Very early assessment of risk for in-hospital death among 11,483 patients with acute myocardial infarction

Background The efficacy of reperfusion therapy after acute myocardial infar ction is time dependent. The risk profile of every patient should be availa ble as soon as possible. Our aim was to determine whether collection of sim ple clinical markers at hospital admission might allow reliable risk strati fication for in-hospital mortality. Methods The subjects were 11,483 patients with acute myocardial infarction from the GISSI-2 cohort. The GISSI-1 and GISSI-3 populations were selected to validate the classification. To stratify patients, the tree-growing meth od called recursive partitioning and amalgamation (RECPAM) was used. This m ethod is used to identify homogeneous and distinct subgroups with respect t o outcome. Results The RECPAM algorithm provided 6 classes. RECPAM class I included Ki llip class 3 to class 4 patients (516 deaths/1000). RECPAM class II include d Killip 2 patients older than 66 years and with anterior infarction or sit es of infarction that could not be evaluated (314 deaths/1000). Killip 1 pa tients older than 75 years and with anterior or multiple sites or sites tha t could not be evaluated were included in RECPAM class III with Killip clas s 2 patients younger than 66 years and with systolic blood pressure less th an 120 mm Hg or older than 66 years and with any other infarction site (207 deaths/1000). The other classes showed lower mortality rates (91, 32, and 12 deaths/1000 For RECPAM classes IV, V, and VI). In the GISSI 1 and GISSI 3 samples the 6 classes ranked in the same order in terms of mortality rate . With respect to low-risk strata, patients belonging to RECPAM class VI wi thout serious clinical events in the first 4 days had a very low incidence of in-hospital death (0.9%) or morbidity. Cumulative 6-month mortality for the 6 RECPAM classes was 59.6%, 41.2%, 26.4%, 12.9%, 4.8%, and 2.2%. Conclusions Four simple clinical markers readily available at admission of patients with myocardial infarction allow a quick, reliable, and inexpensiv e prediction of risk for in-hospital and 6-month mortality. The RECPAM clas sification also helped identify a large subgroup of patients fit for early hospital discharge.