ESJ Featured Article of the Month- November 2024

ESJ Featured Article: Initial blood pressure and adverse cardiac events following acute ischaemic stroke: an individual patient data pooled analysis from the VISTA database. Ishiguchi et al. Published online Oct 30 2024.

https://journals.sagepub.com/doi/full/10.1177/23969873241296391#supplementary-materials

Stroke Heart Syndrome (SHS) is the focus of a few papers in this month’s issue of European Stroke Journal (ESJ). SHS is defined as cardiac complications, including acute coronary syndrome (ACS) myocardial infarction (MI), heart failure or left ventricular dysfunction, atrial fibrillation (AF) or flutter or other arrhythmia, and cardiorespiratory arrest, occurring within 30-days of acute ischaemic stroke. These cardiac complications are believed to stem from physiological reactions to acute ischaemic stroke (AIS), including autonomic dysfunction, triggering of inflammatory cascades and neurohumoral responses¹. The prevalence of SHS after AIS is estimated to be between 10 to 20%¹. The aim of this study was to investigate the association between blood pressure at stroke presentation and the risk of SHS.

Acute stroke guidelines recommend avoiding excessive hypertension (>180/105 mmHg) in patients with AIS undergoing reperfusion therapy². Many clinicians tolerate a degree of permissive hypertension in those not undergoing reperfusion therapy. Cerebral autoregulation is impaired by acute ischaemia, making the brain vulnerable to both hypo- and hyper-perfusion. Therefore extreme changes in blood pressure should be avoided. More recently, INTERACT4 showed that lowering blood pressure of patients with as yet undifferentiated stroke in the ambulance increased the likelihood of poor functional outcomes among those with ischaemic stroke³.

This study⁴ used data from the Virtual International Stroke Trials Archive (VISTA). VISTA combines patient data from acute stroke trials completed between 1998 and 2010. Ishiguchi and colleagues investigated the association between systolic and diastolic blood pressure measured at stroke presentation and SHS. The analysis was adjusted for age, sex, baseline National Institute of Health Stroke Severity score (NIHSS), thrombolysis, antihypertensive agents, and history of AF. Investigators also investigated the relationship between blood pressure and 90-day all-cause mortality.

This analysis included a robust sample of 14,965 individuals, of whom 1774 (11.9%) developed stroke-heart syndrome. The mean blood pressure at stroke presentation was systolic 157±25mmHg and diastolic 85±15mmHg. Participants were on average 69 ± 12 years old, 45% were women. The NIHSS at presentation was 13 ± 6 and 22% of the cohort were treated with thrombolysis. Patients who developed SHS did so a median of 2 days (IQR 1-4) following AIS. The most commonly occurring component was arrhythmia or ECG abnormalities, comprising 52% of all SHS diagnoses. The next most common component of SHS was AF (33%), followed by heart failure (18.3%), then ACS or MI (8.2%). (Of note, some patients experienced more than one event contributing to the SHS composite outcome.) The mortality rate among those who developed SHS was 34%.

The relationship between blood pressure and risk of SHS is demonstrated in the cubic spline curve seen in the visual abstract below depicting a U-shaped curve. The highest risk of SHS was at low systolic blood pressure values of ≤130mmHg. For diastolic BP, the highest risk of SHS was at a low diastolic pressure of ≤55mmHg. For the outcome of 90-day all-cause mortality, the relationship visualised between both SBP and DBP was also a U-shaped curve. This time, however, the highest risk of death was at high values of SBP and DBP, but only DBP ≥115mmHg was statistically significantly associated with increased risk of all-cause death.

This study has some limitations which are worth considering. First, it cannot infer how blood pressure may mediate the increased risk of SHS and death. Stroke location has been suggested as a mediator, for example, insular cortex infarcts may trigger pro-sympathetic signals, causing arrhythmias and raising the risk of cardiac death¹. However, this study did not include data on stroke location. Additionally, there is no information on acute blood pressure management or its trajectory post-presentation, both of which are crucial prognostic factors⁵. Cardiac events may also be under-ascertainment, as event verification against medical records was not possible, potentially leading to conservative estimates. The VISTA database includes studies from 1998–2010, which may limit generalizability given recent advancements in stroke care, including thrombectomy, dual antiplatelet therapy, and expanded use of perfusion scanning for reperfusion therapy.

Despite these limitations, this is a robust observational study in a large cohort of patients, underscoring the prognostic importance of blood pressure at presentation in AIS. It supports the view that extremes of blood pressure are harmful in acute ischaemic stroke. It also draws our focus to stroke-heart syndrome, which is a common and under-recognised complication of stroke. As yet there are no treatments to prevent SHS and further research is needed to address this knowledge gap. Meanwhile, as clinicians we should remain vigilant in our guideline-directed management of blood pressure in acute ischaemic stroke.

To read the full paper visit: https://journals.sagepub.com/doi/full/10.1177/23969873241296391#supplementary-materials

References:

1. Scheitz JF, Sposato LA, Schulz-Menger J, Nolte CH, Backs J, Endres M. Stroke-Heart Syndrome: Recent Advances and Challenges. J Am Heart Assoc 2022; 11(17): e026528.
2. Berge E, Whiteley W, Audebert H, et al. European Stroke Organisation (ESO) guidelines on intravenous thrombolysis for acute ischaemic stroke. Eur Stroke J 2021; 6(1): I-lxii.
3. Li G, Lin Y, Yang J, et al. Intensive Ambulance-Delivered Blood-Pressure Reduction in Hyperacute Stroke. N Engl J Med 2024; 390(20): 1862-72.
4. Ishiguchi H, Huang B, El-Bouri WK, et al. Initial blood pressure and adverse cardiac events following acute ischaemic stroke: An individual patient data pooled analysis from the VISTA database. European Stroke Journal 2024: 23969873241296391.
5. Wang R, Liu Y, Zhang Q, et al. Twenty-four-hour blood pressure trajectories and clinical outcomes in patients who had an acute ischaemic stroke. Heart 2024; 110(11): 768-74.

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