STENOTIC ATHEROSCLEROTIC CORONARY ARTERY DISEASE SATYA SHANBHAG WAIKATO

STENOTIC ATHEROSCLEROTIC CORONARY ARTERY DISEASE SATYA SHANBHAG WAIKATO CARDIOTHORACIC UNIT

DEFINITION Stenotic atherosclerotic coronary artery disease (CAD) is narrowing of the coronary arteries caused by thickening and loss of elasticity of their walls (arteriosclerosis) that, when sufficiently severe, limits blood flow to the myocardium.

ETIOLOGY • INCREASING AGE • DIABETES AND HIGH LIPIDS • RENAL DISEASE • HTN • SMOKING • STRONG FAMILY HISTORY • SEDENTARY LIFESTYLE, HIGH STRESS AND DIETARY HABITS

ATHEROSCLEROTIC PROCESS • LIPOID FOCI ARE ASSOCIATED WITH OR CONVERTED INTO PLAQUES OF FIBROUS OR HYALINE CONNECTIVE TISSUE • FIBROLIPOID PLAQUES MAY BECOME THICK ENOUGH TO ENCROACH ON THE LUMEN OF THE ARTERY, PRODUCING A STENOTIC LESION • GRADUAL REGRESSION OF PLAQUE ENLARGEMENT AND DEVELOPMENT OF COLLATERAL CORONARY BLOOD FLOW CAN RESULT IN AT LEAST PARTIAL SPONTANEOUS RESTORATION OF ANTEGRADE REGIONAL MYOCARDIAL BLOOD FLOW.

Plaque rupture Plaque erosion Age All age, 35 -80 30 -50 Inflammation Macrophages Lymphocytes Risk factors Hyperlipidemia, DM, smoking, genetic Smoking, genetic Incidence of sudden death 25 -30% 70 -75% TYPES OF PLAQUE PROGRESSION Gender Male > Female Male = female

ACS PATHOLOGY • FISSURING, OR RUPTURE, OF ATHEROSCLEROTIC PLAQUES IS THE GENESIS OF THE ACUTE CORONARY SYNDROMES TERMEDUNSTABLE ANGINA AND ACUTE MI • CORONARY STENOSIS THAT PRODUCE LESS THAN 50% REDUCTION IN LUMEN DIAMETER ARE OFTEN THE SITE OF THE ATHEROSCLEROTIC PLAQUE RUPTURE • RUPTURE IS THROUGH THE CAP OF THE PLAQUE, AND AREAS IN WHICH THE CAP LACKS UNDERLYING COLLAGEN SUPPORT SEEM PARTICULARLY VULNERABLE

TYPES OF CORONARY ARTERY DISEASE • STABLE ISCHEMIC HEART DISEASE (STABLE ANGINA) • ACUTE CORONARY SYNDROMES 1) UNSTABLE ANGINA/ NON- ST SEGMENT MI(NSTEMI) 2) ST SEGMENT ELEVATIONMI (STEMI)

DIAGNOSIS • SYMPTOMATOLOGY AND INITIAL ECG’S • CORONARY ANGIOGRAM • CORONARY INTRAVASCULAR ULTRASOUND • CT CORONARY ANGIOGRAM • FRACTIONAL FLOW RESERVE • ECHOCARDIOGRAM • CMR

CORONARY ANATOMY-ANGIOGRAM Left coronary artery: Includes the left main, LAD and the circumflex system. The LAD has one or more diagonal branches whereas the Cx has one or more obtuse marginal arteries

Left coronary artery: Surgeons view showing the LAD system with diagonal artery.

Left coronary artery: Spider view showing the LAD system on left and circumflex artery. Good view to see intermediate artery.

Right coronary artery: RCA with the posterior descending (PDA) and posterior-lateral (PLA).

Intramyocardial LAD artery: Intramyocardial LAD can cause step defect with stenosis. Also difficult to create anastomosis.

FRACTIONAL FLOW RESERVE (FFR)

ECHOCARDIOGRAM

CTCA

CMR AND ISOTOPE STUDY

MANAGEMENT- CABG

IMPORTANT TRIALS/RANDOMISED STUDIES • SYNTAX TRIALS : HOWED CABG IS SUPERIOR TO PCI IN MULTI-VESSEL ANDLMA DISEASE • FREEDOM TRIALS : HOWED CABG TO BE SUPERIOR TO PCI IN DIABETICS

