The influence of statins on aortic aneurysm after operation: A retrospective nationwide study.

Aortic aneurysm (AA) is a disease with substantially higher health care costs and very high mortality upon rupture. Statins have a non-lipid-lowering pleiotropic mechanism that may be beneficial for AA in disease progression and improvement of AA patient outcomes. Previous studies have been conducted with some limitations and without considering immortal time bias, lag time, and adherence. The aim of our study was to analyze the effect of statin use on AA postoperation after controlling for these factors. All postoperative patients with a diagnosis of AA in Taiwan from 2004 to 2012 were included from the National Health Insurance Research Database. We excluded patients without computed tomography within 1 year after diagnosis and those who died within 30 days after the operation. We also analyzed the medication, medication possession ratio (MPR), immortal time bias, and lag time. Statin users were defined as those using statins for more than 30 days. Primary composite outcomes included mortality, reoperation for AA and rehospitalization for AA during the study period. Among the whole study population (n=1633), 199/1633 (12.19%) patients were statin users, while the others (n=1434) were not. Mortality was higher in statin nonusers than in statin users, with a mortality rate of 40% versus 22.61% (P<.0001). There was no significant difference in reoperation or rehospitalization for AA. Statin use may be beneficial for AA patients in our observational study. Prospective randomized controlled studies are needed to define the effect of statin therapy in this population.