AimsEuropean Association of Cardiovascular Imaging/Heart Failure Association Cardiac Oncology Toxicity Registry was launched in October 2014 as a European Society of Cardiology multicentre registry of breast cancer patients referred to imaging laboratories for routine surveillance, suspected, or confirmed anticancer drug‐related cardiotoxicity (ADRC). After a pilot phase (1 year recruitment and 1 year follow‐up), some changes have been made to the protocol (version 1.0) and electronic case report form.Methods and resultsMain changes of the version 2.0 concerned exclusion criteria, registry duration, and clarification of the population characteristics. Breast cancer radiotherapy has been removed as an exclusion criterion, which involves now only history of a pre‐chemotherapy left ventricular dysfunction. The period for long‐term registry recruitment has been reduced (December 2017), but the target study population was extended to 3000 patients. The characteristics of the population are now better defined: patients seen in an imaging lab, which will include patients undergoing chemotherapy with associated targeted therapy or no targeted therapy, at increased risk of ADRC. In total, 1294 breast cancer patients have been enrolled, and 783 case report forms locked from October 2014 to November 2016. Of these, 481 (61.4%) were seen at first evaluation and 302 (38.6%) while on oncologic treatment with anticancer drugs. Fifty‐two patients (17.2%) were not in targeted therapies, 191 (63.3%) were ongoing targeted therapy, and 59 (19.5%) had completed it. Twenty‐three (2.9%) patients had a suspected diagnosis and 35 (4.5%) a confirmed diagnosis of ADRC. Arterial hypertension was the most prevalent cardiovascular risk factor (29.2%) followed by diabetes (6.1%). Previous history of heart failure accounted for 0.5%, whereas previous cardiac disease was identified in 6.3% of population.ConclusionThe changes of the original protocol of the COT Registry and first update allow a first glance to the panorama of cardiovascular characteristics of breast cancer patients enrolled.