Medición del patrón ventilatorio mediante tomografía por impedancia eléctrica en pacientes con EPOC

Background and Objective

The measurement of breathing pattern in patients with chronic obstructive pulmonary disease (COPD) by electrical impedance tomography (EIT) requires the use of a mathematical calibration model incorporating not only anthropometric characteristics (previously evaluated in healthy individuals) but probably functional alterations associated with COPD as well. The aim of this study was to analyze the association between EIT measurements and spirometry parameters, static lung volumes, and carbon monoxide diffusing capacity (DLCO) in a group of male patients to develop a calibration equation for converting EIT signals into volume signals.

Materials and Methods

We measured forced vital capacity (FVC), forced expiratory volume in 1 second (FEV₁), FEV₁/FVC, residual volume, total lung capacity, DLCO, carbon monoxide transfer coefficient (KCO) and standard anthropometric parameters in 28 patients with a FEV₁/FVC ratio of <70%. We then compared tidal volume measurements from a previously validated EIT unit and a standard pneumotachometer.

Results

The mean (SD) lung function results were FVC, 72 (16%); FEV₁, 43% (14%); FEV₁/FVC, 42% (9%); residual volume, 161% (44%); total lung capacity, 112% (17%); DLCO, 58% (17%); and KCO, 75% (25%). Mean (SD) tidal volumes measured by the pneumotachometer and the EIT unit were 0.697 (0.181) L and 0.515 (0.223) L, respectively (P<.001). Significant associations were found between EIT measurements and CO transfer parameters. The mathematical model developed to adjust for the differences between the 2 measurements (R²=0.568; P<.001) was compensation factor=1.81?− 0.82?× height (m)?−0.004×KCO (%).

Conclusions

The measurement of breathing pattern by EIT in patients with COPD requires the use of a previously calculated calibration equation that incorporates not only individual anthropometric characteristics but gas exchange parameters as well.     

Relación del test de control del asma (ACT) con la función pulmonar,niveles de óxido nítrico exhalado y grados de control según la Iniciativa Global para el Asma (GINA)

Introduction

The current goal of asthma treatment is to achieve and maintain control. This study aimed to explore the relationship between the ACT (Asthma Control Test) questionnaire and the levels of control according to GINA (Global Initiative for Asthma) to establish the cut-off points for the ACT and evaluate its relationship with lung function and fractionated exhaled nitric oxide level (FeNO).

Patients and methods

A multi-centre prospective study including 441 patients followed up in an outpatient Chest Clinic. A clinical protocol was followed, and FeNO, spirometry and ACT performed. Disease was classified according to levels of control using GINA. The study analysed sensitivity, specificity and area under the curve (ROC), and the ACT cut-off points. We studied the differences between the functional parameters and FeNO between levels of control.

Results

For controlled asthma the cut-off obtained was ACT≥21 (area under the curve 0.791) and for uncontrolled ≤18 (AUC 0.774). We found significant differences in FeNO levels and pulmonary function among ACT≥21 and ACT≤18, although only 26.3% of patients with ACT≤18 had a FEV1 <80% and 40% higher FeNO (≥35 ppb). We found a correlation between baseline FEV1 and ACT (r=0.19, P<0.01) and between ACT and FeNO (r=−0.16, P<0.01).

Conclusions

The cut-off points would be, for controlled asthma ACT≥21, partly controlled asthma ACT=19–20 and uncontrolled asthma ACT≤18. A more complete assessment would require including monitoring operating parameters and FeNO.     

Importance of slow vital capacity in the detection of airway obstruction

OBJECTIVE:

To investigate the presence of airway obstruction by determining the FEV₁/FVC and FEV₁/slow vital capacity (SVC) ratios.

METHODS:

This was a quantitative, retrospective cross-sectional study. The sample comprised 1,084 individuals who underwent spirometry and plethysmography in a central hospital in Lisbon, Portugal. The study sample was stratified into six groups, by pulmonary function.

