International Differences in the Frequency of Chronic Obstructive Pulmonary Disease Exacerbations Reported in Three Clinical Trials.

Rationale: Exacerbations of chronic obstructive pulmonary disease (COPD) are an important endpoint in multinational clinical treatment trials, but the observed event rate is often lower than anticipated and appears to vary between countries. Objectives: We investigated whether systematic differences in national exacerbation rates might explain this observed variation. Methods: We reviewed data from three large multicenter international randomized trials conducted over an 18-year period with different designs and clinical severities of COPD, comparing bronchodilator and/or inhaled corticosteroids with bronchodilators alone and/or placebo. Exacerbations were defined by antibiotic and/or oral corticosteroid use (moderate) or need for hospitalization (severe). We calculated crude exacerbation rates in the 30 countries contributing 30 or more patients to at least two trials. We grouped data by exacerbation rate based on their first study contribution. Measurements and Main Results: For the 29,756 patients in 41 countries analyzed, the mean exacerbation rate was two- to threefold different between the highest and lowest tertiles of the recruiting nations. These differences were not explained by demographic features, study protocol, or reported exacerbation history at enrollment. Of the 18 countries contributing to all trials, half of those in the highest and half in the lowest tertiles of exacerbation history remained in these groups across trials. Severe exacerbations showed a different rank order internationally. Conclusions: Countries contributing to COPD trials differ consistently in their reporting of healthcare-defined exacerbations. These differences help explain why large studies have been needed to show differences between treatments that decrease exacerbation risk.

Pharmacotherapy and Lung Function Decline in Patients with Chronic Obstructive Pulmonary Disease. A Systematic Review.

Rationale: Whether pharmacological therapy alters decline in FEV1 in chronic obstructive pulmonary disease remains controversial. Because pharmacotherapy improves health status, exacerbation rate, and symptoms, it may be unethical to complete placebo-controlled long-term studies aimed at modifying FEV1 decline.Objectives: We conducted a systematic review of placebo-controlled pharmacological trials lasting ≥1 year to address the question of whether therapy alters FEV1 decline.Methods: A literature search for randomized trials that included repeated spirometry with at least one active and one placebo arm was conducted. Articles were excluded if study duration was <1 year, <3 spirometric measurements, or <100 subjects per arm. Study design was assessed using the Jadad score. To combine studies and find the estimated effect, we used random effects methodology to account for both within-study and between-study variation.Measurements and Main Results: There were 33,051 patients in the analysis (active component, n = 21,941; placebo, n = 11,110 in nine studies). The active treatment arms demonstrated a 5.0 ml/yr reduction (95% confidence interval, 0.8-9.1 ml/yr; P < 0.001) in the rate of FEV1 decline compared with the placebo arms. The relative FEV1 differences between active and placebo arms were within the range of differences reported for health status and for the exacerbation rate in the same studies.Conclusions: In chronic obstructive pulmonary disease, pharmacotherapy ameliorates rate of lung function decline. The relative benefit observed is within the range of those reported for health status and exacerbations in the same studies. Guidelines should be adjusted according to these findings.

Adjudication of cardiovascular events in patients with chronic obstructive pulmonary disease: SUMMIT trial.

