Efficacy and Safety of PCSK9 Inhibitors in Stroke Prevention

Efficacy and safety of PCSK9 inhibitors for stroke prevention: Systematic review and meta-analysis

OBJECTIVE

Investigate the efficacy and safety of proprotein convertase subtilisin/kexin type 9 inhibitors (PCSK9i) on stroke prevention.

BACKGROUND

PCSK9i reduce low-density lipoprotein cholesterol (LDL-C) and lipoprotein a (LpA) levels. Their efficacy in reducing the risk of major cardiovascular events has been shown in multiple randomized clinical trials (RCT). However, clinical equipoise remains on the magnitude and mechanisms by which PCSK9i decrease the risk of stroke.

METHODS

We performed a systematic search of biomedical databases from inception to January 15, 2024, to identify RCTs that investigated the efficacy of PCSK9i versus placebo for major cardiovascular event prevention. The primary outcome was total stroke. The safety outcome was the risk of adverse neurological events, as defined by each trial. Effect size was represented by risk ratio (RR), and analysis was done using random-effects meta-analysis. Heterogeneity was assessed by I2 and Cochrane Q statistics. Meta-regression analyses were performed to assess the association between LDL-C and LpA reduction and stroke risk.

RESULTS

Overall, 20 studies with 93,093 patients were included. The quality of the evidence was moderate and heterogeneity for all comparisons was low (I2 < 25 %). The mean age was 60.1 years for the PCSK9i group and 59.6 years for the placebo group, with a mean follow-up time of 60.1 weeks. PCSK9i reduced the LDL-C levels by 11 % and LpA levels by 8 %. PCSK9i were associated with a significant reduction in stroke risk (RR 0.75, 95 % CI 0.66-0.86, I2 = 0 %), without an increase in mortality (RR 0.97, 95 % CI 0.87-1.08, I2 = 0 %). The risk of adverse neurological events was similar between groups (RR 0.99, 95 % CI 0.84-1.18, I2 = 11 %). In meta-regression analyses, the stroke risk was not associated with the magnitude of the effect of PCSK9i on LDL-C (LDL C β = -0.01, 95 % CI = -0.03-0.02) and LpA (β = -0.01, 95 % CI = -0.06-0.04) levels.

CONCLUSIONS

PCSK9i significantly reduced the stroke risk, without increasing mortality or the risk of adverse neurological events. Our findings also suggest that the beneficial effect of PCSK9i on stroke risk is mediated by LDL-C- and LpA-independent mechanisms.

Elevated SIRT2 of serum exosomes is positively correlated with diagnosis of acute ischemic stroke patients

BACKGROUND

Silent Information Regulator 2 (SIRT2) protein inhibition has been shown to play a neuroprotective role in acute ischemic stroke (AIS) in mice. However, its role in AIS patients has not been fully understood. In this study, we aimed to analyze SIRT2 protein expression in serum exosomes of AIS and non-AIS patients, and evaluate its potential role in diagnosis and prognosis of AIS.

METHODS

Serum exosomes from 75 non-AIS subjects and 75 AIS patients were isolated. The SIRT2 protein levels in exosomes were analyzed using enzyme linked immunosorbent assay (ELISA). The National Institutes of Health Stroke Scale (NIHSS) was used to evaluate the severity of the disease. The modified Rankin Scale (mRS) was employed to assess the functional outcomes of the patients at 3-months following stroke onset.