RESULTS:

The analysis of the FEV₁/FVC ratio revealed the presence of airway obstruction in 476 individuals (43.9%), compared with 566 individuals (52.2%) for the analysis of the FEV₁/SVC ratio. In the airway obstruction, airway obstruction plus lung hyperinflation, and mixed pattern groups, the difference between SVC and FVC (SVC − FVC) was statistically superior to that in the normal pulmonary function, reduced FEF, and restrictive lung disease groups. The SVC − FVC parameter showed a significant negative correlation with FEV₁ (in % of the predicted value) only in the airway obstruction plus lung hyperinflation group.

CONCLUSIONS:

The FEV₁/SVC ratio detected the presence of airway obstruction in more individuals than did the FEV₁/FVC ratio; that is, the FEV₁/SVC ratio is more reliable than is the FEV₁/FVC ratio in the detection of obstructive pulmonary disease.     

Relación entre disfunción de los músculos espiratorios e hiperinflación dinámica en la EPOC avanzada

Background and objectives

Dynamic hyperinflation (DH) and expiratory flow limitation (EFL) are physiologically linked and seem to be involved in the genesis of dyspnea and the quality of life (QL) impairment in chronic obstructive pulmonary disease (COPD). Advanced COPD patients often show expiratory muscles dysfunction that could be involved in DH development. Aim: Study the relationships between expiratory muscle dysfunction and DH, and their association with dyspnea and QL, in advanced COPD.

Patients and methods

In 25 patients we measured lung function, exercise capacity (incremental ergometry and walking test), EFL and end-expiratory lung volume (EELV) at rest and during exercise, respiratory muscles strength and endurance, dyspnea and QL (Saint George Respiratory Questionnaire, SGRQ).

Results

The patients (mean FEV₁=31% predicted) showed a moderate decrease of respiratory muscles strength and endurance. Nineteen patients exhibited EFL at rest and 24 at 70% of maximal workload (W_max). The EELV increased from rest to 70% W_max (9% of predicted FVC). At 70% W_max EELV correlated inversely with the EFL amount (rho=−0.42), the inspiratory and expiratory muscles endurance (rho=−0.43 and −0.42 respectively) and y VO_2max (rho=−0.52). The EELV increase from resting to 70% W_max correlated with dyspnea (rho=0.53) and the amount of EFL at 70%W_max with the activity score of SGRQ. The FEV_1, expiratory muscles endurance and LFE amount were independent predictors of EELV at 70% W_max.

Conclusions

In advanced COPD a poorer expiratory muscles endurance is related with higher DH during exercise (and lower EFL), which is correlated with higher dyspnea and worse QL.     

Diferencias geográficas en la prevalencia de EPOC en España: relación con hábito tabáquico,tasas de mortalidad y otros determinantes

Background

The EPI-SCAN study (Epidemiologic Study of COPD in Spain), conducted from May 2006 to July 2007, determined that the prevalence of COPD in Spain according to the GOLD criteria was 10.2% of the 40 to 80 years population. Little is known about the current geographical variation of COPD in Spain.

Objectives

We studied the prevalence of COPD, its under-diagnosis and under-treatment, smoking and mortality in the eleven areas participating in EPI-SCAN. COPD was defined as a post-bronchodilator FEV₁/FVC ratio <0.70 or as the lower limit of normal (LLN).

Results

The ratio of prevalences of COPD among the EPI-SCAN areas was 2.7-fold, with a peak in Asturias (16.9%) and a minimum in Burgos (6.2 %) (P<0.05). The prevalence of COPD according to LLN was 5.6% (95% CI 4.9–6.4) and the ratio of COPD prevalence using LLN was 3.1-fold, but with a peak in Madrid-La Princesa (10.1%) and a minimum in Burgos (3.2%) (P<0.05). The ranking of prevalences of COPD was not maintained in both sexes or age groups in each area. Variations in under-diagnosis (58.6% to 72.8%) and under-treatment by areas (24.1% to 72.5%) were substantial (P<0.05). The prevalence of smokers and former smokers, and cumulative exposure as measured by pack-years, and the age structure of each of the areas did not explain much of the variability by geographic areas. Nor is there any relation with mortality rates published by Autonomous Communities.

