Hypertension increased cardiac event risk among childhood cancer survivors
The presence of CV risk factors, especially hypertension, increased risk for major cardiac events in adult survivors of childhood cancer, according to recently published data.
Researchers evaluated 10,724 5-year cancer survivors (mean age, 33.7 years) enrolled in the Childhood Cancer Survivor Study, as well as 3,159 siblings of survivors. All participants responded to a baseline questionnaire addressing demographic information, medical history and CV outcomes, and at least one of two follow-up questionnaires.
By age 45 years, cumulative incidence of cardiac events was 1.3% for arrhythmia, 1.5% for valvular disease, 4.8% for HF and 5.3% for CAD. The cumulative incidence of cardiac events was significantly associated with having undergone cardiotoxic therapy, including chest-directed radiotherapy and anthracycline chemotherapy (P<.001).
The risk for all major events increased significantly with the number of CV risk factors present (P<.001 for trend), according to study results.
Among patients exposed to chest-directed radiotherapy, the presence of hypertension alone increased the risk for arrhythmia (RR=6; 95% CI, 1.7-21.8), CAD (RR=6.1; 95% CI, 3.4-11.2), valvular disease (RR=13.6; 95% CI, 5.7-32.4) and HF (RR=19.4; 95% CI, 11.4-33.1). Risk for HF was also significantly elevated among those with hypertension alone who underwent anthracycline chemotherapy (RR=12.4; 95% CI, 7.6-20.1).
Relative excess risk due to interaction (RERI) for patients exposed to chest-directed radiotherapy with hypertension and one or more additional CV risk factors was 8.6 for arrhythmia (95% CI, 1.7-21.7), 18.3 for HF (95% CI, 7.6-37.4), 27.9 for CAD (95% CI, 14.6-51) and 60.9 for valvular disease (95% CI, 18-487). Without hypertension, however, RERI was not significantly increased with the presence of multiple CV risk factors.
Risk for cardiac-related death was significantly elevated among patients with hypertension alone (RR=5.6; 95% CI, 3.2-9.7), and with two or more risk factors present (RR=2.4; 95% CI, 1.2-4.9), but not among those with diabetes, dyslipidemia or obesity alone.
“For doctors who are caring for [cancer] survivors, the key message from this study is that aggressive management of hypertension is especially important for this population,” researcher Greg Armstrong, MD, associate member of the department of epidemiology and cancer control at Saint Jude Children’s Research Hospital, said in a press release.
Disclosure: The researchers report no relevant financial disclosures.
*Photo credit: Saint Jude Biomedical Communications