Résumé : Medical device companies may play a role in the type of treatments provided to patients, namely by influencing physicians to use their products. Physicians interact frequently with medical device representatives, which raises concerns that these relationships might bias healthcare providers. Using data on payments from medical device companies to physicians combined with hospital discharge datasets, I assess the impact of payments on medical treatments. The specific setting of this study is treatment provided to heart attack patients arriving at the Emergency Room (ER) in Florida hospitals. Using an instrumental variables approach, I find that patients treated by doctors who interact with the industry are more likely to receive an invasive procedure. I find no significant impact on healthcare outcomes. However, interactions result in higher medical device costs (up to 16% increase) and total hospital costs (up to 3% increase). The results can have implications for the design of regulations on physician-industry interactions.