Author Archives: Paul Older

Real-Time Analysis of the Heart Rate Variability During Incremental Exercise for the Detection of the Ventilatory Threshold.

Shiraishi Y; Katsumata Y; Sadahiro T; Azuma K; Akita K; Isobe S; Yashima
F; Miyamoto K; Nishiyama T; Tamura Y; Kimura T; Nishiyama N; Aizawa Y;
Fukuda K; Takatsuki S.

Journal of the American Heart Association. 7(1), 2018 01 07.
VI 1

BACKGROUND: It has never been possible to immediately evaluate heart rate
variability (HRV) during exercise. We aimed to visualize the real-time
changes in the power spectrum of HRV during exercise and to investigate
its relationship to the ventilatory threshold (VT).

METHODS AND RESULTS: Thirty healthy subjects (29.1+/-5.7 years of age)
and 35 consecutive patients (59.0+/-13.2 years of age) with myocardial
infarctions underwent cardiopulmonary exercise tests with an RAMP protocol
ergometer. The HRV was continuously assessed with power spectral analyses
using the maximum entropy method and projected on a screen without delay.
During exercise, a significant decrease in the high frequency (HF) was
followed by a drastic shift in the power spectrum of the HRV with a
periodic augmentation in the low frequency/HF (L/H) and steady low HF.
When the HRV threshold (HRVT) was defined as conversion from a predominant
high frequency (HF) to a predominant low frequency/HF (L/H), the VO2 at
the HRVT (HRVT-VO2) was substantially correlated with the VO2 at the
lactate threshold and VT) in the healthy subjects (r=0.853 and 0.921,
respectively). The mean difference between each threshold (0.65 mL/kg per
minute for lactate threshold and HRVT, 0.53 mL/kg per minute for VT and
HRVT) was nonsignificant (P>0.05). Furthermore, the HRVT-VO2 was also
correlated with the VT-VO2 in these myocardial infarction patients
(r=0.867), and the mean difference was -0.72 mL/kg per minute and was
nonsignificant (P>0.05).

CONCLUSIONS: A HRV analysis with our method enabled real-time
visualization of the changes in the power spectrum during exercise. This
can provide additional information for detecting the VT.

Myocardial Infarction Injury in Patients with Chronic Lung Disease Entering Pulmonary Rehabilitation: Frequency and Association with Heart Rate Parameters.

Sima CA; Lau BC; Taylor CM; van Eeden SF; Reid WD; Sheel AW; Kirkham AR;
Camp PG.

2018 American Academy of
Physical Medicine and Rehabilitation.

BACKGROUND: Myocardial infarction (MI) remains under-recognized in chronic
lung disease (CLD) patients. Rehabilitation health professionals need
accessible clinical measurements to identify the presence of prior MI in
order to determine appropriate training prescription.

OBJECTIVES: To estimate prior MI in CLD patients entering a pulmonary
rehabilitation program, as well as its association with heart rate
parameters such as resting heart rate and chronotropic response index.

DESIGN: Retrospective cohort design.

SETTING: Pulmonary rehabilitation outpatient clinic in a tertiary care
university-affiliated hospital.

PATIENTS: Eighty-five CLD patients were studied.

METHODS: Electrocardiograms at rest and peak cardiopulmonary exercise
testing, performed before pulmonary rehabilitation, were analyzed.
Electrocardiographic evidence of prior MI, quantified by the Cardiac
Infarction Injury Score (CIIS), was contrasted with reported myocardial
events and then correlated with resting heart rate and chronotropic
response index parameters.

MAIN OUTCOME MEASUREMENTS: CIIS, resting heart rate, and chronotropic
response index.

RESULTS: Sixteen CLD patients (19%) demonstrated electrocardiographic
evidence of prior MI, but less than half (8%) had a reported MI history (P
< .05). The Cohen’s kappa test revealed poor level of agreement between
CIIS and medical records (kappa = 0.165), indicating that prior MI
diagnosis was under-reported in the medical records. Simple and multiple
regression analyses showed that resting heart rate but not chronotropic
response index was positively associated with CIIS in our population (R2 =
0.29, P < .001). CLD patients with a resting heart rate higher than 80
beats/min had approximately 5 times higher odds of having prior MI, as
evidenced by a CIIS >= 20.

CONCLUSIONS: CLD patients entering pulmonary rehabilitation are at risk
of unreported prior MI. Elevated resting heart rate appears to be an
indicator of prior MI in CLD patients; therefore, careful adjustment of
training intensity is recommended under these circumstances.

