BACKGROUND: SARS-CoV-2 infection has raised concerns about long-term health repercussions. Exercise ventilatory inefficiency (EVin) has emerged as a notable long-term sequela, potentially impacting respiratory and cardiovascular health. This study aims to assess the long-term presence of EVin after 34 months and its association with cardiorespiratory health in post-COVID patients.
METHODS: In a longitudinal study on 32 selected post-COVID subjects, we performed two cardiopulmonary exercise tests (CPETs) at 6 months (T0) and 34 months (T1) after hospital discharge. The study sought to explore the long-term persistence of EVin and its correlation with respiratory and cardiovascular responses during exercise. Measurements included also V̇O2peak, end-tidal pressure of CO2 (PETCO2) levels, oxygen uptake efficiency slope (OUES) and other cardiorespiratory parameters, with statistical significance set at p < 0.05. The presence of EVin at both T0 and T1 defines a persisting EVin (pEVin).
RESULTS: Out of the cohort, five subjects (16%) have pEVin at 34 months. Subjects with pEVin, compared to those with ventilatory efficiency (Evef) have lower values of PETCO2 throughout exercise, showing hyperventilation. Evef subjects demonstrated selective improvements in DLCO and oxygen pulse, suggesting a recovery in cardiorespiratory function over time. In contrast, those with pEvin did not exhibit these improvements. Notably, significant correlations were found between hyperventilation (measured by PETCO2), oxygen pulse and OUES, indicating the potential prognostic value of OUES and Evin in post-COVID follow-ups.
CONCLUSIONS: The study highlights the clinical importance of long-term follow-up for post-COVID patients, as a significant group exhibit persistent EVin, which correlates with altered and potentially unfavorable cardiovascular responses to exercise. These findings advocate for the continued investigation into the long-term health impacts of COVID-19, especially regarding persistent ventilatory inefficiencies and their implications on patient health outcomes.

BACKGROUND: High-altitude exposure changes the electrical conduction of the heart. However, reports on electrocardiogram (ECG) characteristics and potent prophylactic agents during high-altitude acclimatization and de-acclimatization are inadequate. This study aimed to investigate the effects of ubiquinol on electrophysiology after high-altitude hypoxia and reoxygenation.
METHODS: The study was a prospective, randomized, double-blind, placebo-controlled trial. Forty-one participants were randomly divided into two groups receiving ubiquinol 200 mg daily or placebo orally 14 days before flying to high altitude (3900 m) until the end of the study. Cardiopulmonary exercise testing was performed at baseline (300 m), on the third day after reaching high altitude, and on the seventh day after returning to baseline.
RESULTS: Acute high-altitude exposure prolonged resting ventricular repolarization, represented by increased corrected QT interval (455.9 ± 23.4 vs. 427.1 ± 19.1 ms, P < 0.001) and corrected Tpeak-Tend interval (155.5 ± 27.4 vs. 125.3 ± 21.1 ms, P < 0.001), which recovered after returning to low altitude. Ubiquinol supplementation shortened the hypoxia-induced extended Tpeak-Tend interval (-7.7 ms, [95% confidence interval (CI), -13.8 to -1.6], P = 0.014), Tpeak-Tend /QT interval (-0.014 [95% CI, -0.027 to -0.002], P = 0.028), and reserved maximal heart rate (11.9 bpm [95% CI, 3.2 to 20.6], P = 0.013) during exercise at high altitude. Furthermore, the decreased resting amplitude of the ST-segment in the V3 lead was correlated with decreased peak oxygen pulse (R = 0.713, P < 0.001) and maximum oxygen consumption (R = 0.595, P < 0.001).
CONCLUSIONS: Our results illustrated the electrophysiology changes during high-altitude acclimatization and de-acclimatization. Similarly, ubiquinol supplementation shortened the prolonged Tpeak-Tend interval and reserved maximal heart rate during exercise at high altitude.
BACKGROUND: URL: www.chictr.org.cn; Unique identifier: ChiCTR2200059900.

