Coexisting atrial fibrillation and cancer: time trends and associations with mortality in a nationwide Dutch study

Background and Aims Coexisting atrial fibrillation (AF) and cancer challenge the management of both. The aim of the study is to comprehensively provide the epidemiology of coexisting AF and cancer.Methods Using Dutch nationwide statistics, individuals with incident AF (n = 320 139) or cancer (n = 472 745) were identified during the period 2015-19. Dutch inhabitants without a history of AF (n = 320 135) or cancer (n = 472 741) were matched as control cohorts by demographic characteristics. Prevalence of cancer/AF at baseline, 1-year risk of cancer/AF diagnosis, and their time trends were determined. The association of cancer/AF diagnosis with all-cause mortality among those with AF/cancer was estimated by using time-dependent Cox regression.Results The rate of prevalence of cancer in the AF cohort was 12.6% (increasing from 11.9% to 13.2%) compared with 5.6% in the controls; 1-year cancer risk was 2.5% (stable over years) compared with 1.8% in the controls [adjusted hazard ratio (aHR) 1.52, 95% confidence interval (CI) 1.46-1.58], which was similar by cancer type. The rate of prevalence of AF in the cancer cohort was 7.5% (increasing from 6.9% to 8.2%) compared with 4.3% in the controls; 1-year AF risk was 2.8% (stable over years) compared with 1.2% in the controls (aHR 2.78, 95% CI 2.69-2.87), but cancers of the oesophagus, lung, stomach, myeloma, and lymphoma were associated with higher hazards of AF than other cancer types. Both cancer diagnosed after incident AF (aHR 7.77, 95% CI 7.45-8.11) and AF diagnosed after incident cancer (aHR 2.55, 95% CI 2.47-2.63) were associated with all-cause mortality, but the strength of the association varied by cancer type.Conclusions Atrial fibrillation and cancer were associated bidirectionally and were increasingly coexisting, but AF risk varied by cancer type. Coexisting AF and cancer were negatively associated with survival. Structured Graphical Abstract Prevalence, incidence, time trend, and association with all-cause mortality of coexisting atrial fibrillation and cancer in the Netherlands. AF, atrial fibrillation; aHR, adjusted hazard ratio; CI, confidence interval.