The clinical value of cardiopulmonary exercise testing in the modern era.

Cardiopulmonary exercise testing (CPET) has long been used as diagnostic tool for cardiac diseases. During recent years CPET has been proven to be additionally useful for 1) distinguishing between normal and abnormal responses to exercise; 2) determining peak oxygen uptake and level of disability; 3) identifying factors contributing to dyspnoea and exercise limitation; 4) differentiating between ventilatory (respiratory mechanics and pulmonary gas exchange), cardiovascular, metabolic and peripheral muscle causes of exercise intolerance; 5) identifying anomalies of ventilatory (respiratory mechanics and pulmonary gas exchange), cardiovascular and metabolic systems, as well as peripheral muscle and psychological disorders; 6) screening for coexistent ischaemic heart disease, peripheral vascular disease and arterial hypoxaemia; 7) assisting in planning individualised exercise training; 8) generating prognostic information; and 9) objectively evaluating the impact of therapeutic interventions. As such, CPET is an essential part of patients' clinical assessment. This article belongs to the special series on the "Ventilatory efficiency and its clinical prognostic value in cardiorespiratory disorders", addressed to clinicians, physiologists and researchers, and aims at encouraging them to get acquainted with CPET in order to help and orient the clinical decision concerning individual patients.

Reduced ventilatory efficiency during exercise predicts major vascular complications and mortality for interstitial lung disease in systemic sclerosis.

OBJECTIVES: Major vascular complication, such as digital ulcers (DUs), pulmonary arterial hypertension (PAH) and scleroderma renal crisis (SRC) are hallmarks of systemic sclerosis (SSc). Interstitial lung disease (ILD) is the major cause of mortality in SSc. The aim of study is to identify cardiopulmonary exercise testing (CPET) variables that predict MVC and mortality for ILD in SSc patients. METHODS: In this cohort study, 45 SSc patients underwent clinical evaluation, echocardiography, pulmonary function tests (PFTs), high resolution computerised tomography (HRCT) and CPET. PFTs and echocardiography were performed annually for a 5-year follow-up. RESULTS: 16 (35.6%) SSc patients had MVC: 14 new DUs (31.1%), 1 PAH (2.2%) and 1 SRC (2.2%). At univariate regression analysis, mRss [HR 1.099 (1.008-1.199), p<0.05], NVC patterns (active and late) [HR 0.032 (0.004-0.250), p<0.001], V'E/V'CO2 slope [HR 1.123 (1.052-1.198), p<0.001] were predictive of new onset of MVC. In multivariate analysis, NVC patterns (active and late) (HR 0.044 (0.004-0.486), p<0.05), V'E/V'CO2 (HR 1.094 (1.020-1.198), p<0.05) were predictive of new onset of MVC. The 5-year mortality for ILD is 8.9%. In univariate analysis, DLco [(HR 0.927(CI 0.874- 0.983), p<0.05], V'E/V'CO2 slope and lung parenchymal with radiological patterns of ILD [(1.2.02 (CI 1.018-1.419), p<0.05], represent risk factors for 5-year mortality for ILD [HR 1.142 (1.030-1.267), p<0.05]. In multivariate analysis, only V'E/V'CO2 slope [1.268 (CI 1.003-1.602), p<0.05] represents a risk factor for 5-year mortality for ILD. CONCLUSIONS: V' E/V' CO2 slope is a prognostic marker of MVC and five-year mortality for ILD.

False-negative RT-PCR in SARS-CoV-2 disease: experience from an Italian COVID-19 unit.

False-negative cases of #COVID19 are being increasingly reported. Laboratory diagnosis through RT-PCR testing alone lacks adequate sensitivity to be recommended as the only valid criterion to confirm COVID-19 diagnosis. https://bit.ly/2BLFnEe.

Identification of Subclinical Lung Involvement in ACPA-Positive Subjects through Functional Assessment and Serum Biomarkers.