Conclusion

There are significant variations in the distribution of COPD in Spain, either in prevalence or in under-diagnosis and under-treatment     

Prevalencia de enfermedad pulmonar obstructiva crónica en las Islas Canarias

Introduction

The prevalence of chronic obstructive pulmonary disease (COPD) varies significantly among the different geographical areas reported. In Spain, two epidemiological studies have shown a prevalence of 9-10% in the population aged over 40. However, neither of these studies included the Canary Islands, which are of interest due to their climatic conditions and high incidence of smoking.

Materials and methods

A random group of 1,353 subjects aged between 40 and 70 years was selected from a sample population of 596,478 individuals. Participants completed a questionnaire and then performed spirometry with bronchodilator testing if obstruction was observed. COPD was diagnosed when the post-bronchodilator FEV₁/FVC ratio was less than 0.70.

Results

The prevalence of COPD was 7.3% (95% CI: 5.5-9.5) and was higher in males than in females (8.7% vs. 6.3%, P = .134). The incidence of smoking was 29.4% (95% CI: 25.4-33.1) and was also higher in males than in females (35.1% vs 25.4%, P < .001). The prevalence of COPD stratified by severity of obstruction, according to the GOLD criteria, was 16% in group i, 69.9% in group ii, 10.4% in group iii and 3.3% in group iv. 71.6% of the subjects were underdiagnosed and 63.5% undertreated.

Conclusions

Despite having one of the highest rates of smoking in Spain, the prevalence of COPD in the Canary Islands is lower than in most of the Spanish regions studied.     

Validación de la versión española del cuestionario revisado de calidad de vida para fibrosis quística en adolescentes y adultos (CFQR 14+ Spain)

Background

The aim of this study was to assess the validity and reliability of the Spanish version of the revised disease-specific health related quality of life questionnaire for adolescents and adults with cystic fibrosis (CFQR 14+ Spain).

Methods

A total of 43 cystic fibrosis (CF) patients completed the CFQR 14+ Spain. Forced expiratory volume in 1 second, in percentage of predicted - FEV₁ (%)-, number of respiratory exacerbations, 6-minute walk test, Bhalla score (based on computerized tomography of the chest), fat-free mass index, body mass index (BMI), faecal fat and St George's Respiratory Questionnaire were included as measurements of health status.

Results

Ten out of the twelve scales had alpha coefficients above 0.70. Test–retest correlations (Spearman) ranged from 0.49 to 0.95 and they were significant in all scales. Intraclass correlations ranged from 0.47 to 0.95 (ten out of the twelve scales were >0.70) forty out of the fifty ítems have correlations between items and scale above 0.70. All the CFQR+14 scales, except the digestive symptoms scale, discriminated significantly between patients with mild, moderate and severe disease (according to FEV₁ (%)). Other respiratory parameters also discriminated significantly between patients with mild-moderate and severe disease. Only some scales discriminated significantly between nourished and malnourished patients. All of the scales met standards for floor effects (<15% of the responders with the lowest score) but not for ceiling effects (only five out of the twelve).

Conclusion

The Spanish CFQR14+ (Spain) is a reliable and valid instrument for measuring the health-related quality of life in Spanish adolescents and adults with CF, though with the exception of a few of its subscales.     

Consumo máximo de oxígeno durante la prueba de marcha de 6 minutos en la enfermedad pulmonar intersticial difusa y en la hipertensión pulmonar

Introduction

The six-minute walk test (6MWT) is widely used in evaluating diffuse interstitial lung disease (ILD) and pulmonary hypertension (PH). However, their physiological determining factors have not been well defined.

