Maximilian Zoltek1, Therese ML Andersson2, Christel Hedman1, Anders Ekbom3, Caroline Nordenvall1 and Catharina Ihre-Lundgren1*
1Department of Molecular Medicine and Surgery, Karolinska Institute, Sweden
2Department of Medical Epidemiology and Biostatistics, Karolinska Institute, Sweden
3Department of Medicine, Karolinska Institute, Sweden
Background: Patients with differentiated thyroid cancer (DTC) are usually administered lifelong TSH suppression treatment to reduce the recurrence risk, but however concomitantly risk hyperthyroidism and consequently cardiovascular (CV) mortality as an adverse effect. This study’s objective was to assess the risk of CV mortality in Swedish DTC patients relative to the general Swedish population.Methods: In this nationwide cohort-study, each patient was followed from one year post DTC diagnosis to the date of death, migration or 31 of December 2014. CV mortality in DTC patients was compared with the general population through standardized mortality ratios (SMRs). All patients diagnosed with DTC in Sweden in 1987-2013 were at baseline included in the study, and the vast majority of patients were assumed to have received life-long TSH suppression treatment in compliance with the prevalent national guidelines.Results: Out of 6900 DTC patients included, 550 (7.97%) died with an underlying CV diagnosis. On an aggregate level, the cohort did not experience a higher risk of CV mortality, although men ran an increased risk of CV mortality (SMR 1.16 CI 95% 1.02-1.31). The cohort overall also had an elevated risk of mortality in atrial fibrillation (SMR 1.36 CI 95% 1.12-1.64). We found that the age category of <45 years at diagnosis that lived 20 years after diagnosis experienced higher CV mortality (SMR 3.80 95% CI 1.71-8.46) than expected in the general population.Conclusion: We found no increased rate of CV mortality on an aggregate level in patients diagnosed with DTC, compared with CV mortality in the general Swedish population. However, following a DTC diagnosis, the data suggests that young patients with long follow-up duration were observed to face an elevated risk of CV mortality. We also noted that patients encountered elevated risks of AF mortality, and that male DTC patients faced elevated risk of CV mortality in general.
Thyroid stimulating hormone; Cardiovascular; Mortality; Differentiated thyroid cancer
Zoltek M, Andersson TML, Hedman C, Ekbom A, Nordenvall C, Ihre-Lundgren C. Cardiovascular Mortality in 6900 Patients with Differentiated Thyroid Cancer: A Swedish Population-based Study. Clin Surg. 2017; 2: 1519.