Category Archives: Publications

Using predicted 30 day mortality to plan postoperative colorectal surgery care: a cohort study

Swart M, Carlisle JB, Goddard J.

Br J Anaesth. 2017;118(1):100-104.

BACKGROUND: Preoperative identification of high-risk surgical patients might help to reduce postoperative morbidity and mortality. Using a patient’s predicted 30 day mortality to plan postoperative high-dependency unit (HDU) care after elective colorectal surgery might be associated with reduced postoperative morbidity.
METHODS: The 30 day postoperative mortality was predicted for 504 elective colorectal surgical patients in a preoperative clinic. The prediction was used to determine postoperative surgical ward or HDU care. Those with a predicted 30 day mortality of 1-3% mortality, and thus deemed at intermediate risk, had either planned HDU care (n=68) or planned ward care (n=139). The main outcome measures were emergency laparotomy and unplanned critical care admission.
RESULTS: There were more emergency laparotomies and unplanned critical care admissions in patients with a predicted 30 day mortality of 1-3% who went to an HDU after surgery compared with patients who went to a ward: 0 vs 14 (10%), P=0.0056 and 0 vs 22 (16%), P=0.0002, respectively.
CONCLUSIONS: Planned postoperative critical care was associated with a lower rate of complications after elective colorectal surgery.

Cardiorespiratory optimal point during exercise testing as a predictor of all-cause mortality.

Rev Port Cardiol. 2017 Mar 17. pii: S0870-2551(17)30139-7. doi:
10.1016/j.repc.2016.09.017. [Epub ahead of print]

Ramos PS, Araújo CG

INTRODUCTION AND AIM: The cardiorespiratory optimal point (COP) is a novel index,
calculated as the minimum oxygen ventilatory equivalent (VE/VO2) obtained during
cardiopulmonary exercise testing (CPET). In this study we demonstrate the
prognostic value of COP both independently and in combination with maximum oxygen
consumption (VO2max) in community-dwelling adults.

METHODS: Maximal cycle ergometer CPET was performed in 3331 adults (66% men) aged
40-85 years, healthy (18%) or with chronic disease (81%). COP cut-off values of
<22, 22-30, and >30 were selected based on the log-rank test. Risk discrimination
was assessed using COP as an independent predictor and combined with VO2max.
RESULTS: Median follow-up was 6.4 years (7.1% mortality). Subjects with COP >30
demonstrated increased mortality compared to those with COP <22 (hazard ratio [HR] 6.86, 95% confidence interval [CI] 3.69-12.75, p<0.001). Multivariate analysis including gender, age, body mass index, and the forced expiratory volume in 1 s/vital capacity ratio showed adjusted HR for COP >30 of 3.72 (95% CI
1.98-6.98; p<0.001) and for COP 22-30 of 2.15 (95% CI 1.15-4.03, p<0.001). Combining COP and VO2max data further enhanced risk discrimination. CONCLUSIONS: COP >30, either independently or in combination with low VO2max, is
a good predictor of all-cause mortality in community-dwelling adults (healthy or
with chronic disease). COP is a submaximal prognostic index that is simple to
obtain and adds to CPET assessment, especially for adults unable or unwilling to
achieve maximal exercise.

Diagnosis of chronic thromboembolic pulmonary hypertension.

Eur Respir Rev. 2017 Mar 15;26(143).

Gopalan D, Delcroix M, Held M.

Chronic thromboembolic pulmonary hypertension (CTEPH) is the only potentially
curable form of pulmonary hypertension. Rapid and accurate diagnosis is pivotal
for successful treatment. Clinical signs and symptoms can be nonspecific and risk
factors such as history of venous thromboembolism may not always be present.
Echocardiography is the recommended first diagnostic step. Cardiopulmonary
exercise testing is a complementary tool that can help to identify patients with
milder abnormalities and chronic thromboembolic disease, triggering the need for
further investigation. Ventilation/perfusion (V’/Q’) scintigraphy is the imaging
methodology of choice to exclude CTEPH. Single photon emission computed
tomography V’/Q’ is gaining popularity over planar imaging. Assessment of
pulmonary haemodynamics by right heart catheterisation is mandatory, although
there is increasing interest in noninvasive haemodynamic evaluation. Despite the
status of digital subtraction angiography as the gold standard, techniques such
as computed tomography (CT) and magnetic resonance imaging are increasingly used
for characterising the pulmonary vasculature and assessment of operability.
Promising new tools include dual-energy CT, combination of rotational angiography
and cone beam CT, and positron emission tomography. These innovative procedures
not only minimise misdiagnosis, but also provide additional vascular information
relevant to treatment planning. Further research is needed to determine how these
modalities will fit into the diagnostic algorithm for CTEPH.

