Hemodynamic classification in acute myocardial infarction

Current mortality (M(1)) in hemodynamic subgroups of patients with acute myocardial infarction (AMI) was compared to that observed 30 years ago (M(0)), when hemodynamic classification was established. The prognostic value of oxyhemodynamic indexes in predicting M(1) for patients receiving right heart catheterization (RHC) was investigated.

We assigned 393 patients with AMI (mean age, 72 +/- 10 years) to four Killip categories. A fiberoptic reflectance catheter was inserted in the pulmonary artery (PA) in 136 patients. Cardiac index (CI), PA wedge pressure (PWP), PA mixed venous blood oxygen saturation (SvO(2)), oxygen extraction ratio (O(2)ER), and normalized CI (NCI; CI/O(2)ER) were measured. Catheterized patients were classified into four Forrester groups, and M(1) and M(0) were compared. Survivors (group S) were compared to nonsurvivors (group NS), and the prognostic value of oxyhemodynamic parameters in predicting M(1) was estimated.

A significant decline in total mortality was observed (M(1) of 8% vs M(0) of 34%; p < 0.0001). In catheterized patients, total M(1) was also decreased (M(1) of 15% vs M(0) of 26%; p < 0.05). Compared with group S, group NS had lower (mean +/- SD) CI (1.8 +/- 0.4 L/min/m(2) vs 2.4 +/- 0.6 L/min/m(2); p < 0.01), SvO(2) (46.1 +/- 10.6% vs 59.9 +/- 10.0%; p < 0.01), NCI (4.2 +/- 1.4 vs 7.4 +/- 4.1 L/min/m(2); p < 0.01), and higher PWP (22.7 +/- 6.8 mm Hg vs 14. 4 +/- 4.7 mm Hg; p < 0.01). NCI presented the best sensitivity (81%), specificity (78%), and predictive value (40%), in predicting M(1).

The historical AMI hemodynamic classification has lost its semiquantitative value, since mortality has decreased. RHC does not compromise the outcome. NCI has a high prognostic value in predicting early mortality.