INDICATIONS OF CABG

DR ALTAF HUSSAIN JATOIRESIDENT CARDIAC SURGERY CIVIL HOSPITAL KARACHI.

INTRODUCTION

1991 guidelines: the evidence is complete that the coronary artery bypass operation relieves angina in most patients.

Bypass surgery also relieved angina better than coronary stents in a randomized trial

Relief angina symptoms and prolongation of life

7~8 yrs survival superior for CABG compared with PTCA.

EARLY INTERVENTION OF CABG

Advantage Limitation of infarct expansion Avoidance of LV dysfunction, heart failure

Disadvantage Ischemia-reperfusion injury hemorrhagic

infarction

The best window for intervention is quite an art

2004 ACC/AHA GUIDELINES Class I:

procedure/treatment should be performed/ administered

Class IIa:

it is reasonable to perform/administer Class IIb:

procedure/treatment is considered Class III:

procedure/treatment is not helpful and may be harmful

ASYMPTOMATIC OR MILD ANGINA

Indications: class I Significant (50%) left main coronary artery stenosis. Significant (greater than or equal to 70%) stenosis of the

proximal LAD and proximal left circumflex artery. 3-vessel disease (EF less than 0.50)

Indications: class IIa proximal LAD stenosis with 1- or 2-vessel disease. ( Class I

if extensive ischemia is documented by noninvasive study and/or LVEF is less than 0.50.)

Indications: class IIb 1- or 2-vessel disease not involving the proximal LAD (If a

large area of viable myocardium and high-risk criteria are met on noninvasive testing, this recommendation becomes Class I)

STABLE ANGINA Indications: Class I

Significant (50%) left main coronary artery stenosis. Significant (greater than or equal to 70%) stenosis of

the proximal LAD and proximal left circumflex artery.

3-vessel disease (benefits greater: EF less than 0.50 ) 2-vessel disease with significant proximal LAD

stenosis and either EF less than 0.50 or ischemia on noninvasive testing

1- or 2-vessel CAD without significant proximal LAD stenosis but with a large area of viable myocardium and high-risk criteria on noninvasive testing

Disabling angina despite maximal noninvasive therapy

Indications: class II Proximal LAD stenosis with 1-vessel disease

STABLE ANGINA

The patient factors most influencing a decision to recommend CABG Presence of severe proximal multivessel coronary

disease LV dysfunction Strongly positive stress test, Diabetes

PCA did not reduce the risk of death, myocardial infarction, stroke, or hospitalization when added to optimal medical therapy

UNSTABLE ANGINA/ NON-ST-SEGMENT ELEVATION (NSTEMI)

Indications: class I Significant (50%) left main coronary artery stenosis. Significant (greater than or equal to 70%) stenosis of the proximal LAD and LCX. Ongoing ischemia not responsive to maximal nonsurgical

therapy. Indications: class II

Proximal LAD stenosis with 1- or 2-vessel disease

UNSTABLE ANGINA/ NON-ST-SEGMENT ELEVATION (NSTEMI)

5-year overall survival: CABG (88.8%) or PTCA (86.1%, ) Cardiac mortality: PTCA (8.8%) vs CABG (4.9%)

The results for postoperative morbidity six predictors: sex, age, left ventricular function, timing

of surgery, extent of coronary artery disease and the type of myocardial protection used

ST-SEGMENT ELEVATION MI (STEMI)

Emergency or urgent CABG indication:Failed angioplasty (PTCA)Ventricular septal rupture or mitral valve

insufficiency In the early hours(6~12 hrs) of evolving STEMI Persistent or recurrent ischemia refractory to

medical therapyCardiogenic shock in <75 y/o, LBBBPost. MI developed shock within 36 hrs, CABG

should be performed within 18 hrs Life-threatening ventricular arrhythmias with

50% left mainstenosis and/or 3-vessels disease

ST-SEGMENT ELEVATION MI (STEMI)

Indications: Significant (50%) left main coronary artery stenosis. Significant (greater than or equal to 70%) stenosis

of the proximal LAD and LCX. Ongoing ischemia not responsive to maximal

nonsurgical therapy.

Risk factors: Besides time interval between MI and CABG Age renal insufficiency previous stroke LVEF< 40%

POOR LV FUNCTION

LVEF 0.31~0.35 0.26~0.30 <0.25

5 year-survival rate 73% 70% 62%

LVEF >50% <20%

Mortality rate 1.9% 6.7%

LVEF<0.25/0.35~0.5 Medical treatment CABG

5 year-survival rate 43%/ 50% 63%/ 62%

POOR LV FUNCTION

low EF and clinical heart failure are predictive of higher operative mortality rates with CABG

EFs less than 0.30: although having a higher immediate risk for

bypass surgery, may achieve a greater long-term gain in terms of survival advantage

CABG AFTER FAILED PTCA

Emergency bypass for failed PTCA a higher rate of death and subsequent MI compared with

elective bypass surgery Factors that influence the outcome of surgery

LV dysfunction, older age, and previous MI Extent of multivessel disease, collaterals Total ischemic time (a delay in transport to the operating

room) Cooperative interaction between the cardiologist,

cardiac surgeon, and anesthesia team are necessary to expedite resuscitation, transfer, and revascularization of patients with failed PTCA

PATIENTS WITH PREVIOUS CABG

Indication: Repeating angina despite optimal nonsurgical

therapy Vein grafts stenosis, native-vessel CAD

Percutaneous procedures have been ineffective in the treatment of atherosclerotic vein graft stenoses

Use of the left IMA to LAD graft, platelet

inhibitors and statin decreased reoperation rate

GETHOME MESSAGE

Indications for CABG: Significant (50%) left main coronary artery stenosis. Significant (greater than or equal to 70%) stenosis of

the proximal LAD and proximal left circumflex artery. 3-vessel disease (EF less than 0.50)

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