Effect of beta-blockers on perioperative outcomes in vascular and endovascular surgery: a systematic review and meta-analysis

British Journal of Anaesthesia, 118 (1): 11–21 (2017)

S. Hajibandeh, S. Hajibandeh, S. A. Antoniou, F. Torella, and
G. A. Antoniou

Abstract
Background. To investigate the role of perioperative beta-blocker use in vascular and endovascular surgery.
Methods. We performed a systematic review in accordance with Preferred Reporting Items for Systematic Reviews and Meta-Analyses statement standards. The review protocol was registered with International Prospective Register of Systematic Reviews (registration number:CRD42016038111). We searched electronic databases to identify all randomized controlled trials and observational studies investigating outcomes of patients undergoing vascular and endovascular surgery with or without perioperative beta blockade. We used the Cochrane tool and the Newcastle-Ottawa scale to assess the risk of bias of trials and observational studies, respectively. Random-effectsmodels were applied to calculate pooled outcome data.

Results. We identified three randomized trials, five retrospective cohort studies, and three prospective cohort studies, enrolling a total of 32,602 patients. Our analyses indicated that perioperative use of beta-blockers did not reduce the risk of all-cause mortality [odds ratio (OR) 1.10, 95% confidence interval (CI) 0.59-2.04, P¼0.77], cardiac mortality (OR 2.62, 95% CI 0.86-8.05, P¼0.09), myocardial infarction (OR 0.89, 95% CI 0.59-1.35, P¼0.58), unstable angina (OR 1.34, 95% CI 0.41- 4.38, P¼0.63), stroke (OR 2.45, 95% CI 0.89-6.75, P¼0.08), arrhythmias (OR 0.76, 95% CI 0.41-1.43, P¼0.40), congestive heart failure (OR 1.12, 95% CI 0.77-1.63, P¼0.56), renal failure (OR 1.48, 95% CI 0.90-2.45, P¼0.13), composite cardiovascular events (OR 0.88, 95% CI 0.55-1.40, P¼0.58), rehospitalisation (OR 0.86, 95% CI 0.48-1.52, P¼0.60), and reoperation (OR 1.17, 95% CI 0.42-3.27, P¼0.77) in vascular surgery.

Conclusions. Beta-blockers do not improve perioperative outcomes in vascular and endovascular surgery.

Reporting individual surgeon outcomes does not lead to risk aversion in abdominal aortic aneurysm surgery.

Saratzis A;Thatcher A; Bath MF; Sidloff DA; Bown MJ; Shakespeare J; Sayers RD;
Imray C,

Annals Of The Royal College Of Surgeons Of England [Ann R Coll
Surg Engl], ISSN: 1478-7083, 2017 Feb; Vol. 99 (2), pp. 161-165;

INTRODUCTION Reporting surgeons’ outcomes has recently been introduced
in the UK. This has the potential to result in surgeons becoming risk
averse. The aim of this study was to investigate whether reporting
outcomes for abdominal aortic aneurysm (AAA) surgery impacts on the
number and risk profile (level of fitness) of patients offered elective
treatment.
METHODS Publically available National Vascular Registry data
were used to compare the number of AAAs treated in those centres across
the UK that reported outcomes for the periods 2008-2012, 2009-2013 and
2010-2014. Furthermore, the number and characteristics of patients
referred for consideration of elective AAA repair at a single tertiary
unit were analysed yearly between 2010 and 2014. Clinic, casualty and
theatre event codes were searched to obtain all AAAs treated. The
results of cardiopulmonary exercise testing (CPET) were assessed.
RESULTS For the 85 centres that reported outcomes in all three
five-year periods, the median number of AAAs treated per unit increased
between the periods 2008-2012 and 2010-2014 from 192 to 214 per year
(p=0.006). In the single centre cohort study, the proportion of
patients offered elective AAA repair increased from 74% in 2009-2010 to
81% in 2013-2014, with a maximum of 84% in 2012-2013. The age, aneurysm
size and CPET results (anaerobic threshold levels) for those eventually
offered elective treatment did not differ significantly between 2010
and 2014.
CONCLUSIONS The results do not support the assumption that
reporting individual surgeon outcomes is associated with a risk averse
strategy regarding patient selection in aneurysm surgery at present.

Importance of compensatory heart rate increase during myocardial ischemia to preserve appropriate oxygen kinetics.

J Cardiol. 2017 Mar 7. pii: S0914-5087(16)30308-2. [Epub ahead of print]

Yoshida S, Adachi H, Murata M, Tomono J, Oshima S, Kurabayashi
M.