SYNTAX TRIAL • SYNERGY BETWEEN PCI WITHTAXUS AND CORONARY SURGERY (20032007) • 1800 PATIENTS IN TOTAL PCI : ORCABG • MACCE(MAJOR CARDIAC AND CEREBROVASCULAR EVENT) CALCULATED • DEATH AND STROKE NOT DIFFERENT BETWEEN GROUPS AT 1 YR BUT SIGNIFICANTLY HIGHER AT 5 YRS WITHPCI • ALSO, PCI GROUP HAD INCREASED INCIDENCE OF MI, REQUIRED MORE REVASCULARISATION

AHA GUIDELINE 2014

STABLE ISCHAEMIC HEART DISEASE • CLASS I INDICATION : SIGNIFICANT LEFT MAIN DISEASE (>50%), LEFT MAIN EQUIVALENT DISEASE (PROXIMAL STENOSIS OF AT LEAST 70% OF LAD AND CIRCUMFLEX), TRIPLE VESSEL DISEASE (PATIENTS WITHLVEF <50% OR LARGE AREA OF MYOCARDIUM AT RISK) AND PROXIMAL LAD DISEASE WITHLVEF BETWEEN 35 -50%

STABLE ISCHAEMIC HEART DISEASE • CLASS IIA INDICATION: SIGNIFICANT LEFT MAIN DISEASE (>50%), LEFT MAIN EQUIVALENT DISEASE (PROXIMAL STENOSIS OF AT LEAST 70% OF LAD AND CIRCUMFLEX), TRIPLE VESSEL DISEASE (PATIENTS WITHLVEF <50% OR LARGE AREA OF MYOCARDIUM AT RISK) AND PROXIMAL LAD DISEASE WITHLVEF BETWEEN 35 -50%

ACS: UNSTABLE ANGINA/NSTEMI • INDICATION IS ANATOMICALLY IDENTICAL TO STABLE DISEASE • IN UA/NSTEMI, ACHIEVING REVASCULARISATION CREATES A STRONGER MOTIVE IN PREVENTING DEATH • INDICATION FOR CABG FURTHER STRENGTHENED BY ACUITY OF PRESENTATION, DEGREE OF ISCHAEMIA AND BENEFIT OF FULL REVASCULARISATION

ACS: STEMI • MAINSTAY OF TREATMENT IS THROUGH PRIMARYPCI AND IV THROMBOLYSIS • CABG IN ACUTE SETTING: ONGOING ISCHAEMIA, CARDIOGENIC SHOCK, FAILURE OF OPTIMAL MEDICAL MANAGEMENT INCLUDING IABP • OTHER INDICATIONS: FAILED PCI/THROMBOLYSIS, LARGE AREA AT RISK, UNSUITABLE ANATOMY FOR PCI, LMA DISEASE, LIFE THREATENING ARRHYTHMIA (ISCHAEMIC ORIGIN), MECHANICAL COMPLICATION SUCH AS IMR, WALL RUPTURE

CABG: OPERATIVE TECHNIQUE

CABG: OPERATIVE TECHNIQUE

CONDUITS USED (LITA/LIMA)

SVG

RADIAL

CABG: LONG TERM GRAFT PATENCY

LONG TERM PROGNOSIS OF CABG • PREVENT SUDDEN DEATH • REDUCE LONG TERM DEATH (96%, 90%, 76% AND 56% AT 1, 5, 10 AND 15 YEARS) • FREEDOM FROM CARDIAC EVENTS • IMPROVE LEFT VENTRICULAR FUNCTION • IMPROVE FUNCTIONAL QUALITY

FUNCTIONAL STATUS AND QUALITY OF LIFE • FUNCTIONAL STATUS IMPROVES MARKEDLY AND MAY EQUAL NORMAL MATCHED CONTROL POPULATION • SUB-OPTIMAL/ WORSENING STATUS: FEMALE, DM, SMOKERS, LOW SOCIOECONOMIC POPULATION, HTN, LOW EJECTION FRACTION • IMPROVEMENT STARTS FROM 3 MONTHS AND IMPROVES UP TO 12 YEARS

ADVANCES • TMLR • MIDCAB (MINIMALLY INVASIVE DIRECT CORONARY BYPASS) • ROBOTICALLY BY TECAB- CAN BE USED FOR MULTIVESSEL DISEASE

SUMMARY • CAD IS THE LARGEST CAUSE OF DISABILITY & DEATH • ATHEROSCLEROTIC DISEASE AND LIFESTYLE CHANGES ARE THE MAIN CAUSE • CORONARY ANGIOGRAM MAINSTAY OF DIAGNOSIS • PCI ORCABG EMPLOYED FOR DEFINITIVE TREATMENT • NO OTHER OPERATION HAS PROLONGED MORE LIVES, PROVIDED MORE SYMPTOM RELIEF THAN CABG • MINIMALLY INVASIVE REVASCULARATION STRATEGIES EVOLVING

QUESTIONS

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