SOLACI | Latin American Society of Interventional Cardiology

In patients with uncontrolled hypertension who do not comply with treatment, renal denervation can generate benefit by reducing both ambulatory and office blood pressure, compared with patients who underwent a sham procedure.

This new information emerges from the SPYRAL HTN-OFF MED trial, presented virtually at the American College of Cardiology (ACC) 2020 Scientific Session and published simultaneously in Lancet.

At 3 months after the procedure, there was a 4-mmHg difference in ambulatory monitoring in favor of the renal denervation group, and a 6-mmHg reduction in office systolic blood pressure. Denervation also was effective as regards diastolic readings.

This effect was present during 24 hours, which is good news, since the relationship between blood pressure and cardiovascular events is stronger during the night.

These figures, 4 or 6 mmHg, may seem pretty modest, but if maintained over time, they could translate into clinical events and stroke.

The current SPYRAL HTN-OFF MED trial included over 300 patients who were not taking the indicated medication or who could eventually interrupt its use, and whose office systolic blood pressure was >150 mmHg but <180 mmHg, with diastolic blood pressure >90 mmHg. The criterion for ambulatory blood pressure was >140 mmHg but <170 mmHg.

Patients were randomized to denervation with the Symplicity Spyral multielectrode catheter and the Symplicity G3 radiofrequency generator or a sham procedure. Patients who had been using any antihypertensive medication had to undergo a washout period of 3 to 4 weeks, to ensure no drug effect interfered.

The primary endpoint, ambulatory blood pressure reduction at 3 months, was superior in the denervation group (4.7 vs. 0.6 mmHg; p < 0.001).

This study generates several questions: Did researchers know that patients were not taking medication and did nothing about it? Even worse, did they interrupt treatment on purpose, despite all the evidence showing reductions in events? Additionally, sham procedures are always controversial, since we are exposing patients to access site complications, for example, for nothing.

However, this seemed the only way to prove that denervation actually has a therapeutic effect, excluding treatment adherence (which was zero for both groups) and the placebo effect, with the sham procedure.

The SPYRAL HTN-ON MED trial is ongoing, and the difference with this one is that patients receive at least 3 different antihypertensive drugs without achieving blood pressure control.

Original title: Efficacy of catheter-based renal denervation in the absence of antihypertensive medications (SPYRAL HTN-OFF MED pivotal): a multicentre, randomised, sham-controlled trial.

Reference: Böhm M et al. Lancet. 2020; Epub ahead of print y presentado en el ACC 2020.