NSTE-ACS

Question 1

What are the two main types of Acute Coronary Syndrome (ACS)?

Answer 1

Non-ST Elevation ACS (NSTE-ACS), ST-Elevation ACS (STEMI)

Question 2

What two conditions fall under the category of NSTE-ACS?

Answer 2

Unstable Angina (UA), Non-ST Elevation Myocardial Infarction (NSTEMI)

Question 3

What is the fundamental pathophysiology underlying most ACS events?

Answer 3

Atherosclerotic plaque rupture, fissure, or ulceration leading to thrombus formation within a coronary artery, causing an acute imbalance between myocardial oxygen supply and demand. Coronary vasospasm can also contribute.

Question 4

How are UA, NSTEMI, and STEMI differentiated based on ECG and cardiac biomarkers?

Answer 4

UA: No ST elevation, Normal biomarkers. NSTEMI: No ST elevation (may have ST depression or T-wave inversion), Elevated biomarkers (e.g., Troponin). STEMI: ST segment elevation present, Elevated biomarkers.

Question 5

Which cardiac biomarkers are most sensitive and specific for myocardial necrosis? How long do they stay elevated?

Answer 5

Troponin I and Troponin T. They can remain elevated for 7-14 days.

Question 6

What does the Killip Classification assess in the context of MI?

Answer 6

The severity of heart failure based on clinical signs. (Class I: None, II: Mild/rales <50%, III: Pulmonary edema/rales >50%, IV: Cardiogenic shock).

Question 7

What is the purpose of the TIMI Risk Score for UA/NSTE-ACS?

Answer 7

To estimate the short-term risk of adverse cardiac events (death, MI, urgent revascularization) and help guide the intensity and timing of treatment.

Question 8

List 3 of the 7 factors included in the TIMI Risk Score for UA/NSTE-ACS (1 point each).

Answer 8

(Any 3 of): Age ≥65, ≥3 CAD risk factors, Known CAD (stenosis ≥50%), Aspirin use in prior 7 days, ≥2 severe angina episodes in 24h, ST deviation ≥0.5mm, Elevated cardiac biomarkers.

Question 9

How does the TIMI score broadly guide management?

Answer 9

Higher risk scores (e.g., ≥3-4) suggest potential benefit from more aggressive therapies like early invasive strategies (angiography/revascularization), potent antiplatelets, and anticoagulation.

Question 10

What is the key difference between Unstable Angina (UA) and NSTEMI?

Answer 10

The presence of myocardial necrosis, indicated by elevated cardiac biomarkers (Troponins) in NSTEMI, while biomarkers remain normal in UA.

Question 11

List criteria that would classify an NSTE-ACS patient as ‘Very-High-Risk’, warranting immediate (<2h) invasive strategy.

Answer 11

Hemodynamic instability/shock, refractory chest pain, life-threatening arrhythmias/cardiac arrest, mechanical complications, acute HF, recurrent dynamic ST changes.

Question 12

List criteria that would classify an NSTE-ACS patient as ‘High-Risk’, warranting early (<24h) invasive strategy.

Answer 12

Rise/fall in Troponin compatible with MI, Dynamic ST/T changes, GRACE score >140 (or TIMI >4, though GRACE preferred).

Question 13

What is the recommended loading and maintenance dose for Aspirin in NSTE-ACS?

Answer 13

Loading Dose (LD): 300mg (chewed/crushed). Maintenance Dose (MD): 75-100mg daily lifelong. (MD ≤100mg if used with ticagrelor).

Question 14

When should PPI co-therapy be considered with Dual Antiplatelet Therapy (DAPT)?

Answer 14

In patients at high risk of GI bleeding (e.g., history of ulcer/bleed, anticoagulant use, chronic NSAID/steroid use, age ≥65, H. pylori, etc.).

Question 15

What is Dual Antiplatelet Therapy (DAPT) in the context of NSTE-ACS?

Answer 15

The combination of Aspirin plus a P2Y12 inhibitor (Clopidogrel, Ticagrelor, or Prasugrel).

