Heart Failure: Living with a Hurting Heart

James T. DeVries, MDDartmouth-Hitchcock Medical

Center

Outline• Definitions and scope of problem• Diagnosing and classifying heart failure• Approach to management of CHF

– Oral drug therapy (ACE-I, ARB, betablockers, aldosterone blockade, digoxin)

– Device therapy• Biventricular (BiV) pacers• Intracardiac defibrillators (ICD’s)

• Future directions and exciting developments

Congestive Heart Failure

• Heart (or cardiac) failure is the state in which the heart is unable to pump blood at a rate commensurate with the requirements of the tissues or can do so only from high pressures

Braunwald 8th Edition, 2001

Congestive Heart Failure

• Symptoms:– Shortness of breath– Leg swelling (edema)– Breathing worsens with lying flat (orthopnea)– Fatigue

Anatomy 101

A normal heart pumps blood in a smooth and A normal heart pumps blood in a smooth and

synchronized way.synchronized way.

Heart Failure Heart Failure HeartHeart

A heart failure heart has a reduced ability to A heart failure heart has a reduced ability to pump blood.pump blood.

Types of Heart Failure

• Systolic (or squeezing) heart failure– Decreased pumping function of the heart, which

results in fluid back up in the lungs and heart failure

• Diastolic (or relaxation) heart failure– Involves a thickened and stiff heart muscle– As a result, the heart does not fill with blood properly– This results in fluid backup in the lungs and heart

failure

CAD=coronary artery disease; LVH=left ventricular hypertrophy.

Risk Factors for Heart Failure

• Coronary artery disease

• Hypertension (LVH)• Valvular heart disease• Alcoholism• Infection (viral)

• Diabetes• Congenital heart defects• Other:

– Obesity– Age– Smoking– High or low hematocrit level– Obstructive Sleep Apnea

Epidemiology of Heart Failure in the US

• More deaths from heart failure than from all forms of cancer combined

• 550,000 new cases/year

• 4.7 million symptomatic patients; estimated 10 million in 2037

*Rich M. J Am Geriatric Soc. 1997;45:968–974.American Heart Association. 2001 Heart and Stroke Statistical Update. 2000.

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Classifying Heart Failure:Terminology and Staging

A Key Indicator for Diagnosing Heart Failure

Ejection Fraction (EF)• Ejection Fraction (EF) is the percentage of blood

that is pumped out of your heart during each beat

Classification of HF: Comparison Between ACC/AHA HF Stage and

NYHA Functional Class

1Hunt SA et al. J Am Coll Cardiol. 2001;38:2101–2113.

2New York Heart Association/Little Brown and Company, 1964. Adapted from: Farrell MH et al. JAMA. 2002;287:890–897.

ACC/AHA HF Stage1 NYHA Functional Class2

A At high risk for heart failure but withoutstructural heart disease or symptomsof heart failure (eg, patients withhypertension or coronary artery disease)

B Structural heart disease but withoutsymptoms of heart failure

C Structural heart disease with prior orcurrent symptoms of heart failure

D Refractory heart failure requiringspecialized interventions

I Asymptomatic

II Symptomatic with moderate exertion

IV Symptomatic at rest

III Symptomatic with minimal exertion

None

How Heart Failure Is Diagnosed• Medical history is taken to reveal symptoms• Physical exam is done• Tests

– Chest X-ray– Blood tests– Electrical tracing of heart (Electrocardiogram or “ECG”)– Ultrasound of heart (Echocardiogram or “Echo”)– X-ray of the inside of blood vessels (Angiogram)

Pathophysiology

Adapted from Cohn JN. N Engl J Med. 1996;335:490–498.