Objective

To evaluate the physiological changes that occur in ILD and PH during the 6MWT, and compare them with the cardiopulmonary exercise test (CPET).

Material and methods

Thirteen patients with ILD and 14 with PH were studied using the 6MWT and CPET on an ergometer cycle. The respiratory variables were recorded by means of telemetry during the 6MWT.

Results

Oxygen consumption (VO₂), respiratory and heart rate reached a plateau from minute 3 of the 6MWT in both diseases. The VO₂ did not differ from the peak value in the CPET (14±2 and 15±2 ml/kg/min, respectively, in ILD; 16±6 and 16±6 ml/kg/min, in PH). The arterial oxygen saturation decreased in both diseases, although it was more marked in ILD (−12±5%, p<0,01). The ventilatory equivalent for CO₂ (V_E/VCO₂) in PH during the 6MWT was strongly associated with functional class (FC) (85±14 in FC III-IV, 44±6 in FC I-II; p<0,001).

Conclusions

The 6MWT in ILD and PH behaves like a maximal effort test, with similar VO₂ to the CPET, demonstrating a limit in oxygen transport capacity. Monitoring using telemetry during the 6MWT may be useful for the clinical evaluation of patients with ILD or PH.     

Relación entre las calcificaciones ateroscleróticas en el tórax detectadas mediante tomografía computarizada y la función pulmonar

Background and objectives

A few recent epidemiological findings indicate a link between atherosclerosis and some lung functions. We studied further the relation between calcified chest atherosclerosis as seen in computed tomography (CT) and several lung functional parameters.

Patients and methods

Male construction workers originally screened for occupational lung cancer with CT had their chest atherosclerosis (aorta, the origins of its cervical branches, the coronary arteries and heart valves) visually classified. The relation between the atherosclerotic calcification scores and lung function (total lung capacity [TLC], forced expiratory volume in one second [FEV₁%], forced vital capacity [FVC%], maximal expiratory flow when 50% of FVC remains to be exhaled, total and specific diffusing capacities; all above expressed as percent of predicted value, and the FEV₁/FVC% ratio) were studied with the general linear model adjusted for smoking, exposure years for asbestos, and body mass index (n=432).

Results

All lung functions except TLC showed significant negative associations with calcifications in aorta and in its branches. TLC showed such association only with atherosclerosis in the ascending aorta.

Conclusions

Aortic atherosclerosis seems to be related with poor lung function. This may be due to deteriorated bronchial circulation, but other mechanisms can also be involved. Lung function poorer than would be expected due to pulmonary reasons may indicate aortic atherosclerosis.     

El salbutamol mejora la contractilidad diafragmática en la obstrucción crónica de la vía aérea

Introduction

Chronic airflow obstruction in conditions such as chronic obstructive pulmonary disease is associated with respiratory muscle dysfunction. Our aim was to study the effects of salbutamol—a β-adrenergic agonist known to improve muscle strength in physiologic and pathologic conditions—on diaphragm contractility in an animal model of chronic airway obstruction achieved by tracheal banding.

Materials and Methods

Twenty-four Sprague-Dawley rats were randomized into a control group and 3 tracheal banding groups, 1 that received acute salbutamol treatment, 1 that received chronic salbutamol treatment, and 1 that received nothing. Arterial blood gases, acid-base balance, and in vitro diaphragmatic contractility were evaluated by measuring peak twitch tension, contraction time, contraction velocity, half-relaxation time, relaxation velocity, and force-frequency curves.

Results

The 3 study groups had significantly reduced arterial pH and increased PaCO₂ and bicarbonate levels compared to the control group (P<.05). The untreated tracheal banding group had significantly reduced peak twitch tension and contraction velocity, and a significantly lower force-frequency curve in comparison with the other groups (P<.05). The chronic treatment group had a higher relaxation velocity than the untreated study group (P<.05). The mean (SE) peak twitch tension values were 6.46 (0.90) N/cm² for the control group, 3.28 (0.55) N/cm² for the untreated tracheal banding group, 6.18 (0.71) N/cm² for the acute treatment group, and 7.09 (0.59) N/cm² for the chronic treatment group.