BACKGROUND: Adjudicated cause-specific mortality has been used in major trials of chronic obstructive pulmonary disease. However, there is less experience with adjudicated major adverse cardiovascular events as a key efficacy outcome in chronic obstructive pulmonary disease trials. The Study to Understand Mortality and Morbidity in chronic obstructive pulmonary disease trial required a Clinical Endpoint Committee to adjudicate the outcomes of modified major adverse cardiovascular events and cause-specific mortality. METHODS AND RESULTS: A six-member Clinical Endpoint Committee reviewed adverse event and serious adverse event reports included in a list of 204 Medical Dictionary for Regulatory Activities terms. Adverse events were triaged by one Clinical Endpoint Committee member, and then reviewed by three reviewers (round 1). If these three disagreed on the adjudication, the event was discussed by the full committee to reach a consensus (round 2). Among 16,485 participants, 48,105 adverse events were reported, among which 3314 were reviewed by the Clinical Endpoint Committee. After triage, 1827 were adjudicated in round 1; 338 required committee consensus in round 2, yielding 450 myocardial infarctions, strokes, unstable anginas or transient ischaemic attacks. Only 20/1627 (1%) non-serious adverse events were adjudicated as cardiovascular events. Only 45/204 Medical Dictionary for Regulatory Activities terms reviewed yielded cardiovascular events. A total of 430 deaths were adjudicated in round 1 and 631 in round 2, yielding 459 cardiovascular deaths. Adjudication of chest pain and sudden death often required additional information from site investigators. Site assessment of cardiovascular death was moderately specific (501/602 = 83%) but not sensitive (256/459 = 56%). CONCLUSION: A Clinical Endpoint Committee is useful for adjudication of major adverse cardiovascular events in chronic obstructive pulmonary disease trials but requires considerable resources and effort by investigators. This process can be streamlined by reviewing only serious adverse events and filtering by selected Medical Dictionary for Regulatory Activities terms.

Association of platelet count with all-cause mortality and risk of cardiovascular and respiratory morbidity in stable COPD.

BACKGROUND: Platelet count is a prognostic indicator in the general population and elderly. Thrombocytosis during acute exacerbation of COPD (AECOPD) has been associated with mortality; however, the relationship between platelet count and mortality in stable COPD is unknown. METHODS: We performed post hoc secondary analysis on a subsample of 1797 patients in the Study to Understand Mortality and Morbidity in COPD (SUMMIT) who had blood samples drawn at baseline. Participants were current or former smokers, 40-80 years old with moderate COPD and history or increased risk of cardiovascular (CV) disease. The primary outcome was on and post-treatment all-cause mortality. Secondary outcomes included first-on-treatment moderate/severe AECOPD and on-treatment CV composite event (CV death, myocardial infarction, stroke, unstable angina and transient ischemic attack). Multivariable Cox proportional hazards models were used to investigate study endpoint associations with platelet count quintile grouping, continuous platelet count utilizing two-term fractional polynomials, and categories of low, normal and high platelet count (< 150, ≥150 to < 300, ≥300 × 109/L). RESULTS: Patients were followed for 2.3 ± 0.9 years for vital status and 1.6 ± 1.1 years for morbidity endpoints during which 105 (5.8%) died, 651 (36.2%) experienced AECOPD (159 with severe AECOPD) and 86 (4.8%) experienced a CV event. A U-shaped association between platelet count and all-cause mortality was observed. Compared to the third quintile group (Q3) of platelet count, risk of death was increased in the lowest quintile group (Q1; hazard ratio [HR]: 1.73; 95% confidence interval [CI]: 0.93-3.23) and highest quintile group (Q5; HR: 1.66; 95%CI: 0.89-3.10), though point estimates were imprecise. Using clinical cutoffs, compared with normal platelet counts (≥150 to < 300 × 109/L), risk of all-cause mortality was nominally increased among patients with thrombocytopenia (HR: 1.46; 95%CI: 0.81-2.64) and high platelet count (HR: 1.66; 95%CI: 0.96-2.86). Compared with Q3, CV events were nominally increased for Q5 (HR: 1.71; 95%CI: 0.83-3.49) and Q1 (HR: 1.41; 95%CI: 0.70, 2.85). There was no association between platelet count and AECOPD. CONCLUSIONS: In stable COPD platelet count demonstrated a U-shaped association with increased risk of 3-year all-cause mortality, though a platelet count level above or below which risk of mortality was increased could not be definitively identified. TRIAL REGISTRATION: ClinicalTrials.gov NCT01313676 .

Blood pressure, heart rate, and mortality in chronic obstructive pulmonary disease: the SUMMIT trial.