BACKGROUND: Myocardial ischemia induces cardiac dysfunction, resulting in
insufficient oxygen supply to peripheral tissues and mismatched energy production
during exercise. To relieve the insufficient oxygen supply, heart rate (HR)
response is augmented; however, beta-adrenergic receptor blockers (BB) restrict
HR response. Although BB are essential drugs for angina pectoris, the effect of
BB on exercise tolerance in patients with angina has not been studied. The aim of
this study was to clarify the importance of HR augmentation to preserve exercise
tolerance in patients with angina pectoris.
METHODS: Forty-two subjects who underwent cardiopulmonary exercise testing (CPX)
to detect myocardial ischemia were enrolled. CPX was performed until exhaustion
or onset of significant myocardial ischemia using a ramp protocol. Subjects were
assigned to three groups (Group A: with ST depression during CPX with significant
coronary stenosis and taking BB; Group B: with ST depression and not taking BB;
Group C: without ST depression and not taking BB). HR response to exercise was
evaluated during the following two periods: below and above ischemic threshold
(IT). In Group C, it was evaluated during the first 2min and the last 2min of a
ramp exercise.
RESULTS: No significant differences were observed among the three groups with
regard to patients’ basic characteristics. Below IT, there were no differences in
oxygen pulse/watt (O2 pulse increasing rate), HR/watt (ΔHR/ΔWR), and ΔV˙O2/ΔWR.
Above IT, O2 pulse increasing rate was greater in Group A than in Group B.
ΔHR/ΔWR was smaller in Group A than in Group B. ΔV˙O2/ΔWR became smaller in Group
A than in Group B. There was no difference in anaerobic threshold, and peak V˙O2
was smaller in Group A than in Group B.
CONCLUSIONS: Restriction of HR response by a BB is shown to be one of the
important factors in diminished exercise tolerance.

CORP: Measurement of the Maximum Oxygen Uptake (VO2max): VO2peak is no longer acceptable.

J Appl Physiol (1985). 2017 Feb 2: [Epub ahead of print]

Poole DC
, Jones AM.
Abstract

The maximum rate of VO2 uptake (i.e., VO2max), as measured during large muscle mass exercise such as cycling or running, is widely considered to be the gold standard measurement of integrated cardiopulmonary-muscle oxidative function. The development of rapid-response gas analyzers, enabling measurement of breath-by-breath pulmonary gas exchange, has led to replacement of the discontinuous progressive maximal exercise test (that produced an unambiguous VO2-work rate plateau definitive for VO2max) with the rapidly-incremented or ramp testing protocol. Whilst this expedient is more suitable for clinical and experimental investigations and enables measurement of the gas exchange threshold, exercise efficiency, and VO2 kinetics, a VO2-work rate plateau is not an obligatory outcome. This shortcoming has led to investigators resorting to so-called secondary criteria such as respiratory exchange ratio, maximal heart rate and/or maximal blood lactate concentration, the acceptable values of which may be selected arbitrarily and result in grossly inaccurate VO2max determination. Whereas this may not be an overriding concern in young, healthy subjects with experience of performing exercise to volitional exhaustion, exercise test naïve subjects, patient populations and less motivated subjects may stop exercising before their VO2max is reached. When VO2max is a or the criterion outcome of the investigation this represents a major experimental design issue. This CORP presents the rationale for incorporation of a second, constant-work rate test performed at 105-110% of the work rate achieved on the initial ramp test to resolve the classic VO2-work rate plateau that is the unambiguous validation of VO2max. The broad utility of this procedure has been established for children, adults of varying fitness, obese individuals and patient populations.

Cardiopulmonary exercise testing: A contemporary and versatile clinical tool.

Cleve Clin J Med. 2017 Feb;84(2):161-168. doi: 10.3949/ccjm.84a.15013.

Leclerc K1.

Abstract

Cardiopulmonary exercise testing (CPET) helps in detecting disorders of the cardiovascular, pulmonary, and skeletal muscle systems. It has a class I (indicated) recommendation from the American College of Cardiology and American Heart Association for evaluating exertional dyspnea of uncertain cause and for evaluating cardiac patients being considered for heart transplant. Advances in hardware and software and ease of use have brought its application into the clinical arena to the point that providers should become familiar with it and consider it earlier in the evaluation of their patients.

Cardiac rehabilitation after acute coronary syndrome: Do all patients derive the same benefit?

Rev Port Cardiol. 2017 Feb 23

Aguiar Rosa S(1), Abreu A(2), Marques Soares R(2), Rio P(2), Filipe C(3),
Rodrigues I(2), Monteiro A(2), Soares C(2), Ferreira V(2), Silva S(2), Alves
S(2), Cruz Ferreira R(2).