OBJECTIVE: As there is growing interest in the application of cardiopulmonary exercise test (CPX) in chronic kidney disease (CKD), it is important to understand the utility of conventional exercise test parameters in quantifying the cardiopulmonary fitness of patients with CKD. Merely extrapolating information from heart failure (HF) patients would not suffice. In the present study, we evaluated the utility of CPX parameters such as the peak O2-pulse and the estimated stroke volume (SV) in assessing the peak SV by comparing with the actual measured values. Furthermore, we compared the anaerobic threshold (AT), peak circulatory power, and ventilatory power with that of the measured values of the peak cardiac power (CPOpeak) in representing the cardiac functional reserve in CKD. We also performed such analyses in patients with HF for comparison.
METHODS: A cross sectional study of 70 asymptomatic male CKD patients [CKD stages 2-5 (pre-dialysis)] without primary cardiac disease or diabetes mellitus and 25 HF patients. A specialized CPX with a CO2 rebreathing technique was utilized to measure the peak cardiac output and peak cardiac power output. The peak O2 consumption (VO2peak) and AT were also measured during the test. Parameters such as the O2-pulse, stroke volume, arteriovenous difference in O2 concentration [C(a-v)O2], peak circulatory power, and peak ventilatory power were all calculated. Pearson\'s correlation, univariate, and multivariate analyses were applied.
RESULTS: Whereas there was a strong correlation between the peak O2-pulse and measured peak SV in HF, the correlation was less robust in CKD. Similarly, the correlation between the estimated SV and the measured SV was less robust in CKD compared to HF. The AT only showed a modest correlation with the CPOpeak in HF and only a weak correlation in CKD. A stronger correlation was demonstrated between the peak circulatory power and CPOpeak, and the ventilatory power and CPOpeak. In HF, the central cardiac factor was the predominant determinant of the standard CPX-derived surrogate indices of cardiac performance. By contrast, in CKD both central and peripheral factors played an equally important role, making such indices less reliable markers of cardiac performance per se in CKD.
CONCLUSIONS: The results highlight that the standard CPX-derived surrogate markers of cardiac performance may be less reliable in CKD, and that further prospective studies comparing such surrogate markers with directly measured cardiac hemodynamics are required before adopting such markers into clinical practice or research in CKD.

BACKGROUND: The performance of young swimmers is the result of a multifactorial process that is influenced by anthropometric characteristics and biological maturation. The purpose of our study was to investigate the effect of stages of biological maturation and body surface area on cardiopulmonary fitness indicators in preadolescent female swimmers, for whom menstruation has not started.
METHODS: Thirty female preadolescent swimmers (age 13.4 ± 1.0 years) participated in this study. We recorded anthropometric and morphological characteristics, stages of biological maturation, and pulmonary function parameters, and the swimmers underwent cardiopulmonary exercise testing.
RESULTS: The cut-off was set for body surface area (BSA) at 1.6 m2 and for biological maturation stages at score 3. The BSA results showed differences in variabilities in maximal effort oxygen pulse (p < 0.001), oxygen uptake (p < 0.001), ventilation (p = 0.041), tidal volume (p < 0.001), and oxygen breath (p < 0.001). Tanner stage score results showed differences in variabilities in maximal effort breath frequency (p < 0.001), tidal volume (p = 0.013), and oxygen breath (p = 0.045). Biological maturation stages and BSA were correlated during maximal effort with oxygen breath (p < 0.001; p < 0.001), oxygen uptake (p = 0.002; p < 0.001), and oxygen pulse (p < 0.001; p < 0.001).
CONCLUSIONS: In conclusion, the findings of our study showed that the girls who had a smaller body surface area and biological maturation stage presented lower values in maximal oxygen uptake and greater respiratory work.

