Author Archives: Paul Older

Tsuboi Y, Tanaka H, Nishio R, Sawa T, Terashita D, Nakayama K,
Satomi-Kobayashi S, Sakai Y, Emoto N, Hirata KI.

J Cardiopulm Rehabil Prev. 2017 Sep;37(5):341-346

PURPOSE: Pulmonary arterial hypertension (PAH) and chronic thromboembolic
pulmonary hypertension (CTEPH) are the main subgroups of pulmonary hypertension
(PH). Despite differences in their etiologies, both diseases are characterized by
vascular remodeling, resulting in progressive right heart failure. Noninvasive
periodic evaluation of exercise tolerance has become increasingly important.
Cardiopulmonary exercise testing (CPET) and a 6-minute walk test (6MWT) are now
both recommended for evaluating exercise tolerance, but there is insufficient
knowledge about possible differences in the associations of exercise tolerance
with right heart catheterization (RHC) data for patients with PAH and CTEPH.
METHODS: A retrospective study was performed with 57 patients with PH (24 with
PAH and 33 with CTEPH) all of whom underwent echocardiography, CPET, 6MWT, and
RHC.
RESULTS: For both patients with PAH and CTEPH, peak heart rate during CPET was
significantly higher than that from 6MWT, whereas minimum peripheral oxygen
saturation during CPET and 6MWT was similar. For patients with PAH, significant
correlations were observed between peak (Equation is included in full-text
article.)O2 and cardiac index (CI) (r = 0.59; P = .002) and between (Equation is
included in full-text article.)E/(Equation is included in full-text article.)CO2
slopes and CI (r =-0.46, P = .02), as well as a nonsignificant correlation
tendency for peak (Equation is included in full-text article.)O2 and pulmonary
vascular resistance (PVR) and for (Equation is included in full-text
article.)E/(Equation is included in full-text article.)CO2 and PVR (r =-0.39; P =
.05; and r = 0.39; P = .06, respectively). For patients with CTEPH, however, a
significant correlation was observed only between (Equation is included in
full-text article.)E/(Equation is included in full-text article.)CO2 slopes and
CI (r =-0.38; P = .02).
CONCLUSION: PH etiology should be considered when assessing exercise tolerance,
whereas CPET can be effective in addition to hemodynamic assessment by means of
RHC for periodic evaluation during followup.

Contractile reserve and cardiopulmonary exercise parameters in patients with dilated cardiomyopathy, the two dimensions of exercise testing

May 20, 2018

Moneghetti KJ, Kobayashi Y, Christle JW, Ariyama M, Vrtovec
B, Kouznetsova T, Wilson A, Ashley E, Wheeler MT,
Myers J, Haddad F

Echocardiography. 2017 Aug;34(8):1179-1186. doi: 10.1111/echo.13623. Epub 2017
Jul 6

BACKGROUND: Left ventricular (LV) contractile reserve assessed using imaging and
cardiopulmonary exercise testing (CPX) has been shown to predict outcome in
patients with dilated cardiomyopathy (DCM). Few clinical studies have, however,
analyzed the relationship between them.
METHODS: A cohort of 75 ambulatory patients with DCM underwent stress treadmill
echocardiography with CPX. LV contractile reserve was calculated as absolute
change (ΔLVEF=LVEFpeak -LVEFrest ) and percent change (%LVEF=[(LVEFpeak -LVEFrest
)/LVEFpeak) ]×100) in LVEF, circumferential and longitudinal strain (LS).
Exercise capacity was measured as peak oxygen uptake (peak VO2 ) and ventilatory
efficiency as the slope of minute ventilation to CO2 production (VE/VCO2 slope).
Values of contractile reserve were compared to matched controls. We also explored
which metric of ventricular response (absolute or percent change) was less
dependent on baseline LV function.
RESULTS: Patients with DCM had a mean age, rest and peak LVEF of 44±10 years,
42±10% and 50±12%, respectively. Among parameters of contractile reserve, peak
cardiac output was the strongest parameter associated with peak VO2 (r=.63,
P<.001). Along with age, sex, and BMI, it explained more than 70% of the variance
in peak VO2 . In contrast, LVEF and LS were only weakly related to peak VO2 .
With regard to ventilatory efficiency, the strongest parameter that emerged was
right atrial volume index (r=.36, P<.001). Percent change in LVEF was more
independent of baseline function than absolute change.
CONCLUSION: Echocardiographic contractile reserve and CPX provide complementary
information. Percent change in contractile reserve was most independent of
baseline function, therefore may be preferred when analyzing the ventricular
response to exercise.

Oxygen uptake at aerobic threshold is inversely associated with fatal cardiovascular and all-cause mortality events.

May 20, 2018

Kunutsor SK, Kurl S, Khan H, Zaccardi F, Rauramaa R, Laukkanen
JA.

