3.Epidemiological Aspects of CVS_Dr Ayaz Bhatti

8/4/2019 3.Epidemiological Aspects of CVS_Dr Ayaz Bhatti

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Towards the End ofTowards the End ofVascular Disease in theVascular Disease in the

2121stst CenturyCentury

Dr Muhammad Ayaz BhattiDr Muhammad Ayaz Bhatti

Department of CommunityDepartment of Community

MedicineMedicine


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Leaning objectivesLeaning objectivesLECTURE TWO


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Preventive cardiology is the branch of medical science

which deals with the prevention of cardiovascular

problems and their treatment and rehabilitation.


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PREVENTION OF CVDPREVENTION OF CVD

WHO expert committee recommended onthe prevention of CVD as follows.

A. Population Strategy.

Prevention in the whole populations.

Primordial prevention in the whole populations.

B. High Risk strategy

C. Secondary prevention


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Population Strategy.Population Strategy.

CHD a mass disease.

Approach focuses control of underlying causes (Risk

Factors) in the whole populations

The aim is to shift the whole risk factor distribution in the

direction of the biological NORMALITY.


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1.1. Dietary Changes.Dietary Changes.


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2.2. SmokingSmokingThe Goal should be smoke free societyThe Goal should be smoke free society


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3.3. Blood PressureBlood Pressure

1


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4.4. Physical ActivityPhysical Activity

1


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A.A. PRIMORDIAL PREVENTIONPRIMORDIAL PREVENTION

1


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1

B.B. HIGH RISK STRATEGYHIGH RISK STRATEGYi. Identifying risk groupsii. Give them advice


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C.C. SECONDARY PREVENTIONSECONDARY PREVENTION

Prevent recurrence and progression of CHD (Drug trials, coronary surgery, pacePrevent recurrence and progression of CHD (Drug trials, coronary surgery, pace

makersmakers

Principles governing secondary prevention arePrinciples governing secondary prevention are

1


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D.D. TERTIARY PREVENTIONTERTIARY PREVENTION

Revascularization procedures forRevascularization procedures forpatients with Angina pectoris.patients with Angina pectoris.

Coronary artery By Pass Grafting CABG

Percutaneous Transluminal Angioplasty PTCA

1


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Diet High in Elevated AtherosclerosisDiet High in Elevated AtherosclerosisAnimal Fat CholesterolAnimal Fat Cholesterol

HypertensionHypertension

DiabetesDiabetes

SmokingSmoking

PhysicalPhysical

InactivityInactivity

CausalCausal Process in AtherosclerosisProcess in Atherosclerosis


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Percent of Energy from Different Food ComponentsPercent of Energy from Different Food Components

Hunter-Hunter-

GatherersGatherersPeasantPeasant

AgriculturalistsAgriculturalistsModern AffluentModern Affluent

SocietiesSocieties

15-2015-20

50-7050-70

15-2015-20

10-1510-15

55

60-7560-75

10-1510-15

14+14+

2020

25-3025-30

1212

Salt (g/d)Salt (g/d) 11 5-155-15 1010

Fiber (g/d)Fiber (g/d) 4040 60-12060-120 2020

FatFat

SugarSugar

StarchStarch

ProteinProtein


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CHD and Fat Intake in 40 CountriesCHD and Fat Intake in 40 Countries


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CHD and Milk Intake inCHD and Milk Intake in

40 Countries40 Countries


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Serum Cholesterol and Relative RiskSerum Cholesterol and Relative Risk

of CHD, MRFITof CHD, MRFIT


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CHD = ICD-9 410-414, 429.2.

