Effect of PCSK9 inhibitor on early neurological deterioration in acute ischemic stroke patients with a history of coronary heart disease: a study protocol for a randomized controlled trial in Dalian, China

Early neurological deterioration (END) is defined as the progressive or stepwise exacerbation of neurological deficits within 7 days after onset of stroke, with an incidence ranging from 5 to 40% [1–4]. END is a crucial factor in determining short-term prognosis in patients with acute ischemic stroke (AIS); furthermore, it is associated with increased mortality rates among hospitalized individuals [5]. Given the significant clinical implications of END, preventing its occurrence is of paramount importance.

AIS and coronary heart disease (CHD) are leading causes of death worldwide, significantly impacting patients’ quality of life and prognosis while also placing a substantial burden on healthcare systems [6, 7]. Notably, in clinical practice, AIS often coexists with CHD, leading to more severe symptoms, higher mortality risks, and poorer prognoses compared to patients without CHD [8, 9]. However, the best treatment plan for these patients is still uncertain.

CHD and large artery atherosclerotic stroke share common risk factors. Elevated low-density lipoprotein cholesterol (LDL-C) leads to atherosclerosis [3]. In AIS, high levels of oxidized low-density lipoprotein (ox-LDL) activate pro-inflammatory signaling pathways in the affected area. This activation triggers the release of pro-inflammatory cytokines, including interleukin 6 (IL-6), interleukin 8 (IL-8), and tumor necrosis factor alpha (TNF-α) [10]. These cytokines worsen brain tissue damage in the ischemic penumbra [11]. Ox-LDL activation also raises the levels of matrix metalloproteinases (MMPs), which promote plaque instability [12, 13]. Detachment of unstable plaques and local thrombus accumulation that block distal blood vessels are key mechanisms of END in AIS [14]. According to the “Shanghai Expert Consensus on Enhanced Blood Lipid Management in Ischemic Stroke,” achieving LDL-C targets in AIS patients can reduce the risk of secondary early neurological deterioration (END) events and other vascular recurrences Tables 1 and 2.

In this context, proprotein convertase subtilisin/kexin type 9 (PCSK9) inhibitors, a novel and potent class of lipid-lowering drugs, are gaining significant recognition. By competitively inhibiting the binding of PCSK9 to low-density lipoprotein receptors (LDLR), they reduce LDLR degradation effectively [15], thus lowering circulating low-density lipoprotein cholesterol (LDL-C) levels. Studies have demonstrated that PCSK9 inhibitors can suppress pro-inflammatory cytokines release [10], reduce endothelial cell apoptosis [16], and inhibit platelet activation [17]. As a result, these inhibitors hold promise in preventing atherosclerosis progression and reducing cardiovascular events. This study aims to assess the effectiveness of PCSK9 inhibitors in lowering the incidence of END among AIS patients with a history of CHD.

The findings of this study will not only elucidate the potential role of PCSK9 inhibitors in AIS patients with a history of CHD but also provide novel insights and directions for the treatment of this specific patient population.

The primary objective of this study is to investigate the effects of PCSK9 inhibitors on END in AIS patients with a history of CHD within 24 h of symptom onset. Secondary objectives include evaluating changes in daily living abilities, recurrence rates of cardiovascular and cerebrovascular events within 90 days, alterations in blood biochemical indices/markers, and variations in inflammatory factors between the two patient groups after treatment.

This is a prospective, randomized, parallel-group, blinded-endpoint, single-center clinical study aimed at investigating the preventive effects of PCSK9 inhibitors on END in patients with AIS and a history of CHD within 24 h of symptom onset. The study will be conducted from December 2023 to November 2025 at the Neurology Department of the First Affiliated Hospital of Dalian Medical University. A total of 156 AIS patients with a history of CHD and symptom onset within 24 h will be recruited and randomly assigned to either the PCSK9 inhibitor combined with statin treatment group (PI group) or the statin monotherapy group (AT group). The PI group will receive a combination therapy consisting of evolocumab and rosuvastatin calcium tablets, while the AT group will receive only oral rosuvastatin calcium tablets alone. The trial duration will be 90 days and consist of three phases: screening, treatment, and follow-up. Participants will undergo examinations and assessments on days 1, 7, 30, and 90 after enrollment. Written informed consent is mandatory for all participants prior to trial entry. The flow chart of the trial is illustrated in Fig. 1.

