The six-minute step test can predict COPD exacerbations: a 36-month follow-up study.

The six-minute step test (6MST) has been shown to be effective in assessing exercise capacity in individuals with COPD regardless of severity and, despite its easy execution, accessibility and validity, information on the prognostic power of this test remains uncertain. The aim of this study is to investigate whether the 6MST can predict the occurrence of exacerbations in patients with COPD. This is a prospective cohort study with a 36-month follow-up in patients with COPD. All patients completed a clinical assessment, followed by pulmonary function testing and a 6MST. The 6MST was performed on a 20 cm high step; heart rate, blood pressure, oxygen saturation, BORG dyspnea and fatigue were collected. Sixty-four patients were included in the study, the majority being elderly men. Performance on the 6MST demonstrated lower performance compared to normative values proposed in the literature, indicating a reduced functional capacity. Kaplan Meier analysis revealed that ≤ 59 steps climbed during the 6MST was a strong predictor of COPD exacerbation over a 36-month follow-up. We have identified a minimal threshold number of steps (≤ 59) obtained through the 6MST may be able predict the risk of exacerbations in patients with COPD.

Regular Physical Exercise Adherence Scale (REPEAS): a new instrument to measure environmental and personal barriers to adherence to regular physical exercise.

OBJECTIVE: To create, develop, and validate a scale that identifies the environmental and personal barriers that make it difficult to adhere to the practice of physical exercise on a regular basis in a population of Brazilian adults. METHODS: We include adult individuals, aged 18-59 years, practitioners or former practitioners of physical exercise, with Brazilian Portuguese as their mother tongue. In the development and validation phases of the process, 6 specialists in the field of the health assessed the content validity: firstly, the specialists were asked to freely list the questions they would ask to investigate the barriers to adherence to regulating physical activity. Secondly, after compiling all the suggestions listed and eliminating suggestions with similar content, the items suggested in the first round were sent to the specialists so that an evaluation of all questions using a 5-point Likert scale and the content validity coefficient was calculated. We then evaluated the structural validity, construct validity, reliability, internal consistency, and ceiling and floor effects of the Regular Physical Exercise Adherence Scale (REPEAS). RESULTS: Sixteen items were proposed to measure the factors that make it difficult to adhere to the regular practice of physical exercise. The internal structure of the REPEAS initially tested was based on the theoretical proposal of creating the instrument with two domains. After the structural analysis, we used the modification indices to identify the redundant items of the instrument. Consequently, the final version of the REPEAS after factor analysis had 12 items. Thus, the structure with 2 domains and 12 items presented adequate fit indices. With regard to construct validity, the REPEAS scores were compared in two distinct groups: irregular practitioners/ex-practitioners versus regular practitioners of physical exercise, in which a significant difference could be observed between groups (p < 0.001) for both the domains. Acceptable reliability was observed for the environment and personal domains, with ICC values of 0.86 and 0.94, in the same order. For internal consistency, Cronbach's alpha value was 0.908 (environmental domain) and 0.915 (personal domain), these values being adequate for the REPEAS. CONCLUSION: The REPEAS is a scale with a valid two-dimensional internal structure, consisting of 12 items, reliable and with a valid construct, which supports its use in the clinical, epidemiological, and research contexts in Brazil.

Inter- and intrarater reliability of short-term measurement of heart rate variability on rest in chronic obstructive pulmonary disease (COPD).

BACKGROUND: Individuals with COPD have an imbalance of cardiac autonomic control. In this context, HRV is considered an important tool for assessing cardiac sympathetic and parasympathetic balance, however it is a dependent evaluator measure and subject to methodological biases that may compromise the interpretation of results. OBJECTIVE: This study examines the inter- and intrarater reliability of HRV parameters derived from short-term recordings in individuals with COPD. METHODOLOGY: Fifty-one individuals of both genders with COPD clinical diagnosis confirmed by the pulmonary function test and aged ≥50 years were included. The RR interval (RRi) were recorded during a 10 min period on supine position using a portable heart rate monitor (Polar® H10 model). The data were transferred into Kubios® HRV Standard analysis software and analyzed within the stable sessions containing 256 sequential RRi. RESULTS: The intraclass correlation coefficient (ICC) ranged from 0.942 to 1.000 according to the intrarater analysis by Researcher 01 and 0.915 to 0.998 to the intrarater by Researcher 02. The interrater ICC ranged from 0.921 to 0.998. The coefficient of variation was up to 8.28 for Researcher 01 intrarater analysis, 9.06 for Researcher 02 intrarater analysis and 13.07 for interrater analysis. CONCLUSION: The measurement of HRV using a portable heart rate device in individuals with COPD present acceptable values of intra- and interrater reliability, supporting the use of HRV in the clinical and scientific scenario. Furthermore, it is important that the data analysis be performed by the same experienced evaluator.

Non-invasive ventilatory support accelerates the oxygen uptake and heart rate kinetics and improves muscle oxygenation dynamics in COPD-HF patients.