RESULTS

The SIRT2 protein concentration of serum exosomes were higher in AIS patients than non-AIS patients (p < 0.001). Furthermore, the receiver operative characteristic curve (ROC) demonstrated that higher serum exosome SIRT2 could differentiate AIS patients from non-AIS patients with a sensitivity of 81.3% and a specificity of 75.3%. The area under the curve was 0.838 (95% CI: 0.775, 0.902). Additionally, higher SIRT2 concentration of serum exosomes were associated with NIHSS ≥ 4 (p < 0.001) and mRS ≥ 3 (p = 0.025) in AIS patients. The ROC analysis showed SIRT2 could discriminate stroke with NIHSS ≥ 4 from mild stroke (NIHSS < 4) with a sensitivity of 75.0% and a specificity of 69.6%. The area under the curve was 0.771 (95% CI: 0.661,0.881). Similarly, the test showed SIRT2 could differentiate between AIS patients with mRS ≥ 3 from those with mRS < 3 with a sensitivity of 78.3% and a specificity of 51.9%. The area under the curve was 0.663 (95% CI: 0.531,0.796). The logistic regression analysis revealed that SIRT2 concentration in serum exosomes can independently predict the diagnosis of AIS (odd ratio = 1.394, 95%CI 1.231-1.577, p < 0.001) and higher NIHSS scores (≥ 4) (odd ratio = 1.258, 95%CI 1.084-1.460, p = 0.002). However, it could not independently predict the prognosis of AIS (odd ratio = 1.065, 95%CI 0.983-1.154, p = 0.125).

CONCLUSION

The elevation of SIRT2 in serum exosomes may be a valuable biomarker of AIS, which may be a potential diagnostic tool to facilitate decision making for AIS patients.

Efficacy and safety of inclisiran in stroke or cerebrovascular disease prevention: a systematic review and meta-analysis of randomized controlled trials

Aims: As the impact of inclisiran in stroke prevention in atherosclerotic cardiovascular disease (ASCVD) patients or those at high risk of ASCVD is still unclear, we conducted a systematic review and meta-analysis of randomized controlled trials (RCT) to quantify the effectiveness of inclisiran in stroke prevention in these patients. Methods: Literature research was conducted in four electronic databases (PubMed, EMBASE, Web of Science, CENTRAL) and two clinical trials registers (ClinicalTrials.gov, WHO ICTRP) from the inception of the study to 17 October 2022, and was updated by the end of the study on 5 January 2023. Two authors independently screened the studies, extracted the data, and assessed the bias. The risk of bias was assessed using the Cochrane risk-of-bias tool for randomized trials (RoB 2). The intervention effect was estimated by calculating risk ratio (RR), weighted mean difference (WMD), and 95% confidence interval (CI) with R 4.0.5. Sensitivity analysis by changing meta-analysis model was also performed to test the robustness of the pooled results. If this was not possible, a descriptive analysis was conducted. Results: Four RCTs (n = 3,713 patients) were rated as high-risk bias. Meta-analysis of three RCTs (ORION-9, ORION-10, and ORION-11) showed that inclisiran reduced myocardial infarction (MI) risk by 32% (RR = 0.68, 95%CI = 0.48-0.96) but did not reduce stroke (RR = 0.92, 95%CI = 0.54-1.58) and major cardiovascular events (MACE) (RR = 0.81, 95%CI = 0.65-1.02) risk. Sensitivity analysis results were stable. Safety was similar to the placebo group but had frequent injection-site reactions (RR = 6.56, 95%CI = 3.83-11.25), which were predominantly mild or moderate. A descriptive analysis of one RCT (ORION-5) was conducted due to different study designs, and suggested that inclisiran might be given semiannually from the beginning. Conclusion: Inclisiran is not beneficial for stroke or MACE prevention in ASCVD or patients at high risk of ASCVD but is associated with the reduction of MI. Given the limited number and quality of the available studies and the lack of a standardized definition for cardiovascular events, further studies are essential for confirming the results.

Predictors and Outcomes of Stroke After Isolated Coronary Artery Bypass Grafting. A Single-Center Experience in 20,582 Patients

OBJECTIVE

Stroke remains a devastating complication after cardiac surgical procedures despite perioperative monitoring and management advances. This study aimed to determine the predictors of stroke in a large, contemporary coronary artery surgery population.

DESIGN

Patient data were analyzed retrospectively.

SETTING

This single-center study was performed in the Catharina Hospital (Eindhoven).

