Antiplatelet Therapy in Acute Coronary Syndromes. Lights and Shadows of Platelet Function Tests to Guide the Best Therapeutic Approach

The diagnostic role of resting myocardial blood flow in STEMI patients after revascularization

Background

The value of semiquantitative resting myocardial perfusion imaging (MPI) in coronary artery disease (CAD) is limited. At present, quantitative MPI can be performed by a new cadmium zinc tellurium single-photon emission computed tomography (CZT-SPECT) scan. The quantitative index of resting myocardial blood flow (MBF) has received little attention, and its manifestations and clinical value in the presence of unstable coronary blood flow have not been clarified.

Purpose

In patients with ST-segment elevation myocardial infarction (STEMI), whether resting MBF can provide additional value of blood flow than semi-quantitative resting MPI is not sure. We also explored the influencing factors of resting MBF.

Methods

This was a retrospective clinical study. We included 75 patients with STEMI in the subacute phase who underwent resting MPI and dynamic scans after reperfusion therapy. General patient information, STEMI-related data, MPI, gated MPI (G-MPI), and resting MBF data were collected and recorded. According to the clinically provided culprit vessels, the resting MBF was divided into ischemic MBF and non-ischemic MBF. The paired Wilcoxon signed-rank test was used for resting MBF. The receiver operating characteristic (ROC) curves were used to determine the optimal threshold for ischemia, and multiple linear regression analysis was used to analyze the influencing factors of resting MBF.

Results

There was a statistically significant difference between the ischemic MBF and non-ischemic MBF [0.59 (0.47-0.72) vs. 0.76 (0.64-0.93), p < 0.0001]. The ROC curve analysis revealed that resting MBF could identify ischemia to a certain extent, with a cutoff value of 0.5975, area under the curve (AUC) = 0.666, sensitivity = 55.8%, and specificity = 68.7%. Male sex and summed rest score (SRS) were influencing factors for resting MBF.

Conclusion

To a certain extent, resting MBF can suggest residual ischemia after reperfusion therapy in patients with STEMI. There was a negative correlation between male sex, SRS, and ischemic MBF. A lower resting MBF may be associated with more severe myocardial ischemia.

Pan-Immune-Inflammation Value Is Independently Correlated to Impaired Coronary Flow After Primary Percutaneous Coronary Intervention in Patients With ST-Segment Elevation Myocardial Infarction

Immune-inflammatory biomarkers have been shown to be correlated with impaired coronary flow (ICF) in ST-segment elevation myocardial infarction. In this study, we assessed the relation between a novel comprehensive biomarker, pan-immune-inflammation value (PIV), and ICF after primary percutaneous coronary intervention (pPCI) in ST-segment elevation myocardial infarction. A total of 687 patients who underwent pPCI between 2019 and 2023 were retrospectively analyzed. Blood samples were collected at admission. PIV and other inflammation parameters were compared. PIV was calculated as (neutrophil count × platelet count × monocyte count)/lymphocyte count. Postprocedural coronary flow was assessed by thrombolysis in myocardial infarction (TIMI) classification. Patients were divided into 2 groups: a group with ICF defined as postprocedural TIMI 0 to 2 and a group with normal coronary flow defined as postprocedural TIMI flow grade of 3. The mean age was 61 ± 12 years, and 22.4% of the patients were women. Compared with the normal coronary flow group (median 492, interquartile range 275 to 931), the ICF group (median 1,540, interquartile range 834 to 2,909) showed significantly increased PIV (p <0.001). The optimal cutoff for the PIV was 804, as determined by receiver operating characteristic curve. The incidence of ICF was 17.0% in all patients, 6.4% in low-PIV group (<804), and 34.2% in high-PIV group (≥804). Multivariate analyses revealed that a baseline PIV ≥804 was independently associated with post-pPCI ICF (odds ratio 5.226, p <0.001). PIV was superior to neutrophil/lymphocyte ratio and platelet/lymphocyte ratio in determining ICF. In conclusion, a high-PIV was significantly associated with an increased risk of ICF after pPCI. Moreover, PIV was a better indicator of ICF than were other inflammatory markers.