The study will be conducted at the First Affiliated Hospital of Dalian Medical University, located in Dalian, China. This hospital will serve as the primary site for the recruitment of participants and the implementation of the clinical trial. The anticipated duration of the study is 2 years, encompassing participant enrollment, intervention administration, assessments, and data analysis.

Participants will be recruited from the Neurology Department of the First Affiliated Hospital of Dalian Medical University based on predefined inclusion criteria. Only eligible individuals will be invited to enroll in the study.

The inclusion criteria are as follows:

The exclusion criteria are as follows:

All eligible participants will be invited to participate in this study. Two trained research personnel will conduct face-to-face sessions with potential participants or their authorized surrogates, wherein they will provide comprehensive explanations regarding the study’s objectives, procedures, associated risks, and the rights of participants. They will address any queries from participants or surrogates and ensure a thorough comprehension of the provided information. Prior to enrollment, informed consent will be obtained through signed written consent forms from either the participant or their authorized surrogate.

The consent form requests participants’ permission for the continued use of their data even in the event of trial withdrawal. Additionally, participants are requested to grant permission to the research team for sharing pertinent data with applicable regulatory authorities. It is noteworthy that the trial does not encompass the collection of biological specimens.

The selection of comparators in this study is based on the current standard treatment for AIS. Intensified lipid-lowering therapy with statins represents the established treatment regimen for AIS patients with a history of coronary heart disease (CHD). Therefore, comparing PCSK9 inhibitor combined with statin treatment to statin monotherapy aims to evaluate the additional benefits of PCSK9 inhibitors in preventing END in AIS patients with a history of CHD.

After signing the informed consent, participants will be randomly allocated to either the PI group (intervention group) or the AT group (control group). Participants in the PI group will receive a subcutaneous injection of 140 mg (1 ml) of evolocumab (Rephatha®, Amgen Inc.) and orally take 20 mg of rosuvastatin (Crestor®, AstraZeneca Inc.) calcium tablets within 1 h of randomization. Starting from the following day, they will receive 20 mg of rosuvastatin calcium tablets orally every evening and 140 mg of evolocumab subcutaneously once every 2 weeks. Participants in the AT group will receive 20 mg of rosuvastatin calcium tablets orally within 1 h of randomization. Starting from the next day, they will continue to orally receive 20 mg of rosuvastatin calcium tablets orally every evening.

Participants are allowed to withdraw from the study at any time due to various reasons, including failure to meet the inclusion criteria, inability to continue with the intervention treatment, or participant request.

To minimize the risk of missing data, each participant will be furnished with paper reminders containing precise dates and times for all scheduled sessions. Additionally, the investigator will conduct weekly phone calls to prompt participants about upcoming sessions and inquire about their adherence to medication.

During the trial, there will be no regulations or restrictions placed on concomitant care or interventions.

N/A. Given the low-risk nature of this study, we do not anticipate the necessity for posttrial care provisions.

The primary outcome of this study will be the END within 7 days. END will be defined as a 2-point increase in the NIHSS score or a 1-point increase in motor function (specifically NIHSS Items 5, 6, and 7) within 24 h to 7 days of AIS onset. To address the potential impact of END severity on the reliability of the primary outcome, we will conduct a sensitivity analysis using a higher threshold: a 4-point worsening in the NIHSS or a 2-point increase in motor function, which will be classified as severe END.

The secondary outcomes of the study will include:

Safety outcomes will be documented by recording the types and frequencies of all adverse events and abnormalities in laboratory tests throughout the study duration. Safety evaluations will include assessments of the patients’ general condition, vital signs, blood routine tests, blood biochemistry, liver and kidney function, coagulation function, and neuroimaging examinations. All participants will undergo assessments before treatment initiation and at the initial treatment milestones of 30 days and 90 days.

The standard protocol is depicted in Fig. 2.

This study is a randomized controlled trial with the intervention group as the PI group and the control group as the AT group. The study involves AIS patients with a confirmed history of CHD, and the primary outcome is the END in the two groups.

