The Journal of the American Heart Association retracted a research paper Tuesday that linked vaping to heart attacks. 

The study attracted controversy almost immediately on publication in June 2019. One of the authors, University of California San Francisco researcher Stanton Glantz—well-known for his research into the tobacco industry—claimed in a blog post that the findings amounted to “More evidence that e-cigs cause heart attacks.” But another researcher in the field asked that the paper be withdrawn barely a month after it was published over concerns it failed to determine whether the heart attacks occurred before or after subjects began vaping, basing his claims on the same federal data as the study. JAHA peer reviewers found the authors failed to adequately address the question of which came first, in part because they lacked access to a database.

Glantz told Retraction Watch he stood by the paper as published.