Adjuvant Therapies in Acute Stroke

Despite the success of tPA and endovascular therapy, many patients do not achieve full reperfusion or functional recovery. Investigators have explored adjunctive treatments aimed at improving outcomes when added to standard thrombolysis. These fall into three main categories: antiplatelets, neuroprotectives, and sonothrombolysis (microbubbles).

Updated to reflect the 2026 AHA/ASA Guidelines for Early Management of Acute Ischemic Stroke.

1. Antiplatelets

Aspirin Within 48 Hours

2026 Guideline: Aspirin is recommended within 48 hours after stroke onset (Class 1, Level A). This is based on the IST and CAST mega-trials showing reduced death and dependency.

Aspirin Immediately Post-IVT — ARTIS Trial

ARTIS tested IV aspirin 300 mg within 90 minutes of alteplase. The trial was stopped early due to increased symptomatic ICH (4.3% vs. 1.6%) with no functional improvement. Conclusion: Early aspirin post-tPA is not recommended.

Tirofiban — TREND Trial

TREND enrolled 380 patients with NIHSS 4–20 and noncardioembolic stroke (without IVT). Tirofiban was given as IV bolus and 72-hour infusion vs. aspirin. Result: Early neurologic deterioration was reduced (4.2% vs 13.2%; RR 0.32; p = .002), with no increase in ICH.

Tirofiban — RESCUE BT2 Trial

RESCUE BT2 included 948 patients with mild stroke or early neurologic worsening, without thrombolysis. Tirofiban vs. aspirin showed improved excellent outcomes (mRS 0–1: 29.1% vs. 22.2%; RR 1.26; p = .02) and similar sICH rates (1.0% vs. 0%).

2026 Guideline: IV tirofiban efficacy to improve outcomes is not well established (Class 2b, B-R). May have role in selected patients not receiving IVT.

Abciximab — NOT Recommended

2026 Guideline: IV abciximab is NOT recommended (Class 3: Harm, B-R) due to increased bleeding complications. The AbESTT-II trial was stopped early for safety concerns.

2. Neuroprotectives

Citicoline — ICTUS & COBRIT Trials

Citicoline was tested in several large trials including ICTUS. No functional benefit was demonstrated, and it is not routinely used in acute stroke care.

NXY-059 — SAINT I & II Trials

NXY-059, a free-radical scavenger, showed early promise in SAINT I but failed in SAINT II. Result: No proven benefit, not in clinical use.

Nerinetide — ESCAPE-NA1 Trial

Nerinetide was tested in EVT patients. Overall trial was neutral, but in patients not receiving tPA, there was a signal for improved functional outcome. Alteplase appears to degrade nerinetide. ESCAPE-NEXT trial is ongoing.

Colchicine — No Role in Acute Stroke

Colchicine (anti-inflammatory) has been tested for vascular protection:

• CHANCE-3: No benefit for acute stroke prevention (6.3% vs 6.5% at 90 days)
• CONVINCE: No significant benefit (9.8% vs 11.7% MACE; p = 0.12)

No current role in acute thrombolysis or stroke prevention.

3. Intra-Arterial Thrombolytics After EVT

Several recent trials evaluated IA thrombolytics as adjunct therapy following successful mechanical thrombectomy, targeting residual microthrombi or no-reflow phenomena.

Alteplase — CHOICE Trial

CHOICE randomized EVT patients with incomplete reperfusion (eTICI 2b50–2c) to IA alteplase 0.225 mg/kg vs. placebo. Improved mRS 0–1 at 90 days (59% vs 40%; p = .03). No increase in sICH. Suggests benefit of IA alteplase after EVT.

Alteplase — PEARL Trial

PEARL tested IA alteplase 0.225 mg/kg post-EVT in 324 patients (42% with prior IVT). More excellent outcome (mRS 0–1) was seen with IA alteplase: 44.8% vs. 30.2% (RR 1.45; 95% CI 1.08–1.96); no significant increase in sICH or death.

Tenecteplase — ANGEL-TNK Trial

ANGEL-TNK enrolled 255 patients post successful EVT (eTICI ≥2b50) without prior IV lysis. IA tenecteplase 0.125 mg/kg vs. standard care. Results: better mRS 0–1 with IA TNK (40.5% vs. 26.4%; p = 0.02); no increase in sICH or mortality.

4. Sonothrombolysis (Ultrasound + Microbubbles)

Ultrasound — CLOTBUST Trial

CLOTBUST used continuous TCD ultrasound with IV tPA. Improved recanalization rates were seen, especially in M1 occlusion, but limited by skull penetration and operator dependence.

Microbubble Therapy — Experimental

Experimental studies using ultrasound + microbubbles aim to enhance clot lysis and perfusion. Small human trials suggest feasibility but this remains investigational.

Trial Comparison Table

Conclusion

While IV thrombolysis and EVT remain first-line treatments, adjunctive therapies continue to evolve. The 2026 guidelines clarify that IV abciximab is harmful and tirofiban's efficacy remains uncertain. Aspirin within 48h is beneficial but should be held for 24h post-IVT. Intra-arterial lytics post-thrombectomy show consistent benefit in emerging trials and may become standard adjunctive therapy. Neuroprotection remains an unmet goal, and sonothrombolysis awaits broader validation.