PARTICIPANTS

All patients who underwent isolated coronary artery bypass grafting (CABG) between January 1998 and February 2019 were included.

INTERVENTIONS

Isolated CABG.

MEASUREMENTS AND MAIN RESULTS

The primary endpoint was a postoperative stroke, defined according to the international updated definition for stroke. Logistic regression was performed to retrieve variables associated with postoperative stroke. A total of 20,582 patients underwent CABG during the period of the study. Stroke was observed in 142 patients (0.7%), of which 75 (52.8%) occurred during the first 72 hours. The incidence of postoperative stroke declined over the years. A significantly higher 30-day mortality rate was seen in patients with stroke (20.4%) compared with 1.8% in the rest of the population; p < 0.001. Multivariate logistic regression analysis showed age, peripheral arterial disease, reexploration for bleeding, perioperative myocardial infarction, and year of surgery as independent predictors for stroke. Patients with postoperative stroke had worse long-term survival (log-rank p < 0.001). Cox regression analysis revealed postoperative stroke (odds ratio 2.13 [1.73-2.64)) as an independent predictor of late mortality.

CONCLUSIONS

Stroke after CABG is associated with high early and late mortality. Age, peripheral vascular disease, and the year of surgery were associated with postoperative stroke.

Identification of Potent Small-Molecule PCSK9 Inhibitors Based on Quantitative Structure-Activity Relationship, Pharmacophore Modeling, and Molecular Docking Procedure

The leading cause of atherosclerotic cardiovascular disease (ASCVD) is elevated low-density lipoprotein cholesterol (LDL-C). Proprotein convertase subtilisin/kexin type 9 (PCSK9) attaches to the domain of LDL receptor (LDLR), diminishing LDL-C influx and LDLR cell surface presentation in hepatocytes, resulting in higher circulating LDL-C levels. PCSK9 dysfunction has been linked to lower levels of plasma LDLC and a decreased risk of coronary heart disease (CHD). Herein, using virtual screening tools, we aimed to identify a potent small-molecule PCSK9 inhibitor in compounds that are currently being studied in clinical trials. We first performed chemical absorption, distribution, metabolism, excretion, and toxicity (ADMET) filtering of 9800 clinical trial compounds obtained from the ZINC 15 database using Lipinski's rule of 5 and achieved 3853 compounds. Two-dimensional (2D) quantitative structure-activity relationship (QSAR) was initiated by computing molecular descriptors and selecting important descriptors of 23 PCSK9 inhibitors. Multivariate calibration was performed with the partial least square regression (PLS) method with 18 compounds for training to design the QSAR model and 5 compounds for the test set to assess the model. The best latent variables (LV) (LV=6) with the lowest value of Root-Mean-Square Error of Cross-Validation (RMSECV) of 0.48 and leave-one-out cross-validation correlation coefficient (R²CV) = 0.83 were obtained for the QSAR model. The low RMSEC (0.21) with high R²cal (0.966) indicates the probability of fit between the experimental data and the calibration model. Using QSAR analysis of 3853 compounds, 2635 had a pIC₅₀<1 and were considered for pharmacophore screening. The PHASE module (a complete package for pharmacophore modeling) designed the pharmacophore hypothesis through multiple ligands. The top 14 compounds (pIC₅₀>1) were defined as active, whereas 9 (pIC₅₀<1) were considered as an inactive set. Three five-point pharmacophore hypotheses achieved the highest score: DHHRR1, DHHRR2, and DHRRR1. The highest and best model with survival scores (5.365) was DHHRR1, comprising 1 hydrogen donor (D), 2 hydrophobic groups (H), and 2 rings of aromatic (R) features. We selected the molecules with a higher 1.5 fitness score (257 compounds) in pharmacophore screening (DHHRR1) for molecular docking screening. Molecular docking indicates that ZINC000051951669, with a binding affinity: of -13.2 kcal/mol and 2 H-bonds, has the highest binding to the PCSK9 protein. ZINC000011726230 with energy binding: -11.4 kcal/mol and 3 H-bonds, ZINC000068248147 with binding affinity: -10.7 kcal/mol and 1 H-bond, ZINC000029134440 with a binding affinity: -10.6 kcal/mol and 4 H-bonds were ranked next, respectively. To conclude, the archived molecules identified as inhibitory PCSK9 candidates, and especially ZINC000051951669 may therefore significantly inhibit PCSK9 and should be considered in the newly designed trials.