Anaerobic Threshold (AT) is an independent predictor of medium term survival following elective endovascular repair of abdominal aortic aneurysm (EVAR)

Dawkins C, Hollingsworth AC, Walker P, Milburn S, Danjoux G,Cheesman M, Mofidi R

J Cardiovasc Surg (Torino). 2019 Oct 4. doi: 10.23736/S0021-9509.19.11052-X.
[Epub ahead of print]

BACKGROUND: The aim of this study was to examine the value preoperative AT as
predictor of postoperative survival in patients who underwent elective EVAR for
repair of asymptomatic AAA.
METHODS: Consecutive patients who underwent elective EVAR between 2008 and 2018
were analysed. Cardiopulmonary exercise testing was performed. Perioperative/30
day mortality was compared between patients who had AT ≥8 ml kg-1 min-1 and those
with AT<8 ml kg-1 min-1. Risk factors for postoperative survival following EVAR
were examined using Cox’s regression analysis.
RESULTS: Between 1st January 2008 and 31st December 2017, 430 patients underwent
elective EVAR (standard device: 374, fenestrated/ branched: 56), [Median age: 76
years (range: 53-91)]. Median AT was 9.3 (range: 5.4-16.1). 30-day mortality was
0.9%. These patients were followed up for a median of 1630 days. There was no
significant difference in perioperative/30 day mortality between patients who had
AT≥8 and those who had AT<8 (χ2=1.56, P=0.22). Age [HR:1.51 (CI: 1.07-1.99),
(P<0.05)] and AT [HR: 0.59 (0.45-0.76), (P=0.0003)] were predictors of reduced
postoperative survival following elective EVAR whereas gender [HR: 0.75
(0.4-0.1.4), P=0.37)], AAA diameter [HR: 0.95 (0.77-0.1.16), (P=0.6)], AAA
morphology [HR: 1.23 (0.68-1.76), (P=0.95)] were not.
CONCLUSIONS: Anaerobic threshold is an independent predictor of prolonged
survival following elective EVAR and can be used to identify patients who receive
most benefit from elective EVAR.

Workload-indexed blood pressure response is superior to peak systolic blood pressure in predicting all-cause mortality

Kristofer Hedman, Nicholas Cauwenberghs,
Jeffrey W Christle, Tatiana Kuznetsova, Francois Haddad,
Jonathan Myers

European Journal of Preventive Cardiology 0(00) 1–10

Aims: The association between peak systolic blood pressure (SBP) during exercise testing and outcome remains
controversial, possibly due to the confounding effect of external workload (metabolic equivalents of task (METs)) on
peak SBP as well as on survival. Indexing the increase in SBP to the increase in workload (SBP/MET-slope) could provide a more clinically relevant measure of the SBP response to exercise.We aimed to characterize the SBP/MET-slope in a large cohort referred for clinical exercise testing and to determine its relation to all-cause mortality.
Methods and results: Survival status for male Veterans who underwent a maximal treadmill exercise test between the years 1987 and 2007 were retrieved in 2018. We defined a subgroup of non-smoking 10-year survivors with fewer risk factors as a lower-risk reference group. Survival analyses for all-cause mortality were performed using Kaplan–Meier curves and Cox proportional hazard ratios (HRs (95% confidence interval)) adjusted for baseline age, test year, cardiovascular risk factors, medications and comorbidities. A total of 7542 subjects were followed over 18.4 (interquartile range 16.3) years. In lower-risk subjects (n¼709), the median (95th percentile) of the SBP/MET-slope was 4.9 (10.0) mmHg/MET. Lower peak SBP (<210 mmHg) and higher SBP/MET-slope (>10 mmHg/MET) were both associated with 20% higher mortality (adjusted HRs 1.20 (1.08–1.32) and 1.20 (1.10–1.31), respectively). In subjects with high fitness, a SBP/MET-slope>6.2 mmHg/MET was associated with a 27% higher risk of mortality (adjusted HR 1.27 (1.12–1.45)).
Conclusion: In contrast to peak SBP, having a higher SBP/MET-slope was associated with increased risk of mortality.
This simple, novel metric can be considered in clinical exercise testing reports.

Graz European Practicum 2019

The 2019 European Practicum was held at the:
Medical  University of Graz – Horsaalzentrum
Auenbruggerplatz 50 ~ 8036 Graz ~ Austria

It was a great sucess in no small part due to the highly efficient  organising team under the auspices of Irene Czurda. (Left side nearest the camera!)  The doctor behind the organisation was Priv.Doz.Dr Gabor Kovacs (Gabor)

It is no small undertaking to run a Practicum of three days with more than 60 people attending from all over Europe; making this a truly International meeting. Graz University Hospital provided great facilities for the lectures, tutorials and laboratory sessions.