Based on our retrospective observation of 21 AIS patients with a history of CHD and no prior use of PCSK9 inhibitors, hospitalized at the First Affiliated Hospital of Dalian Medical University from April 2022 to June 2023, a total of 7 patients exhibited END within 24 h to 7 days of disease onset, accounting for 33.3%. During the same period, among 22 AIS patients with a history of CHD who were treated with PCSK9 inhibitors within 24 h of onset, 3 patients experienced END, accounting for 13.6%. Assuming the incidence of END in the intervention and control groups are 13.6% and 33.3%, respectively, with a two-sided α level of 0.05 and 80% power, we used the PASS software version 15 (NCSS, LCC, Taiwan 2017) to calculate the sample size. Each group requires 70 patients. Considering a 10% loss to follow-up, both groups will need 78 patients, making a total of at least 156 patients across both groups. The sample size calculation formula is as follows:

where:

n is the sample size per group.

Z_α/2 is the critical value for a two-sided significance level (1.96 for α = 0.05).

Z_β is the critical value for power (0.84 for 80% power).

p is the estimated overall incidence rate.

δ is the expected difference between the two groups.

Potential participants will be recruited from the First Affiliated Hospital of Dalian Medical University. All eligible patients with AIS and a history of CHD within 24 h of onset will be invited to participate in this clinical trial. Recruitment will be managed by XG and XY and will span 18 months. Based on our preliminary intention-to-enroll survey, we estimate a recruitment rate of at least 80%. If we do not reach the required number of participants, we will extend the recruitment period as necessary. The study protocol will be thoroughly explained to potential participants by the investigators.

The allocation sequence for this study will be generated using computer-generated random numbers. The randomization will be stratified by gender. To reduce the predictability of the sequence, blocked randomization will be used to ensure a 1:1 ratio between the PI group (PCSK9 inhibitor with statin) and the AT group (statin monotherapy). Details of the block sizes and the randomization process will be documented separately and will remain unavailable to those who enroll participants or assign interventions.

The allocation sequence will be concealed using sequentially numbered, opaque, sealed envelopes. An independent researcher, not involved in recruitment, treatment, or assessment, will prepare these envelopes, each containing the group assignment (either the AT group or the PI group). After obtaining informed consent and completing baseline measurements, participants will be assigned the next sequential envelope by a designated researcher who is not involved in treatment or outcome assessment. The envelopes will remain sealed until the participant is assigned to an intervention, ensuring the allocation sequence is concealed from those enrolling participants and assigning interventions.

LP will generate the allocation sequence and prepare the opaque, sealed envelopes containing the group assignments. XG and XY will be responsible for enrolling participants and assigning them to their respective groups.

Researchers responsible for data collection and outcome analysis will be blinded to group assignments until after data analysis is completed, as they will not be involved in participant assignment or intervention implementation.

Not applicable to study; the design is open label, so unblinding will not occur.

The principal investigator will ensure that all study team members receive proper training, with access to written instructions and standard operating procedures. Regular meetings will facilitate communication and the sharing of new information. For quality assurance, the ethics committee (EKNZ) or an independent trial monitor may visit the research sites and will have direct access to source data and study-related files. All participant data will be kept strictly confidential and immediately uploaded to the designated cloud server after each assessment.

During the baseline assessment, demographic information will be gathered using standardized questionnaires. A comprehensive medical profile, including current and past treatments, allergies, personal background, surgical history, and family medical history, will be compiled. Assessments will include physical examinations and reliable laboratory tests (blood routine, urine routine, blood biochemistry, coagulation function, inflammatory factors). Additionally, electrocardiograms, NIHSS and mRS scores, documentation of concurrent medications, and recording of adverse events will be conducted.

Eligible patients will be randomly assigned to either the PI group (PCSK9 inhibitor combined with statin) or the AT group (statin monotherapy) to receive the designated interventions. On day 7 after enrollment, a physical examination and laboratory tests will be reassessed. The primary outcomes will be evaluated, mortality data collected, and concomitant medication usage documented.

The follow-up period will start on day 8 after enrollment and continue until day 90, with evaluations on days 30 and 90. Assessments will include concomitant medications, adverse events, physical examinations, laboratory tests, NIHSS and mRS scores, and the occurrence of any recurrent cardiovascular or cerebrovascular events. If a participant experiences an endpoint event (recurrent cardiovascular or cerebrovascular event) during treatment or follow-up, the clinical study will be terminated, and active management will be initiated.

