Slide 1Slide 2Sedentary behavior and CHDPA, Sitting and CVD MortalitySitting and CVD MortalitySitting and CVD MortalitySlide 7How does exercise influence CVD?Role of endotheliumVascular Endothelial DysfunctionSlide 11Slide 12Slide 13Slide 14Treating heart disease - surgicallyTreating heart disease - surgically(Brief) History of rehabilitating the heartComponents Cardiac RehabilitationSlide 19Slide 20Exercise vs. Surgery: Hambrecht, et al. 2004RandomizationResultsResults: Cost comparisonBack to workAnother MISummaryCardiovascular Disease (CVD) Sedentary BehaviorCardiac RehabilitationUnit 2 Lecture 5Sedentary behavior and mortality from CHD (Katmarzyk et al., 2009)•Representative sample of 17,013 Canadians 18–90 yr of age•Prospectively examined daily sitting time and classified sitting categories as follows:–Almost –None of the time–One fourth of the time–Half of the time–Three fourths of the time–Almost all the time•Found:Follow-up = 12 yearsSedentary behavior and CHDAlmost none of the timeOne fourth of the timeHalf of the timeThree fourths of the timeAlmost all the time00.20.40.60.811.21.41.61.8Sitting CategoryRelative Risk of CVD MortalityPA, Sitting and CVD Mortality •Cancer Prevention Study-Nutrition Cohort II–Followed individuals from 1992 to 2006–Used the National Death Index to find out who was alive and who was dead in 2006–Determined cause of death via death certificateSitting and CVD MortalityRelative Risk of Death from Different Diseases According to Leisure Time Sitting Among WomenSitting in 1992 (hours/day)Relative Risk0.0 0.5 1.0 1.50-<33-5>=60-<33-5>=60-<33-5>=6CVDCancerOther CausesSitting and CVD MortalityLonger time spent sitting was associated with increased risk of CVD and All-cause mortality Longer time spent sitting was associated with increased risk of CVD and All-cause mortality Relative Risk of Death from Different Diseases According to Leisure Time Sitting Among MenSitting in 1992 (hours/day)Relative Risk0.0 0.5 1.0 1.50-<33-5>=60-<33-5>=60-<33-5>=6CVDCancerOther CausesAssociations between screen time (per 2 h/day) and cardiovascular events. Earl S Ford, and Carl J Caspersen Int. J. Epidemiol. 2012;ije.dys078Published by Oxford University Press on behalf of the International Epidemiological Association 2012.How does exercise influence CVD?•Individual risk factors for CVD–hypertension–triglycerides and cholesterol–diabetes–obesity•Endothelial dysfunctionRole of endotheliumVascular Endothelial Dysfunction1) Vessel walls become “sticky”–adhesion molecules increase–platelets and other factors stick2) Factors (i.e. LDL) move under endothelial cells–Followed by monocytes and macrophages–Inflammatory cytokines increase 3) Endothelial cell communication with smooth muscle cells changes–vasoconstrictor factors > vasodilatory factorsSmooth MuscleEndotheliumNO Smooth MuscleEndotheliumET-1 VASOCONSTRICTIONVASODILATIONBlood FlowExercise training in subjects with heart failure or type 2 diabetes increases nitric oxide-mediated vasodilatation in response to acetylcholineShort-term exercise training attenuated abnormal vasoconstriction of coronary arteries in CAD patientsHambrecht, et al 2000Exercise:4 weeks6 x 10 min cyclingTreating CVDcardiac rehabilitationTreating heart disease - surgically 1) Bypass surgery : go around blockageTreating heart disease - surgically 2) Angioplasty and stent: open up blockage and put in mesh wire frame(Brief) History of rehabilitating the heart•1912: MI was first described–Treatment: bed rest for 2 months–Mortality around 30-40%•1968: Dallas Bed Rest and Exercise Study– Detrimental effect of prolonged bed rest•1960s: Hellerstein and cardiac rehabilitation–first outpatient cardiac rehab center at Cleveland YMCA- Criticized for “innovative but risky approach”–Improved function, psychology and without a negative effect on morbidity/mortalityComponents Cardiac Rehabilitation•Exercise –To improve CV fitness safely•Education–About heart disease and improving modifiable risk factors•Encourage healthy eating•Improve psychological well beingCardiac Rehab PhasesPhase I—Inpatient hospital phase beginning in the CCUPhase II—Outpatient hospital-based phase for 2 to 4 monthsPhase III—Maintenance phase for 4 to 6 months or even up to 12 months.Components Cardiac RehabilitationHow beneficial is Cardiac Rehabilitation?meta-analysis–48 RCTs, 8940 patients–20% reduction in all-cause mortality–26% reduction in cardiac mortalityEvery 1 MET increase in work capacity = for those who participated in exerciseComponents Cardiac RehabilitationExercise vs. Surgery: Hambrecht, et al. 2004•101 males with significant but stable CAD•Random assignment1) Exercise•In hospital first two weeks, then at home 20 min/day and 1 x week for 60 min in hospital2) Percutaneous coronary intervention (PCI) with stenting•Surgery, “stent”•12 monthsRandomizationResults•___% of PCI group had event-free survival•___% of exercise group had event-free survivalResults: Cost comparison•$6086 was spent per person in the PCI group • $3708 was spent per person in the exercise group•Reduced cost of rehospitalization and repeat surgeryBack to workL D Dugmore, R J Tipson,M H Phillips, E J et al., Heart 1999;81:359–366Randomized Control Trial12-month cardiac rehabilitationAnother MIL D Dugmore, R J Tipson,M H Phillips, E J et al., Heart 1999;81:359–366Randomized Control Trial12-month cardiac rehabilitationSummary•Sedentary behavior is associated with increased CVD risk•One of the major mechanisms by which physical activity reduces CVD risk is through endothelial function•Studies on cardiac rehabilitation show that exercise can have any beneficial effects on the treatment of