Question 16

Which P2Y12 inhibitors are generally preferred over Clopidogrel for NSTE-ACS patients undergoing PCI? Why?

Answer 16

Ticagrelor or Prasugrel. They have a faster onset, more potent and consistent platelet inhibition.

Question 17

What are major contraindications or cautions for Prasugrel?

Answer 17

Absolute CI: Prior stroke or TIA. Relative CI/Dose reduction needed: Age >75 years, Weight <60 kg.

Question 18

What is a characteristic side effect of Ticagrelor?

Answer 18

Dyspnea (shortness of breath), usually mild and transient. Can also cause hyperuricemia.

Question 19

How long is DAPT typically recommended after NSTE-ACS?

Answer 19

Generally for 9-12 months. Shorter durations (e.g., 3-6 months) may be considered in patients with high bleeding risk.

Question 20

When should parenteral anticoagulation be started in NSTE-ACS? What are common choices?

Answer 20

Recommended as soon as possible after diagnosis. Common choices include Fondaparinux (Anti-Xa), Enoxaparin (LMWH), or Unfractionated Heparin (UFH).

Question 21

Which anticoagulant may be preferred in medically managed NSTE-ACS due to lower bleeding risk?

Answer 21

Fondaparinux.

Question 22

What is the role of GP IIb/IIIa inhibitors in NSTE-ACS?

Answer 22

Primarily used as ‘bail-out’ therapy during PCI for patients with large thrombus burden or thrombotic complications. Not for routine upstream use.

Question 23

When should Beta-Blockers generally be initiated in NSTE-ACS?

Answer 23

Within the first 24 hours, provided there are no contraindications (like acute HF, shock, high-degree AV block, severe asthma). Especially indicated if LV dysfunction (LVEF<40%), HF, or hypertension.

Question 24

When should ACE inhibitors (or ARBs) be initiated in NSTE-ACS?

Answer 24

Within the first 24 hours (once stable), especially in patients with LVEF <40%, HF, hypertension, diabetes, or CKD, unless contraindicated.

Question 25

What is the primary role of Nitrates in NSTE-ACS? What are key contraindications?

Answer 25

Role: Symptom relief (angina) via vasodilation. Contraindications: Hypotension (SBP <90), suspected RV infarction, recent use (24-48h) of PDE-5 inhibitors (e.g., sildenafil).

Question 26

When might Calcium Channel Blockers (CCBs) be used in NSTE-ACS? Which type should be avoided in LV dysfunction?

Answer 26

For ongoing ischemia if beta-blockers are contraindicated or insufficient, or for vasospastic angina. Non-dihydropyridines (Verapamil, Diltiazem) should be avoided in patients with LVEF <40% or acute HF.

Question 27

Name other anti-ischemic agents that can be used as second or third-line therapy for persistent angina in NSTE-ACS patients.

Answer 27

Ivabradine (if specific HR/rhythm/LVEF criteria met), Trimetazidine, Ranolazine, Nicorandil, Long-acting nitrates.

Question 28

Summarize the key components of initial pharmacological management in the Emergency Department for NSTE-ACS.

Answer 28

Aspirin (LD), Oxygen (if hypoxic), GTN (for pain), Morphine/Fentanyl (for severe pain), Parenteral Anticoagulation (e.g., Fondaparinux/LMWH/UFH).

Question 29

List the core components of long-term medical therapy recommended at discharge after NSTE-ACS.

Answer 29

DAPT (Aspirin + P2Y12 inhibitor) for ~12 months, High-intensity Statin, Beta-blocker (if indicated/tolerated), ACE inhibitor or ARB (esp. if LVEF<40%, HF, HTN, DM, CKD), +/- Mineralocorticoid Receptor Antagonist (MRA) (if LVEF<40% + HF/DM), +/- SGLT2 inhibitor (if HF or DM), Sublingual GTN for PRN use, Address lifestyle factors (smoking, diet, exercise).