The ADRB3 gene plays a role in energy expenditure by participating in lipolysis, which affects body composition and performance. The ADRB3 rs4994 polymorphism has been studied in groups of athletes, overweight individuals, and obese and diabetic patients, but it has not been studied in young and healthy adults so far. In the present study, we examined the association of ADRB3 rs4994 polymorphism with body composition, somatotype, cardiorespiratory fitness and physical activity in young, healthy adults (N = 304). All subjects had anthropometric measurements, and somatotypes were assessed using the Heath-Carter method. In addition, cardiorespiratory fitness and physical activity levels were assessed. Genotyping for the ADRB3 gene was performed using a PCR-RFLP method. In the male group, body components were associated with the Trp64Trp genotype (waist circumference (p = 0.035), hip circumference (p = 0.029), BF (%) (p = 0.008), and BF (kg) (p = 0.010), BMI (p = 0.005), WHtR (p = 0.021), and BAI (p = 0.006)). In addition, we observed that the Trp64Trp genotype was associated with somatotype components (p = 0.013). In contrast, the Arg allele was associated with the ectomorphic components (0.006). We also observed a positive impact of the Trp64Trp genotype with maximal oxygen uptake (p= 0.023) and oxygen pulse (p = 0.024). We observed a negative relationship of the Trp64Trp genotype in the female group with reported moderate-intensity exercise (p = 0.036). In conclusion, we found an association of the Trp64 allele with anthropometric traits, somatotype and parameters describing physical performance in the male group. In the female subpopulation, we only found an effect of the polymorphism Trp64Arg on the level of physical activity for moderate-intensity exercise.

Several reports have shown the impact of COVID-19 history on exercise capacity. This study compared the blood pressure (BP) response and oxygen pulse (O2 pulse) characteristics in normotensive patients with and without a history of COVID-19 during the cardiopulmonary exercise test (CPET) and post-exercise recovery. This cross-sectional study involved 130 healthy Caucasian adult volunteers (71 participants with a history of COVID-19). All patients underwent the CPET with blood pressure measurements during exercise and post-exercise recovery. The post-COVID group had significantly higher systolic, diastolic, and mean blood pressure after 9 min of recovery and achieved a significantly lower max O2 pulse (2.02 mL/beat on average) than the controls. It should be noted that the COVID group tended to have higher blood pressure values in all steps, with no differences in heart rate, pulse pressure, and saturation at any step. The COVID-19 outbreak was associated with a higher blood pressure response, significantly, in post-exercise recovery, a lower maximum O2 pulse, and a lower maximum load achievement. Future studies are needed to determine if these abnormalities during the CPET and the blood pressure variation have prognostic value.

BACKGROUND: Heart failure (HF) is the only cardiovascular disease with an ever-increasing incidence.
OBJECTIVE: The aim of this study was to assess the predictors of adverse clinical events (CE) and the creation and evaluation of the prognostic value of a novel personalized scoring system in patients with HF.
METHODS: The study included 113 HF patients (median age 64 years (IQR 58-69); 57.52% male). The new novel prognostic score named GLVC (G, global longitudinal peak strain (GLPS); L, left ventricular diastolic diameter (LVDD); V, oxygen pulse (VO2/HR); and C, high sensitivity C-reactive protein (hs-CRP)) was created. The Kaplan-Meier method and log-rank test were used to compare the CE.
RESULTS: Results from final analyses showed that low GLPS (< 13.9%, OR = 2.66, 95% CI = 1.01-4.30, p = 0.002), high LVDD (> 56 mm, OR = 2.37, 95% CI = 1.01-5.55, p = 0.045), low oxygen pulse (< 10, OR = 2.8, 95% CI = 1.17-6.70, p = 0.019), and high hs-CRP (> 2.38 µg/ml, OR = 2.93, 95% CI = 1.31-6.54, p = 0.007) were independent prognostic factors for adverse CE in HF population. All the patients were stratified into a low-risk or high-risk group according to a novel \"GLVC\" scoring system. The Kaplan-Meier analyses demonstrated that patients in the high-risk group were more predisposed to having higher adverse clinical events compared to patients in the low-risk group.
CONCLUSIONS: A novel and comprehensive personalized \"GLVC\" scoring system is an easily available and effective tool for predicting the adverse outcomes in HF.