BACKGROUND: The aim of this study was to explore the effects of non-invasive positive pressure ventilation (NIPPV) associated with high-intensity exercise on heart rate (HR) and oxygen uptake (V̇O2) recovery kinetics in in patients with coexistence of chronic obstructive pulmonary disease (COPD) and heart failure (HF). METHODS: This is a randomized, double blinded, sham-controlled study involving 14 HF-COPD patients, who underwent a lung function test and Doppler echocardiography. On two different days, patients performed incremental cardiopulmonary exercise testing (CPET) and two constant-work rate tests (80% of CPET peak) receiving Sham or NIPPV (bilevel mode - Astral 150) in a random order until the limit of tolerance (Tlim). During exercise, oxyhemoglobin and deoxyhemoglobin were assessed using near-infrared spectroscopy (Oxymon, Artinis Medical Systems, Einsteinweg, Netherland). RESULTS: The kinetic variables of both V̇O2 and HR during the high-intensity constant workload protocol were significantly faster in the NIPPV protocol compared to Sham ventilation (P < 0.05). Also, there was a marked improvement in oxygenation and lower deoxygenation of both peripheral and respiratory musculature in TLim during NIPPV when contrasted with Sham ventilation. CONCLUSIONS: NIPPV applied during high-intensity dynamic exercise can effectively improve exercise tolerance, accelerate HR and V̇O2 kinetics, improve respiratory and peripheral muscle oxygenation in COPD-HF patients. These beneficial results from the effects of NIPPV may provide evidence and a basis for high-intensity physical training for these patients in cardiopulmonary rehabilitation programs.

Intra- and Interrater Reliability of Short-Term Measurement of Heart Rate Variability on Rest in Individuals Post-COVID-19.

Individuals affected by COVID-19 have an alteration in autonomic balance, associated with impaired cardiac parasympathetic modulation and, consequently, a decrease in heart rate variability (HRV). This study examines the inter- and intrarater reliability of HRV) parameters derived from short-term recordings in individuals post-COVID. Sixty-nine participants of both genders post-COVID were included. The RR interval, the time elapsed between two successive R-waves of the QRS signal on the electrocardiogram (RRi), were recorded during a 10 min period in a supine position using a portable heart rate monitor (Polar® V800 model). The data were transferred into Kubios® HRV standard analysis software and analyzed within the stable sessions containing 256 sequential RRi. The intraclass correlation coefficient (ICC) ranged from 0.920 to 1.000 according to the intrarater analysis by Researcher 01 and 0.959 to 0.999 according to the intrarater by Researcher 02. The interrater ICC ranged from 0.912 to 0.998. The coefficient of variation was up to 9.23 for Researcher 01 intrarater analysis, 6.96 for Researcher 02 intrarater analysis and 8.83 for interrater analysis. The measurement of HRV in post-COVID-19 individuals is reliable and presents a small amount of error inherent to the method, supporting its use in the clinical environment and in scientific research.

Publisher Correction: The Value of Cardiopulmonary Exercise Testing in Determining Severity in Patients with both Systolic Heart Failure and COPD.

An amendment to this paper has been published and can be accessed via a link at the top of the paper.

The Value of Cardiopulmonary Exercise Testing in Determining Severity in Patients with both Systolic Heart Failure and COPD.

Our aim was to identify optimal cardiopulmonary exercise testing (CPET) threshold values that distinguish disease severity progression in patients with co-existing systolic heart failure (HF) and chronic obstructive pulmonary disease (COPD), and to evaluate the impact of the cut-off determined on the prognosis of hospitalizations. We evaluated 40 patients (30 men and 10 woman) with HF and COPD through pulmonary function testing, doppler echocardiography and maximal incremental CPET on a cycle ergometer. Several significant CPET threshold values were identified in detecting a forced expiratory volume in 1 second (FEV1) < 1.6 L: 1) oxygen uptake efficiency slope (OUES) < 1.3; and 2) circulatory power (CP) < 2383 mmHg.mlO2.kg-1. CPET significant threshold values in identifying a left ventricular ejection fraction (LVEF) < 39% were: 1) OUES: < 1.3; 2) CP < 2116 mmHg.mlO2.kg-1.min-1 and minute ventilation/carbon dioxide production (V̇E/V̇CO2) slope>38. The 15 (38%) patients hospitalized during follow-up (8 ± 2 months). In the hospitalizations analysis, LVEF < 39% and FEV1 < 1.6, OUES < 1.3, CP < 2116 mmHg.mlO2.kg-1.min-1 and V̇E/V̇CO2 > 38 were a strong risk predictor for hospitalization (P ≤ 0.050). The CPET response effectively identified worsening disease severity in patients with a HF-COPD phenotype. LVEF, FEV1, CP, OUES, and the V̇E/V̇CO2 slope may be particularly useful in the clinical assessment and strong risk predictor for hospitalization.