Killip Classification

Class I: Individuals with no clinical signs of heart failure. Typical mortality 6% (historical), now 2-3% in modern PCI eras.

Class II: Individuals with rales or crackles in the lungs, an S3 gallop, and elevated jugular venous pressure. Lung findings limited to the lower half of the lung fields. Typical mortality 17% (historical), now ~5-8%.

Class III: Individuals with frank acute pulmonary edema. Typical mortality 38% (historical), now ~10-15%.

Class IV: Individuals in cardiogenic shock or hypotension (systolic blood pressure < 90 mmHg), and evidence of peripheral vasoconstriction (oliguria, cyanosis or diaphoresis). Typical mortality 81% (historical), but remains extremely high today even with advanced MCS/ECMO (~40-50%).