To run this Practicum depends on participation fees and sponsors and we are very grateful to our (CPX International Inc) sponsors. These were Cortex, Cosmed and Schiller – I really do thank them.

There were over 30 lectures plus two laboratory sessions where actual cardiopulmonary exercise tests (CPET) were performed. The people to whom I spoke were very happy with the Practicum and the way that it was run.

The tutorials were divided into three levels. One for ‘beginners’; one for ‘intermediate’ and one for ‘advanced’ participants. This was a sucessful inovation and feel sure will be repeated.

 

 

 

 

The traditional course dinner was held at the Gosserbrau Restaurant, the most traditional brewery in Graz. The atmosphere was pleasant which facilitated the exchange between participants and the teaching Faculty. Typical local food such as pumpkin soup and Schnitzel were washed down with traditional Gosser beer.

There was a young investigators award with over Euros 2,000 available as prize money. The winner was Julia Hock, from the Munich Heart Centre, runner up was Max Potratz with third place going to Massimo Mapelli

 

 

 

 

For those who were not shy there was the traditional group photo …Unfortunately my camera was unable to see around corners or through people, so some of the participants were not seen. I do apologise but as the saying goes ‘if you can’t see the camera, it won’t see you.’

My thanks to all of you and I will start sending out abstracts very soon. I really hope that you enjoyed the Practicum. You are always able to contact me with briqbats or bouquets.

Dr Paul Older

 

 

Heart rate recovery and morbidity after noncardiac surgery: Planned secondary analysis of two prospective, multi-centre, blinded observational studies.

Ackland GL; Abbott TEF; Minto G; Owen T; Prabhu P; May SM; Reynolds JA; Cuthbertson BH; Wijesundera D; Pearse RM;

Plos One [PLoS One] 2019 Aug 21; Vol. 14 (8), pp. e0221277. Date of Electronic Publication: 20190821 (Print Publication: 2019).

Background: Impaired cardiac vagal function, quantified preoperatively as slower heart rate recovery (HRR) after exercise, is independently associated with perioperative myocardial injury. Parasympathetic (vagal) dysfunction may also promote (extra-cardiac) multi-organ dysfunction, although perioperative data are lacking. Assuming that cardiac vagal activity, and therefore heart rate recovery response, is a marker of brainstem parasympathetic dysfunction, we hypothesized that impaired HRR would be associated with a higher incidence of morbidity after noncardiac surgery.
Methods: In two prospective, blinded, observational cohort studies, we established the definition of impaired vagal function in terms of the HRR threshold that is associated with perioperative myocardial injury (HRR ≤ 12 beats min-1 (bpm), 60 seconds after cessation of cardiopulmonary exercise testing. The primary outcome of this secondary analysis was all-cause morbidity three and five days after surgery, defined using the Post-Operative Morbidity Survey. Secondary outcomes of this analysis were type of morbidity and time to become morbidity-free. Logistic regression and Cox regression tested for the association between HRR and morbidity. Results are presented as odds/hazard ratios [OR or HR; (95% confidence intervals).
Results: 882/1941 (45.4%) patients had HRR≤12bpm. All-cause morbidity within 5 days of surgery was more common in 585/822 (71.2%) patients with HRR≤12bpm, compared to 718/1119 (64.2%) patients with HRR>12bpm (OR:1.38 (1.14-1.67); p = 0.001). HRR≤12bpm was associated with more frequent episodes of pulmonary (OR:1.31 (1.05-1.62);p = 0.02)), infective (OR:1.38 (1.10-1.72); p = 0.006), renal (OR:1.91 (1.30-2.79); p = 0.02)), cardiovascular (OR:1.39 (1.15-1.69); p<0.001)), neurological (OR:1.73 (1.11-2.70); p = 0.02)) and pain morbidity (OR:1.38 (1.14-1.68); p = 0.001) within 5 days of surgery.
Conclusions: Multi-organ dysfunction is more common in surgical patients with cardiac vagal dysfunction, defined as HRR ≤ 12 bpm after preoperative cardiopulmonary exercise testing.

Cardiopulmonary Exercise Testing Following Open Repair for a Proximal Thoracic Aortic Aneurysm or Dissection.

