Non-Pharmacological Treatment for NSTEMI
The cornerstone of non-pharmacological NSTEMI management is bed rest with continuous ECG monitoring, supplemental oxygen when indicated (oxygen saturation <90%), and an early invasive strategy with coronary angiography within 24-48 hours for high-risk patients, followed by revascularization (PCI or CABG) based on coronary anatomy. 1
Immediate Non-Pharmacological Interventions
Monitoring and Supportive Care
- Admit all NSTEMI patients to a monitored unit with continuous rhythm monitoring for at least 24 hours (or until PCI, whichever comes first) 1, 2
- Enforce bed or chair rest with continuous ECG monitoring to reduce myocardial oxygen demand 1
- Administer supplemental oxygen (2-4 L/min) if arterial oxygen saturation is <90%, or if the patient has respiratory distress or other high-risk features for hypoxemia 1, 2
- Pulse oximetry should be used for continuous measurement of oxygen saturation 1
Risk Stratification for Invasive Strategy
An early invasive strategy (diagnostic angiography with intent to revascularize within 24-48 hours) is mandatory for patients with any of the following high-risk features: 1, 2
- Refractory angina or recurrent ischemia despite intensive medical therapy
- Hemodynamic instability or cardiogenic shock
- Electrical instability (life-threatening arrhythmias, ventricular tachycardia, ventricular fibrillation)
- Elevated cardiac biomarkers (troponin positive)
- Heart failure symptoms, new S3 gallop, or new/worsening mitral regurgitation
- High GRACE or TIMI risk score
- Depressed left ventricular function
Revascularization Procedures
Percutaneous Coronary Intervention (PCI)
- PCI is the preferred revascularization method for most NSTEMI patients undergoing early invasive strategy 1, 2
- The use of early angiography (<72 hours) increased from 9% in 1995 to 60% in 2015, with PCI during initial hospitalization increasing from 12.5% to 67%, resulting in 6-month mortality reduction from 17.2% to 6.3% 1
Coronary Artery Bypass Grafting (CABG)
- CABG should be considered based on coronary anatomy findings at angiography, particularly for patients with left main disease, three-vessel disease, or complex multivessel disease 2
Intra-Aortic Balloon Pump (IABP)
- IABP counterpulsation is reasonable for severe ischemia that continues or recurs frequently despite intensive medical therapy, for hemodynamic instability before or after coronary angiography, and for mechanical complications of MI 1
Conservative Strategy Considerations
A conservative (selectively invasive) strategy may be considered only for initially stabilized patients without high-risk features, though this approach is associated with less favorable outcomes compared to early invasive strategy in troponin-positive patients 1
Contraindications to Early Invasive Strategy
- Do not pursue early invasive strategy in patients with extensive comorbidities (liver failure, pulmonary failure, advanced cancer) where risks of revascularization outweigh benefits 1
- Avoid invasive strategy in patients with acute chest pain and low likelihood of ACS 1
Extended Monitoring
- Rhythm monitoring beyond 24 hours is recommended for NSTEMI patients at increased risk for cardiac arrhythmias 1
- For low-risk patients, monitoring up to 24 hours or until PCI (whichever comes first) is sufficient 1
Important Caveats
What to Avoid
- Discontinue all NSAIDs (except aspirin) immediately upon NSTEMI presentation due to increased risks of mortality, reinfarction, hypertension, heart failure, and myocardial rupture 1, 2
- Do not delay revascularization in high-risk patients—the mortality benefit of early invasive strategy is time-dependent 1, 2
Special Populations
- Patients with chronic renal insufficiency may still benefit from an invasive strategy, though careful consideration of contrast-induced nephropathy risk is warranted 1
- Unstable angina patients (troponin-negative) derive less benefit from early invasive strategy compared to NSTEMI patients and have substantially lower mortality risk 1