Transcript File - CENTER FOR AORTIC DISEASE

THE DOCTORS GUIDE
TO PATIENT SURVIVAL
AFTER ACUTE AORTIC DISSECTION
Mark J. Russo, MD, MS
Co-Director, Center for Aortic Diseases
University of Chicago
THE NUMBERS
• Incidence - uncertain
– 5,000 – 15,000 cases/year in U.S.
– Likely higher (not reportable condition, few autopsies now)
• Autopsy series – 0.2% autopsies
• Males 2-5x > females
• Ascending dissections: 50-55 years old
– <40 years: Marfan, pregnancy, AV disease
• Descending dissections: 60-70 years old
NATURAL HISTORY
NATURAL HISTORY
• 1934 Shennan: >300 cases autopsies reviewd
40% acute ascending dissections died suddenly
None lived > 5 weeks
• 1972 Anagnostopoulos : 973 pts w untreated proximal and
distal dissections
50% died with 48 hours
84% died within 1 month
NATURAL HISTORY
• As many as 40% die before reaching the
hospital
• Mortality increases 1-3% per hour
• At 48 hours, 50% are dead
• At 2 weeks 75-90% are dead
MECHANISM
MECHANISM
• Initiating event may be
is a primary rupture of
the intima with
secondary dissection of
the media
-- OR -• Hemorrhage within the
media and subsequent
rupture of the
overlying intima.
MECHANISM
• Blood flow is
redirected from the
“true lumen” of the
aorta into a “false
lumen”
MECHANISM
• As a result, dissection
propagates in
“dissection plane”
separating the intima
from the overlying
adventitia
• Usually the dissection
proceeds distally/
retrograde/direction of
blood flow
MECHANISM
• Dissection may
shear off or
extend into
branch arteries > complications
COMPLICATIONS - MALPERFUSION
arm ischemia
(25-60%)
Stroke
(3-13%)
arm ischemia
(25-60%)
Paralysis
(2-9%)
kidney dysfunction
(25%-75%)
MI (5-10%)
Tamponade (10%)
bowel ischemia
(10%-20%)
leg ischemia
(25-60%)
CLASSIFACTION
Debakey
I
II
IIIa
IIIb
Stanford
A
A
B
B
LOCATION OF DISSECTION
Type A vs B Determines
Management,
but . . .
It Is Not Your Role To
Differentiate Type A vs B
YOUR ROLE
• Diagnosis
– Suspicion
• Treatment
– Medical Management - Always
– Consult a Surgeon - Always
TIME MATTERS
• As many as 40% die before reaching the hospital
• Mortality increases 1-3% per hour
• At 48 hours, 50% are dead
• At 2 weeks 75-90% are dead
DIAGNOSIS
Most important factor
leading to a correct diagnosis is
a high clinical suspicion
PRESENTATION
• Pain - severe chest, back, and/or limb – 90%
• Severe uncontrolled hypertension – 50-60%
• Loss of consciousness (syncope) – 15%
• Weakness
• Difficulty walking
• Slurred speech
• Blurry/loss or vision
PAIN CHARACTERISTICS
• Occurs in 90% of cases
– Ripping, tearing
– Migratory
– Never experienced before
– Restless, sense of doom
• Most Severe at Onset
– Anterior Pain: Proximal Dissection
– Posterior Pain: Distal Dissection
– Migratory Pain
PAIN CHARACTERISTICS
• Chest pain – 2/3
• Back pain – 1/2
• Abdominal pain – 1/3
• Painless dissection is relatively uncommon (6.4%)
– Presenting symptoms of syncope, heart failure, or stroke were
seen more often in this group.
• Pain in these locations usually due to other more common
disorders (MI, pneumonia, pleurisy, pulmonary embolism,
pneumothorax, ulcer, cholecystitis, pancreatitis) BUT….