Data source: CDC Wonder

500


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The Development Process of CVDThe Development Process of CVD

Social andSocial and

EnvironmentalEnvironmental

ConditionsConditions

AdverseAdverse

BehavioralBehavioral

PatternsPatterns

MajorMajor

RiskRisk

FactorsFactors

First Event/First Event/

Sudden DeathSudden DeathDisability/Disability/

Risk ofRisk of

RecurrenceRecurrence

LateLate

DeathDeath

WholeWhole

PopulationPopulationWholeWhole

PopulationPopulationPersonsPersons

with Riskwith Risk

FactorsFactors

Cases withCases with

First Fatal orFirst Fatal or

Non-FatalNon-Fatal

EventsEvents

SurvivorsSurvivors LateLate

DeathsDeaths

Policy andPolicy andEnvironmentalEnvironmental

ChangeChange

BehaviorBehaviorChangeChange Risk FactorRisk FactorDetectionDetection

and Controland Control

EmergencyEmergencyCare/AcuteCare/Acute

CaseCase

ManagementManagement

RehabilitationRehabilitation/Long-Term/Long-Term

CareCare

End-Of-End-Of-Life CareLife Care

PathwayPathway

Target PopulationTarget Population

InterventionsInterventions


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0

10

20

30

40

50

60

70

C

HD

SBP: 142

Chol: 245

Smoking: NoSmoking: No NoNo Yes YesYes Yes

CHD among Low and High RiskCHD among Low and High Risk

Men in MRFITMen in MRFIT


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Phases of CHD Decline in the USPhases of CHD Decline in the US

Phase 1 1960-Phase 1 1960-8585

Rapid fall in mortality; SignificantRapid fall in mortality; Significantin smoking and intake of animal fat;in smoking and intake of animal fat;

Treatment of high BP.Treatment of high BP.

Phase 2 1985Phase 2 1985 2000 2000

National decline slows for all but white men;National decline slows for all but white men;Large regional/ethnic disparitiesLarge regional/ethnic disparities

emerge; Tertiary careemerge; Tertiary careplays a bigger role.plays a bigger role.

?? Phase?? Phase3 2000 153 2000 15

Decline continues for all groups; HighDecline continues for all groups; Highcholesterol now effectively treated;cholesterol now effectively treated;

Cigarette smoking drops to low levels;Cigarette smoking drops to low levels;

Dietary goals achieved; Obesity/diabetesDietary goals achieved; Obesity/diabetesepidemic reversed.epidemic reversed.


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How Can We Eliminate CHD asHow Can We Eliminate CHD as

a Mass Disease?a Mass Disease?

1.1. Eliminate smokingEliminate smoking

2.2. Reduce total fat to


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Steps to Eliminate Vascular DiseaseSteps to Eliminate Vascular Disease

1.1. CigarettesCigarettes

** taxtax

** Enforce sales lawsEnforce sales laws

** Mount vigorous anti-smokingMount vigorous anti-smokingadvertising campaignadvertising campaign


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Steps to Eliminate Vascular DiseaseSteps to Eliminate Vascular Disease

continuedcontinued

2.2. FoodFood** salt content 5% / yearsalt content 5% / year

** Regulate fast food industryRegulate fast food industry

** Promote alternate take out foodsPromote alternate take out foods


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Steps to Eliminate Vascular DiseaseSteps to Eliminate Vascular Diseasecontinuedcontinued

3.3. Obesity/ExerciseObesity/Exercise

** Take up 10% of streetsTake up 10% of streets

** Create walking and bike boulevardsCreate walking and bike boulevards

** Require employers to provideRequire employers to provide

exercise facilitiesexercise facilities** Restore PE in schoolsRestore PE in schools


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Steps to Eliminate Vascular DiseaseSteps to Eliminate Vascular Diseasecontinuedcontinued

4.4. Racial/Ethnic/SES DisparitiesRacial/Ethnic/SES Disparities

** Develop national health systemDevelop national health system

** Invest in economically depressedInvest in economically depressed

regions/neighborhoodsregions/neighborhoods

** Provide Scandinavian level socialProvide Scandinavian level socialservicesservices


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SURVEYSSURVEYS

The widely reportedThe widely reported


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The widely reportedThe widely reported

intervention trials areintervention trials are

1. FRAMINGHAM HEART STUDY2. The Stanford Heart Disease prevention

programme in California.