Machine learning-based prediction of composite risk of cardiovascular events in patients with stable angina pectoris combined with coronary heart disease: development and validation of a clinical prediction model for Chinese patients

Objective: To develop a risk score model for the occurrence of composite cardiovascular events (CVE) in patients with stable angina pectoris (SA) combined with coronary heart disease (CHD) by comparing the modeling effects of various machine learning (ML) algorithms. Methods: In this prospective study, 690 patients with SA combined with CHD attending the Department of Integrative Cardiology, China-Japan Friendship Hospital, from October 2020 to October 2021 were included. The data set was randomly divided into a training group and a testing group in a 7:3 ratio in the per-protocol set (PPS). Model variables were screened using the least absolute shrinkage selection operator (LASSO) regression, univariate analysis, and multifactor logistic regression. Then, nine ML algorithms are integrated to build the model and compare the model effects. Individualized risk assessment was performed using the SHapley Additive exPlanation (SHAP) and nomograms, respectively. The model discrimination was evaluated by receiver operating characteristic curve (ROC), the calibration ability of the model was evaluated by calibration plot, and the clinical applicability of the model was evaluated by decision curve analysis (DCA). This study was approved by the Clinical Research Ethics Committee of China-Japan Friendship Hospital (2020-114-K73). Results: 690 patients were eligible to finish the complete follow-up in the PPS. After LASSO screening and multifactorial logistic regression analysis, physical activity level, taking antiplatelets, Traditional Chinese medicine treatment, Gensini score, Seattle Angina Questionnaire (SAQ)-exercise capacity score, and SAQ-anginal stability score were found to be predictors of the occurrence of CVE. The above predictors are modeled, and a comprehensive comparison of the modeling effectiveness of multiple ML algorithms is performed. The results show that the Light Gradient Boosting Machine (LightGBM) model is the best model, with an area under the curve (AUC) of 0.95 (95% CI = 0.91-1.00) for the test set, Accuracy: 0.90, Sensitivity: 0.87, and Specificity: 0.96. Interpretation of the model using SHAP highlighted the Gensini score as the most important predictor. Based on the multifactorial logistic regression modeling, a nomogram, and online calculators have been developed for clinical applications. Conclusion: We developed the LightGBM optimization model and the multifactor logistic regression model, respectively. The model is interpreted using SHAP and nomogram. This provides an option for early prediction of CVE in patients with SA combined with CHD.

Short-term antithrombotic strategies after left atrial appendage occlusion: a systematic review and network meta-analysis

Background: Percutaneous left atrial appendage occlusion (LAAO) has emerged as a stroke prevention strategy in patients with nonvalvular atrial fibrillation (NVAF), and these patients were required to receive antithrombotic therapy post-procedure. However, the optimal antithrombotic strategy after LAAO remains controversial. This study explored the safety and efficacy of different antithrombotic strategies after LAAO through a network comparison method. Methods: We systematically searched the MEDLINE, Embase, and Cochrane Library databases for studies that reported the interested efficacy and safety outcomes (stroke, device-related thrombus (DRT), and major bleeding) of different antithrombotic strategies [DAPT (dual antiplatelet therapy), DOACs (direct oral anticoagulants), and VKA (vitamin k antagonist)] in patients who had experienced LAAO. Pairwise comparisons and network meta-analysis were performed for the interested outcomes. Risk ratios (RRs) with their confidence intervals (CIs) were calculated using a random-effects model. The rank of the different strategies was calculated using the surface under the cumulative ranking curve (SUCRA). Results: Finally, 10 observational studies involving 1,674 patients were included. There was no significant difference in stroke, DRT, and major bleeding among the different antithrombotic strategies (DAPT, DOACs, and VKA). Furthermore, DAPT ranked the worst in terms of stroke (SUCRA: 19.8%), DRT (SUCRA: 3.6%), and major bleeding (SUCRA: 6.6%). VKA appeared to be superior to DOACs in terms of stroke (SUCRA: 74.9% vs. 55.3%) and DRT (SUCRA: 82.3% vs. 64.1%) while being slightly inferior to DOACs in terms of major bleeding (SUCRA: 71.0% vs. 72.4%). Conclusion: No significant difference was found among patients receiving DAPT, DOACs, and VKA in terms of stroke, DRT, and major bleeding events after LAAO. The SUCRA indicated that DAPT was ranked the worst among all antithrombotic strategies due to the higher risk of stroke, DRT, and major bleeding events, while VKAs were ranked the preferred antithrombotic strategy. However, DOACs are worthy of consideration due to their advantage of convenience.