The National Institutes of Health Stroke Scale (NIHSS) and the modified Rankin Scale (mRS) are standardized tools for evaluating stroke severity and outcomes. The NIHSS assesses various neurological functions such as consciousness, vision, motor function, sensation, speech, and language. Scores range from 0 to 42, with higher scores indicating more severe impairment [18]. Motor function is specifically assessed through Item 5 (Motor Arm), Item 6 (Motor Leg), and Item 7 (Limb Ataxia). The mRS evaluates disability and dependence in daily activities, ranging from 0 (no symptoms) to 6 (death). In this study, validated Chinese versions of both scales will be used [19]. Assessments will be conducted by two independent neurologists, and if discrepancies arise in their scores, a third senior neurologist will be consulted for the final assessment. All raters will receive comprehensive training before the trial begins, and repeated measurements will be conducted to ensure reliability and accuracy.

To enhance participant retention and ensure complete follow-up, we will establish regular communication and engagement with participants, implement flexible scheduling for follow-up visits, and provide reminders through phone calls and messages.

This study will employ an electronic data management system (EDMS) with an electronic case report form (eCRF) constructed in accordance with the study protocol. Individuals responsible for data entry will be granted the necessary permissions to enter, modify, and resolve queries. Researchers will have permissions for modification, browsing, query resolution, and verification, whereas data management personnel will be permitted to browse, submit queries, and lock data.

To ensure the authenticity, completeness, and accuracy of the data, it is imperative that all trial records be fully completed with no empty or missing entries. Researchers are required to retain all original participant documents to maintain accurate and timely data. Original documents and medical records must be clear, detailed, and easily identifiable by clinical trial personnel. Data in the eCRF can only be modified by authorized researchers. All original trial data records will be preserved for a minimum of 5 years.

Personal information about participants will be collected, shared, and maintained with strict confidentiality throughout the trial. Each participant will be assigned a unique identification number, which will label all study-related documents and data to ensure anonymity. Data will be stored in secure, password-protected electronic databases, and physical records will be kept in locked cabinets accessible only to authorized personnel.

Data sharing will be restricted to the research team and authorized monitors, auditors, and regulatory authorities as required. Any shared data will be de-identified. Electronic data transfers will be encrypted for added security.

Regular audits and data checks will ensure compliance with confidentiality protocols. After the trial, personal data will be securely stored for at least 5 years. Participants’ personal information will not be disclosed in any publications or reports.

Not applicable. This study does not involve the use of biological samples for genetic or molecular analysis.

Once all participants have completed their assessments, data analysis will commence. To reduce bias, the data analyst will remain blinded during the analysis process. Only participants who strictly adhere to the intervention protocol will be included in the analysis. Data that are missing or deviate from the protocol will be excluded from the analysis.

The primary and secondary outcomes will be combined as dependent variables in the generalized linear model (GLM). First, a univariate analysis of the treatment groups will be performed to determine the unadjusted risk ratio (RR) and odds ratio (OR), along with a 95% confidence interval (CI). Next, continuous variables like the NIHSS score at admission, mRS score, and age will serve as covariates. Categorical variables such as sex, hypertension, diabetes, and prior strokes will be included as factors in the GLM to reduce variance error. If the outcomes show statistical significance for the main effects, interaction effects will be used to assess differences between the groups. Changes in blood biochemical indices will be analyzed using repeated measures ANOVA or mixed-effects models, accounting for measurements taken at baseline, 7 days, 30 days, and 90 days. Changes in inflammatory factors (IL-6, IL-8, TNF-α) from baseline to 7 days will be evaluated using paired t-tests or Wilcoxon signed-rank tests, based on data distribution. Sensitivity analysis will use the criterion for severe END, defined as either a 4-point increase in NIHSS or a 2-point worsening in motor function based on a higher threshold. All analyses will be conducted using SPSS (IBM Corp., Armonk, NY, USA), with a significance threshold of α = 0.05.

Not applicable to the study. Data analysis will not commence until all participants have completed the study.

Additional analyses will explore potential subgroup differences and interaction effects. Subgroup analyses will stratify by age, gender, baseline stroke severity (NIHSS), and comorbid conditions such as diabetes or hypertension. These analyses will be conducted using stratified chi-square tests for categorical outcomes and stratified Wilcoxon rank-sum tests or mixed-effects models for continuous outcomes. Interaction effects will be assessed with multivariable logistic regression models for binary outcomes. All statistical tests will be two-tailed, with a p-value of less than 0.05 considered statistically significant.

