Acute Aortic Syndromes

By

Dr. Tamer Taha Ismail

Associate Professor of Cardiology, GMU

Specialist Cardiology , Thumbay Hospital , Dubai

Acute aortic syndrome is a modern term, that

consists of interrelated emergency conditions with

similar clinical characteristics and challenges.

Causes include:• Aortic dissection• Intramural hematoma• Penetrating ulcer• Traumatic transection

Erbel R, Alfonso F, Boileau C, Dirsch O, Eber B, Haverich A, et al. Diagnosis and management of aortic dissection. Eur Heart J 2001;22:1642-81.

Hayter RG, Radiology 2006; 238:841-852

Suspected Acute Aortic SyndromeMDCT in 373 Emergency Evaluation

• N=365 patients; men: 56%; women: 44%

• Mean age: 61 years old.

• 67 cases (18%) positive for acute aortic disorders (n=112)• Acute Aortic Dissections: 23 (34%) ; A=13 (19%), B=10 (15%) • Acute Aortic IMH: 14 (21%); A=1 (2%), B=13 (19%)• Acute penetrating ulcer: 20 (30%); A=3 (5%), B=17 (25%)• New or enlarging aortic aneurysms: 44 (67%)• Acute Aortic ruptures: 11 (17%)

• Overall hospital mortality: 6%.

Hayter RG, Radiology 2006; 238:841-852

Diagnosis of Chest Pain in the ER

0% 5% 10% 15% 20% 25%Percentage

Aortic dissectionNo clear diagnosis

Cardiac arrhythmiaVasovagal

Pulmonary diseaseNeuro-radicular pain

Acute coronary syndromes

ED Diagnosis

von Kodolitsch Y, et al. Arch Intern Med. 2000;160:2977-82.

Contributing conditions for aortic dissectionEpidemiology

75%

Contributing conditions for aortic dissection

Genetic risk factors• Usually Autosomal Dominant.

• Strongest in younger patients, particularly aortic

dissection and thoracic aneurysm.

• 20% of patients have an underlying genetic disorder

and altered connective tissues (Marfan syndrome,

Turner syndrome, or Ehlers–Danlos syndrome,

especially Type IV).

AORTIC DISSECTION • Most common aortic catastrophe.

• Incidence: 5 - 30 per 1 million

people/year

• Primary tear in aortic intima with

bleed into diseased media.

• Rupture of vasa vasorum -->

Hemorrhage in aortic wall with

subsequent intimal disruption.

Classification

According to time from onset of symptoms to

presentation, dissection is classified into:

1- Acute dissection: within 2 weeks of onset.

2- Subacute: 2 to 6 weeks from onset.

3- Chronic: > 6 weeks from onset.

Anatomical Classification • Aortic dissection can be classified according to the

origin of intimal tear or whether the dissection

involves the ascending aorta (regardless of the site of

origin).

• Accurate classification is important as it drives

decisions regarding surgical vs. non-surgical treatment.

• The two most commonly used classification schemes

are the DeBakey and the Stanford systems.

For purposes of classification, the ascending

aorta refers to the aorta proximal to the

brachiocephalic artery, and the descending

aorta refers to the aorta distal to the left

subclavian artery.

The DeBakey classification system is based on the origin

of the intimal tear and the extent of the dissection

• Type I: Dissection originates in the AA and propagates

distally to include at least the aortic arch and typically the

DA (surgery usually recommended).

• Type II: Dissection originates in and is confined to the AA

(surgery usually recommended).

The DeBakey classification system is based on the origin of the

intimal tear and the extent of the dissection.

• Type III: Dissection originates in the DA and

propagates most often distally (non-surgical treatment usually

recommended)

* Type IIIa: Limited to the descending thoracic aorta

* Type IIIb: Extending below the diaphragm

The Stanford classification system classifies dissections into 2 categories, those that involve the AA and those that do not.

• Type A: involve the AA regardless of the site of origin (surgery

usually recommended)

• Type B: do not involve the AA (non-surgical treatment usually

recommended)

Involvement of the aortic arch without involvement of AA in the

Stanford classification is labelled as Type B.

Aortic dissection classificationDeBakey and Stanford classifications

Intramural Hematoma

• Rupture of vasa vasorum or plaque collection of blood in media w/o

intimal tear.• May extend toward lumen and lead to dissection.• High rate of rupture.• Ascending aorta IMHs are surgical.

Penetrating atherosclerotic ulcer

•Erosion of intimal plaque into media•May lead to IMH, dissection, aneurysm, or rupture

Clinical symptoms associated with AASs

Clinical signs associated with AASs

Clinical symptoms associated with AASs

Prognostic considerations

Risk of death is increased in patients who present with

or develop complications of pericardial tamponade,

involvement of coronary arteries causing AMI, or

malperfusion of the brain.