Aims: To characterize the relationship between blood pressure (BP) or heart rate and mortality and morbidity in chronic obstructive pulmonary disease (COPD). Methods and results: We performed post hoc analysis of baseline BP or heart rate and all-cause mortality and cardiovascular events in the SUMMIT trial. SUMMIT was a randomized double-blind outcome trial of 16 485 participants (65 ± 8 years, 75% male, and 47% active smokers) enrolled at 1368 sites in 43 countries. Participants with moderate COPD with or at risk for cardiovascular disease (CVD) were randomized to placebo, long-acting beta agonist, inhaled corticosteroid, or their combination. All-cause mortality increased in relation to high systolic [≥140 mmHg; hazard ratio (HR) 1.27, 95% confidence interval (CI) 1.12-1.45] or diastolic (≥90 mmHg; HR 1.35, 95% CI 1.14-1.59) BP and low systolic (<120 mmHg; HR 1.36, 95% CI 1.13-1.63) or diastolic (<80 mmHg; HR 1.15, 95% CI 1.00-1.32) BP. Higher heart rates (≥80 per minute; HR 1.39, 95% CI 1.21-1.60) and pulse pressures (≥80 mmHg; HR 1.39, 95% CI 1.07-1.80) were more linearly related to increases in all-cause mortality. The risks of cardiovascular events followed similar patterns to all-cause mortality. Similar findings were observed in subgroups of patients without established CVD. Conclusion: A 'U-shaped' relationship between BP and all-cause mortality and cardiovascular events exists in patients with COPD and heightened cardiovascular risk. A linear relationship exists between heart rate and all-cause mortality and cardiovascular events in this population. These findings extend the prognostic importance of BP to this growing group of patients and raise concerns that both high and low BP may pose health risks.

Effect of Fluticasone Furoate and Vilanterol on Exacerbations of Chronic Obstructive Pulmonary Disease in Patients with Moderate Airflow Obstruction.

RATIONALE: Inhaled corticosteroids have been shown to decrease exacerbations in patients with moderate to severe chronic obstructive pulmonary disease (COPD). Their effects in patients with milder airflow obstruction remain unclear. OBJECTIVES: This was an analysis of exacerbations in the SUMMIT (Study to Understand Mortality and Morbidity) study. METHODS: In a double-blind, randomized controlled trial, once-daily inhaled placebo, fluticasone furoate (FF; 100 µg), vilanterol (VI; 25 µg), or the combination of FF/VI was administered. The primary outcome was all-cause mortality. Exacerbations of COPD were an additional predefined endpoint. A total of 1,368 centers in 43 countries and 16,485 patients with moderate COPD and heightened cardiovascular risk were included in the study. MEASUREMENTS AND MAIN RESULTS: Compared with placebo, FF/VI reduced the rate of moderate and/or severe exacerbations by 29% (95% confidence interval [CI], 22-35; P < 0.001) and the rate of hospitalized exacerbations by 27% (95% CI, 13-39; P < 0.001). These relative effects were similar regardless of whether subjects had a history of exacerbation in the year before the study or an FEV1 <60% or ≥60% of predicted. The number needed to treat was not influenced by baseline FEV1 but was influenced by the history of exacerbations. FF/VI also reduced the rate of exacerbations treated with corticosteroids alone or with corticosteroids and antibiotics but not the rates of those treated with antibiotics alone. CONCLUSIONS: Patients with moderate chronic airflow obstruction experienced a reduction in exacerbations with FF/VI compared with placebo, irrespective of a history of exacerbations or baseline FEV1. Clinical trial registered with www.clinicaltrials.gov (NCT 01313676; GSK Study number 113782).

Evaluation of a dried blood spot assay to measure prenatal screening markers pregnancy-associated plasma protein a and free ß-subunit of human chorionic gonadotropin.

