New Hypertension Threshold Guides Blood Pressure Management During Cancer Treatment

Over the last 15 years, considerable changes have been made in the hypertension guidelines from JNC 7 (the Seventh Report of the Joint National Committee on Prevention, Detection, Evaluation, and Treatment of High Blood Pressure) to JNC 8. However, both observational and randomized trials have suggested that lower blood pressure treatment thresholds and targets are more beneficial for higher-risk patients. Using this new data, the American College of Cardiology and the American Heart Association published new hypertension guidelines. The question remains, how will these new thresholds and targets impact the blood pressure management of patients with a cancer diagnosis?¹

“The importance of adequately diagnosing and managing hypertension in this patient population arises from the facts that hypertension is well established as a risk factor for chemotherapy-induced cardiotoxicity and that poorly controlled hypertension can significantly influence cancer management and even lead to the discontinuation of certain therapies,” according to a paper by Elie Mouhayar, MD, FACC, FSVM, associate professor of medicine, Department of Cardiology at University of Texas MD Anderson Cancer Center.²

Multiple observational studies have tied higher systolic blood pressure and diastolic blood pressure to increased cardiovascular disease risk including risk of death from stroke, heart disease, and vascular disease. Furthermore, elevated blood pressure was the leading cause of death and disability-adjusted life years globally in 2010.³

Interacting Risk Factors

Patients with hypertension can have several modifiable and fixed risk factors for cardiovascular disease. Modifiable risk factors included tobacco use, diabetes mellitus, dyslipidemia, excess weight, inactivity, and poor diet. Fixed risk factors include age, socioeconomic status, education, male sex, family history, psychosocial stress.³

Likewise, cardiovascular disease and cancer have a higher coprevelance related to shared risk factors such as obesity, inactivity, hypertension, tobacco and alcohol abuse, and poor diet. These similarities highlight the need for adequate blood pressure control in patients with a cancer diagnosis.⁴

Prior to the onset of treatment, patients with cancer have a prevalence of hypertension similar to the general population, however, the prevalence increases with the use of angiogenesis inhibitors, alkylating agents, and immunosuppression after stem-cell transplants.²

Mechanisms of action leading to increased blood pressure vary based on the chemotherapeutic agent. For instance, VEGF inhibitors can lead to increased vascular tone related to decreased nitric oxide production and increased vascular resistance related to endothelial damage. Alkylating agents can cause renal toxicity and impaired endothelial function. Increased blood viscosity, changes in endogenous vasopressors, changes in smooth muscle function, and increased vascular cell growth are associated with the use of erythropoietin. Immunosuppressive agents can be associated with increased renal proximal tubular resorption, alterations in vasodilating prostaglandins, and disruption in the renin-angiotensin system.  Finally, steroids impact the mineralocorticoid receptor, increase blood volume, and suppress plasma renin and aldosterone.⁵