Conclusions

Diaphragmatic dysfunction associated with chronic airflow obstruction improves with both the acute and chronic administration of salbutamol. The mechanisms involved in respiratory muscle dysfunction warrant further study.     

El factor de crecimiento de hígado mejora la fibrosis pulmonar inducida tras la administración de cadmio en ratas

Introduction

Liver growth factor (LGF) is a liver mitogen with regenerating and anti-fibrotic activity even at extrahepatic sites. We used LGF in a lung fibrosis model induced by cadmium chloride (CdCl₂), to study its antifibrotic capacity.

Methods

Forty-two male Wistar rats were administered a single dose of 0.5 ml/rat of CdCl2 0.025% (n=21) or the same volume of saline (control group, n=21). After 35 days, once a lesion was established, we started a 3 week treatment with LGF, after which we determined lung function —inspiratory capacity (IC), lung compliance (LC), forced vital capacity (FVC) and expiratory flow at 75% (FEF75%)—, lung morphometry —alveolar internal area (AIA), mean linear intersection (LM)—, and collagen (both by Sirius red and hydroxyproline residues) and elastin contents.

Results

Pulmonary fibrosis in CdCl₂ rats was characterized by a marked decrease in pulmonary function with respect to healthy controls —reductions of 28% in IC, 38% in CL, 31% in FVC, and 54% in FEF75%— which was partially recovered after LGF injection —18% IC, 27% CL, 19% FVC and 35% FEF75%—; increase in collagen and elastin contents —165% and 76%, respectively, in CdCl2 rats, versus 110% and 34% after LGF injection—; and increases in AIA and LM, partially reverted by LGF. Conclusions: Together, these data seem to demonstrate that LGF is able to improve lung function and partially reverts the increase in lung matrix proteins produced by CdCl₂ instillation.     

Primera fase de validación del algoritmo europeo de evaluación funcional previa a la resección pulmonar: cuantificación del cumplimiento de las recomendaciones en la práctica clínica real

Objective

To quantify the degree of compliance with the recommendations of the clinical practice guidelines published in 2009 by the ERS and the ESTS regarding the preoperative assessment of risk of lung resection in daily clinical practice at a tertiary hospital.

Method

A prospective, observational study of real-time data collected from consecutive patients who had been referred for evaluation from September 2009 to December 2010. We recorded the presence or absence of the recommended studies included in the algorithm, their results and, when a test was missing, the reasons why it was not performed. Hospital mortality and cardio-respiratory morbidity rates are also presented.

Results

173 patients were evaluated. In 171 cases, lung resection was performed, with a mortality of 1.2% and a cardio-respiratory morbidity of 11.7%. The failure rate of the first level of the algorithm was 4.6% and for the second level (VO_2max test) it was 26%. The absence of exercise tests was mainly due to hospital structural problems and the patients’ inability to perform it. Out of the patients who performed the exercise testing, 31 reached a VO_2max of 20 ml/kg-min or more and underwent surgery without calculation of FEV₁ppo and DCLOppo; 35 patients required the calculation to determine their operability and in 2 cases the intervention was not recommended due to functional inoperability of the patient.

Conclusions

The validation process found lack of compliance with the proposed algorithm in 18.5% of the cases basically due to the absence of the exercise tests. The rate of adherence to the algorithm recommendations should be improved before performing any other validation studies.     

The prognostic significance of lung function in stable heart failure outpatients

Background

This study investigated the impact on all‐cause mortality of airflow limitation indicative of chronic obstructive pulmonary disease or restrictive spirometry pattern (RSP) in a stable systolic heart failure population.

Hypothesis

Decreased lung function indicates poor survival in heart failure.