Lung involvement is related to the natural history of anti-citrullinated proteins antibodies (ACPA)-positive rheumatoid arthritis (RA), both during the pathogenesis of the disease and as a site of disease-related injury. Increasing evidence suggests that there is a subclinical, early lung involvement during the course of the disease, even before the onset of articular manifestations, which can potentially progress to a symptomatic interstitial lung disease. To date, reliable, non-invasive markers of subclinical lung involvement are still lacking in clinical practice. The aim of this study is to evaluate the diagnostic potential of functional assessment and serum biomarkers in the identification of subclinical lung involvement in ACPA-positive subjects. Fifty ACPA-positive subjects with or without confirmed diagnosis of RA (2010 ARC-EULAR criteria) were consecutively enrolled. Each subject underwent clinical evaluation, pulmonary function testing (PFT) with assessment of diffusion lung capacity for carbon monoxide (DLCO), cardiopulmonary exercise testing (CPET), surfactant protein D (SPD) serum levels dosage and high-resolution computed tomography (HRCT) of the chest. The cohort was composed of 21 ACPA-positive subjects without arthritis (ND), 10 early (disease duration < 6 months, treatment-naïve) RA (ERA) and 17 long-standing (disease duration < 36 months, on treatment) RA (LSRA). LSRA patients had a significantly higher frequency of overall HRCT abnormalities compared to the other groups (p = 0.001). SPD serum levels were significantly higher in ACPA-positive subjects compared with healthy controls (158.5 ± 132.3 ng/mL vs 61.27 ± 34.11 ng/mL; p < 0.0001) and showed an increasing trend from ND subjects to LSRD patients (p = 0.004). Patients with HRCT abnormalities showed significantly lower values of DLCO (74.19 ± 13.2% pred. vs 131.7 ± 93% pred.; p = 0.009), evidence of ventilatory inefficiency at CPET and significantly higher SPD serum levels compared with subjects with no HRCT abnormalities (213.5 ± 157.2 ng/mL vs 117.7 ± 157.3 ng/mL; p = 0.018). Abnormal CPET responses and higher SPD levels were also associated with specific radiological findings. Impaired DLCO and increased SPD serum levels were independently associated with the presence of HRCT abnormalities. Subclinical lung abnormalities occur early in RA-associated autoimmunity. The presence of subclinical HRCT abnormalities is associated with several functional abnormalities and increased SPD serum levels of SPD. Functional evaluation through PFT and CPET, together with SPD assessment, may have a diagnostic potential in ACPA-positive subjects, contributing to the identification of those patients to be referred to HRCT scan.

Minimal clinically important difference for asthma endpoints: an expert consensus report.

Minimal clinically important difference (MCID) can be defined as the smallest change or difference in an outcome measure that is perceived as beneficial and would lead to a change in the patient's medical management.The aim of the current expert consensus report is to provide a "state-of-the-art" review of the currently available literature evidence about MCID for end-points to monitor asthma control, in order to facilitate optimal disease management and identify unmet needs in the field to guide future research.A series of MCID cut-offs are currently available in literature and validated among populations of asthmatic patients, with most of the evidence focusing on outcomes as patient reported outcomes, lung function and exercise tolerance. On the contrary, only scant and partial data are available for inflammatory biomarkers. These clearly represent the most interesting target for future development in diagnosis and clinical management of asthma, particularly in view of the several biologic drugs in the pipeline, for which regulatory agencies will soon require personalised proof of efficacy and treatment response predictors.

A case of acanthosis nigricans in a HIV-infected patient.

BACKGROUND: To date, very little information is available concerning the relationship between acanthosis nigricans (AN) and infection with human immunodeficiency virus type 1 (HIV-1). CASE PRESENTATION: Herein, we report the case of a middle-aged man admitted for fever and progressively worsening dyspnea in the context of an opportunistic pneumonia and firstly diagnosed with acquired immunodeficiency syndrome (AIDS). At the time of diagnosis, physical examination revealed the presence of a palpable, hyperpigmented skin lesion on the left areola with surface desquamation and velvety texture consistent with AN. Of note, the most common primary etiologies related to AN were excluded and the complete regression of the skin lesion was observed once antiretroviral therapy was started. CONCLUSION: This is the second report of AN found in patients with AIDS and apparently responsive to prolonged antiretroviral treatment. Possible explanations of this association are still not completely understood, probably related to virus-induced changes in lipid metabolism. Our experience suggests that HIV testing should always be considered in the setting of apparently idiopathic AN.

Pancreatic cystosis in cystic fibrosis: Sometimes a bike ride can help you decide.