The SALINE Technique for the Treatment of the No-Reflow Phenomenon during Percutaneous Coronary Intervention in STEMI

BACKGROUND

Primary percutaneous coronary intervention (pPCI) performed for STEMI may be complicated by the "no-reflow" phenomenon.

AIMS

A super-selective intracoronary injection of saline solution through a thrombus aspiration catheter (SALINE technique), was investigated for the treatment of no-reflow as compared with the standard care of therapy (SCT).

METHODS

Among the 1471 patients with STEMI undergoing pPCI between May 2015 and June 2020, 168 patients developed no-reflow. Primary endpoints were the incidence of ST-segment resolution (STR) ≥ 70% at 90 min after PCI and the rate of flow restoration (TIMI flow grade 3 with an MBG > 1). The secondary endpoint was the incidence of major adverse cardiac and cerebrovascular events at 3 years follow-up.

RESULTS

After propensity score matching analysis, patients treated with SALINE showed STR ≥ 70% in twelve out of the sixteen patients (75.0%), compared to only three patients out of the sixteen in the SCT control group (19.0%), (p < 0.004). SALINE was associated with a higher probability of final TIMI flow grade 3 with an MBG > 1, as shown in fourteen out of sixteen patients (87.5%), as compared to only seven out of sixteen patients in the SCT group (43.8%), (p < 0.03). MACCE at 3 years follow-up occurred in only one patient (6.3%) in the SALINE group, as compared to eight patients (50%) in the SCT group (p = 0.047).

CONCLUSIONS

The SALINE technique showed to be a safe and effective strategy to reduce "no-reflow" in STEMI patients as assessed by significant STR, improvement of TIMI flow grade, and better 3-year outcomes.

Comparison of revascularization with conservative medical treatment in maintenance dialysis patient with coronary artery disease: a systemic review and meta-analysis

Background

The primary cause of death among maintenance dialysis patients is coronary artery disease (CAD). However, the best treatment plan has not yet been identified.

Methods

The relevant articles were retrieved from various online databases and references from their inception to October 12, 2022. The studies that compared revascularization [percutaneous coronary intervention (PCI) or coronary artery bypass grafting (CABG)] with medical treatment (MT) among maintenance dialysis patients with CAD were selected. The outcomes evaluated were long-term (with a follow-up of at least 1 year) all-cause mortality, long-term cardiac mortality, and the incidence rate of bleeding events. Bleeding events are defined according to TIMI hemorrhage criteria: (1) major hemorrhage, intracranial hemorrhage or clinically visible hemorrhage (including imaging diagnosis) with decrease of hemoglobin concentration ≥5 g/dl; (2) minor hemorrhage, clinically visible bleeding (including imaging diagnosis) with a drop in hemoglobin of 3-5 g/dl; (3) minimal hemorrhage, clinically visible bleeding with hemoglobin drop <3 g/dl. In addition, revascularization strategy, CAD type, and the number of diseased vessels were considered in subgroup analyses.

