By Denise Fischer
Hypertension is associated with psychological comorbidities such as anxiety disorders and depression, either contributing to or initiating the condition. Dysfunction of the autonomic nervous system is considered to be the pathophysiological link between hypertension and psychological factors. Psychological comorbidities, such as anxiety and depression, in addition to an aggravating cardiovascular disease, may contribute to a significant impairment of quality of life and consequently to increased hospitalisation and morbidity.
The sympathetic nervous system, as well as the hypothalamic-pituitary-adrenal axis, is involved in stress reactions and blood pressure regulation and the development of treatment resistance in hypertension and cardiovascular diseases. Renal afferent and efferent sympathetic drive has been identified as a main contributor to the complex pathophysiology of hypertension and the development of comorbidities and complications.
Renal denervation has been demonstrated to reduce central and renal sympathetic activity, thereby improving blood pressure in patients with resistant hypertension. Little is known about the extent of psychological impairments and stress tolerance in patients with resistant hypertension and the effect of renal denervation on these psychological entities.
Therefore, we analysed anxiety, depression, quality of life and stress levels in 119 patients (age 62±11 years, 55% male) with resistant hypertension before and after renal denervation. At baseline, three and six months after renal denervation psychological status and stress tolerance were documented. Patients were instructed to rate their physical and mental state and arousal level on a 0–100% scale. Stress was induced by a multitasking situation (Wiener Determination Task). Total numbers of correct reactions, omission and commission errors as well as reaction times were registered. Furthermore depression and anxiety (Hospital Anxiety and Depression Scale, HADS) and quality of life (Short Form-12 Health Survey, SF-12) were assessed.
Patients with resistant hypertension were characterised by an impaired cognitive function and reduced stress tolerance both of which improved after renal denervation. Notably, 21% of all patients suffered from clinical relevant anxiety and 17% suffered from clinical relevant depression. Depression and anxiety symptoms as well as quality of life improved after renal denervation. Furthermore, patients reported an improvement of mental and physical health status as well as a reduction of arousal levels.
The high prevalence of anxiety and depression in patients with resistant hypertension is a very important finding because it might be of prognostic relevance. As shown in previous studies, psychological comorbidities lead to an impairment of quality of life and influence healthcare behavior. Depression in particular affects compliance and adherence to therapeutic interventions, increasing cardiovascular risk and outcomes. Depression and cognitive dysfunction affect decision making and subsequent self-care and as a consequence, may lead to an increase of hospitalisation and mortality.
In patients with resistant hypertension renal denervation significantly reduces office blood pressure and resting heart rate while being a safe method that does not affect psychological processes in a negative way. Moreover, renal denervation may have a positive effect in psychological processes, stress perception and processing as well as in quality of life. Patients may better focus on rapidly changing situations and may be more flexible in their reactions after renal denervation. Due to the prognostic relevance and considering consecutive healthcare costs of cognitive dysfunction, depression and anxiety disorders, it is important to take these psychological factors into consideration during the process of prevention and treatment of hypertension.
Denise Fischer is psychoterapist, Saarland University Hospital, Clinic of Internal Medicine III, Homburg, Germany.
Other investigators in the study include Ingrid Kindermann, Matthias Lenski, Christian Ukena, Felix Mahfoud and Michael Böhm.