Must consider aortic dissection in
cases without other confirmed
cause of pain
RISK FACTORS
•
Hypertension - Present in 70-90% of dissections, but 20-40% of adults
•
Aortic aneurysm – 13%
•
Family history of aortic disease – 19%
•
Connective tissue diseases - Marfans (2%), Ehlers-Danlos, Lowy-Dietz
•
Bicuspid aortic valve – 1%
•
Aortic coarctation
•
Turner syndrome
•
Cardiac intervention – CABG, AVR, Cath (2%)
•
Pregnancy
•
Trauma
•
High Intensity weightlifting
•
Crack – 37% in an inner city population, usually < 12 hours after last use
PHYSICAL EXAMINATION
•
Acutely ill
•
Tachycardia
•
Hypertension – particularly if severe HTN
– Results catecholamines, renal ischemia
•
Hypotension (20%)
– Due to acute complications
•
Widen Pulse Pressure
– Aortic insufficiency: (50-60% ascending dissections)
•
Differential pressure from Left to Right Arm (when dissection is distal to BCA)
•
Pulse deficits: (60% ascending dissections)
– May change over time
D-DIMER
•
D-Dimer is an important and well-known marker for pulmonary embolism
(PE), especially in outpatients and the emergency department.
•
Also a biomarker for aortic dissection, because of the associated large
intramural hematoma often present in aortic dissections.
•
Initial D-Dimer value in symptomatic patients with concerns for aortic
dissection:
•
D-Dimer < 0.5 μg/ml: Thoracic Ascending Aortic Dissection unlikely
•
D-Dimer >1.6 μg/ml: Thoracic Ascending Aortic more likely,
– proceed with aortic imaging with CT C/A/P with IV contrast or TEE
•
Thoracic Ascending Aortic Dissection (TAAD) elevates D-Dimer Earlier
Than Pulmonary Embolus
CXR
• Mediastinal widening - 63% w type A dissections
• Pleural effusion - 19% of dissections
• Other findings:
– widening of the aortic contour,
– displaced calcification,
– aortic kinking, and
– opacification of the aorticopulmonary window
• Normal - 11%
CXR
Features of acute type A
dissection,
CXR
Features of acute type A
dissection,
• Widened
mediastinum
CXR
Features of acute type A
dissection,
• Widened
mediastinum
• Rightward tracheal
displacement
CXR
Features of acute type A
dissection,
• Widened
mediastinum
• Rightward tracheal
displacement
• Irregular aortic
contour with loss of
the aortic knob
CXR
Features of acute type A
dissection,
• Widened
mediastinum
• Rightward tracheal
displacement
• Irregular aortic
contour with loss of
the aortic knob
• Indistinct
aortopulmonary
window
• Left pleural effusion
A diagnosis of dissection should not
rest on a CXR
IMAGING - PURPOSE
• Dissection flap
• Dilated aorta
• Aortic insufficiency
• Pericardial effusion
• Involvement of the ascending aorta
• Branch vessel or coronary artery involvement
• Extent of dissection and the sites of entry and reentry
• Thrombus in the false lumen
IMAGING - OPTIONS
• Most have multiple imaging studies performed
• mean of 1.83 per patient
• Transthoracic echocardiogram – 33%
• Transesophageal echocardiogram - 33%
• Computed tomography - 61%
• Aortography – 4%
• Magnetic resonance imaging – 2%
CT SCAN
• Sensitivity - 83 and 98%; specificity - 87 and 100%
• Advantages
– Availability at most hospitals
– Identification of intraluminal thrombus and pericardial
effusion
• Disadvantages
–
–
–
–
Intimal flap is seen in < 75%
Site of entry is rarely identified
Nephrotoxic iodinated contrast is required
No capability to assess for aortic insufficiency
CT
CT
Transthoracic Echo
• Sensitivity and specificity inferior to CT, MRI, and TEE
• Advantages
– Noninvasive
– Fast, low risk
– Intimal flap may be seen in the proximal aorta in some
patients
– Useful for the assessment of cardiac complications of
dissection, including aortic insufficiency, pericardial
effusion/tamponade, and RV function.
