Author Archives: Paul Older

van Kan C; Department of Respiratory Medicine OLVG Amsterdam The Netherlands.
Tramper J; Bresser P; J Meijboom L; Symersky P; Winkelman JA; Nossent EJ; Aman J; Bogaard HJ; Vonk Noordegraaf A; van Es J;

Pulmonary circulation [Pulm Circ] 2024 Jan 24; Vol. 14 (1), pp. e12316.
Date of Electronic Publication: 2024 Jan 24 (Print Publication: 2024).

The correlation between hemodynamics and degree of pulmonary vascular obstruction (PVO) is known to be poor in chronic thromboembolic pulmonary hypertension (CTEPH), which makes the selection of patients eligible for pulmonary endarterectomy (PEA) challenging. It can be postulated that patients with similar PVO but different hemodynamic severity have different postoperative hemodynamics and exercise capacity. Therefore, we aimed to assess the effects of PEA on hemodynamics and exercise physiology in mild and severe CTEPH patients. We retrospectively studied 18 CTEPH patients with a mild hemodynamic profile (mean pulmonary arterial pressure [mPAP] between 25 and 30 mmHg at rest) and CTEPH patients with a more severe hemodynamic profile (mPAP > 30 mmHg), matched by age, gender, and PVO. Cardiopulmonary exercise testing parameters were evaluated at baseline and 18 months following PEA. At baseline, exercise capacity, defined as oxygen uptake, was less severely impaired in the mild CTEPH group compared to the severe CTEPH group. After PEA, in the mild CTEPH group, ventilatory efficiency and oxygen pulse improved significantly ( p < 0.05), however, the change in ventilatory efficiency and oxygen pulse was smaller compared to the severe CTEPH group. Only in the severe CTEPH group exercise capacity improved significantly ( p < 0.001). Hence, in the present study, postoperative hemodynamic outcome and the CPET-determined recovery of exercise capacity in mild CTEPH patients did not differ from a matched group of severe CTEPH patients.

Using Machine Learning-Based Algorithms to Identify and Quantify Exercise Limitations in Clinical Practice: Are We There Yet?

January 13, 2024

SCHWENDINGER, F; Multi centre study from many European countries
BIEHLER, A; NAGY-HUBER,M; KNAIER, R; ROTH,V; DUMITRESCU,D; MEYER,J;
HAGER, A; SCHMIDT-TRUCKSÄSS,A;

Med Sci Sports Exerc 2024 Vol. 56 Issue 2 Pages 159-169

INTRODUCTION: Well-trained staff is needed to interpret cardiopulmonary exercise tests (CPET). We aimed to examine the accuracy of machine learning-based algorithms to classify exercise limitations and their severity in clinical practice compared with expert consensus using patients presenting at a pulmonary clinic.
METHODS: This study included 200 historical CPET data sets (48.5% female) of patients older than 40 yr referred for CPET because of unexplained dyspnea, preoperative examination, and evaluation of therapy progress. Data sets were independently rated by experts according to the severity of pulmonary-vascular, mechanical-ventilatory, cardiocirculatory, and muscular limitations using a visual analog scale. Decision trees and random forests analyses were calculated.
RESULTS: Mean deviations between experts in the respective limitation categories ranged from 1.0 to 1.1 points (SD, 1.2) before consensus. Random forests identified parameters of particular importance for detecting specific constraints. Central parameters were nadir ventilatory efficiency for CO2 , ventilatory efficiency slope for CO2 (pulmonary-vascular limitations); breathing reserve, forced expiratory volume in 1 s, and forced vital capacity (mechanical-ventilatory limitations); and peak oxygen uptake, O2 uptake/work rate slope, and % change of the latter (cardiocirculatory limitations). Thresholds differentiating between different limitation severities were reported. The accuracy of the most accurate decision tree of each category was comparable to expert ratings. Finally, a combined decision tree was created quantifying combined system limitations within one patient.
CONCLUSIONS: Machine learning-based algorithms may be a viable option to facilitate the interpretation of CPET and identify exercise limitations. Our findings may further support clinical decision making and aid the development of standardized rating instruments.

