Comparison of the physiological responses of cardiopulmonary testing of upper and lower limbs in patients with chronic thromboembolic pulmonary hypertension and healthy controls

Introdução: Indivíduos com hipertensão pulmonar (HP) apresentam limitação na capacidade de exercício. No teste cardiopulmonar, o consumo de oxigênio (v̇O2) está diminuído tanto no limiar anaeróbio quanto no pico do exercício. Em outras variáveis, como por exemplo na carga de trabalho, eficiência ventilatória, frequência cardíaca pico, saturação pulso de oxigênio estão piores e podem estar reduzidas com a gravidade da doença. Acreditamos que essa limitação ao exercício pode comprometer não só os membros inferiores, mas também os membros superiores. Objetivos: Comparar a capacidade de exercício de membros superiores e inferiores de indivíduos com hipertensão pulmonar tromboembólica crônica (HPTEC) e controles saudáveis. Casuística e método: Foram avaliados 33 indivíduos com HPTEC (46,5 anos e 45,5% mulheres) e 22 controles (39,8 anos e 59,1% mulheres). Todos os participantes realizaram avaliação clínica (dispneia, Classe Funcional e medicação), testes de exercícios (testes cardiopulmonares em cicloergômetro de membros superiores e inferiores, teste da caminhada de seis minutos), testes de função pulmonar (espirometria, plestismografia) em três dias de avaliações. Resultados: o v̇O2 PICO nos testes cardiopulmonares de membros superiores (815,9mL/min versus 1066,8mL/min) e membros inferiores (967,3mL/min versus 1570,4mL/min) estavam reduzidos no grupo HPTEC em comparação ao grupo controle, respectivamente. Porém, o v̇O2 PICO de membros superiores são menos reduzidos do que os membros inferiores no grupo HPTEC. As respostas cardiovasculares, ventilatórias e de trocas gasosas ao teste de exercício são piores no grupo HPTEC em comparação ao grupo controle, tanto para os testes cardiopulmonares de membros superiores quanto membros inferiores. Conclusão: Pacientes com HPTEC apresentam redução da capacidade de exercício tanto de membros superiores quanto membros inferiores comparados ao grupo controle, sendo mais evidente nos membros inferiores. Porém, uma redução aeróbia proporcionalmente menor nos membros superiores em comparação aos membros inferiores.Introduction: Individuals with pulmonary hypertension (PH) have limited exercise capacity. In cardiopulmonary testing, oxygen consumption (v̇O2) is decreased both at the anaerobic threshold and at peak exercise. In other variables, such as workload, ventilatory efficiency, peak heart rate, pulse oxygen saturation are worse and may be reduced with the severity of the disease. We believe that this exercise limitation can compromise not only the lower limbs, but also the upper limbs. Objectives: To compare the exercise capacity of upper and lower limbs of individuals with chronic thromboembolic pulmonary hypertension (HPTEC) and healthy controls. Material and method: 33 individuals with HPTEC (46.5 years and 45.5% women) and 22 controls (39.8 years and 59.1% women) were evaluated. All participants underwent clinical evaluation (dyspnea, Functional Class and medication), exercise tests (cardiopulmonary tests in cycle ergometer of upper and lower limbs, six-minute walk test), pulmonary function tests (spirometry, plethysmography) in three days of assessments. Results: the peak v̇O2 in cardiopulmonary tests of upper limbs (815.9mL/min versus 1066.8mL/min) and lower limbs (967.3mL/min versus 1570.4mL/min) were reduced in the HPTEC group compared to the control group , respectively. However, the peak v̇O2 of the upper limbs are less reduced than the lower limbs in the HPTEC group. The cardiovascular, ventilatory and gas exchange responses to the exercise test are worse in the HPTEC group compared to the control group, both for the cardiopulmonary tests of the upper and lower limbs. Conclusion: Patients with HPTEC have reduced exercise capacity in both upper and lower limbs compared to the control group, being more evident in the lower limbs. However, a proportionally smaller aerobic reduction in the upper limbs compared to the lower limbs

