N. Kumar, S. Choudhry

PURPOSE: Prospective study to examine the diagnostic accuracy of a new exercise-based parameter (abrupt steepening of HR response) in late exercise to diagnose macro-vascular CAD.
METHOD: 1000 CPX performed in symptomatic patients & 50 Angiograms in a single centre.
RESULTS: Patients without inducible ischemia have a linear HR response as a function of VO2 throughout exercise (Fig 1). Patients with inducible ischemia  develop mechanical dysfunction and a compensatory steepening of HR response (curvilinear) (Fig 2); this signifies clinically significant global ischemic burden. Fifty consecutive patients with an abnormal response underwent angiography.  The sensitivity and specificity for significant large vessel atherosclerosis (one or more vessels with >50% stenosis) was 92% (Fig 3).
CONCLUSION: In the contracting Ischemic Myocardium, an oxygen supply-demand mismatch results in diastolic dysfunction causing the stroke volume response to deteriorate and HR response to steepen with a progressively increasing work rate past the ischemic threshold.  This methodology is seen far more frequently than ST depression and is highly sensitive to the presence of a physiologically significant ischemic burden

Lee, R.N.C.; Kelly,
E.; Nolan, G.; Eigenheer, S.; Boylan, D.; Murphy, D.; Dodd, J.; Keane,
M.P.; McNicholas, W.T

An International Journal of Medicine,
April 2015, Vol. 108 Issue: Number 4 p315-315, 1p

Abstract: Background
and objective: Idiopathic pulmonary fibrosis (IPF) patients report
fatigue, possibly reflecting sleep disturbance, but little is known
about sleep-related changes. We compared ventilation and gas exchange
during sleep and exercise in a cohort of IPF patients, and evaluated
associations with selected biological markers. Methods: Twenty stable
IPF patients (aged 67.9 ± 12.3 [SD]) underwent overnight
polysomnography following an acclimatization night. Cardiopulmonary
exercise testing was performed and inflammatory markers measured
including TNF-α, IL-6, CXCL8, C-C motif ligand 18 (CCL-18) and
C-reactive protein (CRP) Results: Nine patients had sleep-disordered
breathing (SDB) with an apnea–hypopnea frequency (AHI) ≥ 5/h, but only
two had Epworth sleepiness score ≥10, thus having an obstructive sleep
apnea syndrome. Sleep quality was poor. Transcutaneous carbon dioxide
tension (PtcCO<inf>2</inf>) rose by 2.56 ± 1.59 kPa overnight (P</it> =
0.001), suggesting hypoventilation. Oxygen saturation (SaO<inf>2</inf>)
was lower during sleep than exercise (P</it> < 0.01), and exercise
variables correlated with resting pulmonary function. CCL-18 and CRP
levels were elevated and correlated with PtcCO<inf>2</inf> rise during
sleep (P</it> < 0.05). CCL-18 negatively correlated with diffusion
capacity of carbon monoxide (DLCO), arterial oxygen (PaO<inf>2</inf>)
and mean arterial carbon dioxide (PaCO<inf>2</inf>) (P</it> < 0.05) and
CRP negatively correlated with DLCO, PaO<inf>2</inf>, sleep
SaO<inf>2</inf> and oxygen uptake (VO<inf>2</inf>) during exercise
(P</it> < 0.05).
Conclusions: IPF patients desaturate more during sleep
than exercise; thus, nocturnal pulse oxymetry could be included in
clinical assessment. CCL-18 and CRP levels correlate with physiological
markers of fibrosis.

Barakat, H. M.; Shahin, Y.; McCollum, P. T.; Chetter, I. C.

Anaesthesia, June 2015, Vol. 70 Issue: Number 6 p679-685, 7p

Abstract: This study aimed
at assessing whether measures of aerobic fitness can predict
postoperative cardiac and pulmonary complications, 30‐day mortality and
length of hospital stay following elective abdominal aortic aneurysm
repair. We prospectively collected cardiopulmonary exercise testing
data over two years for 130 patients. Upon multivariate analysis, a
decreased anaerobic threshold (OR (95% CI) 0.55 (0.37–0.84); p = 0.005)
and open repair (OR(95% CI) 6.99 (1.56–31.48); p = 0.011) were
associated with cardiac complications. Similarly, an increased
ventilatory equivalent for carbon dioxide (OR(95% CI) 1.18 (1.05–1.33);
p = 0.005) and open repair (OR (95% CI) 14.29 (3.24–62.90); p < 0.001)
were associated with pulmonary complications. Patients who had an
endovascular repair had shorter hospital and critical care lengths of
stay (p < 0.001). Measures of fitness were not associated with 30‐day
mortality or length of hospital stay. Cardiopulmonary exercise testing
variables, therefore, seem to predict different postoperative
complications following abdominal aortic aneurysm repair, which adds
value to their routine use in risk stratification and optimisation of
peri‐operative care.;

Barber, Nathaniel J; Ako, Emmanuel
O; Kowalik, Grzegorz T; Steeden, Jennifer A; Pandya, Bejal; Muthurangu,
Vivek.