3. The North Kerelia Project in Finland

4. The OSLO study

5. The Multiple Risk Factor Intervention Trial

(MRFIT in USA

6. Lipid Research Clinics Study.


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FRAMINGHAM HEARTFRAMINGHAM HEART


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FRAMINGHAM HEARTFRAMINGHAM HEART

STUDYSTUDY1. 1951 one of the best known Prospective study

2. Established the nature of risk factors and their relative

importance .

3. Major risk factors were identified.

4. According to this study four main possibilities to

intervention in prevention of

5. Reduction of serum cholesterol

6. Cessation of smoking

7. Control of hypertension

8. Promotion of physical activity.

The Stanford Heart Disease preventionThe Stanford Heart Disease prevention


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The Stanford Heart Disease preventionThe Stanford Heart Disease prevention

programme in California.programme in California.

1. To determine whether community healtheducation can reduce the risk ofcardiovascular disease a field experiment wasundertaken in 1972 in three towns withpopulation varying 12000 to 15000. in two

towns intensive mass education campaignswere conducted .

2. The third community served as control3. After two years knowledge and behavior was

assessed and diet smoking, blood pressure

serum cholesterol.4. The risk was reduced in the intervention group

as compared to the Control group.


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The North Kerelia Project in FinlandThe North Kerelia Project in Finland

North Keralia is a country in the Eastern part of Finland, where

CHD is particularly common.

Its 185000 work mostly farming and forestry and live in the

countryside

A multiple risk factor intervention trial was started in 1972. The aim was

1. To reduce the high level of risk factors for CVD(smoking, blood

pressure and serum cholesterol).

2. To promote the early diagnosis, treatment and rehabilitation of

patients with CVD.



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A control population was established in aneighbouring country which has similar CV mortality

The main strategy was employed community actionagainst risk factors and advice on their avoidance.

Follow up 5 years demonstrated a significantreduction in all three major risk factors. By 1979mortality began to decline by 24 % in men and 51%in women compared with 12% in men and 26% inrest of Finland.


continuedcontinued

h l i l i kMRFIT th lti l Ri k F t


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MRFIT the multiple Risk FactorMRFIT the multiple Risk Factor

Intervention TrialIntervention Trial

Carried out in USA on 12866 men aged 35-57years.

Half group randomly allocated to anintervention programme being seen every 4

months to ensure adequate control of riskfactors.

The other half Control group received medicalexamination once yearly and no specific advice

was given to them.Over 7 years follow up IHD mortality reduced22% more intervention group.

OSLO DIET /SMOKINGOSLO DIET /SMOKING


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OSLO DIET /SMOKING/

INTERVENTION STUDYINTERVENTION STUDY1. Study began in 1973

2. 16202 Norwegian men age 40-49 years were screened for

CHD risk factors.

3. Of these 1232 healthy normotensive men at risk (total

cholesterol 290-379 and smoking) were selected for a 5

year randomized trial.

4. The aim of the study was to determine whether lowering of

serum lipids and cessation of smoking would reduce theincidence of first attack of CHD in males aged 40-49 years.

5. The intervention was lowering cholesterol through dietary

means (polyunsaturated fat in diet and cessation of

smoking.

6. At the end of the incidence of myocardial infarction waslower by 47% in the intervention group than in the control

group.

Th Li id R h Cli i CTh Li id R h Cli i C


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The Lipid Research Clinics CoronaryThe Lipid Research Clinics Coronary

Primary Prevention TrialPrimary Prevention Trial

Randomized, double-blind study, tested the efficacy of cholesterol

lowering in reducing risk of coronary heart disease (CHD) in 3,806

asymptomatic middle-aged American men with primary

hypercholesterolemia (type II hyperlipoproteinemia).

The treatment group received the bile acid cholestyramine resin and

the control group received a placebo for an average of 7.4 years.

Both groups followed a moderate cholesterol-lowering diet.

The treatment group had an 8.5 % and 12.5% reduction in total

cholesterol than placebo. This resulted in 24% reduction in mortality

This resulted in drug treatment of elevated serum cholesterol levels

3.Epidemiological Aspects of CVS_Dr Ayaz Bhatti

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