Cost-effectiveness of Barostim therapy for the treatment of resistant hypertension in European settings.

OBJECTIVE: The purpose of this study is to simulate the cost-effectiveness and the long-term clinical performance of the Barostim neo System for the treatment of resistant hypertension when compared to optimal medical treatment. METHODS: A decision analytic model with a combination of a decision tree and Markov process was used to evaluate the cost-effectiveness of Barostim. The clinical effectiveness of Barostim was based on the results of the randomized, placebo-controlled Rheos trial and the follow-up substudy of the DEBuT-HT trial. The cost-effectiveness was modelled from a German societal perspective over a lifetime horizon. Patients with high SBP levels have an increased risk of myocardial infarction, stroke, heart failure and end-stage renal disease. RESULTS: In a simulated cohort of 50-year-old patients at high risk of end-organ damage, Barostim therapy generated 1.66 additional life-years and 2.17 additional quality-adjusted life years with an incremental cost of &OV0556;16 891 when compared with continuation of medical management. Barostim was estimated to be cost-effective compared with optimal medical treatment with an incremental cost-effectiveness ratio of &OV0556;7 797/QALY. In the model, Barostim reduced over a lifetime the rates of myocardial infarction by 19%, stroke by 35%, heart failure by 12% and end-stage renal disease by 23%. The cost-effectiveness of Barostim can be greater in younger patients with resistant hypertension and in patients with significant risk factors for end-organ damage. CONCLUSION: Barostim may be a cost-effective treatment when compared with optimal medical management in patients with resistant hypertension.

Variability of the haemodynamic responses to laboratory tests employed in assessment of neural cardiovascular regulation in man.

In man evaluation of neural cardiovascular regulation makes use of a variety of tests which address the excitatory and reflex inhibitory neural influences that control circulation. Because interpretation of these tests is largely based on the magnitude of the elicited haemodynamic responses, their reproducibility in any given subject is critical. In 39 subjects with continuous blood pressure (intra-arterial catheter) and heart rate monitoring we measured the blood pressure and heart rate rises during hand-grip and cold-pressor test, the heart rate changes occurring during baroreceptor stimulation and deactivation by injection of phenylephrine and trinitroglycerine, and the heart rate and blood pressure changes occurring with alteration in carotid baroreceptor activity by a neck chamber. Each test was carefully standardized and performed at 30 min intervals for a total of six times in each subject. The results showed that the responses to any test were clearly different from one another and that this occurred in all subjects studied. For the group as a whole the average response variability (coefficient of variation) ranged from 10.2% for the blood pressure response to carotid baroreceptor stimulation to 44.2% for the heart rate response to cold-pressor test. The variability of the responses was not related to basal blood pressure or heart rate, nor to the temporal sequence of the test performance. Thus tests employed for studying neural cardiovascular control in man produce responses whose reproducibility is limited. This phenomenon may make it more difficult to define the response magnitude typical of each subject, as well as its comparison in different conditions and diseases.