ACS Caused by SCAD-experience from shanghai sixth people’s hospital

Shixin Ma

Shanghai Sixth People’s Hospital

Spontaneous Coronary Artery Dissection (SCAD)

Incidence and Prevalence

ranging from 0.1% to 1.1% in most angiographic series

The prevalence and incidence of SCAD have been largely

underestimated

• initial presentation as sudden death

• underuse of coronary angiography (CAG) in young females with chest

pain

• the well-known inherent limitations of CAG to detect disease of the

vessel wallCirculation 2012; 126: 667 – 670.

Can J Cardiol 2013; 29: 1027 – 1033.

Int J Cardiol 2014; 175: 8 – 20.

Pathogenesis

Causation:

• An intimal tear

• Primary disruption of the “vasa vasorum”

The term “SCAD” generally implies and is synonymous with “non-

atherosclerotic SCAD”

Circulation 2012; 126: 667 – 670.

Can J Cardiol 2013; 29: 1027 – 1033.

Int J Cardiol 2014; 175: 8 – 20.

Pathogenesis for SCAD

Intimal tear

Circ J 2014; 78: 2099 – 2110

JACC Cardiovasc Imaging 2013; 6: 830 – 832.

Intramural hematoma without contrast indicating

vasa vasorum rupture

Predisposing factors

Pregnancy and postpartum are high-risk periods in young

females.

• Estrogen modifies the arterial wall architecture, inducing hypertrophy of

the smooth muscle cells, loosens the intercellular matrix with an increase

in acid mucopolysaccharides and decrease in collagen production.

Accumulation of eosinophilic and cytotoxic activity of these cells

might lead to cystic medial necrosis.

An association between SCAD and fibromuscular dysplasia

Cardiovasc Res 1997; 33: 527 – 532.

Circulation 2012; 126: 667 – 670.

Can J Cardiol 2013; 29: 1027 – 1033.

Int J Cardiol 2014; 175: 8 – 20.

SCAD associated With FMD?

FMD is a non-inflammatory, non-atherosclerotic vascular disease

of unknown etiology.

It tends to affect young females and usually presents as arterial

stenosis, aneurysms, dissection or thrombosis.

The renal and carotid arteries are most often affected.

The angiographic characteristics present “string of beads”

appearance that is the hallmark of this disease.

Studies showed 25-50% SCAD patients had non-coronary FMD.

Association With FMD

Circulation 2012; 126: 667 – 670.

baseline Follow-up Angiogram of the right renal artery

showing irregular beading of the

mid-segment (arrow) of the main

renal artery, representing FMD in

this woman with SCAD.

Triggers

Emotion stress

vigorous physical exercise

repeat coughing or squeezing

blunt chest trauma

cocaine abuse

coronary spasm

Diagnosis Approach

CAG remains the main diagnostic tool for the diagnosis of SCAD.

• A diffuse lesion in a young patient with smooth appearance in the

remaining coronary arteries should always raise the clinical

suspicious of an underlying intramural hematoma.

CTA is the important diagnostic tool for large vessels.

• Presenting a double lumen or a low-density signal surrounding the

lumen.

Typical CAG image for SCAD

baseline Follow-up

Diffuse long stenosis with smooth appearance in the remaining coronary arteries

Circulation 2012; 126: 667 – 670.

The value of CTA for diagnosis of SCAD

Diagnosis Approach

IVUS is critical for the diagnosis of intramural hematoma.

The diagnostic value of IVUS

IVUS gives a clear picture of the vessel wall (axial resolution 150

μm) and can identify the intramural hematoma.

Because of inadequate resolution, sometimes the dissection

flap or intimal rupture may be difficult to visualize.

Diagnosis Approach

OCT is also very important for diagnosis of SCAD.

OCT is more sensitive for identification of intimal

tear and thrombus (both in true and false lumen)

J Am Coll Cardiol 2012;59:1073–1079

The diagnostic value of OCT

Superiority over IVUS: Superior resolution of this technique (15

μm) helps to identify the “entry door” (intimal tear).