Physiological Measurement, May 2015, Vol. 36 Issue: Number 5
pN85-N94, 10p

Abstract: The purposes of this study were: (1) to
evaluate feasibility and acceptability of MRI augmented cardiopulmonary
exercise testing (MR-CPET) in healthy adults and (2) to test whether
peak values obtained at conventional and MR-CPET correlate and to
demonstrate variation in peak oxygen consumption (VO2) relates to both
peak cardiac output (CO) and peak oxygen extraction (DcO2).

Seventeen  healthy adults underwent CPET and MR-CPET using an MR compatible
ergometer and CPET system customised for MR use. Continuous aortic flow
measurement used a validated UNFOLD-SENSE spiral phase contrast
magnetic resonance (PCMR) sequence.Fifteen of 17 volunteers completed
exercise; exclusions were due to claustrophobia and inability to
effectively master exercise technique. Measures of acceptability were
lower but still satisfactory for MR-CPET.There were strong correlations
between conventional and MR-CPET for peak VO2 (r = 0.94, p < 0.001);
VCO2 (r = 0.87, p < 0.001) and VE (r = 0.88, p < 0.001).Multiple linear
regression analysis demonstrated peak CO and DcO2 were independent
predictors of peak VO2 measured during MR-CPET (b = 0.73 and 0.38 p <
0.0001) and conventional CPET (b = 0.78, 0.28 p < 0.0001).MR-CPET is
feasible, acceptable and demonstrates physiology not apparent with
conventional CPET.
MR-CPET allows differentiation of the contributions
of CO and DcO2 to variation in peak VO2. We believe that this will be
useful in understanding the origin of reduced exercise capacity in
cardiac disease.

A 23‐year Single‐center Experience of Cardiopulmonary
Exercise Testing

Ohuchi, Hideo; Negishi, Jun; Noritake, Kanae;
Hayama, Yosuke; Sakaguchi, Heima; Miyazaki, Aya; Kagisaki, Koji;
Yamada, Osamu.

Congenital Heart Disease, March 2015, Vol. 10 Issue:
Number 2 p105-116, 12p;

Douglas PS, Hoffmann U, Patel MR, Mark DB, Al-Khalidi HR, Cavanaugh B, et al.

N Engl J Med. 2015;372(14):1291-300

BACKGROUND: Many patients have symptoms suggestive of coronary artery disease (CAD) and are often evaluated with the use of diagnostic testing, although there are limited data from randomized trials to guide care.
METHODS: We randomly assigned 10,003 symptomatic patients to a strategy of initial anatomical testing with the use of coronary computed tomographic angiography (CTA) or to functional testing (exercise electrocardiography, nuclear stress testing, or stress echocardiography). The composite primary end point was death, myocardial infarction, hospitalization for unstable angina, or major procedural complication. Secondary end points included invasive cardiac catheterization that did not show obstructive CAD and radiation exposure.
RESULTS: The mean age of the patients was 60.8+/-8.3 years, 52.7% were women, and 87.7% had chest pain or dyspnea on exertion. The mean pretest likelihood of obstructive CAD was 53.3+/-21.4%. Over a median follow-up period of 25 months, a primary end-point event occurred in 164 of 4996 patients in the CTA group (3.3%) and in 151 of 5007 (3.0%) in the functional-testing group (adjusted hazard ratio, 1.04; 95% confidence interval, 0.83 to 1.29; P=0.75). CTA was associated with fewer catheterizations showing no obstructive CAD than was functional testing (3.4% vs. 4.3%, P=0.02), although more patients in the CTA group underwent catheterization within 90 days after randomization (12.2% vs. 8.1%). The median cumulative radiation exposure per patient was lower in the CTA group than in the functional-testing group (10.0 mSv vs. 11.3 mSv), but 32.6% of the patients in the functional-testing group had no exposure, so the overall exposure was higher in the CTA group (mean, 12.0 mSv vs. 10.1 mSv; P<0.001).
CONCLUSIONS: In symptomatic patients with suspected CAD who required noninvasive testing, a strategy of initial CTA, as compared with functional testing, did not improve clinical outcomes over a median follow-up of 2 years. (Funded by the National Heart, Lung, and Blood Institute; PROMISE ClinicalTrials.gov number, NCT01174550.).

