Answer to the Letter to the Editor of T. Imamura concerning "The incidence of myocardial infarction after lumbar spine surgery" by Harwin B, Formanek B, Spoonamore M, Robertson D, Buser Z, Wang JC (Eur Spine J. 2019; doi:10.1007/s00586-019-06072-4).

However, given that 664 patients in our study were identified with myocardial infarction and were further stratified based on the approach and timing, the propensity matching was not possible. We believe that information of the surgical approach and timing of myocardial infarction after lumbar surgery is novel and important information. [Extracted from the article]