Disadvantage:

• Need complete blood-free lumen.

• Expensive and not popular.

Treatment

Management of patients with SCAD remains empirical and

controversial.

conservative medical management (recommended for most

patients)

• Classically, thrombolytics and glycoprotein IIb/IIIa inhibitors are considered to be

contraindicated. So accurate diagnosis is crucial.

• Potent antiplatelet drugs and anticoagulants may act as a double-edged sword in this

challenging condition.

• Calcium-channel blockers are recommended in patients with vasospastic vessels.

• Beta-blockers are considered the mainstay of therapy.

• Statins are untested in SCAD

Treatment

PCI

• Overall technical success rate of PCI was only 65% (28/43 procedures).

• PCI should be considered in patients with localized proximal dissections

in large vessels associated with ongoing ischemia or with a TIMI

grade 0–1 coronary flow.

Surgery

• Almost no consideration.

Intramural hematoma can be pushed forward or

backward by stents

Case Rep Med. 2013;2183-2189

A: Diffuse narrowing in mid- and prox-LAD with TIMI flow grade 1; A’: OCT shows

intramural hematoma; B and B’: fenestration of hematoma using scoring balloon guided

by OCT; C and C’: BVS was deployed in proximal LADCirc Cardiovasc Interv. 2015;8:e002266

Fenestration of diffuse intramural hematoma by

scoring balloon and stenting of dissection site

Concern about PCI of SCAD

Late stent malapposition with resorption of intramural hematoma

is a concern for very late stent thrombosis.

The use of a cutting balloon to fenestrate the membrane and

decompress the false lumen.

The use of bioresorbable vascular scaffolds appears very

attractive and promising.

Experience for SCAD from

Shanghai Sixth People’s Hospital

Demography, Incidence and Prevalence for SCAD

Age Female Incidence

50.9 y/o (28-68) 71.4% (2/7) 1.2% (6/508)

2014.1-2015.12

Except for one

patient in 2011.12

Triggers

Postpartum Emotion stress others

14.3% (1/7) 57.1% (4/7) 28.6% (2/7)

Clinical characteristics

STEMI Vessel involved Diagnosed by

LAD Cx RCA CAG CAG+CTA CAG+IVUS

85.7% (6/7) 42.8% (3/7) 0 57.2% (4/7) 28.5% (2/7) 14.3% (1/7) 57.2% (4/7)

and intra-

luminal

thrombus

was detected

by IVUS in 1

patient

Diagnosis only by CAG (confirmation by follow-up)

Female 55 y/o; presented with STEMI

(inferior wall)

Female 28 y/o; presented with STEMI

(anterior wall)

Diagnosis by CAG+CTA

Female 60 y/o; presented with NSTEMI

Diagnosis by CAG+IVUS

Male 58 y/o; presented with STEMI (inferior wall)

Intra-luminal thrombus was detected by IVUS

Male 58 y/o; presented with STEMI (inferior wall)

Treatment

Conservative

therapy

PCI Standard

antithrombotic

therapy

Conservative

antithrombotic

therapy

85.7% (6/7) 14.3% (1/7) 14.3% (1/7) 85.7% (6/7)

All the patients were followed up with good prognosis

Conservative therapy and prognosis

The RCA picture STEMI occured CTA picture 4 months later

Conservative therapy and prognosis

CTA image at ACS CTA image at 6 months follow-up

Conservative therapy and prognosis

CAG image at ACS CTA image at 1 year follow-up

Stenting the intramural hematoma site

29 y/o female patent presented with STEMI (inferior wall); stent: PE 3.5*38mm released by 12atm

Hematoma was pushed ahead by stent

Proximal end of the stent About 9mm hematoma before the stent

1 year follow-up

Intramural hematoma dissolved and no late stent malapposition maybe because

of enough stent size

Summary

SCAD is much more prevalent as compared to our

imagination.

Emotion stress and pregnancy or postpartum are often

triggers.

Angiography is essential, CTA maybe useful, IVUS and OCT

are always critical for detection of SCAD.

Conservative therapy should be considered for most of

SCAD patients