INTRODUCTION: Cardiac rehabilitation (CR) has been demonstrated to improve
exercise capacity in acute coronary syndrome (ACS), but not all patients derive
the same benefit. Careful patient selection is crucial to maximize resources.
OBJECTIVE: To identify in a heterogeneous ACS population which patients would
benefit the most with CR, in terms of functional capacity (FC), by using
cardiopulmonary exercise testing (CPET).
METHODS: A retrospective analysis of consecutive ACS patients who underwent CR
and CPET was undertaken. CPET was performed at baseline and after 36 sessions of
exercise. Peak oxygen uptake (pVO2), percentage of predicted pVO2, minute
ventilation/CO2 production (VE/VCO2) slope, VE/VCO2 slope/pVO2 and peak
circulatory power (PCP) (pVO2 times peak systolic blood pressure) were assessed
in two moments. The differences in pVO2 (ΔpVO2), %pVO2, PCP and exercise test
duration were calculated. Patients were classified according to baseline pVO2
(group 1, <20 ml/kg/min vs. group 2, ≥20 ml/kg/min) and left ventricular ejection
fraction (group A, <50% vs. group B, ≥50%).
RESULTS: We analyzed 129 patients, 86% male, mean age 56.3±9.8 years. Both group
1 (n=31) and group 2 (n=98) showed significant improvement in FC after CR, with a
more significant increase in pVO2, in group 1 (ΔpVO2 4.4±7.3 vs. 1.6±5.4;
p=0.018). Significant improvement was observed in CPET parameters in group A
(n=34) and group B (n=95), particularly in pVO2 and test duration.
CONCLUSION: Patients with lower baseline pVO2 (<20 ml/kg/min) presented more
significant improvement in FC after CR. CPET which is not routinely used in
assessement before CR in context of ACS, could be a valuable tool to identify
patients who will benefit the most

Cardiopulmonary exercise testing improves diagnostic specificity in patients with echocardiography-suspected pulmonary hypertension.

Clin Cardiol. 2017 Feb;40(2):95-101. doi: 10.1002/clc.22635. Epub 2016 Nov 2.

Zhao QH(1), Wang L(1), Pudasaini B(1), Jiang R(1), Yuan P(1), Gong SG(1), Guo
J(2), Xiao Q(1), Liu H(1), Wu C(3), Jing ZC(4), Liu JM(1,)(2).

(1)Department of Pulmonary Circulation, Shanghai Pulmonary Hospital, Tongji
University, School of Medicine, Shanghai, China. (2)Department of Pulmonary
Function, Shanghai Pulmonary Hospital, Tongji University, School of Medicine,
Shanghai, China. (3)Department of Statistics, the Second Military Medical
University, Shanghai, China. (4)State Key Laboratory of Cardiovascular Disease,
Fu Wai Hospital, Peking Union Medical College and Chinese Academy of Medical
Science, Beijing, China.

BACKGROUND: Doppler echocardiography is usually the first diagnostic
investigation for patients suspected with pulmonary hypertension (PH), but it is
often inaccurate when used alone, especially in mild PH.
HYPOTHESIS: Cardiopulmonary exercise testing (CPET) may serve as a complementary
tool to improve diagnostic accuracy in echocardiography-suspected “PH possible”
patients.
METHODS: Eighty-eight consecutive patients with suspected PH (referred to as “PH
possible” hereafter) based on echocardiography were included in the study. CPET
was assessed subsequently and PH was confirmed by right-heart catheterization in
all subjects. We analyzed CPET data from patients and derived a CPET prediction
rule to hemodynamically differentiate PH.
RESULTS: Eighty-eight patients (27 patients with confirmed PH, and PH ruled out
in 61 patients) were included in the study. Compared with non-PH patients, the PH
subjects had lower peak oxygen uptake (VO2 ), aerobic capacity (AT), peak partial
pressure of end-tidal CO2 (PET CO2 ), oxygen uptake efficiency plateau (OUEP),
and oxygen uptake efficiency slope (OUES), along with higher minute ventilation
(VE)/carbon dioxide output (VCO2 ) slope and lowest VE/VCO2 (P < 0.001). VE/VCO2
slope and AT were independent predictors of PH derived from multivariate logistic
regression adjusted for age and body mass index. A score combining VE/VCO2 slope
and AT reached a high area under the curve value of 0.98. A score ≥0.5 had 95%
specificity and 92.6% sensitivity for diagnosis of PH.
CONCLUSIONS: A score combining VE/VCO2 slope and AT provides high specificity in
screening out PH from a pool of echocardiography-suspected PH patients.