Pathologicremodeling

Low ejectionfraction Death

Symptoms:DyspneaFatigueEdema

Chronicheartfailure

•Neurohormonalstimulation

•Myocardial toxicity

SuddenDeath

Pump failure

Coronary artery disease

Hypertension

Cardiomyopathy

Valvular disease

Myocardialinjury

Pathologic Progression of CV Disease

Diabetes

Compensatory Mechanisms:Compensatory Mechanisms:Renin-Angiotensin-Aldosterone SystemRenin-Angiotensin-Aldosterone System

Renin + Angiotensinogen

Angiotensin I

Angiotensin II

Peripheral Vasoconstriction

Afterload

Cardiac Output

Heart FailureHeart Failure

Cardiac Workload

Preload

Plasma Volume

Salt & Water Retention

Edema

Aldosterone Secretion

ACE

Kaliuresis

BetaBetaStimulationStimulation

• COCO• NaNa++

Fibrosis

Drug Therapy

Heart Failure Treatments: Medication Types

•ACE inhibitor (angiotensin-converting enzyme)

•ARB (angiotensin receptor blockers)

•Beta-blocker•Digoxin

•Diuretic

•Aldosterone blockade

Type What it does•Expands blood vessels which

lowers blood pressure, neurohormonal blockade

•Similar to ACE inhibitor—lowers blood pressure

•Reduces the action of stress hormones and slows the heart rate•Slows the heart rate and improves the heart’s pumping function (EF)

•Filters sodium and excess fluid from the blood to reduce the heart’s workload•Blocks neurohormal activation and controls volume

Rational for Medications(Why does my doctor have me on

so many pills??)• Improve Symptoms

– Diuretics (water pills)– digoxin

• Improve Survival– Betablockers– ACE-inhibitors– Aldosterone blockers– Angiotensin receptor

blockers (ARB’s)

Lifestyle Changes

•Eat a low-sodium, low-fat diet

•Lose weight

•Stay physically active

•Reduce or eliminate alcohol and caffeine

•Quit Smoking

What Why•Sodium is bad for high blood pressure, causes fluid retention

•Extra weight can put a strain on the heart

•Exercise can help reduce stress and blood pressure

•Alcohol and caffeine can weaken an already damaged heart

•Smoking can damage blood vessels and make the heart beat faster

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Device Therapy:Biventricular Pacing

Overview of Device Therapy 25

Biventricular PacingVentricular Dysynchrony

• Abnormal ventricular conduction resulting in a mechanical delay and dysynchronous contraction

BiV Pacing

Cardiac Resynchronization TherapyKey Points

• Indications– Moderate to severe CHF who have failed optimal

medical therapy– EF<30%– Evidence of electrical conduction delay

• Timing of Referral Important– Patients often not on optimal Medical Rx– Patients referred too late- Not a Bail Out

Defibrillators (ICD’s)

Heart Failure and Sudden Cardiac Death

Sudden Cardiac Death (SCD) – Your heart suddenly goes into a very fast and chaotic

rhythm and stops pumping blood

– Caused by an “electrical” problem in your heart

– SCD is one of the leading causes of death in the U.S. – approximately 450,000 deaths a year

– Patients with heart failure are 6-9 times as likely to develop sudden cardiac death as the general population

How does a defibrillator for sudden cardiac death work?

Device Shown:Combination Pacemaker & Defibrillator

Implantable Cardiac Defribrillators

EBM Therapies Relative RiskReduction

Mortality2 year

ACE-I 23% 27%

Β-Blockers 35% 12%

Aldosterone Antagonists

30% 19%

ICD 31% 8.5%

Who should Consider an ICD?• Patients with weakend heart, New York

Heart Association (NYHA) Class II and III heart failure, and measured left ventricular ejection fraction (LVEF) < 35%

• Patients who meet all current requirements for a cardiac resynchronization therapy (CRT) device and have NYHA Class IV heart failure;

Other Therapies?

• Transplant• Artificial hearts• New “gadgets” to help doctors manage

heart failure

Heart Transplantation

• A good solution to the failing heart– get a new heart

• Unfortunately we are limited by supply, not demand

• Approximately 2200 transplants are performed yearly in the US, and this number has been stable for the past 20 years.

Worldwide Heart Transplants

http://www.time.com/time/magazine/0,9263,7601841210,00.html

Newer Generation Artificial Hearts

Future Tech

Intrathoracic Impedance for Heart Failure

One of the Best Devices for Monitoring Heart Failure

What have we learned?

In Summary….

• Heart failure is common and has high mortality• Drug therapy improves survival

– Betablockers, ACE-I, aldosterone antagonists• Newer device therapies are showing promise for

symptom relief and improved survival– Biventricular pacing, ICD’s

• Transplants remain rare, but technology for mechanical assist devices continues to improve- stay tuned!