Background: Preoperative cardiovascular evaluations are frequently done before ambulatory ophthalmologic procedures. However, whether these procedures can trigger an acute myocardial infarction (AMI) is unknown.
Objective: To assess the short-term risk for AMI associated with ophthalmologic procedures.
Design: Case-crossover design.
Setting: Population-based nationwide study from Norway and Sweden.
Participants: First-time patients with AMI, aged 40 years and older, identified via inpatient registries and linked to outpatient surgical procedures in Norway (2008 to 2014) and Sweden (2001 to 2014), respectively.
Measurements: Using self-matching, for each participant, exposure to ophthalmologic procedures in the 0 to 7 days before AMI diagnosis (hazard period) was compared with an 8-day period 30 days earlier, that is, days 29 to 36 before AMI (control period) to estimate the relative risk for an AMI the week after an ophthalmologic procedure. The odds ratios (ORs) with 95% CIs were calculated, using conditional logistic regression. Only patients who had a procedure of interest during either the hazard or control period were included.
Results: For the 806 patients with AMI included in this study, there was a lower likelihood of AMI in the week after an ophthalmologic procedure than during the control week (OR, 0.83; 95% CI, 0.75 to 0.91). Furthermore, there was no evidence of increased risk for AMI when analyses were stratified by surgery subtype, anesthesia (local or general), duration, invasiveness (low, intermediate, or high), patient's age (<65 years or ≥65 years), or comorbidity (none vs. any).
Limitation: Potential bias from time-varying confounders between the hazard and the control periods.
Conclusion: Ophthalmologic procedures done in an outpatient setting did not seem to be associated with an increased risk for AMI.
Primary funding source: Central Norway Regional Health Authority and the Swedish Research Council.