In an adult patient with ST‑segment elevation myocardial infarction who has achieved successful fibrinolysis with alteplase or tenecteplase and has no contraindications to antiplatelet or anticoagulant therapy, why is a routine early percutaneous coronary intervention strategy superior to a watch‑and‑wait approach?

Why Routine PCI After Successful Fibrinolysis is Superior to Watchful Waiting in STEMI

Routine early PCI (within 3-24 hours) after successful fibrinolysis significantly reduces death and reinfarction compared to a watchful waiting strategy, and should be performed in all STEMI patients without excessive bleeding risk. 1

Mortality and Reinfarction Benefits

The evidence overwhelmingly supports routine early intervention over conservative management:

• Pooled analysis of 7 contemporary trials (1,996 patients) demonstrated a 38% reduction in mortality (4.4% vs 7.1%, RR 0.62, p=0.015) and a 41% reduction in reinfarction (3.6% vs 6.1%, RR 0.59, p=0.009) with routine early PCI compared to delayed or ischemia-guided strategies. 1

• The CARESS-AMI trial specifically showed that routine transfer for immediate catheterization reduced the composite endpoint of death, reinfarction, or refractory ischemia from 10.7% to 4.4% (p=0.004), driven primarily by reduced refractory ischemia (4.0% vs 0.3%, p=0.003). 1

• GRACIA-1 trial demonstrated that routine invasive strategy within 24 hours reduced the 1-year composite endpoint of death, reinfarction, or ischemia-driven revascularization from 21% to 9% (p=0.0008). 1

Myocardial Salvage and Ventricular Function

Beyond mortality reduction, routine PCI preserves cardiac function:

• The Leipzig trial showed reduced infarct size on delayed-enhancement MRI (median 5.2% vs 10.4%, p=0.001) with immediate PCI after fibrinolysis. 1

• SIAM-III demonstrated improved left ventricular ejection fraction at both 2 weeks (56.7% vs 52.5%, p=0.037) and 6 months (61.5% vs 56.4%, p=0.018) with early stenting. 1

• CAPITAL-AMI showed a trend toward greater LVEF at 30 days (median 55% vs 52%, p=0.08) and reduced composite clinical endpoints at 6 months (11.6% vs 24.4%, p=0.04). 1

Safety Profile

The mortality and reinfarction benefits are achieved without significant increases in major bleeding or stroke:

• Pooled analysis showed no significant increase in major bleeding (3.9% vs 3.2%, RR 1.21, p=0.45) or stroke (1.0% vs 1.1%, RR 0.99, p=0.99). 1

• While CARESS-AMI noted increased minor bleeding with urgent PCI (10.8% vs 4.0%, p=0.002), major bleeding was not significantly increased (3.4% vs 2.3%, p=0.47). 1

• The 2015 International Consensus found moderate-quality evidence showing no differential mortality benefit at 30 days (OR 0.96,95% CI 0.64-1.44), but this analysis compared routine early PCI to rescue PCI (not true watchful waiting), which explains the neutral finding. 1

Optimal Timing Window

Transfer for PCI should be initiated immediately after fibrinolysis without waiting to assess reperfusion success:

• TRANSFER-AMI (1,030 patients) demonstrated that urgent transfer for catheterization within 6 hours (median 3 hours) reduced the 30-day composite endpoint from 16.6% to 10.6% (p=0.001) compared to delayed catheterization at 27 hours. 1

• The ESC guidelines recommend PCI between 3-24 hours after successful fibrinolysis as Class IIa, Level of Evidence B, with transfer indicated in all patients irrespective of baseline risk. 1

• Contemporary meta-analyses support intervention within 3-12 hours for maximum benefit, with one study showing reduced no-reflow phenomenon (p=0.005) and recurrent ischemia when PCI performed within 3-12 hours versus 12-24 hours. 2

Clinical Algorithm for Implementation

All STEMI patients receiving fibrinolysis should follow this pathway:

1. Administer fibrinolytic therapy (tenecteplase, alteplase, or reteplase preferred over streptokinase due to non-antigenic properties). 1

2. Initiate immediate transfer arrangements to PCI-capable facility without waiting for reperfusion assessment. 1

3. Target PCI timing of 3-6 hours after fibrinolysis administration (acceptable range 3-24 hours). 1

4. Perform angiography and PCI with stenting when anatomy is appropriate, regardless of clinical stability or presence of ongoing ischemia. 1

5. Continue dual antiplatelet therapy (aspirin plus ticagrelor or clopidogrel) and anticoagulation throughout transfer and procedure. 3, 4

Critical Caveats

The only exception to routine early PCI is excessive bleeding risk:

• Patients with absolute contraindications to anticoagulation or recent major bleeding should be managed conservatively with ischemia-guided approach only. 1

• The CARESS-AMI investigators specifically noted that routine immediate PCI is reinforced "in patients not at excessive risk for bleeding." 1

Do not confuse this with "facilitated PCI" (immediate PCI with pharmacologic pretreatment before primary PCI), which showed increased mortality (4.7% vs 3.4%, p=0.028), reinfarction, and bleeding compared to primary PCI alone. 1 The pharmacoinvasive strategy discussed here applies only to patients who have already received full-dose fibrinolysis at non-PCI-capable facilities.

Why Watchful Waiting Fails

The conservative "ischemia-guided" approach fails because:

• Recurrent ischemia occurs in 25-50% of patients managed conservatively, requiring urgent intervention under suboptimal conditions. 1

• Residual stenosis after fibrinolysis remains highly thrombogenic, with 75% of conservatively managed patients still having significant lesions requiring eventual revascularization. 1

• Delayed intervention misses the window for myocardial salvage, resulting in larger infarct size and worse ventricular remodeling. 1