Download Return to higher level activities for cardiac patients

Return to Higher Level
Activities for
Cardiac Patients
Niall M. Moyna, DCU
Copyright © 2011 Wolters Kluwer Health | Lippincott Williams & Wilkins
Exercise Paradox!
Evidence for transient elevation in risk with exercise,
countered by a protective effect of regular
exercise
Aging and SCD
Middle-aged and older athletes are at significantly higher
risk for sudden cardiac death (SCD) compared with
younger athletes
SCD - Current Burden
• 13 per 100,000 joggers/year
• 0.8 to per 100,000 marathon runners (retrospective
studies)
General Population
Annual incidence of 4.6 sports-related SCDs per 1 million
residents
Age and Sports-Related Sudden Deaths
Overall population
Competitive athletes
Overwhelming majority of sports-related
sudden deaths occur among those ≥ 35
years of age
J Am Col Cardiol, 65, (5), 2015, 493 – 50, 2015
Circulation. 2011;124:672-681,2011
Eloi Marijon et al. Circulation. 2011;124:672-681, 2011
Sports Engaged at the time of Sudden Death
N = 820
6% (50 of 820) of all cases of sports-related SCDs involved
young, competitive athletes
Primarily men
US Athletes Completing Road Races
State of the Sport - Part III: U.S. Race Trends. Running USA. July 9, 2014.
http://www.runningusa.org/2014-state-of-the-sport-part-III-us-race-trends
Exercise Paradox
Long Term Protective Effect vs. Transient Risk of Exercise
Risk of SCD  during strenuous exercise
60
Relative Risk
50
56
Sedentary
High Fit
Men with the highest habitual level of PA
have a 60% lower relative risk of global
SCD compared with sedentary controls
40
30
20
10
0
5
Siscovick et al., N Engl J Med
311, 874-7, 1984
5-fold residual risk
Overall RR = 16.9
SCD
RR within 30 min of Vigorous Exercise
80
70
Relative Risk
74
60
<1/wk
≥ 5/wk
50
40
30
20
10
11
0
Albert et al., N Engl J Med 343,
1355-61, 2000
Myocardial Infarction
RR During Exercise
120
Relative Risk
100
50-fold difference
Sedentary
107
Active
80
60
40
20
2.4
0
Mittleman et al., N Engl J Med
329, 1677-83, 1993
Global Benefits of Exercise
• Global mortality benefits of exercise far
outweigh the  risk
• Regular exercise of mild to moderate intensity provides a
7-10 fold risk reduction for SCD
• Regular exercise of mild to moderate intensity provides a
50-fold risk reduction for MI
• Dose-related beneficial impact of regular exercise on
global CV risk - independent of sex, ethnicity, and
probably of age
Nerve Fibres
Skeletal Muscles
B\rain
Myostatin
Liver
IL-10
IL-6
IL-15
Adipose
Tissue
IL-1
IL-7
IL-4
SPARC
IL-13
Follistatin
Iriscin
Myonectin
Visfatin
BDNF
IGF/PI3K/Akt
Endothelial
Cells
Heart
SIRT1
IL-8
Spinal
Cord
sTNF-R
Immune
System
Pituritary
Gland
Fat metabolism
Neuroplasticity
Motor unit regeneration
Endothelial repair
Endothelial function
Revascularization
Muscle growth
Muscle repair
Antiinflammatory
Anti-obesogenic
Insulin-sensitizing
Thermogenesis
Vasculogenesis
Glucose metabolism
Cancer cell proliferation
Myocardial remodelling
Endurance Exercise
Physiological Cardiac Remodelling
Efficient fuel handling
Bi ventricular
Hypertrophy
Angiogenesis
 Coronary blood flow
Hyperplasia
Altered Ca2+ handling
Improved EDD
 O2 extraction
 Capillary density
Enhanced systolic function
Enhanced diastolic function
Mitochondrial
Improved
biogenesis
contractility
Exercise Induced Cardiac Remodeling
Key Signaling Pathways
Exercise-Induced SCD
Mechanisms
•
•
•
•
•
•
CAD account for up to 80%
Hypertrophic cardiomyopathy
Arrhythmogenic right ventricular dysplasia
Myocarditis
Valvular heart disease
Small distinct subgroup - unexplained
CAD Associated SCD
Mechanisms
Ischemic ventricular arrhythmia – final common pathway
• Exercise related sympathetic activation – may sensitize
vulnerable myocardium to ischemia and arrhythmias
• Electrolyte and metabolic factors – prolonged exercise
• Activation of haemostatic and thrombosis in response to
plaque rupture
• Hemodynamic effects of vulnerable coronary plaque
CAD Associated SCD
Mechanisms
Plaque morphology in men whose
death was temporally linked to
physical or emotional stress versus
men who did at rest
Acute Plaque Rupture
Intra Plaque Haemorrhage
80
70
80
68
70
Stress
Rest
50
40
23
Stress
60
Percent
Percent
60
30
71
50
Rest
41
40
30
20
20
10
10
0
0
Burke et al., JAMA, 281; 2015, 921-926, 1999
Plaque Rupture with Exertion and at Rest
Characteristics
Remote
Vasa Vasorum
Subjacent