BACKGROUND: Pneumonia in cancer patients is often problematic in order to decide whether to admit and administer antibiotics or pursue a comfort care pathway that may avoid in-hospital death. We aimed to identify factors which are easily assessed at admission in Thailand\'s healthcare context that could serve as prognostic factors for in-hospital death.
METHODS: Regression analysis was utilized to identify the prognostic factors from clinical factors collected at admission. The primary outcome was in-hospital death. Data was collected from the electronic medical records of Chiang Mai University Hospital, Thailand, from 2016 to 2017. Data on adult cancer patients admitted due to pneumonia were reviewed.
RESULTS: In total, 245 patients were included, and 146 (59.6%) were male. The median age of the patients was 66 years (IQR: 57-75). A total of 72 (29.4%) patients died during admission. From multivariate logistic regression, prognostic factors for in-hospital death included: Palliative Performance Scale (PPS) ≤ 30 (OR: 8.47, 95% CI: 3.47-20.66), Palliative Performance Scale 40-50% (OR: 2.79, 95% CI: 1.34-5.81), percentage of lymphocytes ≤ 8.0% (OR: 2.10, 95% CI: 1.08-4.08), and pulse oximetry ≤ 90% (OR: 2.01, 95% CI: 1.04-3.87).
CONCLUSIONS: The in-hospital death rate of cancer patients admitted with pneumonia was approximately 30%. The PPS of 10-30%, PPS of 40-50%, percentage of lymphocytes ≤ 8%, and oxygen saturation < 90% could serve as prognostic factors for in-hospital death. Further prospective studies are needed to investigate the usefulness of these factors.

UNASSIGNED: Cardiopulmonary exercise testing (CPET) has been found high sensitivity and specificity in cardiac ischemia. However, the role of CPET in coronary artery disease (CAD) is unclear. This study was to explore the diagnostic value of CPET indicators in CAD.
UNASSIGNED: A total of 138 symptomatic patients with suspected CAD who underwent a CPET were included in this cross-sectional study. CPET indicators of all individuals were collected. ΔVO2/HR(Peak-AT) defined as the difference between the value of the oxygen consumption/heart rate (VO2/HR) at anaerobic threshold and peak exercise. The synergy between percutaneous coronary intervention with taxus and cardiac surgery (SYNTAX) score of all the CAD patients was calculated based on the complexity of the coronary lesions. The diagnostic performance of the CPET indicators was assessed by the area under the curve (AUC), sensitivity, and specificity.
UNASSIGNED: No significant differences in the CPET indicators were observed among the patients with or without CAD. The high SNYTAX score (≥22) group showed a significant reduction in the ΔVO2/HR(Peak-AT) compared to the low SNYTX score (<22) group (P=0.004). The AUC of the ΔVO2/HR(Peak-AT) was 0.804 (P=0.005), with the sensitivity of 95.7% and the specificity of 62.5%. The other CPET indicators did not differ significantly between the 2 groups. Oxygen pulse variation after the anaerobic threshold (AT) is superior to other CPET-derived variables in detecting intermediate to severe stenosis of the coronary artery in CAD patients.
UNASSIGNED: The ΔVO2/HR(Peak-AT) is a quantitative indicator of the variation of the oxygen pulse response after the AT during incremental exercise. However, due to sample limitations, our results need to be interpreted with caution.

UNASSIGNED: This study evaluated the effect of maximal oxygen pulse (O 2P max) on patients with chronic obstructive pulmonary disease (COPD) and confirmed the predictive effect on acute exacerbations of COPD (AECOPD).
UNASSIGNED: This retrospective study included 91 participants who underwent cardiopulmonary exercise testing (CPET), lung function testing, a dyspnea scale assessment, and a 3-year follow-up. The participants were divided into two groups according to the O 2P max value. Exercise capacity, ventilatory conditions, gas exchange efficiency, and dyspnea symptoms were compared, and the correlations between O 2P max and these indices were evaluated. The ability of O 2P max to predict AECOPD was examined.
UNASSIGNED: Exercise capacity, ventilatory conditions, and gas exchange efficiency were lower, and dyspnea symptom scores were higher in the impaired O 2P max group ( P < 0.05). O 2P max was positively correlated with forced vital capacity (FVC)%, forced expiratory volume in 1 sec (FEV 1)%, FEV 1/FVC%, anaerobic threshold (AT), work rate (WR)%, aximal oxygen uptake (V̇O 2max)%, V̇O 2/kg max, V̇O 2/kg max%, WR AT, WR max, V̇O 2AT, V̇O 2max, and V̇ Emax, and was negatively correlated with EqCO 2AT, and EqCO 2max ( P < 0.05). Most importantly, O 2P max could be used to predict AECOPD, and the best cut-off value was 89.5% (area under the curve, 0.739; 95% CI, 0.609-0.869).
UNASSIGNED: O 2P max reflected exercise capacity, ventilation capacity, gas exchange capacity, and dyspnea symptoms in patients with COPD and may be an independent predictor of AECOPD.