LandmarkRCT

SHOCK

Early Revascularization in Acute Myocardial Infarction Complicated by Cardiogenic Shock

New England Journal of Medicine, 1999 · Multicenter, randomized controlled trial.

Clinical question

Does emergency revascularization improve survival compared with initial medical stabilization in cardiogenic shock complicating acute MI?

Population: 302 patients with cardiogenic shock due to left ventricular failure complicating acute MI.
Intervention: Emergency revascularization (PCI or CABG).
Comparator: Initial medical stabilization, with delayed revascularization if the patient improved.
Primary outcome: All-cause mortality at 30 days.
Secondary outcomes: 6-month mortality.
Result: No significant difference in 30-day mortality, but a significant survival benefit with early revascularization by 6 months.

What the trial found

Emergency revascularization did not significantly reduce mortality at 30 days, but the survival curves separated by 6 months in favor of early revascularization, establishing it as standard of care.

Current guideline position

Emergency revascularization for MI-related cardiogenic shock remains standard of care in current ACC/AHA guidance, built on this trial.

Clinical interpretation

SHOCK established emergency revascularization as the standard approach to MI-related cardiogenic shock, based primarily on its longer-term (6-month) survival benefit rather than a significant 30-day effect — an important nuance often lost in shorthand summaries of the trial.

Limitations

Underpowered relative to its original target enrollment.
30-day primary outcome was not statistically significant; the guideline-shaping result is the 6-month secondary finding.

Moderate certainty

Clinical Context & Relevant Topics (1)

Disease Reference

Cardiogenic Shock

Primary pump failure, SCAI staging (A–E), PAC hemodynamics (CPO, PAPi), inotrope selection, emergent revascularization, and mechanical circulatory support.

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