High Exercise Levels
Potential Hazards
• Quantified CAC in 108 experienced male marathon runners > 50 years of age
• CAC score ≥100 was present in 36% of runners (not different from age-matched
controls, even though the FRS was much lower)
• CAC score exceeded controls matched for age and FRS
• 12% had detectable LGE in patterns with diffuse myocardial scarring
• Presence of myocardial LGE predicts cardiac events in patients with CAD
• In marathon runners, such damaged myocardium may be a substrate for an
susceptibility to cardiac arrhythmias in response to exercise-related
catecholamine levels
Estimates of Event-Free Survival by Extent
of CAC
8%
14.3%
Stefan Möhlenkamp et al. Eur Heart J 2008;29:1903-1910
Marathon
Right Ventricle
• Repeated RV insult, injury and fibrosis that can
evolve late into substrate for ventricular arrhythmias
• Elevated RV pressures and dimensions at conclusion of
marathons
• 2x elevation in B type-NP and Trop-T in 60% with 40%
exceeding the threshold for diagnosis of MI
•  levels of biomarkers related to i) impaired LV diastolic
function, ii)  pulmonary artery pressure and iii) RV
dysfunction
• More severely effected in the least well-trained vs best
Exercise
Myocardial Ischemia
Noel M, Eur Heart J. 28(13):1559-65, 2007
Compared intense and prolonged exercise training above the threshold for
myocardial ischemia -1 mm ST-segment depression)
Randomization
Control (N = 9)
Ischemia (n=11)
• CR training 3 d/wk for 6 wk
• CR training 3 d/wk for 6 wk
• As per guidelines (i.e. 10 bpm < HR
• 5-10 min warm-up @ light intensity
@ 1 mm ST-segment depression
• 20-60 min endurance exercise @ intensity
= 1 mm but no more than 3 mm of STsegment depression
• 15 min strength training
• 10 min cool down
• cTnT at 18-24 h after the first 20, 40, and 60 min of continuous training
• Corresponded to the 1st, 12th, and 21st exercise sessions
• cTnT again after the first 3 sessions that involved 60 min of end exercise
Repeated Bouts of Exercise Induced Ischemia
Patients with Stable IHD
•
•
•
•
Well tolerated
Not deleterious
No malignant or significant arrhythmias while exercising
No malignant or significant arrhythmias during Holter
monitoring
• No myocardial injury (cTnT levels)
• No sustained LV systolic dysfunction
• No change LV systolic & diastolic dimensions
Results suggest that progressive exposure to repeated
ischemic exercise periods is not pro-arrhythmic
Exercise Above the Ischemic Threshold and Serum Markers of Myocardial Injury
M. Juneau et al. 2009
Effects of a single session of exercise above the IT on biochemical markers of
myocardial injury in stable coronary pts in response to exercise-induced ischemia
Random order
72 hr
Session 1
Session 2
Tm Exercise (20 min)
HR < IT
TM Exercise (20 min)
(~10 bpm < HR associated with the appearance of an ST
segment depression ≥1mm)
(~10 bpm > HR associated with the appearance of an ST
segment depression ≥1mm)
CK
CK-MB
Troponin T
CK
CK-MB
Troponin T
HR > IT
6 h & 24 h after session
No CK, CK-MB or troponin T
Results
Data presented as mean ± SD. Normal ranges: CK 24 U/L to 195 U/L;
CK-MB isoenzyme 0 U/L to 30 U/L; troponin T < 0.1 ng/mL.
No significant differences noted for all comparisons
High-Intensity Interval Exercise (HIIE)
Definition
Series of repeated bouts of short duration ( 5 min) high
intensity exercise (70 – 100% of maximal effort),
alternated with periods of active or passive recovery
Optimisation of High Intensity Interval Exercise in CAD
T. Guiraud et al. Eur J Appl Physiol, 108, 733-740, 2009
• Compared 4 diff bouts of HIIE (cycling) on time to exhaustion, time spent near VO2max ,
and comfort and safety in pts (N = 20, Age = 65± 8, VO2max = 27.1± 6.7) with stable
CAD
• Hx of ≥ 70% arterial diameter narrowing of ≥ 1major coronary artery., prior MI and
perfusion defect on exercise nuclear imaging
• 8 min standardised warm up followed by 5 min passive recovery
A
C
B
D
HIIE Modes
Typical VO2 Response of a Participant During each HIIE
Mode
Acute Responses
VO2max
VO2max
95%
85%
80%
95%
80%
80%
A
B
C
D
15/15
15/15
60/60
60/60
Passive
Recovery
Active
Recovery
Passive
Recovery
Active
Recovery
‡
‡ A v C p<0.06
Reached VO2max: A= 13(68%); B = 17(89%); C= 15(79%); D= 14(73%)
Acute
Responses
to High-Intensity
Intermittent
Optimisation
of High
Intensity Interval
Exercise Exercise
in CAD in CHD Patients
T.T.Guiraud
et al.
