In light of the current debate regarding the role of renal denervation (RDN) for the management of treatment-resistant hypertension (TRH), to determine the thresholds for cardiovascular risk and costs of RDN which would make the strategy cost-effective.
A Markov model was constructed to simulate the onset of cardiovascular disease and death among a hypothetical cohort of 1000 TRH patients aged <65 years who either received standard treatment of care (SoC) or RDN plus SoC. The time horizon was 20 years. The effectiveness and cost-effectiveness of RDN were estimated relative to current SoC using decision analysis from the Australian public healthcare system perspective. The effect on lowering office blood pressure due to RDN was based on results observed in SIMPLICITY HTN-3 trial, and the expected subsequent change to cardiovascular risk was drawn from a published meta-regression. Cost data were drawn from published sources. An annual discount rate of 5% was applied to both costs and outcomes (years of life and quality-adjusted life-years, QALYs).
Over a 20-year time horizon, the model predicted that at the current estimated costs of RDN (AUD 9531/€6573, 1€ = 1.45AUD), it would be cost-effective (incremental cost-effectiveness ratio at or below AUD 50,000 per year of life gained) only if targeted to patients whose absolute annual cardiovascular risk was at least 4.2% initially (approximately 21% over 5 years). With a 4.2% initial cardiovascular risk, the ICERs were AUD 49,519 (∼ € 34,151, 1€ = 1.45 AUD) per life-year saved gained and AUD 44,987 (∼ € 31,024) per QALY gained. If the costs of RDN were reduced to AUD 9000 and AUD 8500, cost-effectiveness would be achieved at annual risk thresholds of at least 3.8% and 3.5, respectively. Figure 1 showing the RDN effectiveness in terms of ICER value for treating TRH patients with different levels of initial cardiovascular risk.
At current costs and based on currently-observed effects on blood pressure, RDN is cost-effective only among patients at very high absolute cardiovascular risks. This sets parameters for the future health economic evaluation of next-generation RDN strategies currently being evaluated in clinical trials.
1Department of Epidemiology and Preventive Medicine, Monash University, Melbourne, Australia
2School of Public Health, Curtin University, Perth, Australia
3Department of Medicine, St. Vincents Hospital, University of Melbourne, Melbourne, Australia