RT Journal Article
SR Electronic
T1 Cancer risk related to low-dose ionizing radiation from cardiac imaging in patients after acute myocardial infarction
JF Canadian Medical Association Journal
JO CMAJ
FD Canadian Medical Association
SP 430
OP 436
DO 10.1503/cmaj.100463
VO 183
IS 4
A1 Mark J. Eisenberg
A1 Jonathan Afilalo
A1 Patrick R. Lawler
A1 Michal Abrahamowicz
A1 Hugues Richard
A1 Louise Pilote
YR 2011
UL http://www.cmaj.ca/content/183/4/430.abstract
AB Background Patients exposed to low-dose ionizing radiation from cardiac imaging and therapeutic procedures after acute myocardial infarction may be at increased risk of cancer. Methods Using an administrative database, we selected a cohort of patients who had an acute myocardial infarction between April 1996 and March 2006 and no history of cancer. We documented all cardiac imaging and therapeutic procedures involving low-dose ionizing radiation. The primary outcome was risk of cancer. Statistical analyses were performed using a time-dependent Cox model adjusted for age, sex and exposure to low-dose ionizing radiation from noncardiac imaging to account for work-up of cancer. Results Of the 82 861 patients included in the cohort, 77% underwent at least one cardiac imaging or therapeutic procedure involving low-dose ionizing radiation in the first year after acute myocardial infarction. The cumulative exposure to radiation from cardiac procedures was 5.3 milliSieverts (mSv) per patient-year, of which 84% occurred during the first year after acute myocardial infarction. A total of 12 020 incident cancers were diagnosed during the follow-up period. There was a dose-dependent relation between exposure to radiation from cardiac procedures and subsequent risk of cancer. For every 10 mSv of low-dose ionizing radiation, there was a 3% increase in the risk of age- and sex-adjusted cancer over a mean follow-up period of five years (hazard ratio 1.003 per milliSievert, 95% confidence interval 1.002–1.004). Interpretation Exposure to low-dose ionizing radiation from cardiac imaging and therapeutic procedures after acute myocardial infarction is associated with an increased risk of cancer.