Methods

Inclusion criteria: NYHA class II‐IV and left ventricular ejection fraction (LVEF) < 45%. Prognosis was assessed with multivariate Cox proportional hazards models. Two criteria of obstructive airflow limitation were applied: FEV₁/FVC < 0.7 (GOLD), and FEV₁/FVC < lower limit of normality (LLN). RSP was defined as FEV₁/FVC > 0.7 and FVC<80% or FEV₁/FVC > LLN and FVC <LLN.

Results

There where 573 patients in the cohort (85% of eligible patients in study period). Median follow‐up was 4.7 years and 176 patients died (31%). Age, NYHA class, smoking, body mass index and LVEF were independent prognostic factors (p<0.01). Obstructive airflow limitation increased mortality using both criteria (HR_GOLD 2.07 [95% CI 1.45–2.95] p<0.01 and HR_LLN 2.00 [1.40–2.84] p<0.01) and was an independent marker when using LLN criteria (HR 1.74 [1.17‐2.59] p=0.006). RSP was independently associated with mortality when defined as FVC < LLN (HR 1.54 [1.01–2.35] p=0.04) but not as FVC < 80%. Multivariate hazard ratios for a 10% decrease in predicted value of FEV1 or FVC were 1.42 (p<0.001) and 1.33 (p<0.001) in patients exhibiting airflow obstruction, and 1.36 (p=0.031) and 1.38 (p=0.041) in RSP.

Conclusions

Presence of obstructive airflow limitation indicative of COPD or RSP were associated with increased all‐cause mortality, however only independently when using the LLN definition.

     

Eco-Doppler de ejercicio en pacientes con miocardiopatía hipertrófica. Factores determinantes de la limitación funcional

Introduction and objectives

At-rest echocardiography is a poor predictor of exercise capacity in patients with hypertrophic cardiomyopathy. We aimed to test the performance of treadmill exercise Doppler echocardiography in the prediction of functional limitations in these patients.

Methods

Eighty-seven consecutive patients with hypertrophic cardiomyopathy underwent treadmill exercise echocardiography with direct measurement of oxygen consumption. Both at rest and at peak exercise, the mitral inflow, mitral regurgitation, left ventricular outflow tract obstruction and mitral annulus velocities were assessed.

Results

Forty-three patients developed left ventricular outflow tract obstruction during exercise, which significantly decreased oxygen consumption (21.3 [5.7] mL/kg/min vs 24.6 [6.1] mL/kg/min; P=.012), and had greater left atrial volume (42.1 [14.5] mL/m² vs 31.1 [11.6] mL/m²; P<.001) and a higher degree of mitral regurgitation and E/E’ ratio during exercise. Exercise variables improved the predictive value of functional capacity (adjusted R² rose from 0.38 to 0.49). Independent predictors of oxygen consumption were age, left atrial volume, E/E’ ratio and the presence of left ventricular outflow tract obstruction. In a subset of patients without left ventricular outflow obstruction, only left ventricular and atrial volume indexes were independent predictors of exercise capacity.

Conclusions

In patients with hypertrophic cardiomyopathy, left ventricular outflow tract obstruction and left atrial volume are the main predictors of exercise capacity. Exercise echocardiography is a better predictor of functional performance than at-rest echocardiography, although its predictive power is under 50%. In nonobstructed patients, left atrial and ventricular volumes were the independent factors.Full English text available from:www.revespcardiol.org/en     

Rangos de referencia en niños preescolares mexicanos con el empleo de la técnica de oscilación forzada

Introduction

Recently, multi-ethnic reference ranges for spirometry have been created for use worldwide. In comparison, forced oscillation technique (FOT) reference values are limited to specific equipment and study populations, with current FOT reference ranges created in a Caucasian population. We aimed to develop FOT reference ranges for preschool-aged Mexican children and to compare these with current FOT reference ranges.

