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 Stroke (3-13%) arm ischemia (25-60%) arm ischemia (25-60%) Paralysis (2-9%) kidney dysfunction (25%-75%) bowel ischemia (10%-20%) MI (5-10%) Tamponade (10%) 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

leading to a correct diagnosis is a high clinical suspicion 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 False Lumen True Lumen [tear]

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

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, Loeys-Dietz 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.