Pancreatic cystosis (PC) is an uncommon manifestation of pancreas involvement in cystic fibrosis (CF), characterized by the presence of multiple macrocysts partially or completely replacing pancreas. Only few reports are available from literature and management (surgery vs follow up) is commonly based on the presence of symptoms or complications due to local mass effect, although evidence-based recommendations are still not available. We here report the case of a young adult CF patient with PC, in which cardiopulmonary exercise testing (CPET) provided important information to be integrated to the radiological finding of inferior vena cava compression by the multicystic pancreas complex. Through the analysis of oxygen kinetic cardiodynamic phase pattern, CPET may be helpful to safely exclude significant mass effects on blood venous return and to improve the decision-making process on whether to consider surgery or not in patients with PC.

Reduced exercise ventilatory efficiency in adults with cystic fibrosis and normal to moderately impaired lung function.

Despite being a hallmark and an independent prognostic factor in several cardiopulmonary diseases, ventilatory efficiency-i.e., minute ventilation/carbon dioxide output relationship (V̇e/V̇co2)-has never been systematically explored in cystic fibrosis (CF). To provide a comprehensive frame of reference regarding measures of ventilatory efficiency in CF adults with normal to moderately impaired lung function and to confirm the hypothesis that V̇e/V̇co2 is a sensitive marker of early lung disease. CF patients were divided into three groups, according to their spirometry: normal (G1), mild impairment (G2), and moderate impairment (G3) in lung function. All participants underwent incremental cardiopulmonary exercise testing on a cycle ergometer. Lowest V̇e/V̇co2 ratio (nadir) and the slope and the intercept of the linear region of the V̇e/V̇co2 relationship were contrasted in a two-center retrospective analysis, involving 72 CF patients and 36 healthy controls (HC). Compared with HC, CF patients had significantly higher V̇e/V̇co2 nadir, slope, and intercept (P < 0.001, P < 0.001, and P = 0.049, respectively). Subgroup analysis revealed significant differences in nadir (P = 0.001) and slope (P = 0.012) values even between HC and G1. Dynamic hyperinflation related negatively with slope (P = 0.045) and positively with intercept (P = 0.001), while no impact on nadir was observed. Ventilatory inefficiency is a clear feature of adults with CF, even among patients with normal spirometry. V̇e/V̇co2 nadir seems to be the most reliable metric to describe ventilatory efficiency in CF adults. Further prospective studies are needed to clarify whether V̇e/V̇co2 could represent a useful marker in the evaluation of early lung disease in CF.NEW & NOTEWORTHY This is the first study to investigate ventilatory efficiency in a cohort of adult cystic fibrosis (CF) patients with nonsevere lung disease. The finding of impaired ventilatory efficiency in patients with normal lung function confirms the higher sensitivity of exercise testing in detecting early lung disease compared with spirometry. Dynamic hyperinflation plays a significant role in determining the behavior of V̇e/V̇co2 slope and intercept values with increasing lung function impairment. Apparently free from interference from mechanical constraints, V̇e/V̇co2 nadir seems the most reliable parameter to evaluate ventilatory efficiency in CF adults.

The value of high-resolution computed tomography (HRCT) to determine exercise ventilatory inefficiency and dynamic hyperinflation in adult patients with cystic fibrosis.

INTRODUCTION: In Cystic Fibrosis (CF), exercise ventilatory inefficiency and dynamic hyperinflation (DH) cause exercise limitation and induce poor exercise tolerance. High-resolution computed tomography (HRCT) of the lung can detect pulmonary abnormalities in CF patients. We aimed to identify the determinants of exercise ventilatory inefficiency and DH using HRCT-derived metrics. METHODS: Fifty-two adult CF patients were prospectively enrolled; all participants underwent cardio-pulmonary exercise test (CPET) and HRCT. Radiological impairment was evaluated by the Brody II scoring system. Slope and intercept of the minute ventilation/CO2 production (V'E/V'CO2) regression line and the ratio of inspiratory capacity/total lung capacity (IC/TLC) at rest and at peak of exercise were measured. RESULTS: Four groups of patients were identified based on the combination of ventilatory efficiency (Vef) or inefficiency (Vin) and the presence/absence of DH. Compared to other groups, CF adults with Vin and DH had worse functional status and higher total (T), bronchiectasis (B) and air trapping (AT) scores at HRCT. Significant correlations were found between V'E/V'CO2 intercept and V'E/V'CO2 slope (ρ - 0.455, p = 0.001) and between V'E/V'CO2 intercept and Δ inspiratory capacity (IC) (ρ - 0.334, p = 0.015). Regression analysis identified AT score (cut-off 7.9, odds ratio-OR 3.50) as the only independent predictor of Vin and T (cut-off 53.6, OR 4.98), B (cut-off 16.1, OR 4.88), airways wall thickening (AWT) (cut-off 13, OR 3.41), and mucous plugging (MP) scores (cut-off 11.7, OR 4.18) as significant predictors of DH. CONCLUSION: In adult CF cohort, values of HRCT metrics are determinants of Vin (AT) and DH (T, B, AWT, MP).