Validation and development of an immunonephelometric assay for the determination of alpha-1 antitrypsin levels in dried blood spots from patients with COPD

OBJECTIVE: To validate and develop an immunonephelometric assay for the determination of alpha-1 antitrypsin (AAT) levels in dried blood spots from COPD patients in Brazil. METHODS: We determined AAT levels in serum samples and dried blood spots from 192 COPD patients. For the preparation of dried blood spots, a disk (diameter, 6 mm) was placed into a tube, eluted with 200 µL of PBS, and stored overnight at 4ºC. All of the samples were analyzed by immunonephelometry in duplicate. We used the bootstrap resampling method in order to determine a cut-off point for AAT levels in dried blood spots. RESULTS: The correlation coefficient between the AAT levels in serum samples and those in dried blood spots was r = 0.45. For dried blood spots, the cut-off value was 2.02 mg/dL (97% CI: 1.45-2.64 mg/dL), with a sensitivity, specificity, positive predictive value, and negative predictive value of 100%, 95.7%, 27.2%, and 100%, respectively. CONCLUSIONS: This method for the determination of AAT levels in dried blood spots appears to be a reliable screening tool for patients with AAT deficiency

Inspiratory muscle weakness contributes to exertional dyspnea in chronic thromboembolic pulmonary hypertension.

Determination of potentially-reversible factors contributing to exertional dyspnea remains an unmet clinical need in chronic thromboembolic pulmonary hypertension (CTEPH). Therefore, we aimed to evaluate the influence of inspiratory muscle weakness (IMW) on exercise capacity and dyspnea during effort in patients with CTEPH. We performed a prospective cross-sectional study that included thirty-nine consecutive patients with CTEPH (48 ± 15 yrs, 61% female) confirmed by right heart catheterization that underwent an incremental cardiopulmonary exercise test, 6-minute walk test and maximum inspiratory pressure (MIP) measurement. MIP < 70%pred was found in 46% of patients. On a multiple linear regression analysis, MIP was independently associated with 6MWD and [Formula: see text]. Patients with MIP < 70% presented greater [Formula: see text] than those with MIP ≥ 70%. Additionally, they also presented stronger sensations of dyspnea throughout exercise, even when adjusted for ventilation. At rest and at different levels of exercise, mean inspiratory flow (VT/TI) was significantly higher in patients with MIP < 70%. In conclusion, IMW is associated with a rapid increase of dyspnea, higher inspiratory load and poor exercise capacity in patients with CTEPH

Prevalence of alpha-1 antitrypsin deficiency and allele frequency in patients with COPD in Brazil

ABSTRACT Objective: To determine the prevalence of alpha 1-antitrypsin (AAT) deficiency (AATD), as well as allele frequency, in COPD patients in Brazil. Methods: This was a cross-sectional study involving 926 COPD patients 40 years of age or older, from five Brazilian states. All patients underwent determination of AAT levels in dried blood spot (DBS) samples by nephelometry. Those with DBS AAT levels ≤ 2.64 mg/dL underwent determination of serum AAT levels. Those with serum AAT levels of < 113 mg/dL underwent genotyping. In case of conflicting results, SERPINA1 gene sequencing was performed. Results: Of the 926 COPD patients studied, 85 had DBS AAT levels ≤ 2.64 mg/dL, and 24 (2.6% of the study sample) had serum AAT levels of < 113 mg/dL. Genotype distribution in this subset of 24 patients was as follows: PI*MS, in 3 (12.5%); PI*MZ, in 13 (54.2%); PI*SZ, in 1 (4.2%); PI*SS, in 1 (4.2%); and PI*ZZ, in 6 (25.0%). In the sample as a whole, the overall prevalence of AATD was 2.8% and the prevalence of the PI*ZZ genotype (severe AATD) was 0.8% Conclusions: The prevalence of AATD in COPD patients in Brazil is similar to that found in most countries and reinforces the recommendation that AAT levels be measured in all COPD patients