Causes of Death and Prediction of Mortality in COPD

A Pilot Study on Proteomic Predictors of Mortality in Stable COPD

Chronic Obstructive Pulmonary Disease (COPD) is the third leading cause of global mortality. Despite clinical predictors (age, severity, comorbidities, etc.) being established, proteomics offers comprehensive biological profiling to obtain deeper insights into COPD pathophysiology and survival prognoses. This pilot study aimed to identify proteomic footprints that could be potentially useful in predicting mortality in stable COPD patients. Plasma samples from 40 patients were subjected to both blind (liquid chromatography-mass spectrometry) and hypothesis-driven (multiplex immunoassays) proteomic analyses supported by artificial intelligence (AI) before a 4-year clinical follow-up. Among the 34 patients whose survival status was confirmed (mean age 69 ± 9 years, 29.5% women, FEV1 42 ± 15.3% ref.), 32% were dead in the fourth year. The analysis identified 363 proteins/peptides, with 31 showing significant differences between the survivors and non-survivors. These proteins predominantly belonged to different aspects of the immune response (12 proteins), hemostasis (9), and proinflammatory cytokines (5). The predictive modeling achieved excellent accuracy for mortality (90%) but a weaker performance for days of survival (Q2 0.18), improving mildly with AI-mediated blind selection of proteins (accuracy of 95%, Q2 of 0.52). Further stratification by protein groups highlighted the predictive value for mortality of either hemostasis or pro-inflammatory markers alone (accuracies of 95 and 89%, respectively). Therefore, stable COPD patients' proteomic footprints can effectively forecast 4-year mortality, emphasizing the role of inflammatory, immune, and cardiovascular events. Future applications may enhance the prognostic precision and guide preventive interventions.

The impact of hydration status and fluid distribution on pulmonary function in COPD patients

Chronic Obstructive Pulmonary Disease (COPD) patients have alterations in body composition. Bioelectrical impedance analysis (BIA) evaluates body composition, hydration status, and fluid distribution. Subjects with fluid disturbances have been found to have lower FEV1, respiratory muscle strength, and poor prognosis. We aimed to evaluate the effect of hydration status and fluid distribution on pulmonary function in COPD patients. A cross-sectional study, 180 patients with a confirmed diagnosis of COPD were included. Patients with asthma, advanced renal or liver disease, acute HF, exacerbation of COPD, or pacemakers were excluded. Hydration status variables (TBW, ECW, ICW) and disturbance of fluid distribution [impedance ratio (IR) > 0.84 and phase angle (PhA)] were evaluated by BIA. Pulmonary function was assessed by spirometry. The mean population age was 71.55 ± 8.94 years; 55% were men. Subjects were divided into two groups according to the IR ≥ 0.84 or < 0.84. The group with higher IR ≥ 0.84 had lower FEV1, FVC, FEV1/FVC, DLCO and, PhA compared to those with IR < 0.84. After adjusting for confounding variables TBW, ECW, IR ≥ 0.84, PhA, and resistance/height increase were associated with decreased FEV1. In the same way, with IR ≥ 0.84, edema index ≥ 0.48, trunk and abdominal IR were negatively associated with FVC, and PhA had a positive association with FVC. Fluid distribution, especially IR and PhA, could be a useful parameter for predicting pulmonary function in COPD patients.

Analysis of two questionnaires on quality of life of Chronic Obstructive Pulmonary Disease patients

Objective:

to evaluate the efficacy of quality of life questionnaires St. George Respiratory Questionnaire and Chronic Obstructive Pulmonary Disease Assessment Test in patients with chronic obstructive pulmonary disease based on correlation and agreement analyses, and identify the most effective tool to assess their quality of life.

Method:

cross-sectional cohort study with patients hospitalized in a Spanish hospital for exacerbation of chronic obstructive pulmonary disease. Health-related quality of life was assessed with both questionnaires. The correlation and the agreement between the questionnaires were analyzed, as well as the internal consistency. Associations were established between the clinical variables and the results of the questionnaire.

Results:

one hundred and fifty-six patients participated in the study. The scales had a correlation and agreement between them and high internal consistency. A higher sensitivity of the Chronic Obstructive Pulmonary Disease Assessment Test was observed for the presence of cough and expectoration.

