Myocardial infarct extension. Identification of subgroups by the pattern of the serum CKMB level.

To examine the clinical course of patients with acute myocardial infarction complicated by "extension", we studied prospectively 141 patients who had been diagnosed as having acute myocardial infarction. The serum CKMB level of these patients was determined at 8-h intervals during the first 5 days following admission. The patients were classified into 3 groups. Group A (early extension): patients who showed CKMB re-elevation before the CKMB values reached normal levels (28%). Group B (late extension): patients who showed CKMB re-elevation after the normalization of serum CKMB levels (21%). Group C (control group): patients without CKMB re-elevation (51%). Patients in group A showed the most unfavourable clinical course with a greater rate of haemodynamic deterioration compared with patients in the B or C groups, and a higher rate of recurrent ischemic pain. We found no significant differences in these parameters between the B and C groups. We were unable to find any risk factor associated with the development of extension. The pattern of the serum CKMB curve may allow a separation of two different subgroups of patients with acute myocardial infarct extension: patients with early extension, who show a high prevalence of haemodynamic deterioration, and patients with late extension, characterized by small infarcts and a benign clinical course.

[Age as a prognostic factor in intensive care]. / La edad como factor pronóstico en cuidados intensivos.

In order to define the prognostic impact of the age of critical patients as well as its association with the initial severity of illness (SAPS index) and therapeutic effort (TISS index), we studied 1.102 patients older than 14 years admitted consecutively to 3 general intensive care units. The oldest patients (more than 65 years) showed a higher mean SAPS (11.00 versus 8.58, p less than 0.0001) and mortality (odds ratio = 1.99, p less than 0.0001) than the younger ones. The association between age and mortality showed a "dose-response" pattern, even after controlling for the effect of initial severity (p less than 0.0001). The effect of age was stronger in the groups of patients with low SAPS (odds ratio = 2.94, p = 0.0007) or admitted for acute myocardial infarction (odds ratio = 3.28, p less than 0.0001). The oldest group showed a lower TISS/SAPS ratio and a shorter stay in the intensive care unit than younger patients, suggesting a low relative therapeutic effort in the latter. The differential therapeutic effort did not explain, however, the mortality excess in the oldest group, because the gradient of mortality increased after adjusting for TISS/SAPS ratio (adjusted odds ratio = 2.42, p less than 0.0001).