Toulis KA, et al. - Prevention of differentiated thyroid cancer (DTC) recurrence has been achieved with exogenous suppression of TSH for many years, although it may be associated with increased risk of circulatory disease, so researchers analyzed the risk of circulatory disease in patients without a history of DTC-treated cardiovascular disease. A total of 3,009 patients treated for DTC without pre-existing cardiovascular disease were identified and matched to 11,303 controls and followed up to a median of 5 years. During the observation period, a total of 1,259 incident circulatory events were recorded. In patients with DTC, the risk of atrial fibrillation and stroke was significantly higher. Overall, the authors concluded that periodic screening for this arrhythmia is needed due to the increased risk of AF in DTC-treated patients without pre-existing CVD. While no evidence of increased ischemic heart disease or heart failure risk was observed, further investigation is warranted by the increased risk of stroke/TIA.