Prehabilitation before general surgery: Worth the effort?

J. G. Kovoor, S. D. Nann, C. Chambers, K. Mishra, S. Goel, I. Thompson, Koh D; Litwin P; Bacchi S; Harford PJ; Stretton B; Gupta AK,

J Perioper Pract 2023 Pages 17504589231214395

Prehabilitation, or interventions before surgery aimed at improving preoperative health and postoperative outcomes, has various forms. Although it may confer benefit to patients undergoing general surgery, this is not certain. Furthermore, although it may yield a net monetary gain, it is also likely to require substantial monetary and non-monetary investment. The impact of prehabilitation is highly variable and dependent on multiple factors. Physical function and pulmonary outcomes are likely to be improved by most forms of prehabilitation involving physical and multimodal exercise programmes. However, other surgical outcomes have demonstrated mixed results from prehabilitation. Within this issue, the measures used for evaluating baseline patient biopsychosocial health are important, and collecting sufficient data to accurately inform patient-centred prehabilitation programmes is only possible through thorough clinical and laboratory investigation and synthesised metrics such as cardiopulmonary exercise testing. Although a multimodal approach to prehabilitation is the current gold standard, societal factors may affect engagement with programmes that require a significant in-person activity. However, this is weighed against the substantial financial and non-financial investment that accompanies many programmes. The overall effectiveness and optimal mode of intervention across the discipline of general surgery remains unclear, and further research is needed to prove prehabilitation’s full worth.

Reduced tidal volume-inflection point and elevated operating lung volumes during exercise in females with well-controlled asthma.

Brotto AR; Faculty of Medicine and Dentistry, University of Alberta, Edmonton, Alberta, Canada.;
Phillips DB; Rowland SD; Moore LE; Wong E;Stickland MK;

BMJ open respiratory research [BMJ Open Respir Res] 2023 Dec 22; Vol. 10 (1).
Date of Electronic Publication: 2023 Dec 22.

Introduction: Individuals with asthma breathe at higher operating lung volumes during exercise compared with healthy individuals, which contributes to increased exertional dyspnoea. In health, females are more likely to develop exertional dyspnoea than males at a given workload or ventilation, and therefore, it is possible that females with asthma may develop disproportional dyspnoea on exertion. The purpose of this study was to compare operating lung volume and dyspnoea responses during exercise in females with and without asthma.
Methods: Sixteen female controls and 16 females with asthma were recruited for the study along with 16 male controls and 16 males with asthma as a comparison group. Asthma was confirmed using American Thoracic Society criteria. Participants completed a cycle ergometry cardiopulmonary exercise test to volitional exhaustion. Inspiratory capacity manoeuvres were performed to estimate inspiratory reserve volume (IRV) and dyspnoea was evaluated using the Modified Borg Scale.
Results: Females with asthma exhibited elevated dyspnoea during submaximal exercise compared with female controls (p<0.05). Females with asthma obtained a similar IRV and dyspnoea at peak exercise compared with healthy females despite lower ventilatory demand, suggesting mechanical constraint to tidal volume (V _T ) expansion. V _T -inflection point was observed at significantly lower ventilation and V̇ O ₂ in females with asthma compared with female controls. Forced expired volume in 1 s was significantly associated with V _T -inflection point in females with asthma (R ² =0.401; p<0.01) but not female controls (R ² =0.002; p=0.88).
Conclusion: These results suggest that females with asthma are more prone to experience exertional dyspnoea, secondary to dynamic mechanical constraints during submaximal exercise when compared with females without asthma.

Invasive haemodynamics at rest and exercise in cardiac amyloidosis.

Holt MF; Institute of Clinical Medicine, Faculty of Medicine, University of Oslo, Oslo, Norway.
Flø A;Ravnestad H; Bjørnø V; Gullestad L; Andreassen AK; DBroch K; Gude E

ESC heart failure [ESC Heart Fail] 2023 Dec 29.
Date of Electronic Publication: 2023 Dec 29.