BACKGROUND: First-trimester prenatal screening for aneuploidy by use of dried blood spots (DBSs) may offer practical benefits in settings where the instability of intact human chorionic gonadotropin (hCG) is problematic. We evaluated a DBS pregnancy-associated plasma protein A (PAPP-A) and free ß-subunit of hCG (free hCGß) dual assay and compared it to serum screening. METHODS: Hematocrit-corrected DBS PAPP-A and free-hCGß concentrations were measured and compared with serum concentrations in 252 first-trimester samples. Serum intact hCG was also measured and, with serum free hCGß, was used to fit a model to predict serum-equivalent DBS free-hCGß concentrations. In a separate experiment, we investigated the effects of temperature and relative humidity during the blood spot drying process. RESULTS: The DBS assay for PAPP-A performed similarly to the serum assay, whereas free-hCGß DBS measurements were consistently higher than in serum. Purifying blood spots of intact hCG suggested that the free-hCGß DBS assay is measuring a composite of free hCGß and additional ß-subunits from intact hCG. The drying experiment showed that increased temperature and relative humidity during the drying process resulted in increased free hCGß and reduced PAPP-A. CONCLUSIONS: Despite measuring additional free hCGß compared to the serum assay, DBS analysis has a role in first-trimester combined screening for trisomy 21.

Effect of gestational age on first trimester maternal serum prenatal screening correction factors for ethnicity and IVF conception.

OBJECTIVE: The aim of this study is to investigate gestational age effects of maternal ethnicity and in vitro fertilization (IVF) pregnancy correction factors of first trimester trisomy 21 screening markers pregnancy associated plasma protein A (PAPP-A) and free-ß human chorionic gonadotropin (free hCGß) in a large dataset. METHODS: Data from 205,341 normal singleton pregnancies were retrieved, and PAPP-A and free hCGß concentrations were converted to multiples of the medians (MoMs) uncorrected for either maternal ethnicity or IVF pregnancy. Log(10) transformed MoMs were plotted against gestational age in each group to examine gestational age effects RESULTS: Significant gestational age effects were found for correction factors for PAPP-A in Afro-Caribbean, South Asian and East Asian, and for free hCGß in Afro-Caribbean and IVF pregnancy. CONCLUSIONS: Current single correction factors for PAPP-A and free hCGß based on maternal ethnicity and IVF pregnancy are inappropriate, and future screening algorithms need to take into account the change in effect of these factors with gestational age.

Analytical goal setting in aneuploidy screening: within person biological variability of first trimester biochemical markers.

OBJECTIVE: To determine the average within person biological variability of free-ß human chorionic gonadotrophin (free hCGß), intact hCG and pregnancy-associated plasma protein A (PAPP-A), and to establish analytical goals for the measurement of these markers when used in first trimester screening. METHODS: Free hCGß, PAPP-A and intact hCG were measured on paired first trimester samples collected during the same pregnancy. Results were converted to Multiple of the Median (MoMs).The overall total variation at each day log was determined from a correlation of the marker MoMs in the log domain. Biological variation was calculated after taking into account analytical variation. RESULTS: The within person biological variability for free hCGß varied from 1.30% at 2 days separation to 5.25% at 5 days. For PAPP-A this was 1.96% and 5.03%, respectively, and for intact hCG this was 14.59% and 21.09%. All markers exhibit a rapid increase in biological variability as the time separation increased. CONCLUSIONS: Setting analytical goals for precision of measurement of first trimester biochemical markers from within person biological variability would suggest that free hCGß and PAPP-A needs to be measured with a precision of 2.5%, targets close to those set empirically by the Fetal Medicine Foundation and achieved in practice by some analytical system in routine use.

Correction of first trimester biochemical aneuploidy screening markers for smoking status: influence of gestational age, maternal ethnicity and cigarette dosage.

OBJECTIVE: To examine the gestational age, maternal ethnicity and cigarette dosage effects of the reduction of maternal serum pregnancy-associated plasma protein A (PAPP-A) and free-ß human chorionic gonadotrophin (free hCGß) in smokers. METHODS: Maternal serum PAPP-A and free hCGß corrected for confounders, excluding smoking, in first trimester smokers and nonsmokers were compared by gestational age, maternal ethnicity and cigarette dosage. A small set of second trimester smokers and nonsmoker controls were analysed for PAPP-A along with free hCGß and assessed for gestational age effects of smoking. RESULTS: Pregnancy-associated plasma protein A reduction by smoking in the first trimester was not influenced by gestational age, however free hCGß levels were only significantly reduced in weeks 12 and 13 in smokers. Ethnicity and cigarette dosage were also found to influence the reduction of both makers in smokers in the first trimester. In second trimester smokers, PAPP-A was found to be reduced by less and free hCGß reduced by more than in the first trimester, although no second trimester gestational age effect on smoking was found. CONCLUSIONS: Current methods of correcting for smoking status may be an oversimplification of a more complex subject.

