Association of elevated radiation dose with mortality in patients with acute myocardial infarction undergoing percutaneous coronary intervention.

OBJECTIVES: This study sought to identify clinical and procedural predictors of elevated radiation dose received by patients with acute myocardial infarction (AMI) undergoing percutaneous coronary intervention (PCI) and to determine if elevated radiation dose was predictive of mortality in this population.

BACKGROUND: Little data exist regarding the impact of excessive radiation burden on clinical outcomes in patients undergoing PCI.

METHODS: The study population included 1,039 patients who underwent PCI for an AMI between January 1, 2007 and December 31, 2008 at an academic tertiary care teaching hospital. Cumulative skin dose (measured in milligray [mGy]) was selected as a measurement of patient radiation burden. Clinical and procedural variables were analyzed in multiple logistic and linear regression models to determine predictors of higher skin dose, and its impact was evaluated on all-cause intermediate-term mortality at two years.

RESULTS: Median skin dose was 2120 mGy (IQR 1379-3190 mGy) in the overall population, of which 153 (20.8%) patients received an elevated skin dose (defined as a skin dose>4,000 mGy). Independent predictors of elevated skin dose included male gender, obesity, multivessel intervention, and presentation with a non-ST-elevation MI (NSTEMI) versus an ST-elevation MI (STEMI). Increased skin dose was not predictive of intermediate-term mortality by multivariate analysis in the overall population or in either subgroup of STEMI and NSTEMI.

CONCLUSIONS: In this contemporary observational study examining patients with AMI undergoing PCI, male gender, obesity, multivessel intervention, and presentation with a NSTEMI were associated with increased radiation exposure.