To address protocol non-adherence, we will define the analysis populations as follows: the intention-to-treat (ITT) population will include all randomized participants who have at least one treatment record and will be used for analyzing the primary outcome. The per-protocol (PP) population will include only those participants who fully adhere to the study protocol without major deviations and will be used for analyzing the secondary outcomes. Experience indicates that dropouts are rare. If the proportion of missing data exceeds 10%, multiple imputation techniques will be employed to ensure the robustness of our study results.

Upon reasonable request, the full protocol, participant-level data, and statistical code will be made available from the corresponding author.

The Department of Neurology at the First Affiliated Hospital of Dalian Medical University will serve as the trial coordinating center. The trial steering committee (TSC) will consist of one principal investigator and two co-investigators. The TSC will be responsible for ensuring the trial is conducted according to the protocol and for providing oversight throughout the study. This will include approving the final protocol, monitoring study progress, making decisions regarding any protocol amendments, and ensuring the overall integrity of the trial. The committee will meet bi-monthly to review progress and address any issues that may arise.

The trial management committee (TMC) will consist of two co-investigators, two master’s students, and an independent scientific assistant. The TMC will be responsible for the day-to-day management of the trial, including planning, coordination, and execution of the study. Their duties will encompass overseeing patient recruitment, ensuring protocol compliance, managing data collection and quality control, and maintaining participant safety and trial integrity. The independent scientific assistant will be solely responsible for generating the random allocation sequence, ensuring unbiased assignment of participants. The TMC will hold weekly meetings to review trial operations and address any immediate concerns.

In consideration of the relatively low-risk profile of the trial as determined by the hospital’s ethics committee and the study’s steering committee, there will be no formal data monitoring committee (DMC). Instead, an internal trial monitor, independent of the study team, will be responsible for regular onsite monitoring according to the established monitoring plan.

Adverse events (AEs) are defined as any clinical manifestation, syndrome, or worsening of pre-existing conditions that affect the health of participants during the clinical trial. These events may not necessarily be related to the PCSK9 inhibitor and statin treatment and can include new illnesses or exacerbation of existing symptoms. All solicited and spontaneously reported AEs, as well as other unintended effects of trial interventions or conduct, will be documented from participant enrollment until the study concludes. All AEs will be recorded in the electronic case report form (eCRF). Participants will be monitored for AEs through regular visits, phone calls, and during any unscheduled visits. The study team will assess AEs for severity, duration, and causality. The severity of AEs will be classified according to the Common Terminology Criteria for Adverse Events (CTCAE), and causality will be determined based on the relationship between the AE and the study intervention, categorized as unrelated, unlikely, possible, probable, or definite. Serious adverse events (SAEs) will be reported to the ethics committee and relevant regulatory authorities within 24 h of awareness by researchers. Following the occurrence of an SAE, researchers must provide appropriate treatment to the participant and submit a follow-up report to the ethics committee within 15 days, detailing the cause of the event and the measures taken.

The hospital’s ethics committee will audit the study every 6 months to ensure compliance with the protocol, ethical guidelines, and regulatory requirements. The auditing process will include a comprehensive review of trial documentation, participant records, and data management practices.

Any modifications will first be discussed within the Steering Committee to reach a consensus. Amendments will then be submitted to the hospital’s Ethics Committee and the Department of Scientific Research for approval. Once approved, a formal document outlining the protocol revisions will be provided to all relevant parties. Trial participants will be informed of any changes that may affect their participation, and their consent will be re-obtained if necessary.

At the conclusion of the study, participants interested in the results will receive a summary via email. The study findings will be published in peer-reviewed scientific journals and presented to the medical community through talks at national and international conferences and seminars. Furthermore, the results will be made available in the Chinese Clinical Trial Registry and relevant databases to ensure open access to the data.

This trial is conducted under protocol version 1.1, dated November 30, 2023. Recruitment commenced in December 2023 and is anticipated to be completed by November 2025.

Ethical approval of the study was obtained within the First Affiliated Hospital of Dalian Medical University in Liaoning, China. The Protocol Record number is YJ-KY-2024-109. Informed consent is obtained from all study participants. SPIRIT guidance: Plans for seeking research ethics committee/institutional review board (REC/IRB) approval.

This manuscript does not contain individual personal data from patients. The participant information materials and informed consent form are available from the corresponding author on request.

The authors declare that they have no competing interests.

Data from this study are available upon reasonable request from the corresponding authors. The data are monitored by the corresponding authors and the scientific research department of the hospital.