Despite showing a significant reduction in "Office BP" and a Win Ratio analysis favoring renal denervation compared with sham, the SPYRAL HTN-ON MED trial did not meet the primary efficacy endpoint of change in 24-hour systolic ambulatory blood pressure monitoring (ABPM) at six months. The trial was presented Nov. 7 during AHA 2022 in Chicago.

The trial assessed results from 337 patients at 42 sites worldwide who were part of the SPYRAL Pilot and SPYRAL Expansion groups. Participants were randomized to renal denervation or sham control. While falling short of meeting the endpoint, the primary safety endpoint of major adverse events at one month was met with low incidence of procedural-related and clinical adverse events, according to David E. Kandzari, MD, FACC, who presented the findings. He also noted that absolute reduction in both Office BP and ABPM for radiofrequency renal denervation were consistent.

According to Kandzari, the trial faced several challenges including substantial ABPM outcome differences between the pilot and expansion groups that limited utilization of data between cohorts for Bayesian analysis. Additionally, enrollment for the expansion group occurred over the course of the COVID-19 pandemic and "demonstrated differences in baseline ABPM patterns between pre- and during-COVID cohorts, in contrast to consistent baseline Office BP assessments."

Other limitations included disproportionate differences in both medication prescription and burden in favor of the sham group. "These imbalanced medication changes impact 24-hr ABPM more than Office BP and bias ABPM towards the null given timing of both witnessed pill intake and next day morning pill intake occurring during 24-hr ABPM," said Kandzari.

Clinical Topics: Prevention, Hypertension

Keywords: AHA Annual Scientific Sessions, AHA22, Antihypertensive Agents, Sympathectomy, Hypertension

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