Aims: Our aim was to investigate haemodynamics at rest and during exercise in patients with transthyretin cardiomyopathy (ATTR-CM) in light of the 2022 European Society of Cardiology (ESC) and European Respiratory Society (ERS) guidelines on pulmonary hypertension (PH).
Methods and Results: We performed right heart catheterization (RHC) in 57 subjects with ATTR-CM. The proportion of patients with PH was 77% according to the 2022 guidelines versus 47% when applying the 2015 guidelines. Isolated post-capillary PH and combined pre- and post-capillary PH were most prevalent. Thirty-six patients underwent a supine bicycle cardiopulmonary exercise test during RHC. Exercise-induced PH was defined as an increase in mean pulmonary arterial pressure from rest to exercise per increase in cardiac output (ΔmPAP/ΔCO) of > 3 mmHg/L/min. An increase in pulmonary arterial wedge pressure per change in cardiac output (ΔPAWP/ΔCO) from rest to exercise >2 mmHg/L/min was considered suggestive of post-capillary exercise-induced PH. All but two patients who exercised during RHC developed exercise-induced PH. The median ΔmPAP/ΔCO was 7.2 mmHg/L/min and ΔPAWP/ΔCO was 5.1 mmHg/L/min. The median ΔRAP/ΔCO was 3.6 mmHg/L/min and ΔRAP/ΔPAWP was 0.6 mmHg/L/min.
Conclusions: Most patients with ATTR-CM have isolated post-capillary or combined pre- and post-capillary PH at rest, and almost all patients develop exercise-induced PH with a large post-capillary component. There was a pronounced, but balanced increase in atrial pressures on exercise.

Peak oxygen uptake in combination with ventilatory efficiency improve risk stratification in major abdominal surgery.

Kristenson K; Linköping University, Linköping, Sweden.
Gerring E; Björnsson B; Sandström P; Hedman K;

Physiological reports [Physiol Rep] 2024 Jan; Vol. 12 (1), pp. e15904.

This pilot study aimed to evaluate if peak VO ₂ and ventilatory efficiency in combination would improve preoperative risk stratification beyond only relying on peak VO ₂ . This was a single-center retrospective cohort study including all patients who underwent cardiopulmonary exercise testing (CPET) as part of preoperative risk evaluation before major upper abdominal surgery during years 2008-2021. The primary outcome was any major cardiopulmonary complication during hospitalization. Forty-nine patients had a preoperative CPET before decision to pursue to surgery (cancer in esophagus [n = 18], stomach [6], pancreas [16], or liver [9]). Twenty-five were selected for operation. Patients who suffered any major cardiopulmonary complication had lower ventilatory efficiency (i.e., higher VE/VCO ₂ slope, 37.3 vs. 29.7, p = 0.031) compared to those without complications. In patients with a low aerobic capacity (i.e., peak VO ₂ < 20 mL/kg/min) and a VE/VCO ₂ slope ≥ 39, 80% developed a major cardiopulmonary complication. In this pilot study of patients with preoperative CPET before major upper abdominal surgery, patients who experienced a major cardiopulmonary complication had significantly lower ventilatory efficiency compared to those who did not. A low aerobic capacity in combination with low ventilatory efficiency was associated with a very high risk (80%) of having a major cardiopulmonary complication.

Clinical and functional effects of beta-blocker therapy discontinuation in patients with biventricular heart failure.

Slavich M; Cardiology, San Raffaele Scientific Institute, Milan Italy
Ricchetti G; Demarchi B; Cavalli G;Spoladore R;DFederico A; Federico F; Bezzi C; NMargonato A; Fragasso G

Journal of cardiovascular medicine (Hagerstown, Md.) [J Cardiovasc Med (Hagerstown)] 2024 Feb 01; Vol. 25 (2), pp. 141-148.
Date of Electronic Publication: 2023 Dec 22.