First trimester maternal serum placental growth factor levels in twin pregnancies.

BACKGROUND: An understanding of the normal behavior of biochemical markers in twin pregnancies is necessary in order to offer prenatal screening to this subgroup. This study investigates the levels of first trimester maternal serum placental growth factor (PlGF) in twin and singleton pregnancies. METHODS: The PlGF concentrations were measured by an automated assay in the first trimester maternal serum of 440 dichorionic twin, 116 monochorionic twin, and 607 singleton pregnancy samples thawed from frozen storage. RESULTS: The PlGF concentrations in singleton levels were predicted by gestational age, maternal ethnicity, and smoking status. Following the correction for these variables, PlGF levels were, on average, 41% higher in dichorionics, but only 16% higher in monochorionics, compared to singleton pregnancies. CONCLUSIONS: First trimester maternal serum PlGF levels are increased in twin pregnancies compared with singleton pregnancies, but to less of an extent than is common with other screening markers, especially in monochorionic twins.

Accuracy of self-reported smoking status in first trimester aneuploidy screening.

OBJECTIVES: To review the accuracy of self-reporting of smoking status in our first trimester screening population and to assess the levels of pregnancy-associated plasma protein-A (PAPP-A) and free-ß human chorionic gonadotropin (free-hCGß) in women who were classified for smoking status by serum cotinine concentrations and self-reporting. METHODS: Cotinine concentration was determined in the stored serum 696 self-reported smokers and 442 self-reported non-smokers. PAPP-A and free-hCGß multiples of the medians (MoMs) determined at screening were reverted to uncorrected for self-reported smoking status. RESULTS: A total of 21.7% of those self-reporting as non-smokers had increased serum cotinine concentrations (using a cut-off of 13.7 ng/mL), indicating a positive smoking status. This under-reporting meant that serum PAPP-A and free-hCGß MoMs were greater reduced in smokers classified by cotinine levels (17.2% and 9.7%) than in those classified by self-reporting (14.6% and 2.8%). Women who were classified as smokers at conception but had stopped at some time afterwards did not have significantly reduced marker MoMs to non-smokers. CONCLUSIONS: Self-reporting results in under-representation of smoking in our population, resulting in a significant bias and inflated screen-positive rates.

The relationship between maternal body mass, smoking status and ethnicity and first trimester nuchal translucency thickness.

OBJECTIVE: To investigate the existence of a relationship between maternal body mass, maternal ethnicity and maternal smoking status and nuchal translucency (NT) in the first trimester of pregnancy. METHODS: NT measurements from 130 339 euploid, singleton pregnancies were converted to NT multiples of the median (MoM) and delta NT using expected medians determined using regression analysis. Relationships between maternal body mass index (BMI), maternal weight, maternal ethnicity and maternal smoking status and NT MoM and delta NT were examined. RESULTS: NT increased with gestational age. Uncorrected NT MoM and delta NT demonstrated small but significant positive relationships with either maternal BMI or maternal weight. Both NT MoM and delta NT were slightly, but significantly, increased in smokers compared to non-smokers and Afro-Caribbean compared to Caucasians, and slightly, but significantly, decreased in Asians compared to Caucasians. CONCLUSION: Although statistically significant, all the changes reported are likely to be too small to be relevant in terms of correcting in prenatal screening.

The stability of free-ß human chorionic gonadotrophin and pregnancy-associated plasma protein-A in first trimester dried blood spots.

