coronary heart disease /
IHD
- stable angina
- ACS
types of ACS
STEMI
NSTE-ACS
= NSTEMI (+ve enzyme rise)
= unstable angina (-ve enzyme rise)
cardiac enzymes to monitor
CK (rhabdo)
troponin (cardiac muscle death)
angiogram
x-ray with contrast dye to see where blockage is located and extent of blockage
CT scan vs MRI scan vs US
CT: uses x-ray. 5-15mins. sometimes contrast needed
MRI: magnetic field, radio freq waves. 45mins-2hrs. sometime contrast needed
US; see gross structure (EF, preg, GI)
coronary angioplasty
catheter with inflated balloon to compress plaque, achieve reperfusion of blood vessel
reperfusion
1) primary PCI (aspirin + P2Y12i, UFH, eptifibatide)
- usually radial approach > femoral
2) fibrinolytics
MI pt steps
1) load aspirin
2) PCI = load P2Y12i // thrombolytics
3) anticoagulants (UFH, eptifibatide)
4) PCI
5) DAPT
6) add high intensity statins if no CI
atorvastatin 40-80mg OD
rosu 20-40mg OD
UFH Intravenous (ACT)
- 2000-5000 units (no more than 50-70 units/kg)
to achieve ACT of 250 – 300 seconds
- repeat bolus (max 10 000 units) as needed to maintain ACT throughout PCI.
if ACT > 2000 secs, not to bolus
UFH and Eptifibatide // previous LMWH use
- If GPIIb/IIIa inhibitor used (e.g. eptifibatide) used, repeat bolus of up to max 7000 units as needed to maintain ACT throughout PCI.
- previous LMWH use: Check ACT prior to bolus
duration of UFH
until PCI complete/ 48hrs
LMWH enoxaparin based on when PCI is
Last SQ LMWH 8-12h before PCI: 0.3mg/kg bolus
Last SQ LMWH >12h before PCI: Use UFH
Last SQ LMWH <8h before PCI: Nil need for further LMWH
MI with previous thrombolytics
Start SQ Enox between 15min before and 30 min after fibrinolytic.
NSTEMI and STEMI PCI dose
LMWH
NSTEMI: 1 mg/kg every 12 hours
STEMI: 15before and 30min after fibrinolytic
- < 75yo, bolus IV 30mg followed by SQ 1mg/kg Q12H
- if ≥75yo, omit bolus, followed by SQ 0.75mg/kg Q12H
duration of LMWH
duration of 48h and up to 8d or until revascularisation.
eptifibatide dose
(anticoag, glycoprotein 2b3a)
Double bolus of 180ug/kg iv
(10min interval)
Follow: infusion 2.0ug/kg/min for 72h
- short t1/2, need infusion.
feature of eptifibatide
- Renal dose adj CrCl < 50 ml.min
Not for ESRD = Cock-gault eqn - Short t1.2, Infused for 72h
- use in pPCI before potent antiPLT
FU plans
- duration of antiplt (DAPT)
- monitor and FU (bleeding risk, SE)
- counsel
(DAPT duration and lifelong aspirin: stent is thrombogenic)
(invasive procedure when to stop DAPT?)
monitor labs
bleeding
FBC
dyspnea (ticagrelor)
stents
- stent platform
- polymer coating/ embedded drug
bare metal stent (high thrombogenicity)
1st gen –> 3rd gen drug eluting stents
(polymer free, bioresorbable stent,
biolimus drug w/ high lipo)
immunosuppressant + DAPT limus from stent
prevent overproliferation, stent recognised as foreign body –> clot on stent –> MI
- in-stent thrombosis
- or in-stent restenosis
12mn (usual) SAPT for
prevent recurrence of ASCVD
stop at 3mnth if high bleeding risk
bleeding risk assessment at time of PCI
precise-DAPT score > 25
major, minor criteria ARC-HBR
HIGH RISK: 1 major risk or 2 minor risk
major bleed risk ARC-HBR
to shorten duration
- anticipated use of LT OAC
- end stage CKD
- Hb <11g/dL
- spontaneous bleed (hosp/ transfusion: <6mn)
- mod-severe thrombocytopenia (PLT)
- chronic bleeding diathesis
- liver cirrhosis, protal HTN
- active malignancy (<12mn)
- previous spontanous ICH (<12mn)
- nodeferrable major surgery on DAPT
- recent major surgery/ trauma within 30d before PCI
