Table 3.

Potential advantages and disadvantages of using blood pressure as an endpoint for outcome data in renal denervation trials

Advantages	Disadvantages
BP is historically recognised as one of the most consistently useful surrogate endpoints.	The ‘true endpoint’ (MACE) is not directly measured, with interpretation required for causality.
Smaller patient numbers are required for sufficient power which has positive financial implications.	Since RDN trials that use BP as a surrogate will have a shorter time span, they will be limited in their evaluation of safety endpoints.
Trials that demonstrate BP reduction via RDN have used statistically robust methods.
Results that demonstrate BP reduction via RDN can be interpolated with pharmacological trials that prove MACE reduction through BP reduction.
Trials with BP surrogate endpoints that do not show efficacy may obviate the need for endpoint trials, saving time, costs, and avoiding unnecessary patient risk.
Trial durations are shorter which avoids potential confounders, including:
▪ Unblinding of patients and outcome assessors, leading to performance bias
▪ Crossover of control group to undergo RDN
▪ Patients’ age-, weight- and disease-status related changes (i.e. longitudinal BP changes)
▪ The addition of antihypertensives to medication regimes
▪ Potential lifestyle modifications

BP blood pressure, RDN renal denervation, MACCE major adverse cardiac events