OBJECTIVES: To determine the stability of first trimester free-ß human chorionic gonadotrophin (free-ß hCG) and pregnancy-associated plasma protein-A (PAPP-A) in dried blood spots (DBSs) under typical storage conditions. METHODS: First trimester maternal blood was spotted onto filter paper and left to dry. DBSs were analysed for PAPP-A and free-ß hCG using an AutoDELFIA dual assay at t = 0. Cards were stored at one of - 20 °C, refrigerator temperature, room temperature or 30 °C and reanalysed at set future time points. RESULTS: Free-ß hCG was stable (<10% change in concentration) under all temperatures tested for at least 35 days. PAPP-A was stable at - 20 °C and refrigerator temperature for at least 35 days. However, PAPP-A levels decreased by 10% at 4.1 days at room temperature and at 3.9 days at 30 °C. Longer-term storage at - 20 °C and refrigerator temperature showed that both PAPP-A and free-ß hCG levels were significantly decreased by 107 and 244 days. CONCLUSIONS: Free-ß hCG stability is greatly improved in DBS compared to serum storage; however PAPP-A stability is decreased in the DBS medium. Despite this DBS, screening may not necessitate such strict storage and transportation rules compared to serum screening programmes.

Challenging the obesity paradox: extreme obesity and COPD mortality in the SUMMIT trial.

Populations with COPD demonstrate higher survival in overweight and obese compared with normal weight; the "obesity paradox". Relationships in less-severe COPD are unclear, as is the impact of cardiovascular risk, and few studies include individuals at extremes of obesity. We examined the relationship between body mass index (BMI; defined as underweight: <20 kg·m-2, normal: 20-25 kg·m-2, overweight: 25- <30 kg·m-2, obese class I: 30- <35 kg·m-2, class II: 35- <40 kg·m-2 and class III: ≥40 kg·m-2), morbidity, and mortality in the SUMMIT trial population (n=16 485), characterised by moderate COPD and heightened cardiovascular risk with a substantial proportion with class III obesity. The association between BMI category and time to event was modelled via proportional hazards (reference normal weight) adjusted for demographics and cardiorespiratory disease. Consistent with the paradox, underweight individuals demonstrated higher mortality (hazard ratio (HR) 1.31 (95% CI 1.04-1.64)), with lower mortality among overweight (HR 0.62 (95% CI 0.52-0.73)) and obese class I (HR 0.75 (95% CI 0.62-0.90)). However, mortality increased in obese class III (HR 1.36 (95% CI 1.00-1.86)). Death was primarily attributable to cardiovascular causes. Within a large, multinational cohort with moderate COPD and increased cardiovascular risk, the phenomenon of reduced mortality with obesity did not persist at BMI >40 kg·m-2, suggesting that obesity may not remain protective at the extremes in this population.

PAPP-A and free ss-hCG stability in first trimester serum using PerkinElmer AutoDELFIA and DELFIA Xpress systems.

BACKGROUND: In this study we aim to investigate the stability of free-beta-hCG and PAPP-A over time in serum and whole blood in typical routine temperatures. METHODS: Serum pools were stored under the following temperatures: 30 degrees C, room temperature, refrigerator temperature and -20 degrees C, for up to 240 days. Stability of the markers in whole blood was examined in a shorter study and compared to serum. Samples were analysed using the AutoDELFIA and DELFIA Xpress analysers. RESULTS: On the AutoDELFIA, considering a 10% change acceptable, PAPP-A levels are stable in serum for 142 days at refrigerator temperature, 37 days at room temperature and 20 days at 30 degrees C. Free-beta hCG is stable in serum for 94 days at refrigerator temperature, 3 days at room temperature and 12 h at 30 degrees C. There was no significant change with either analyte after -20 degrees C storage for up to 240 days or after six repeated freeze-thaw cycles. In whole blood, free-beta hCG levels increased more rapidly compared to serum, especially at 30 degrees C. CONCLUSION: Normal handling of samples is only likely to minimally effect the risk assessment of chromosomal anomalies. However, careful attention should be paid to minimise the increase of free-beta hCG levels in samples shipped as whole blood.