Hornsby WE; Departments of Internal Medicine, Division of Cardiovascular Medicine (Drs Hornsby, Saberi, Brook, Willer, Eagle, and Rubenfire and Ms Fink) and Cardiac Surgery (Drs Wu, Patel, and Yang), University of Michigan, Michigan Medicine, Ann Arbor; Creighton University School of Medicine, Omaha, Nebraska (Ms Norton); Department of Kinesiology, University of Windsor, Windsor, Ontario, Canada (Dr McGowan); Department of Medicine, Memorial Sloan Kettering Cancer Center, New York City, New York (Dr Jones); Departments of Computational Medicine and Bioinformatics and Human Genetics, University of Michigan, Ann Arbor (Dr Willer); and Department of Cardiovascular Diseases, John Ochsner Heart and Vascular Institute, Ochsner Clinical School-The University of Queensland School of Medicine, New Orleans, Louisiana (Dr Lavie).

Journal Of Cardiopulmonary Rehabilitation And Prevention [J Cardiopulm Rehabil Prev] 2019 Aug 29. Date of Electronic Publication: 2019 Aug 29.

Purpose: There are limited data on cardiopulmonary exercise testing (CPX) and cardiorespiratory fitness (CRF), following open repair for a proximal thoracic aortic aneurysm or dissection. The aim was to evaluate serious adverse events, abnormal CPX event rate, CRF (peak oxygen uptake, Vo2peak), and blood pressure.
Methods: Patients were retrospectively identified from cardiac rehabilitation participation or prospectively enrolled in a research study and grouped by phenotype: (1) bicuspid aortic valve/thoracic aortic aneurysm, (2) tricuspid aortic valve/thoracic aortic aneurysm, and (3) acute type A aortic dissection.
Results: Patients (n = 128) completed a CPX a median of 2.9 mo (interquartile range: 1.8, 3.5) following repair. No serious adverse events were reported, although 3 abnormal exercise tests (2% event rate) were observed. Eighty-one percent of CPX studies were considered peak effort (defined as respiratory exchange ratio of ≥1.05). Median measured Vo2peak was <36% predicted normative values (19.2 mL·kgmin vs 29.3 mL·kg·min, P < .0001); the most marked impairment in Vo2peak was observed in the acute type A aortic dissection group (<40% normative values), which was significantly different from other groups (P < .05). Peak exercise systolic and diastolic blood pressures were 160 mm Hg (144, 172) and 70 mm Hg (62, 80), with no differences noted between groups.
Conclusions: We observed no serious adverse events with an abnormal CPX event rate of only 2% 3 mo following repair for a proximal thoracic aortic aneurysm or dissection. Vo2peak was reduced among all patient groups, especially the acute type A aortic dissection group, which may be clinically significant, given the well-established prognostic importance of reduced cardiorespiratory fitness.

Acquired loss of cardiac vagal activity is associated with myocardial injury in patients undergoing noncardiac surgery: prospective observational mechanistic cohort study.

May SM; Reyes A; Martir G; Reynolds J; Paredes LG; Karmali S; Stephens RCM; Brealey D; Ackland GL;

British Journal Of Anaesthesia [Br J Anaesth] 2019 Sep 03. Date of Electronic Publication: 2019 Sep 03.

Background: Myocardial injury is more frequent after noncardiac surgery in patients with preoperative cardiac vagal dysfunction, as quantified by delayed heart rate (HR) recovery after cessation of cardiopulmonary exercise testing. We hypothesised that serial and dynamic measures of cardiac vagal activity are also associated with myocardial injury after noncardiac surgery.
Methods: Serial autonomic measurements were made before and after surgery in patients undergoing elective noncardiac surgery. Cardiac vagal activity was quantified by HR variability and HR recovery after orthostatic challenge (supine to sitting). Revised cardiac risk index (RCRI) was calculated for each patient. The primary outcome was myocardial injury (high-sensitivity troponin ≥15 ng L-1) within 48 h of surgery, masked to investigators. The exposure of interest was cardiac vagal activity (high-frequency power spectral analysis [HFLn]) and HR recovery 90 s from peak HR after the orthostatic challenge.
Results: Myocardial injury occurred in 48/189 (25%) patients, in whom 41/48 (85%) RCRI was <2. In patients with myocardial injury, vagal activity (HFLn) declined from 5.15 (95% confidence interval [CI]: 4.58-5.72) before surgery to 4.33 (95% CI: 3.76-4.90; P<0.001) 24 h after surgery. In patients who remained free of myocardial injury, HFLn did not change (4.95 [95% CI: 4.64-5.26] before surgery vs 4.76 [95% CI: 4.44-5.08] after surgery). Before and after surgery, the orthostatic HR recovery was slower in patients with myocardial injury (5 beats min-1 [95% CI: 3-7]), compared with HR recovery in patients who remained free of myocardial injury (10 beats min-1 [95% CI: 7-12]; P=0.02).
Conclusions: Serial HR measures indicating loss of cardiac vagal activity are associated with perioperative myocardial injury in lower-risk patients undergoing noncardiac surgery.