Conclusion:

the questionnaires have similar reliability and validity to measure the quality of life in patients with acute chronic obstructive pulmonary disease, and the Chronic Obstructive Pulmonary Disease Assessment Test is more sensitive to detect cough and expectoration and requires a shorter time to be completed.

Application of a parametric model in the mortality risk analysis of ICU patients with severe COPD

OBJECTIVE

To evaluate the mortality risk factors of patients with severe chronic obstructive pulmonary disease (COPD) in the intensive care unit (ICU) by utilizing parametric model of survival analysis, and to estimate patients' prognoses based on the risk and survival functions in the model.

METHODS

The clinical data and outcomes of COPD patients admitted to a respiratory intensive care unit (RICU) at Beijing Chao-Yang Hospital from January 2009 to June 2014 were prospectively collected. Based on the clinical outcomes, these patients were divided into a survival group and a death group. A univariate analysis was conducted to identify statistically significant variables. According to the distribution characteristics of these data, residual plots were prepared for an exponential model, a Weibull model and a Gamma model. The Gamma model was determined to be the best fitted for these data and was used as the analytical tool. Therefore, the variables with differences obtained from the univariate analysis were put into the Gamma model to determine the patients' mortality risk factors. The risk and survival functions were also generated according to the model formula.

RESULTS

A total of 160 patients (111 survival, 49 death) were enrolled. The univariate analysis showed that, compared with the survival group, patients in the death group had higher Charlson Comorbidity Index score (CCI), higher body temperature, higher white blood cell counts, higher proportions of neutrophils, higher serum creatinine levels and higher pH levels; lower resting carbon dioxide pressure (PCO₂ ); and more cases complicated with invasive pulmonary aspergillosis (IPA). A further analysis with the Gamma model revealed that concurrent or non-concurrent IPA, white blood cell count, pH level and PCO₂ were associated with the patients' mortality risk and that the predicted value (PV) of the patients' mortality risk = 2.8655 + 0.4070 × IPA + 0.0048 × WBC + 0.0049 × pH - 0.0097 × PCO₂ . Moreover, the survival function formula was obtained according to the Gamma model: S(x) = 1 - I (0.7507 x, -3.3773), where I is an incomplete gamma function.

CONCLUSION

Formula generated from parametric model may help to predict the prognosis of patients with severe COPD in ICU, and this method need to be evaluated in further studies. According to our formula, IPA is an important risk factor of mortality for patients with severe COPD in the ICU.

HOLD study (Home care Obstructive Lung Disease): natural history of patients with advanced COPD

Background

Chronic obstructive pulmonary disease (COPD) is the fourth cause of death in western countries. Its final stage has clearly been forgotten by medical research in recent years. There exists consensus regarding the need to integrate palliative care in assisting these patients, but the difficulty in establishing a prognosis for the disease, establishing limits for life support measures, the lack of information about the disease’s natural course and ignorance as to the most effective health-care structure for these patients’ palliative treatment may be responsible for their late inclusion or non-inclusion in specific programmes. The main purpose of this work is to find out the natural background of patients with stage IV COPD and the main prognostic factors that influence these patients’ survival.

Methods/design

Prospective observational study of a home patient cohort with stage IV COPD sent from Neumology consultations and Palliative Care Unit in La Paz Hospital in Madrid and Primary Care Health Centres in the area to the palliative care home support team. The goal is to study socio-demographic variables, prognosis, nutritional status, use of health resources, perceived quality of life, functionality, main symptomatology, use and effectiveness of opioids, adherence to treatment, prognostic information regarding the disease, information given by professionals, advance directives, social backup requirements and overburden level of the main caregiver.

Discussion

The HOLD study is a project aimed at finding out the prognostic factors and evolution of the disease COPD in its most advanced stage. The final goal is to improve the health and quality of life, in a personalised, integral way up to end of life and explore and foster communication with patients, as well as their participation and collaboration in decision-taking. The HOLD study can help us better understand what these patients’ real palliative and care needs are, in order to more efficiently organise their treatment at end of life.