Outcomes of Malignancy in Adults with Congenital Heart Disease: A Single Center Experience

Background: Malignancy is known to be a major cause of death in adult congenital heart disease (ACHD). However, data regarding cardiovascular and cancer-related outcomes in ACHD are lacking. Methods: We conducted a retrospective single-center cohort study comprising patients with ACHD and malignancy. The primary outcome was all-cause mortality. Key Secondary outcomes included major adverse cardiovascular and cerebrovascular events (MACCE), cardiotoxicity events and consequent cancer therapy modifications. Results: Sixty-eight patients with ACHD and a history of cancer were included in the study. 82% of patients had moderate or great ACHD anatomic complexity. Over a median follow-up of 5 years after cancer diagnosis, 16 (24%) patients died, with 69% of deaths being due to cancer. Univariate predictors of mortality were baseline arrhythmia (OR 3.82, 95% CI 1.15-12.67, p = 0.028), baseline diuretic therapy (OR 3.54, 95% CI 1.04-12.04, p = 0.044) and advanced cancer stage at diagnosis (OR 2.37, 95% CI 1.32-4.25, p = 0.004). MACCE occurred in 40 (59%) patients and was independently predicted by baseline diuretic requirement (OR 9.91, 95% CI 1.12 - 87.85, p = 0.039). A14% incidence of cardiotoxicity was seen; 3 patients needed modification and 1 patient needed temporary interruption of cancer therapy for 2 weeks. Conclusions: Considerable mortality occurred in this cohort of patients with ACHD and cancer; most deaths were cancer-related. A high rate of MACCE was observed, yet rates of obligatory modification of cancer therapy due to cardiotoxicity were low.