Atherogenic Dyslipidemias: Unmet Needs and the Therapeutic Potential of Emerging and Novel Approaches and Drugs

Innovative lipid-modifying agents are valuable resources to improve the control of atherogenic dyslipidemias and reduce the lipid-related residual cardiovascular risk of patients with intolerance or who are not fully responsive to a consolidated standard of care (statins plus ezetimibe). Moreover, some of the upcoming compounds potently affect lipid targets that are thus far considered "unmodifiable". The present paper is a viewpoint aimed at presenting the incremental metabolic and cardiovascular benefits of the emerging lipid-modulating agents and real-life barriers, hindering their prescription by physicians and their assumption by patients, which need to be worked out for a more diffuse and appropriate drug utilization.

Reduction of cerebrovascular and peripheral events with PCSK9 inhibitors: Does it just depend on the lowering of the low-density lipoprotein?

Atherosclerotic cardiovascular disease is a systemic condition involving several vascular districts. The most involved vascular bed, beyond the coronary district, is represented by the peripheral arteries, whose involvement can give rise to cerebrovascular or peripheral events. PCSK9 inhibitors (PCSK9i) have established themselves as safe and effective drugs in reducing cholesterol linked to low-density lipoprotein (LDL-C), a causative factor of disease, with a consequent reduction in cardiovascular events. The two main studies on anti-PCSK9 antibodies, the FOURIER study for evolocumab and the ODYSSEY OUTCOMES study for alirocumab, highlighted the effectiveness in reducing LDL-C levels and its translation in a lower event rate of around 15%. Sub-analysis of these two trials showed how PCSK9i prevent cerebrovascular and/or peripheral events and how patients with already known cerebrovascular or peripheral disease benefit more from the action of these drugs than patients who do not have a widespread disease. Current evidence suggests that the preventive action of cerebrovascular and peripheral events is mainly expressed through reducing LDL-C levels. Although there are data regarding the association of PCSK9 levels and inflammatory status, propensity for thrombosis and platelet aggregation, these are currently less robust and do not justify a cardiovascular event reduction action that is independent of the action on LDL-C.

The prevention of stroke by statins: A meta-analysis

PURPOSE

The objectives of this study were to determine the preventive effects of statins on stroke.

METHODS

The published randomized controlled trials of statins for stroke prevention were searched from PubMed, EMBASE, Cochrane Library, and China Journal databases. We performed the meta-analysis via calculating the odds ratio (OR) and 95% confidence interval (CI) to study the mortality rate, incidence, and recurrence rate of patients with stroke in the prevention group and the control group. Chi-square-based Q test and I2 statistics were performed to test the potential heterogeneity; we conducted the sensitivity analysis to assess the stability of our analysis. Moreover, we performed the Begg and Egger tests to assess the publication bias.

RESULTS

Nine studies were included to perform meta-analysis, which included 15,497 patients (prevention group [n = 4114]; control group [n = 11383]). We found that the statins were not associated with the patients with stroke in mortality rate (OR = 1.00, 95% CI [0.82, 1.23]) and incidence (OR = 0.94, 95% CI [0.46, 1.92]) between the 2 groups. However, there was a significant differences in recurrence rate between the 2 groups (OR = 0.31, 95% CI [0.19, 0.51]).

CONCLUSIONS

Our findings indicated that the statins were associated with the patients with stroke in recurrence rate, but there was no significant correlation with the mortality and morbidity of patients with stroke.