Predictors of survival in unselected patients with acute myocardial infarction requiring continuous catecholamine support.

Background: Several predictors of survival have been described in selected subgroups of patients suffering from acute myocardial infarction. However, data on unselected patients with acute myocardial infarction and cardiogenic shock, including patients with out-of hospital cardiac arrest, are missing. We aimed to assess predictors of survival for an unselected cohort of patients representative of clinical practice who experienced acute myocardial infarction and required continuous catecholamine support for circulatory failure.

Methods: The study was performed at a 2000 bed university hospital. All consecutive patients admitted to our emergency department with acute myocardial infarction were prospectively enrolled in a clinical trial from 1993 to 2000.

Design: A retrospective cohort study was performed on patients with myocardial infarction requiring catecholamine support within the first 24 h. Primary endpoint was in-hospital mortality.

Results: The analysis was carried out on 262 patients, 189 men (72%), median age 65 years (IQR 53-73). Out-of-hospital cardiac arrest was reported in 47% (122/262). In-hospital mortality was 53% (138/262). Survivors as compared to non-survivors exhibited significant differences with respect to age (60 vs. 68 years, P<0.0001), systolic and diastolic blood pressure on admission (110 vs. 102 mmHg, P=0.01 and 64 vs. 58 mmHg, P=0.006, respectively), initial blood serum lactate (6.8 vs. 8.3, P=0.01), peak CKMB level (93 vs. 138 U/l, P=0.005), use of adrenaline (epinephrine) (38 vs. 68%, P<0.0001) and any attempt of revascularisation (76 vs. 63%, P=0.03). In a multivariate model younger age [OR 1.06 (CI 1.03-1.10), P<0.001], no use of adrenaline [OR 2.63 (CI 1.35-5.26) P=0.005] and lower peak CKMB [OR 1.01 (CI 1.01-1.01), P<0.0001] were independently associated with in-hospital survival.

Conclusion: In unselected patients including CPR survivors with acute myocardial infarction requiring continuous catecholamine support, younger age, the absence of continuous adrenaline administration and a lower peak CKMB were independently associated with increased in-hospital survival.