Cardiovascular risk factor control and risk of future cardiovascular events in survivors of childhood cancer: A report from the St. Jude Lifetime cohort.

Abstract

10065 Background: Modifiable cardiovascular risk factors (CVRFs; hypertension, diabetes, dyslipidemia) contribute to the excess health-related death in long-term survivors of childhood cancer. However, whether control of CVRFs reduces the risk of major adverse cardiovascular events (MACE) in survivors is not known. Methods: Prevalence of hypertension (HTN), diabetes (DM) and LDL cholesterol elevation (LDL) was assessed via in-person assessments in 5+ year survivors ≥18 years old in the St. Jude Lifetime Cohort. Based on ACC/AHA primary prevention guideline recommendations, sub-optimal CVRF control was defined as blood pressure ≥140/90 mmHg, hemoglobin A1c ≥7.0%, and LDL ≥130 mg/dl. MACE was defined as new onset cardiomyopathy, myocardial infarction, stroke and/or cardiovascular death. Piecewise exponential models estimated the multivariable adjusted relative risk (RR) with 95% confidence intervals (CI) for MACE among survivors according to degree of CVRF control. Models were adjusted for sociodemographic factors, physical activity, smoking status, chronic kidney disease, and cancer treatment exposures (anthracycline chemotherapy, chest and/or brain irradiation). Results: Among 4876 adult survivors of childhood cancer, 36.1% had HTN, 8.4% DM and 56.5% elevated LDL at first assessment (mean age 28.6 years, standard deviation 9.1). One-third of survivors (33.5%) had at least one sub-optimally controlled CVRF. Among those with HTN, DM or LDL, 30%, 33% and 52% were sub-optimally controlled, respectively. In multivariable models, sub-optimal LDL control was associated with a > 8-fold higher risk of MACE compared to those with no LDL elevation (RR 8.4, CI 4.2 – 19.3; Table). This was more than twice the risk observed in those with well-controlled LDL compared to no LDL elevation (RR 4.0, CI 1.9 – 9.4; p-value <0.001). Similarly, sub-optimal DM control vs never having DM was associated with increased MACE risk (RR 3.4, CI 1.8 – 6.1) with twice the risk in those with sub-optimal control compared to well-controlled DM (p = 0.05; RR well-controlled DM vs no DM 1.6, CI 0.9 – 2.8). HTN, compared to no HTN, was associated with a 3 to 4-fold increase in risk of subsequent MACE, regardless of degree of control. Conclusions: Survivors of childhood cancer had a high prevalence of sub-optimally controlled CVRFs that was associated with an increased MACE risk. Optimal control of CVRFs among adult survivors of childhood cancer may reduce the risk of MACE. These findings motivate an intervention trial in intensive CVRF control. CVRF Control RR of MACE (95% CI) P-value comparing RR LDL elevation Sub-optimal LDL vs no LDL elevation 8.4 (4.2 – 19.3) <0.001 Controlled LDL vs no LDL elevation 4.0 (1.9 – 9.4) Diabetes Sub-optimal DM vs no DM 3.4 (1.8 – 6.1) 0.05 Controlled DM vs no DM 1.6 (0.9 – 2.8) Hypertension Sub-optimal HTN vs no HTN 3.9 (2.2 – 7.0) 0.28 Controlled HTN vs no HTN 3.0 (1.9 – 4.8)