Statin therapy prior to ICU admission: protection against infection or a severity marker?

Examine the impact of previous statin therapy on hospital mortality and whether it is due to a protective effect against ICU-acquired infections.

Cohort comparison study by retrospective chart-based analysis in a 26-bed, university-affiliated, medical-surgical ICU.

We analyzed data from 438 patients at high risk of ICU-acquired infections, i.e., those receiving mechanical ventilation for more than 96 h, 38 (8.7%) of whom had been treated with statins prior to and during ICU admission.

We recorded clinical characteristics, number and type of ICU-acquired infections, and ICU and hospital mortality. Statin-treated patients were older (71.7+/-8.3 vs. 61.5+/-18.3 years), but differences in predicted mortality risk by APACHE II (39.5+/-24.7 vs. 35.8+/-24.3%) did not reach statistical significance. The ICU-acquired infection rate in statin-treated patients was nonsignificantly lower (29% vs. 38%) and delayed (median 12 vs.10 days), without differences regarding the source of infections. Nevertheless, hospital mortality was significantly higher in statin-treated patients (61% vs. 42%), even after adjustment for APACHE II predicted risk (observed/expected ratio 1.53 vs. 1.17).

Statin therapy is associated with worse outcome, probably because underlying clinical conditions are insufficiently considered in mortality predictors. Its presumed protective effect against ICU infections remains unconfirmed.