Effects of autonomic dysfunction on exercise tolerance in systemic sclerosis patients without clinical and instrumental evidence of cardiac and pulmonary involvement.

OBJECTIVES: Autonomic dysfunction (AD) in systemic sclerosis (SSc) was already confirmed through heart rate variability (HRV) analysis. Cardio-pulmonary exercise testing (CPET) is a useful tool in early detection of exercise tolerance in SSc patients. Aim of the study was to assess the relationships existing between AD and exercise tolerance. METHODS: Thirty-two [4 M, 28 F; median age: 47.5 (20-65) years] consecutive SSc patients were enrolled. All patients underwent pulmonary function testing, incremental symptom-limited CPET and twenty-four hours ECG Holter recording with HRV analysis in time and frequency domain. Multiple regression analysis was performed in order to identify independent HRV predictors of exercise tolerance and cardiac efficiency during the effort. RESULTS: HRV analysis showed significant differences in power in low and high frequency (LF and HF, respectively) and their ratio (LF/HF) compared to healthy controls. Nocturnal ratio be- tween power in low and high frequency at HRV (LF/HFnight) was shown to be the only independent positive predictor of maximal work load (R2=18.6%, p=0.014) and maximal oxygen consumption (V' O2 peak) expressed both as absolute value (R2=24.2%, p=0.004) and as corrected for body weight (R2=21.6%, p=0.007). A positive linear relationship was also found between nocturnal LF (LFnight) and the oxygen uptake/work rate (V'O2/W) slope (R2=15.8%, p=0.024). CONCLUSIONS: In SSc patients without cardiopulmonary involvement AD is associated with better exercise tolerance and cardiac function during physical effort. Further studies are needed to confirm these results.

Is daily physical activity affected by dynamic hyperinflation in adults with cystic fibrosis?

BACKGROUND: The aim of this study was to investigate the relationship between dynamic hyperinflation and daily physical activity (DPA) in adults with cystic fibrosis (CF). METHODS: Thirty-four clinically stable CF were studied. All patients undertook incremental cardiopulmonary exercise testing (CPET). CPET-related measurements included: oxygen uptake (V'O2), carbon dioxide production (V'CO2), ventilatory profile, work rate (W), inspiratory capacity (IC), end-expiratory lung volume (EELV). PA was assessed using the accelerometer SenseWear Pro3 Armband. RESULTS: Exercise tolerance was reduced in most of patients and the mean V'O2,peak value was 75.2% of predicted (28.5 ± 4.8 ml/min/kg). Seventy % of patients responded to CPET with dynamic hyperinflation. Higher incidence of dynamic hyperinflation was found in CF males compared to CF females (p = 0.026). Patients who developed dynamic hyperinflation during CPET had higher vigorous PA (p = 0.01) and more total energy expenditure (p = 0.006) than patients who did not. EELVΔ was related to activities requiring vigorous intensity and total energy expenditure (R = 0.46, p = 0.001; R = 0.57, p <  0.001). CONCLUSIONS: In adults with CF and mild to moderate lung impairment, DPA might not be limited by dynamic hyperinflation.

BMI, nephroangiosclerosis and glomerulonephritis: Is there any meeting point?