Ann Med. 2017 Dec;49(8):698-709. doi: 10.1080/07853890.2017.1367958. Epub 2017
Aug 22

PURPOSE: We aimed to assess the associations of oxygen uptake at aerobic
threshold (VO2 at AT) with cardiovascular and all-cause mortality.
DESIGN: VO2 at AT was assessed in 1663 middle-aged men in a cohort study. Hazard
ratios (HRs) were calculated for sudden cardiac death (SCD), fatal coronary heart
disease (CHD) and cardiovascular disease (CVD) and all-cause mortality.
RESULTS: During a median follow-up of 25.6 years, 138 SCDs, 209 fatal CHDs, 333
fatal CVDs and 719 all-cause mortality events occurred. On adjustment for
established risk factors, the HRs (95% CIs) for SCD, fatal CHD, fatal CVD and
all-cause mortality were 0.48 (0.28-0.82), 0.48 (0.31-0.74), 0.57 (0.41-0.79) and
0.66 (0.53-0.82), respectively comparing extreme quartiles of VO2 at AT. On
further adjustment for peak VO2, the HRs were 0.87 (0.48-1.56), 0.83 (0.52-1.34),
0.91 (0.63-1.30) and 0.88 (0.69-1.12), respectively. Addition of VO2 at AT to a
standard CVD mortality risk prediction model was associated with a C-index change
of 0.0085 (95% CI: -0.0002-0.0172; p = .05) at 25 years.
CONCLUSIONS: VO2 at AT is inversely associated with cardiovascular and all-cause
mortality events, but the associations are partly dependent on peak VO2. VO2 at
AT may improve the prediction of the long-term risk for CVD mortality. KEY
MESSAGES Oxygen uptake at aerobic threshold (VO2 at AT), a cardiopulmonary
exercise testing parameter, may be a useful prognostic tool for adverse clinical
outcomes in the general population. In a population-based prospective cohort
study of men, VO2 at AT was inversely associated with cardiovascular and
all-cause mortality events and improved the prediction of cardiovascular
mortality. In populations who cannot achieve maximal VO2, VO2 at AT may serve as
a useful prognostic tool; however, further studies are warranted.

Cardiopulmonary Exercise Testing in Pediatrics.

Takken T, Bongers BC, van Brussel M, Haapala EA, Hulzebos EHJ

Ann Am Thorac Soc. 2017 Jul;14(Supplement_1):S123-S128. doi:
10.1513/AnnalsATS.201611-912FR.

Aerobic fitness is an important determinant of overall health. Higher aerobic
fitness has been associated with many health benefits. Because myocardial
ischemia is rare in children, indications for exercise testing differ in children
compared with adults. Pediatric exercise testing is imperative to unravel the
physiological mechanisms of reduced aerobic fitness and to evaluate intervention
effects in children and adolescents with a chronic disease or disability.
Cardiopulmonary exercise testing includes the measurement of respiratory gas
exchange and is the gold standard for determining aerobic fitness, as well as for
examining the integrated physiological responses to exercise in pediatric
medicine. As the physiological responses to exercise change during growth and
development, appropriate pediatric reference values are essential for an adequate
interpretation of the cardiopulmonary exercise test.

Inspiratory Muscle Training Is Associated With Improved Inspiratory Muscle Strength, Resting Cardiac Output, and the Ventilatory Efficiency of Exercise in Patients With a Fontan Circulation.

Laohachai K, Winlaw D, Selvadurai H, Gnanappa GK, d’Udekem
Y, Celermajer D, Ayer J

J Am Heart Assoc. 2017 Aug 21;6(8). pii: e005750. doi: 10.1161/JAHA.117.005750.

BACKGROUND: Patients with a Fontan circulation have reduced exercise capacity and
respiratory muscle strength. Inspiratory muscle training (IMT) improves exercise
capacity and quality of life in adults with heart failure. We assessed whether
6 weeks of a home-based program of IMT improves inspiratory muscle strength and
the ventilatory efficiency of exercise in adolescent patients with a Fontan
circulation.
METHODS AND RESULTS: Twenty-three adolescent participants (aged 16±2 years) with
a Fontan circulation underwent 6 weeks of IMT for 30 minutes daily. Respiratory
muscle strength (maximal inspiratory pressure and expiratory pressure), lung
function, and exercise capacity (cardiopulmonary exercise testing) were assessed.
Fourteen of 23 participants also underwent exercise cardiac magnetic resonance
imaging to examine the effects of IMT on cardiac output and systemic and
pulmonary blood flow. Six weeks of IMT improved maximal inspiratory pressure by
36±24 cm H2O (61±46%) with no change in maximal expiratory pressure. Ventilatory
efficiency of exercise improved after 6 weeks of IMT (from 34.2±7.8 to 32.2±5.6,
P=0.04). In those who underwent exercise cardiac magnetic resonance imaging, IMT
increased resting cardiac output (from 4.2±1.2 to 4.5±1.0 L/min, P=0.03) and
ejection fraction (from 50.1±4.3 to 52.8±6.1%, P=0.03).
CONCLUSIONS: Six weeks of IMT is associated with improved inspiratory muscle
strength, ventilatory efficiency of exercise, and resting cardiac output in young
Fontan patients. IMT may be a simple beneficial addition to the current
management of Fontan patients, potentially reducing exercise intolerance and
long-term morbidity and mortality.

