Reader response: Comparative safety and efficacy of combined IVT and MT with direct MT in large vessel occlusion

In their article, Goyal et al.¹ questioned the added benefit of IV thrombolysis (IVT) prior to mechanical thrombectomy (MT) in patients with ischemic stroke and a large vessel occlusion. As we await the results of ongoing randomized trials (Multicenter Randomized Clinical Trial of Endovascular Treatment for Acute Ischemic Stroke in the Netherlands [MR CLEAN–NO IV], ISRCTN80619088; Bridging Thrombolysis Versus Direct Mechanical Thrombectomy in Acute Ischemic Stroke [SWIFT DIRECT], NCT03192332; Direct Intra-arterial Thrombectomy in Order to Revascularize AIS Patients With Large Vessel Occlusion Efficiently in Chinese Tertiary Hospitals [DIRECT-MT], NCT03469206), we must rely on observational data with adequate adjustment for potential confounding variables to estimate the value of IVT in MT-eligible patients.² Goyal et al.¹ rightfully stated that no statistical method can completely adjust for allocation bias. However, current American Heart Association guidelines state that a blood pressure above 185/110 mm Hg and impaired hemostasis (direct oral anticoagulant use or international normalized ratio >1.7) are contraindications for IVT.³ These variables have also been associated with worse outcomes⁴ and, therefore, are true confounders. Much to our surprise, data on baseline blood pressure and hemostasis were not reported in by Goyal et al.,¹ and it does not appear that these variables were used in the propensity score matching. We invite the authors to comment on why information on baseline blood pressure and hemostasis was not reported and how this may have affected their results.