🫀Myocardial Ischaemic + ACS

What is stable angina?

Predictable chest pain or pressure due to physical exertion or emotions

What’s the initial treatment for stable angina?

GTN: take at 5 minute intervals → Medical emergency if no resolution after 2 doses. Can be taken prophylactically or when symptoms arise.

Treatment pathway for long-term prevention of stable angina

BB (RL-CCB if BB contraindicated)

→ BB + normal CCB (Amlodipine, Lacidipine) → Long-acting nitrate (Isosorbide mononitrate), Nicorandil, Ivabradine or Ranolazine.

Which nitrate-derivative can cause GI and mucosal ulceration?

Nicorandil

In addition to specific drug treatment, what else is part of stable angina prevention?

Healthy lifestyle measures. Introduce 75mg aspirin and low dose statin.

Stable angina: secondary prevention of cardiovascular events

Low-dose aspirin and statin

(Treatment with an ACE inhibitor should be considered, particularly if the patient has diabetes)

Which nitrate is classed as a “special container,” and what are the specific instructions?

GTN sublingual tablets - discard 8 weeks after opening, even if unused

What is the nitrate dosing regimen to minimise patients developing tolerance?

Nitrate free period.

• Oral - give second dose 8hrs after first dose instead of 12hrs.

• Transdermal patch - leave off for 8-12hrs a day.

What are the key side effects of nitrates?

Dizziness. Flushing. Headaches.

Important counselling point for nitrate therapy

Headache occurrence tends to decrease with continued therapy/after a few days

(Headache is associated with peripheral vasodilation and is one of the most common side-effects of nitrate therapy)

In which patient group should nitrates be prescribed with caution, and why?

Elderly - risk of falls (as a result of side effects)

What are the major risk factors for ACS?

Family history. HTN. Hypercholesterolaemia. Diabetes. Smoking.

What is the initial management for ACS?

MONA. 300mg Aspirin PO STAT. GTN (sublingual or buccal) +/- IV morphine (esp if MI suspected). Oxygen if needed. 12-lead ECG and biomarkers evaluated to determine if unstable angina, STEMI or NSTEMI.

What biomarker can be used to rule out NSTEMI/suggests unstable angina?

Raised troponin

Why does raised troponin indicate unstable angina?

Troponin is a protein released from damaged heart muscle, and unstable angina, involves a reduction in blood flow to the heart, potentially causing such damage.

What are the types of ACS?

• Unstable angina - partial artery blockage.

• NSTEMI - partial artery blockage. ST-zone of ECG not elevated.

• STEMI - complete artery blockage. Elevated ST-zone of ECG.

Within what time frame should Percutaneous Coronary Intervention (PCI) be performed in STEMI?

Within 2hrs

What drug should patients be given if PCI is done through radial access?

Heparin

Treatment Regimen for Secondary Prevention of MI

Dual antiplatelet therapy (DAPT) - Lifelong aspirin + clopidogrel, prasugrel or ticagrelor for 12 months. ACEi (ARB if contraindicated). BB. High strength statin (atorvastatin 80mg). (Remember DABS)

Preferred antiplatelet with aspirin if patient had a PCI

Prasugrel

Patients with which conditions may have BB used for secondary prevention of MI withdrawn after 12 months?

Left ventricular systolic dysfunction or HF

Do ACS patients need to be assessed for risk of heart failure?

Yes

Only ACS that causes myocardial necrosis

NSTEMI