Evidence on Exercise Training in Pulmonary Hypertension.

Babu AS, Arena , Morris NR.

Adv Exp Med Biol. 2017;1000:153-172. doi: 10.1007/978-981-10-4304-8_10.

Pulmonary hypertension (PH) is a chronic, debilitating condition which gravely
affects exercise tolerance and quality of life. Though most therapies focus
purely on medical intervention, there is a growing body of evidence to suggest
the role and benefits of exercise training. This chapter discusses the various
physiological basis for exercise intolerance observed in PH and highlights the
rationale for exercise training. Recent evidence related to exercise training is
summarized and potential pathways to suggest adaptations to exercise training are
put forward. While keeping the paper applicable to clinicians, details on
evaluating exercise intolerance, prescribing exercise and setting up
rehabilitation centers for PH are discussed.

Testing physical function in children undergoing intense cancer treatment-a RESPECT feasibility study.

Nielsen MKF;Christensen JF; Frandsen TL; Thorsteinsson T; Andersen LB; Christensen KB; Nersting J; Faber M; Schmiegelow K; Larsen HB;

Pediatric Blood & Cancer [Pediatr Blood Cancer] 2018 May 09, pp. e27100. Date of Electronic Publication: 2018 May 09.

Background: The physical function of children with cancer is reduced during treatment, which can compromise the quality of life and increase the risk of chronic medical conditions. The study, “REhabilitation, including Social and Physical activity and Education in Children and Teenagers with cancer” (Clinicaltrials.gov: NCT01772862) examines the efficacy of multimodal rehabilitation strategies introduced at cancer diagnosis. This article addresses the feasibility of and obstacles to testing physical function in children with cancer.
Methods: The intervention group comprised 46 males and 29 females aged 6-18 years (mean ± SD: 11.3 ± 3.1 years) diagnosed with cancer from January 2013 to April 2016. Testing at diagnosis and after 3 months included timed-up-and-go, sit-to-stand, flamingo balance, handgrip strength, and the bicycle ergometer cardiopulmonary exercise test (CPET).
Results: Of the 75 children, 92% completed a minimum of one test; two children declined testing and four were later included. Completion was low for CPET (38/150, 25%) but was high for handgrip strength (122/150, 81%). Tumor location, treatment-related side effects, and proximity to chemotherapy administration were primary obstacles for testing physical function. Children with extracranial solid tumors and central nervous system tumors completed significantly fewer tests than those with leukemia and lymphoma. Children with leukemia demonstrated reduced lower extremity function, that is, 24% reduction at 3 months testing in timed-up-and-go (P = 0.005) and sit-to-stand (P = 0.002), in contrast with no reductions observed in the other diagnostic groups.
Conclusion: Children with cancer are generally motivated to participate in physical function tests. Future studies should address diagnosis specific obstacles and design testing modalities that facilitate physical function tests in this target group.

Reliability of repeated arm-crank cardiopulmonary exercise tests in patients with small abdominal aortic aneurysm.

May 13, 2018

Durrand JW; Wagstaff K; Kasim A; Cawthorn L; Danjoux GR; Kothmann E

Anaesthesia [Anaesthesia], ISSN: 1365-2044, 2018 May 04

Arm-crank ergometry may be useful in patients unable to pedal, for instance due to peripheral arterial disease. Twenty participants with small abdominal aortic aneurysm undertook two serial arm-crank tests and then a pedal test, four of whom had indeterminate anaerobic thresholds, precluding analysis. The mean (SD) peak arm and leg oxygen consumptions in 16 participants were 13.71 (2.62) ml.kg-1 .min-1 and 16.82 (4.44) ml.kg-1 .min-1 , with mean (SD) individual differences of 3.11 (2.48) ml.kg-1 .min-1 , p = 0.0001. The respective values at the anaerobic thresholds were 7.83 (1.58) ml O2 .kg-1 .min-1 and 10.09 (3.15) ml O2 .kg-1 .min-1 , with mean (SD) individual differences of 2.26 (2.34) ml O2 .kg-1 .min-1 , p = 0.0001. The correlation coefficients (95%CI) for peak oxygen consumption and anaerobic threshold were 0.88 (0.62-1.0) and 0.70 (0.32-1.0). There were no significant differences in serial arm-crank tests, with intracluster correlations (95%CI) of 0.87 (0.86-0.88) and 0.65 (0.61-0.69) for peak oxygen consumption and anaerobic threshold, respectively.

Short-term preoperative exercise therapy does not improve long-term outcome after lung cancer surgery: a randomized controlled study

May 13, 2018