Day 2 Clinical Trials Highlights at WSC 2026

SEOUL, 22 October 2026 — After a complete reperfusion with thrombectomy, keeping systolic blood pressure under 140 mmHg was linked to roughly a third fewer brain bleeds. The risk climbed steeply once mean pressure stayed at or above 160 mmHg for the first 12 hours. These new findings come from a post hoc analysis of the Spanish HOPE trial, presented in the plenary session of the 18th World Stroke Congress.

The study was presented by Joan Miquel Fernández-Vidal of Hospital de la Santa Creu i Sant Pau, Barcelona. It suggests the key is not driving pressure as low as possible. Instead, it is avoiding sustained high pressure in the hours after the vessel has been fully reopened. The data are unpublished.

A question guidelines left open

Hemorrhagic transformation (HT) is bleeding into the infarcted tissue after the clot is removed. It is one of the main faces of reperfusion injury, and it worsens recovery. Even asymptomatic HT has been tied to worse disability at three months.

Blood pressure seemed the obvious lever. Yet several randomized trials found that pushing systolic pressure (SBP) aggressively low after thrombectomy was neutral or harmful. As a result, both the AHA/ASA and the European Stroke Organisation now advise against targeting SBP below 140 mmHg after successful reperfusion.

The HOPE trial (Camps-Renom et al., JAMA Neurology 2026) took a different approach. It tailored targets to how well the vessel had been reopened. Patients with complete or near-complete reperfusion were kept at 100–140 mmHg, and those with partial reperfusion at 140–160 mmHg. Functional independence at 90 days rose from 47.1% to 60.0%. HT at 24 hours fell from 31.6% to 22.3%, with no increase in symptomatic bleeding.

The new analysis asked what drives that reduction in bleeding: which blood-pressure measures matter, at what level, and when.

How the study was done

HOPE was a multicenter, open-label phase 3 trial with blinded endpoint assessment, run at 11 stroke centers in Spain. It enrolled 440 patients with anterior-circulation large-vessel occlusion treated within 24 hours. Randomization happened within an hour of the final angiogram, and patients did not need to be hypertensive to enter. The control arm was managed to the standard ceiling of 180 mmHg.

The investigators focused on patients with complete or near-complete reperfusion (mTICI 2c–3). Partial reperfusion was excluded because that subgroup showed no apparent benefit in the main trial. After excluding patients without follow-up imaging, 378 patients were analyzed.

A blinded core lab of two neuroradiologists and two neurologists read the 24-hour CT scans using the Heidelberg classification. Blood pressure was recorded every 30 minutes in the intensive arm and every 60 minutes in the standard arm. The team examined mean SBP, time in target range, peaks above 180 mmHg and pressure variability. Each was measured across windows from the first hour to the first 24 hours.

What they found

One in three patients bled despite a fully reopened artery. HT occurred in 139 of 378 patients: 42.6% in the standard arm and 30.9% in the intensive arm. Patients who bled had more severe strokes, larger early infarcts, more thrombectomy passes and later reperfusion.

Intensive control was linked to less bleeding, even after accounting for those factors (adjusted OR 0.62, 95% CI 0.39–0.99; p=0.046). The bleeds mattered for recovery. Only 39.1% of patients with HT were functionally independent at three months, against 64.7% of those without (p<0.001). The type of bleed and the rate of symptomatic hemorrhage did not differ between arms.

Surprisingly, the usual blood-pressure summaries barely separated the groups. Average pressure, time in target and variability over 24 hours were almost identical in patients with and without HT. The only exception was greater beat-to-beat variability in the very first hour.

The signal appeared once the analysts looked at shape and duration. Over the first hour or three, pressure showed no link with bleeding. From six hours onward, the association became significant and clearly nonlinear. Risk stayed flat across the usual range and then rose sharply at higher levels.

Only one threshold held up after adjustment: a mean SBP of 160 mmHg or more. Over the first 12 hours, it carried more than four times the odds of HT (adjusted OR 4.27, 95% CI 1.48–13.54). Over 24 hours, the odds were three times higher (adjusted OR 3.22, 95% CI 1.06–10.49). Such exposure was rare under intensive care (1.2%) but more common under standard care (8.9% over 12 hours).

Pressure trajectories also diverged over time. Patients who bled ran consistently higher curves (time × HT p=0.011). This divergence was concentrated in the intensive arm during the first 12 hours.

What it means

The authors’ message was “not the lower, the better” but “avoid sustained high SBP” in fully reperfused patients. What counts is hours spent above roughly 160 mmHg, not a single reading. They also stressed that asymptomatic HT should not be dismissed, given how strongly it tracked with worse recovery.

The talk closed with an open question for the field. Is the guideline ceiling of 180 mmHg too permissive once the artery has been completely reopened?

The authors flagged clear limits. This was a post hoc, exploratory analysis that tested many parameters, time windows and thresholds. Few patients were exposed to very high pressures. Mean SBP may miss the size and length of individual spikes. Finally, the timing of cause and effect is uncertain: up to 20% of HT appears early after thrombectomy, and pressure during the procedure was not measured.

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