AIM: Overweight has been related to renal arteriolosclerosis and is able to modify intrarenal haemodynamics. Increasing evidence suggests an association between weight in excess and primary glomerulonephritis (GN). The aim of this study was to evaluate the relationship between nutritional status and intrarenal arterial stiffness in primary GN associated to arteriolosclerosis. We have considered the glomerular diameter (GD) as morphological parameter in overweight and obese patients. METHODS: Clinical, laboratory, anthropometric data and renal Doppler ultrasound were performed immediately before kidney biopsy. RESULTS: Primary GN was diagnosed in 92 patients. Mild arteriolosclerosis was found in 19.6% of patients, moderate in the 20.6%, severe in the 10.9% while nephroangiosclerosis was diagnosed in 8.7% of patients. A positive correlation was found between body mass index (BMI) and renal resistive index (RRI) (P < 0.01, r = 0.34). RRI were significantly higher in patients with severe arteriolosclerosis at kidney biopsy (P < 0.05). Furthermore, higher BMI (P < 0.01) was found in patients with renal arteriolosclerosis than patients without renal arteriolosclerosis (26.1 ± 4.4 kg/m2 vs. 24.4 ± 4.5 kg/m2 ). Finally, in overweight and obesity patients we found a positive correlation between maximal GD and BMI (P < 0.01) and maximal GD and RRI (P < 0.01). CONCLUSION: In overweight and obese patients affected by primary GN, it might be found not only glomerular but also renal vascular lesions. Finally, we believe that nephroangiosclerosis, in combination with weight in excess, is able to modify intrarenal haemodynamic parameters. Moreover, in response to these changes, the renal tissue morphologically promotes a GD increase regardless of the underlying GN.

Relationship between pulmonary exacerbations and daily physical activity in adults with cystic fibrosis.

BACKGROUND: The aim of this study was to examine the relationship between pulmonary exacerbations and physical activity (PA) in adults with cystic fibrosis (CF). METHODS: We grouped adults with CF according to their exacerbation status in the year before study enrollment: (1) <1 exacerbation/year; (2) 1-2 exacerbations/year; and (3) >2 exacerbations/year. PA was assessed objectively by means of an accelerometer at the time of study enrollment. RESULTS: Patients with >2 exacerbations/year spent less time in PA; specifically, fewer activities of mild intensity [>3 metabolic equivalents (METs)], and lower active energy expenditure (P = 0.01 and P = 0.03, respectively). After correcting for relevant confounders, PA levels were not related to the exacerbation frequency in the preceding year. PA at moderate intensity (4.8-7.2 METs) or greater (> 7.2 METs) was independently associated with gender and FEV1 % predicted (P = 0.007 and P = 0.04, respectively). Compared with men, women had reduced vigorous activities (P = 0.01) and active energy expenditure (P = 0.01). CONCLUSIONS: Adult CF patients with more pulmonary exacerbations in the preceding year have more advanced disease and are less active than their peers. PA was independently associated with gender and airflow obstruction. Gender differences in PA are evident in CF adults.

Relationship between daily physical activity and aerobic fitness in adults with cystic fibrosis.

BACKGROUND: The best clinical practice to investigate aerobic fitness includes measurements obtained during cardiopulmonary exercise testing (CPET), however it remains an underutilised clinical measure in cystic fibrosis (CF). To investigate this further, different methods of quantifying exercise capacity in CF are required. The possibility that measuring physical activity (PA) by a portable accelerometer could be used to assess the CF aerobic state and could be added among the CPET surrogates has not been investigated. The aim of this study was to examine the relationship between PA and exercise fitness both at submaximal and maximal levels in clinically stable adults with CF. METHODS: Thirty CF patients (FEV1 71 ± 19% predicted) and fifteen healthy controls undertook an incremental CPET on a cycle ergometer. CPET-related measurements included: oxygen uptake (V'O2), carbon dioxide production (V'CO2), ventilatory profile, heart rate (HR) and oxygen pulse (V'O2/HR) throughout exercise and at lactic threshold (LT) and peak. LT measures represent submaximal exercise related data. PA was assessed using the accelerometer SenseWear Pro3 Armband. RESULTS: Moderate (>4.8 metabolic equivalents (METS)) and moderate + vigorous (>7.2 METS) PA was related to V'O2 (p = 0.005 and p = 0.009, respectively) and work rate (p = 0.004 and p = 0.002, respectively) at LT. Moderate PA or greater was positively related to peak V'O2 (p = 0.005 and p = 0.003, respectively). Daily PA levels were similar in CF and healthy controls. Except for peak values, V'O2 profile and the V'O2 at LT were comparable between CF and healthy controls. CONCLUSIONS: In adult CF patients daily PA positively correlated with aerobic capacity. PA measurements are a valuable tool in the assessment of exercise performance in an adult CF population and could be used for interventional exercise trials to optimize exercise performance and health status. PA levels and parameters obtained at submaximal exercise are similar in CF and in healthy controls.