MedEur
Sci JSports
43, 108,
211-217,
2011 2009
Guiraud
et al.
Appl Exerc,
Physiol,
733-740,
• Compared the acute cardiovascular physiological responses between high intensity interval
exercise (HIIE) and moderate intensity continuous exercise (MICE) of similar energy
expenditure in men and women (N = 20, Age = 62±11, VO2max = 28.4± 9.1) with CHD
• Compared the acute ST segment changes, ventricular arrhythmias, blood pressure and
cardiac troponin T (cTnT) between HIIE and MICE of similar energy expenditure in CHD pts
Max
Relative
Power
MICE
HIIE
Relative
Power
10 min
100%
10 min
70%
15 sec
15 sec
50%
10 min
WU
4 min
PR
5 min
WD
27.8
min
 Time To Exhaustion
 Ventilation

 RPE
Achieved 35 min of exercise
Max
Acute Responses to High-Intensity Intermittent Exercise in CHD Patients
T. Guiraud et al. Med Sci Sports Exerc, 43, 211-217, 2011
Group
Values are absolute number (%) and
mean ± SD; ‡ p<0.001 vs HIIE
HIIE
MICE
Ventricular arrythmias
0
0
Abnormal BP responses
0
0
Prolonged ischemia
0
0
>2mm ST depression
0
0
Demonstrable ST dep (< 2 mm)*
3
0
Maximal ST depression
1.2 ± 0.3
*ST segment normalising
during 15 s recovery period
Cardiac troponin C (mg/L) - rest
< 0.04
< 0.04
Cardiac troponin C (mg/L) - 20 min
< 0.04
< 0.04
Cardiac troponin C (mg/L) – 24 h
< 0.04
< 0.04
49.8 ± 8.2
58.9 ± 14.2‡
14 ± 2
16 ± 2
Values are means  SD
Ventilation (L/min)
RPE
HIIE
Protocol
Block 3
8 x 45 s HII
2 min Seated Rest
2 min Seated Rest
Warm-Up
%HRpeak
50%
2 min Seated Rest
90%
Block 2
8 x 45 s HII
2 min Seated Rest
Block 1
8 x 45 s HII
Cool
Down
10 min
Total Session Time: 47 min
Total HIIE: 18 min
5 min
45 s High-intensity Intervals
15 s Passive Recovery
ECG Changes & Clinical Symptoms
HIIE
• HIIE – safe for study participants
• ST-segment changes ranged from 1 – 3 mm, and
returned to normal during passive recovery
• None of the participants reported angina symptoms
during the acute bout of SRE or HIIE
• Ventricular ectopics – single and couplets
Sept 2014
• Evaluated whether excessive exercise is associated with
progressively lower mortality after a cardiac event in 2377
self-identified MI survivors
• Estimated energy expended from running or walking
• EE was measured as metabolic equivalents (3.5 mL O2/kg
per min per day or metabolic equivalent of task-h/d [METh/d])
• 1 MET-h/d is the energy equivalent of running 1 km/d
Sept 2014
1.
2.
3.
4.
5.
6.
<1.07 MET-h/d
1.07 -1.8 MET-h/d
1.8 - 3.6 MET-h/d
3.6 - 5.4 MET-h/d
5.4 – 7.2 MET-h/d
≥7.2 MET-h/d
Inadequately active
Satisfies current PA recommendations (150 min MI or 75 min VI)
Exceeds recommendations 1-2x
Exceeds recommendations 2-3x
Exceeds recommendations 3-4x (15-23 miles/wk)
Exceeds recommendations ≥4x (23-30 miles/wk)
Sept 2014
• Greater exercise EE by walking and running was
associated with a significantly lower risk for CVD related
mortality in proportion to the exercise dose through 7.2
MET-h/d
• EE ~ equivalent to running 30 miles (50 km)/week
or
• Walking briskly 46 miles (75 km)/week
• Increased risk relative to less active runners at EE >
30 miles/wk
• Unrelated to traditional risk factors
CVD Mortality
N=2377
Energy Expenditure
Harard Ratio
1.0
0.8
0.6
0.88
1
0.4
0.501
21%
0.2
0.0
0.764
0.786
<1.07
24%
1.07-1.8 1.8-3.6
Guidelines
Williams et al., Mayo Clin Proc, 2014
50%
0.369
63%
3.6-5.4
5.4-7.2
15-23
23-30
Energy Expenditure
(MET-h/d)
>7.2
15.4%  in risk for CVD related mortality
per MET-h/d between 0 and 7.2 MET-h/d
2.62-fold  risk for CVD related mortality
per MET-h/d above 7.2 MET-h/d relative
to the risk at 7.2 MET-h/d
Williams et al., Mayo Clin Proc, 2014
Conclusions
• Exercise induced Ischemia not always bad
• Recommend short duration events
• Aging combined to CAD may increase risk for MI and
SCD
• Individual approach
• Common sense
• More research needed!!!