Neves CD; Lacerda AC; Lage VK; Lima LP; Fonseca SF; de
Avelar NC; Teixeira MM; Mendonça VA,

Plos One [PLoS One], ISSN:
1932-6203, 2015 Feb 06; Vol. 10 (2), pp. e0117563; Publisher: Public
Library of Science; PMID: 25659094;

Background: The application of the
Shuttle Walking Test (SWT) to assess cardiorespiratory fitness and the
intensity of this test in healthy participants has rarely been studied.
This study aimed to assess and correlate the cardiorespiratory
responses of the SWT with the cardiopulmonary exercise testing (CEPT)
and to develop a regression equation for the prediction of peak oxygen
uptake (VO2 peak) in healthy sedentary adult men.

Methods: In the first
stage of this study, 12 participants underwent the SWT and the CEPT on
a treadmill. In the second stage, 53 participants underwent the SWT
twice. In both phases, the VO2 peak, respiratory exchange ratio (R),
and heart rate (HR) were evaluated.

Results: Similar results in VO2 peak
(P>0.05), R peak (P>0.05) and predicted maximum HR (P>0.05) were
obtained between the SWT and CEPT. Both tests showed strong and
significant correlations of VO2 peak (r = 0.704, P = 0.01) and R peak
(r = 0.737, P<0.01), as well as the agreement of these measurements by
Bland-Altman analysis. Body mass index and gait speed were the
variables that explained 40.6% (R2 = 0.406, P = 0.001) of the variance
in VO2 peak. The results obtained by the equation were compared with
the values obtained by the gas analyzer and no significant difference
between them (P>0.05) was found.

Conclusions: The SWT produced maximal
cardiorespiratory responses comparable to the CEPT, and the developed
equation showed viability for the prediction of VO2 peak in healthy
sedentary men.

Grant SW, Hickey GL, Wisely NA, Carlson ED, Hartley RA, Pichel AC, et al.

Br J Anaesth. 2015;114(3):430-6.

ABSTRACT
BACKGROUND: Cardiopulmonary exercise testing (CPET) is increasingly used in the preoperative assessment of patients undergoing major surgery. The objective of this study was to investigate whether CPET can identify patients at risk of reduced survival after abdominal aortic aneurysm (AAA) repair. METHODS: Prospectively collected data from consecutive patients who underwent CPET before elective open or endovascular AAA repair (EVAR) at two tertiary vascular centres between January 2007 and October 2012 were analysed. A symptom-limited maximal CPET was performed on each patient. Multivariable Cox proportional hazards regression modelling was used to identify risk factors associated with reduced survival. RESULTS: The study included 506 patients with a mean age of 73.4 (range 44-90). The majority (82.6%) were men and most (64.6%) underwent EVAR. The in-hospital mortality was 2.6%. The median follow-up was 26 months. The 3-year survival for patients with zero or one sub-threshold CPET value ([Formula: see text] at AT<10.2 ml kg(-1) min(-1), peak [Formula: see text]<15 ml kg(-1) min(-1) or [Formula: see text] at AT>42) was 86.4% compared with 59.9% for patients with three sub-threshold CPET values. Risk factors independently associated with survival were female sex [hazard ratio (HR)=0.44, 95% confidence interval (CI) 0.22-0.85, P=0.015], diabetes (HR=1.95, 95% CI 1.04-3.69, P=0.039), preoperative statins (HR=0.58, 95% CI 0.38-0.90, P=0.016), haemoglobin g dl(-1) (HR=0.84, 95% CI 0.74-0.95, P=0.006), peak [Formula: see text]<15 ml kg(-1) min(-1) (HR=1.63, 95% CI 1.01-2.63, P=0.046), and [Formula: see text] at AT>42 (HR=1.68, 95% CI 1.00-2.80, P=0.049). CONCLUSIONS: CPET variables are independent predictors of reduced survival after elective AAA repair and can identify a cohort of patients with reduced survival at 3 years post-procedure. CPET is a potentially useful adjunct for clinical decision-making in patients with AAA.