Transcript Update in Heart Failure - Dartmouth

Heart Failure: Living with a
Hurting Heart
James T. DeVries, MD
Dartmouth-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 synchronized way.
Heart Failure Heart
A heart failure heart has a reduced ability to 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
Risk Factors for Heart Failure
• Coronary artery
• Diabetes
disease
• Congenital heart defects
• Hypertension (LVH)
• Valvular heart disease • Other:
– Obesity
• Alcoholism
– Age
• Infection (viral)
– Smoking
– High or low hematocrit level
– Obstructive Sleep Apnea
CAD=coronary artery disease; LVH=left ventricular hypertrophy.
Epidemiology of Heart Failure
in the US
Heart Failure Patients in US
(Millions)
12
10
10
8
• 550,000 new cases/year
6
4
• More deaths from heart failure
than from all forms of cancer
combined
4.7
• 4.7 million symptomatic
patients; estimated 10 million
in 2037
3.5
2
0
1991
2000
2037*
*Rich M. J Am Geriatric Soc. 1997;45:968–974.
American Heart Association. 2001 Heart and Stroke Statistical Update. 2000.
“Wow! Brazil is big."
—George W. Bush, after being shown a
map of Brazil by Brazilian president Luiz
Inacio Lula da Silva, Brasilia, Brazil, Nov.
6, 2005
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
ACC/AHA HF Stage1
NYHA Functional Class2
None
A At high risk for heart failure but without
structural heart disease or symptoms
of heart failure (eg, patients with
hypertension or coronary artery disease)
B Structural heart disease but without
symptoms of heart failure
C Structural heart disease with prior or
current symptoms of heart failure
D Refractory heart failure requiring
specialized interventions
I
Asymptomatic
II
Symptomatic with moderate exertion
III Symptomatic with minimal exertion
IV Symptomatic at rest
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.
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
Pathologic Progression of CV Disease
Sudden
Death
Coronary artery
disease
Hypertension
Diabetes
Myocardial
injury
Pathologic
remodeling
Low ejection
fraction
Death
Cardiomyopathy
Pump
failure
Valvular disease
• Neurohormonal
stimulation
• Myocardial
toxicity
Adapted from Cohn JN. N Engl J Med. 1996;335:490–498.
Symptoms:
Dyspnea
Fatigue
Edema
Chronic
heart
failure
Compensatory Mechanisms:
Renin-Angiotensin-Aldosterone System
Beta
Stimulation
• CO
• Na+
Renin + Angiotensinogen
Angiotensin I
ACE
Angiotensin II
Peripheral
Vasoconstriction
Kaliuresis
Aldosterone Secretion
Salt & Water Retention
 Plasma Volume
 Afterload
 Cardiac Output
 Preload
 Cardiac Workload
Heart Failure
Fibrosis
Edema
Drug Therapy
Heart Failure Treatments:
Medication Types
Type
What it does
•ACE inhibitor
(angiotensin-converting
enzyme)
•Expands blood vessels which lowers
blood pressure, neurohormonal
blockade
•ARB (angiotensin receptor
blockers)
•Similar to ACE inhibitor—lowers
•Beta-blocker
•Reduces the action of stress
blood pressure
hormones and slows the heart rate
•Digoxin
•Slows the heart rate and improves the
heart’s pumping function (EF)
•Diuretic
•Filters sodium and excess fluid from the
blood to reduce the heart’s workload
•Aldosterone
blockade
•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
What
Why
•Eat a low-sodium, low-fat
diet
•Sodium is bad for high blood pressure,
causes fluid retention
•Lose weight
•Extra weight can put a strain on
the heart
•Stay physically active
•Exercise can help reduce stress
and blood pressure
•Reduce or eliminate alcohol
and caffeine
•Alcohol and caffeine can weaken an
•Quit Smoking
•Smoking can damage blood vessels and
make the heart beat faster
already damaged heart
"During my service in the United States
Congress, I took the initiative in creating the
Internet"
Al Gore said when asked to cite
accomplishments that separate him from
another Democratic presidential hopeful, former
Sen. Bill Bradley of New Jersey, during an
interview with Wolf Blitzer on CNN on March 9,
1999.
Device Therapy:
Biventricular Pacing
Biventricular Pacing
Ventricular Dysynchrony
• Abnormal ventricular conduction resulting
in a mechanical delay and dysynchronous
contraction
Overview of Device Therapy
25
BiV Pacing
Cardiac Resynchronization Therapy
Key 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 Risk
Reduction
Mortality
2 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
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 improvestay tuned!