Background: Nearly two-thirds of patients with heart failure with reduced ejection fraction (HFrEF) have right ventricular dysfunction, previously identified as an independent predictor of reduced functional capacity and poor prognosis. Beta-blocker therapy (β-BT) reduces mortality and hospitalizations in patients with HFrEF and is approved as first-line therapy regardless of concomitant right ventricular function. However, the exact role of sympathetic nervous system activation in right ventricular dysfunction and the potential usefulness (or harmfulness) of β-BT in these patients are still unclear.
Objectives: The aim of the study is to evaluate the medium-term effect of β-BT discontinuation on functional capacity and right ventricular remodelling based on cardiopulmonary exercise testing (CPET), echocardiography and serum biomarkers in patients with clinically stable biventricular dysfunction.
Methods: In this single-centre, open-label, prospective trial, 16 patients were enrolled using the following criteria: patients were clinically stable without signs of peripheral congestion; NYHA II-III while on optimal medical therapy (including β-BT); LVEF 40% or less; echocardiographic criteria of right ventricular dysfunction. Patients were randomized 1 : 1 either to withdraw (group 0) or continue (group 1) β-BT. In group 0, optimal heart rate was obtained with alternative rate-control drugs. Echo and serum biomarkers were performed at baseline, after 3 and 6 months; CPET was performed at baseline and 6 months. Mann–Whitney U test was adopted to determine the relationships between β-BT discontinuation and effects on right ventricular dysfunction.
Results: At 6 months’ follow up, S’ DTI improved (ΔS’: 1.01 vs. -0.92 cm/s; P = 0.03), while estimated PAPs (ΔPAPs: 0.8 vs. -7.5 mmHg; P = 0.04) and echo left ventricular-remodelling (ΔEDVi: 19.55 vs. -0.96 ml/mq; P = 0.03) worsened in group 0. In absolute terms, the only variables significantly affected by β-BT withdrawal were left ventricular EDV and ESV, appearing worse in group 0 (mean EDVi 115 vs. 84 ml/mq; mean ESVi 79 vs. 53.9 ml/mq, P = 0.03). No significant changes in terms of functional capacity were observed after β-BT withdrawal.
Conclusion: In HFrEF patients with concomitant right ventricular dysfunction, β-BT discontinuation did not produce any beneficial effects. In addition, despite maintenance of optimal heart rate control, β-BT discontinuation induced worsening of left ventricular remodelling. Our study corroborates the hypothesis that improvement in left ventricular function may likewise be a major determinant for improvement in right ventricular function, reducing pulmonary wedge pressure and right ventricular afterload, with only a marginal action of its negative inotropic effect. In conclusion, β-BT appears beneficial also in heart failure patients with biventricular dysfunction.

Peak oxygen uptake in combination with ventilatory efficiency improve risk stratification in major abdominal surgery.

January 9, 2024

Kristenson K; Linkoping University, Linkoping, Sweden
Gerring E; Bjornsson B; Sandstrom P; Hedman K

Physiological Reports. 12(1):e15904, 2024 Jan.

This pilot study aimed to evaluate if peak VO2 and ventilatory efficiency
in combination would improve preoperative risk stratification beyond only
relying on peak VO2 . This was a single-center retrospective cohort study
including all patients who underwent cardiopulmonary exercise testing
(CPET) as part of preoperative risk evaluation before major upper
abdominal surgery during years 2008-2021. The primary outcome was any
major cardiopulmonary complication during hospitalization. Forty-nine
patients had a preoperative CPET before decision to pursue to surgery
(cancer in esophagus [n = 18], stomach [6], pancreas [16], or liver [9]).
Twenty-five were selected for operation. Patients who suffered any major
cardiopulmonary complication had lower ventilatory efficiency (i.e.,
higher VE/VCO2 slope, 37.3 vs. 29.7, p = 0.031) compared to those without
complications. In patients with a low aerobic capacity (i.e., peak VO2 <
20 mL/kg/min) and a VE/VCO2 slope >= 39, 80% developed a major
cardiopulmonary complication. In this pilot study of patients with
preoperative CPET before major upper abdominal surgery, patients who
experienced a major cardiopulmonary complication had significantly lower
ventilatory efficiency compared to those who did not. A low aerobic
capacity in combination with low ventilatory efficiency was associated
with a very high risk (80%) of having a major cardiopulmonary
complication.

Interleukin-1 blockade in heart failure: an on-treatment and off-treatment cardiorespiratory fitness analysis.

January 9, 2024