Patients and methods

Respiratory resistance (Rrs) and reactance (Xrs) was measured in healthy Mexican children three to five years of age using commercial FOT equipment. The relationship between height and Rrs and Xrs was determined using regression analyses, taking into account age, weight, sex, and exposure to tobacco smoke. Reference equations were calculated for the Mexican children and Z-scores determined for Rrs and Xrs at 6 and 8 Hz. A paired t-test assessed the difference in Z-scores between the Australian reference values and those created for the Mexican cohort.

Results

FOT was successfully measured in 584 children. Height was a significant predictor of Rrs and Xrs at 6 and 8 Hz (P < .05). Z-scores calculated using the Australian reference equations overestimated lung function in Mexican children for both Rrs and Xrs at 6 and 8 Hz (P < .001).

Conclusion

The development of FOT reference ranges specific to Mexican preschool-aged children will allow for the correct interpretation of FOT measurements. This study also showed that current FOT reference ranges overestimate lung function in Mexican children. Highlighting, the importance of using ethnic appropriate reference ranges for interpreting lung function.     

The Diagnostic Importance of a Reduced FEV1/FEV6

Abstract

Background: On spirometry the FEV₁/FEV₆ ratio has been advocated as a surrogate for the FEV₁/FVC. The significance of isolated reductions in either the FEV₁/FEV₆ or FEV₁/FVC is not known. Methods: First-time adult spirograms (n = 22,837), with concomitant lung volumes (n = 12,040), diffusion (n = 14,154), and inspiratory capacity (n = 12,480) were studied. Four groups were compared. 1) Only FEV₁/FEV₆ reduced (n = 302). 2) Only FEV₁/FVC reduced (n = 1158). 3) Both ratios reduced (n = 6593). 4) Both ratios normal (n = 14,784). Results: In patients with obstructed spirometry (either a reduced FEV₁/FVC and/or FEV₁/FEV₆), 3.8% only had a reduced FEV₁/FEV₆, while 14.4% only had a reduced FEV₁/FVC. The mean FEV₁ was lower when both ratios were reduced. The group with only a reduced FEV₁/FEV₆, compared to only the FEV₁/FVC reduced, had a lower FEV₁, FVC, BMI, Expiratory Time, and IC (p values < 0.0001). DLCO was also lower (p = 0.005), and the FEV₁/FVC and RV/TLC were higher (p values < 0.0001). When the patients with only a reduced FEV₁/FEV₆ had a subsequent spirogram, 60% had a reduced FEV₁/FVC when their mean expiratory times were 3.5 seconds longer. Ninety percent of this group had strong clinical evidence of airways obstruction. Conclusions: The FEV₁/FEV₆ is not as sensitive as the FEV₁/FVC for diagnosing airways obstruction, but in the presence of a normal FEV₁/FVC, subjects have greater physiologic abnormalities than when only the FEV₁/FVC is reduced. The FEV₁/FEV₆ ratio should not replace the FEV₁/FVC as the standard for airways obstruction, but there is benefit including this measurement to identify individuals with greater air trapping and diffusion abnormalities.     

COPD in chronic heart failure: Less common than previously thought?

Background

Using a fixed ratio of forced expiratory volume in 1 s to forced vital capacity (FEV₁/FVC) < 0.70 instead of the lower limit of normal (LLN) to define chronic obstructive pulmonary disease (COPD) may lead to overdiagnosis of COPD in elderly patients with heart failure (HF) and consequently unnecessary treatment with possible adverse health effects.

Objective

The aim of this study was to determine COPD prevalence in patients with chronic HF according to two definitions of airflow obstruction.

Methods

Spirometry was performed in 187 outpatients with stable chronic HF without pulmonary congestion who had a left ventricular ejection fraction <40% (mean age 69 ± 10 years, 78% men). COPD diagnosis was confirmed 3 months after standard treatment with tiotropium in newly diagnosed COPD patients.