• Disadvantages - inability to adequately visualize the distal
ascending, transverse, and descending aorta in a substantial
majority of patients
Transesophageal Echo
•
•
•
Sensitivity 97 to 99 percent; , the specificity 77 to 85 percent
Advantages
– Rapid; useful in patients too unstable for CT/MRI
– True and false lumens can be identified
– Intimal dissection flaps can be identified
– Thrombosis in the false lumen, pericardial effusion, concomitant aortic
regurgitation, and the proximal coronary arteries can be readily
visualized.
Disadvantages
– Requires esophageal intubation
– Requires the availability of experienced operators (both physicians and
technicians)
– Inability to visualize the upper portion of the ascending aorta due to the
interposed trachea (between the aorta and esophagus).
MRI
•
Sensitivity and specificity of MRI were both 98%
•
Advantages
•
–
85% sensitivity for identification of the site of entry
–
MR contrast agents have a more favorable safety profile than iodinated contrast agents.
–
ability to assess branch vessels.
Disadvantages
–
Long study
–
limited applicability (MRI cannot be performed in patients with claustrophobia, pacemakers,
or certain types of aneurysm clips or metallic ocular/auricular implants).
–
not readily available on an emergency basis at many institutions
–
concerns about patient monitoring and relative patient inaccessibility during prolonged
scanning
–
Unable to assess for aortic insufficiency
MANAGEMENT
• Mean arterial pressure of 60-75 mmHg:
• 1st line treatment: Beta blockers (eg esmolol, propranolol, or
labetalol)
• If there is a contraindication to beta blockers, calcium-channel
blockers (eg verapamil and diltiazem) can be used
• For refractory hypertension: Nitroprusside, in addition to a beta- or
calcium-channel blockers.
• DO NOT USE: Hydralazine or minoxidil or beta-blockers with
intrinsic sympathomimetic action (eg, acebutolol, pindolol)
MANAGEMENT
• It is not your job to make a definitive
diagnosis
• If you suspect….call a surgeon
– Call a surgeon
– Call a surgeon
RITTERS RULES
• Life-saving reminders to recognize, treat and
prevent thoracic aortic dissection
• Named for actor John Ritter, who died of a
thoracic aortic dissection, Ritter Rules combine
knowledge with action.
• Address urgency, symptoms, who is most at
risk and which imaging tests
URGENCY
• Thoracic aortic dissection is a medical
emergency.
• The death rate increases 1% every hour the
diagnosis and surgical repair are delayed.
PAIN
• Severe pain is the #1 symptom.
• Sudden onset of severe pain in the chest,
stomach, back or neck.
• is likely to be sharp, tearing, ripping, moving
or so unlike any pain you have ever had that
you feel something is very wrong.
MISDIAGNOSIS
• Aortic dissection can mimic heart attack.
• If a heart attack or other important
diagnosis is not clearly and quickly
established, then aortic dissection should be
quickly considered and ruled out,
– particularly if a patient has a family history or
features of a genetic syndrome that predisposes
the patient to an aortic aneurysm or dissection.
IMAGING
• Get the right scan to rule out aortic dissection.
• Only three types of imaging studies can identify
aortic aneurysms and dissections: CT, MRI and
transesophageal echocardiogram.
• A chest X-ray or EKG cannot rule out aortic
dissection.
RISK FACTOR
• Aortic aneurysm
• Family history
• Genetic Syndromes: Marfan syndrome, LoeysDietz syndrome, Turner syndrome and
vascular Ehlers-Danlos syndrome
• Bicuspid aortic valve
TRIGGER
• Trauma
• Extreme straining associated with body
building
• Illicit drug abuse
• Poorly controlled high blood pressure or by
discontinuing necessary blood pressure
medications.
• Pregnancy
PREVENTION
• Medical management is essential to
preventing aortic dissection. If you have
thoracic aortic disease, medical
management that includes optimal blood
pressure control, aortic imaging and genetic
counseling is strongly recommended. Talk
with your physician.