,21-49]. Progression of CAC and emphysema was observed in 182(71.7%) and 145(56.6%) participants, respectively, over a median follow-up of 18.3(IQR:16.7,20.5) years. Participants with CAC progression had significantly higher rates of any emphysema both at baseline(70.9%vs.54.2%; p=0.011) and at follow-up(75.8%vs.56.9%;p=0.003). This group also showed higher median CLE scores at baseline(2.00vs.0.00;p<0.001) and follow-up(5.00 vs. 0.00; p<0.001). In multivariable logistic regression adjusted for age, smoking status, and pack-years, CLE progression was strongly associated with CAC progression(OR 3.32; 95% CI, 1.75-6.63; p<0.001). In contrast, PSE showed no significant association with CAC progression(OR1.17; 95%CI,0.32-5.64;p=0.83). INTERPRETATION: In this long-term screening cohort, progression of CLE-but not PSE-was linked to CAC progression, highlighting the value of detailed emphysema assessment in screening programs and supporting CLE as a systemic disorder with prognostic relevance.