Other predictors of increased in-hospital death include

age (≥70 years), hypotension or cardiac tamponade,

RF, and pulse deficits.

Prognostic considerations

In the absence of immediate surgery, medical treatment

of proximal dissection is associated with a mortality of

20% by 24 h after presentation, 30% by 48 h, 40% by Day

7, and 50% by 1 month.

Even with surgical repair, mortality rates are 10% by 24 h,

13% by 7 days, and 20% by 30 days.

Prognostic considerations Patients with uncomplicated Type B dissection have a 30-

day mortality of 10%.

However, patients who develop ischaemic complications

such as RF, visceral ischaemia, or contained rupture often

require urgent aortic repair which carries a mortality of

20% by Day 2 and 25% by Day 3.

Diagnostic evaluation by imaging modalities

Clinical suspicion of AAS Non Imaging Tests:

ECG, chest radiography, biomarkers

(Troponin and D-dimer tests).

Imaging tests: TEE & MDCT with CTA

Aim of imaging tests :

1. Confirmation of clinical suspicion.

2. Classification of dissection.

3. Localization of tears.

4. Assessment of both the extent of dissection and

indicators of emergency (e.g. pericardial,

mediastinal, or pleural haemorrhage).

•Selection of most appropriate imaging study

depends upon:

• Patient factors: hemodynamic status, renal failure,

contrast allergy.

• Availability.

• Initial imaging modality was CT(61%),

TEE(33%), MRI(1%)

MDCT•Advantages:

• Availability• Entire aorta imaged + coronaries• Short time• Branch vessels

MRI• Advantages:

• No radiation.• Identification of anatomic variants of AoD.

• Disadvantages:• Prolonged duration: This disadvantage is the main reason why MRI is not currently included in the diagnostic workup of AASs.

• Gadolinium contrast not used in renal impairment.

Echocardiography

• Proximal AoD:

• TEE sensitivity 88-98%,specificity 90-95%

• TTE 77-80% and 93-96%

• Distal Aorta Dissection: TEE better

• TEE blind spot: distal ascending aorta & prox.

arch, interposition of trachea & Lt. main bronchus.

Treatment concepts• AASs (dissection or IMH) involving the ascending aorta

are surgical emergencies.

• In selected cases, hybrid approaches of an endovascular

and open surgery may be considered.

Treatment concepts

Conversely, acute aortic pathology confined to the

descending aorta is treated medically unless complicated by

organ or limb malperfusion, progressive dissection, extra

aortic blood collection (impending rupture), intractable pain

or uncontrolled hypertension.

Type A

Type B

Initial medical therapy

Initial management of AAS, particularly

dissection, is directed at limiting propagation of

dissected wall by control of BP and reduction in

dP/dt (shear force ).

Reduction in BP to just maintain sufficient end-

organ perfusion.

Initial medical therapy

First-line therapy is intravenous b-blockade is useful for

lowering both BP and dP/dt, with a target SBP of 100–

120 mmHg and HR of 60–80 bpm.

Often multiple agents are required, with patients ideally

managed in an ICU.

Opiate analgesia should be prescribed to attenuate the

sympathetic release of catecholamines to pain with

resultant tachycardia and hypertension.

Initial medical therapy Endovascular intervention is dictated by the site

of the lesion and evidence of complications

(persisting pain, organ malperfusion), as well as

evidence of disease progression on serial

imaging

There is no evidence for endovascular repair of

uncomplicated Type B dissection.

Long-term follow-up

The 10-year survival rate of patients with AAS

who leave the hospital ranges from 30 - 60% in

different studies.

Dissection of the aorta represents a systemic

problem with the entire aorta and its branches

predisposed to dissection, aneurysm formation,

and/or aortic rupture in the future.

Long-term follow-up

Systemic hypertension, advanced age, aortic size, and the

presence of a patent false lumen are all predictors of late

complications.

Therefore, medical therapy including b-blockers is needed to

minimize aortic wall stress, and serial imaging to detect signs

of progression, redissection, or aneurysm formation.

Conclusions

Technological advances in imaging techniques and better

understanding of the pathophysiology of acute aortic

conditions have lead to the discovery of variants known as

AAS.

Furthermore, various surgical and percutaneous

endovascular treatment strategies are established and

continue to improve.

As a result of increasing scientific interest, outcomes of

patients treated for AASs have also improved.

However, clinical pathways that facilitate efficient care

similar to ACS or stroke are not yet implemented.

Meanwhile, emerging serum biomarkers may soon offer

hope for easier identification of patients with AAS.

Finally, continued enthusiasm and further technical

improvement will eventually improve the management of

low-incidence–high-impact AAS.

THANK YOU