Results

COPD prevalence varied substantially between 19.8% (LLN-COPD) and 32.1% (GOLD-COPD). Twenty-three of 60 patients (38.3%) with GOLD-COPD were potentially misclassified as having COPD (FEV₁/FVC < 0.7 but > LLN). In contrast to patients with LLN-COPD, potentially misclassified patients did not differ significantly from those without COPD regarding respiratory symptoms and risk factors for COPD.

Conclusions

One fifth, rather than one third, of the patients with chronic HF had concomitant COPD using the LLN instead of the fixed ratio. LLN may identify clinically more important COPD than a fixed ratio of 0.7.     

Prevalencia de la fibrilación auricular desconocida y la no tratada con anticoagulantes. Estudio AFABE

Introduction and objectives

Atrial fibrillation constitutes a serious public health problem because it can lead to complications. Thus, the management of this arrhythmia must include not only its treatment, but antithrombotic therapy as well. The main goal is to determine the proportion of cases of undiagnosed atrial fibrillation and the proportion of patients not being treated with oral anticoagulants.

Methods

A multicenter, population-based, retrospective, cross-sectional, observational study. In all, 1043 participants over 60 years of age were randomly selected to undergo an electrocardiogram in a prearranged appointment. Demographic data, CHA₂DS₂-VASc and HAS-BLED scores, international normalized ratio results, and reasons for not receiving oral anticoagulant therapy were recorded.

Results

The overall prevalence of atrial fibrillation was 10.9% (95% confidence interval, 9.1%-12.8%), 20.1% of which had not been diagnosed previously. In the group with known atrial fibrillation, 23.5% of those with CHA₂DS₂-VASc≥2 were not receiving oral anticoagulant therapy, and 47.9% had a HAS-BLED score≥3. The odds ratio for not being treated with oral anticoagulation was 2.04 (95% confidence interval, 1.11-3.77) for women, 1.10 (95% confidence interval, 1.05-1.15) for more advanced age at diagnosis, and 8.61 (95% confidence interval 2.38-31.0) for a CHA₂DS₂-VASc score<2. Cognitive impairment (15.2%) was the main reason for not receiving oral anticoagulant therapy.

Conclusions

The prevalence of previously undiagnosed atrial fibrillation in individuals over 60 years of age is 20.1%, and 23.5% of those who have been diagnosed receive no treatment with oral anticoagulants.Full English text available from:www.revespcardiol.org/en     

Utilización de procalcitonina y proteína C reactiva como marcadores de infección en la neutropenia febril de pacientes sometidos a trasplante de progenitores hematopoyéticos

Introduction and objective

Neutropenia is a frequent sign in patients who are going to have a haematopoietic stem cell transplant (HSCT). Infection is an important complication in these patients, which is favoured by immunosuppression and the degree of neutropenia. This study aims to evaluate the diagnostic usefulness of procalcitonin (PCT) and C-reactive protein (CRP) in onco-haematological patients undergoing chemotherapy and HSCT to determine the origin of the fever.

Patients and methods

PCT and CRP values were measured in 30 episodes of febrile neutropenia: before starting chemotherapy, appearance of neutropenia, onset of fever, days 1, 2, 3 and 6 after the onset of fever, and when the febrile episode ended. The episodes were classified as 5 bacteraemia, 3 microbiologically documented infections, 10 clinical infections, and 12 fevers of unknown origin.

Results

The highest PCT mean values corresponded to the group of patients with bacteraemia. Statistically significant differences (P = .04) were found on the second day after the onset of fever. The cut-off point of 0.5 ng/ml showed a sensitivity of 66% and a specificity of 75%. PCR results showed statistically significant differences on days 1, 2 and 3 after the onset of fever (P = .01, P = .003, and P = .002, respectively). The cut-off point of 7.5 mg/L had a sensitivity of 88% and a specificity of 58%.

Conclusions

The combination of PCT and CRP is an insufficient method to detect bacterial infections and may not replace the proper clinical and microbiological diagnosis.