Results

A total of eight studies with 1,685 patients were selected for this meta-analysis. The current findings suggested that revascularization was associated with low long-term all-cause mortality and long-term cardiac mortality but a similar incidence rate of bleeding events compared to MT. However, subgroup analyses indicated that PCI is linked to decreased long-term all-cause mortality compared to MT but CABG did not significantly differ from MT in terms of long-term all-cause mortality. Revascularization also showed lower long-term all-cause mortality compared to MT among patients with stable CAD, single-vessel disease, and multivessel disease but did not reduce long-term all-cause mortality among patients with ACS.

Conclusion

Long-term all-cause mortality and long-term cardiac mortality were reduced by revascularization in comparison to MT alone in patients undergoing dialysis. Larger randomized studies are needed to confirm the conclusion of this meta-analysis.

Predictive value of myocardial strain on myocardial infarction size by cardiac magnetic resonance imaging in ST-segment elevation myocardial infarction with preserved left ventricular ejection fraction

Background: The correlation between myocardial strain and infraction size by cardiac magnetic resonance imaging in ST-segment elevation myocardial infarction (STEMI) with preserved left ventricular ejection fraction (LVEF) is not clear.

Objective: To investigate the correlation between myocardial strain and myocardial infarction size in patients of acute STEMI with preserved LVEF.

Materials and Methods: A retrospective study was conducted to assess 31 patients with acute ST-segment elevation myocardial infarction (STEMI)after primary percutaneous coronary intervention (PCI) who received cardiac magnetic resonance (CMR) imaging during hospitalization at the Central Hospital of Shandong First Medical University from 2019 to 2022 and whose echocardiography indicated preserved LVEF (LVEF≥50%). The control group consisted of 21 healthy adults who underwent CMR during the same period. We compared the CMR characteristics, global and segmental strain between the two groups. Furthermore, the correlation between the global strain and the segmental strain of the left ventricle and late gadolinium enhancement (LGE) were evaluated.

Results: Compared with healthy controls, the left ventricular ejection fraction (LVEF) of STEMI patients with preserved LVEF was significantly decreased (p < 0.05). Moreover, the global radial strain (GRS) (24.09% [IQR:17.88–29.60%] vs. 39.56% [IQR:29.19–42.20%], p < 0.05), global circumferential strain (GCS) [−14.66% (IQR: 17.91–11.56%) vs. −19.26% (IQR: 21.03–17.73%), p < 0.05], and global longitudinal strains (GLS) (−8.88 ± 2.25% vs. −13.46 ± 2.63%, p < 0.05) were damaged in patients. Furthermore, GCS and GLS were associated with LGE size (%left ventricle) (GCS: r = 0.58, p < 0.05; GLS: r = 0.37, p < 0.05). In the multivariate model, we found that LGE size was significantly associated with GCS (β coefficient = 2.110, p = 0.016) but was not associated with GLS (β coefficient = −0.102, p = 0.900) and LVEF (β coefficient = 0.227, p = 0.354). The receiver operating characteristic (ROC) results showed that GCS emerged as the strongest LGE size (LGE >25%) prognosticator among strain parameters (AUC: 0.836 [95% CI, 0.692—0.981], sensitivity: 91%, specificity: 80%) and was significantly better (p = 0.001) than GLS [AUC: 0.761 (95% CI, 0.583—0.939), sensitivity: 64%, specificity: 85%] and LVEF [AUC: 0.673 (95% CI, 0.469—0.877), sensitivity: 73%, specificity: 70%].

Conclusion: Among STEMI patients with preserved LVEF after PCI, CMR-FT-derived GCS had superior diagnostic accuracy than GLS and LVEF in predicting myocardial infarction size.

The Use of Thromboelastography in Percutaneous Coronary Intervention and Acute Coronary Syndrome in East Asia: A Systematic Literature Review

Dual antiplatelet therapy (DAPT), alongside percutaneous coronary intervention (PCI), is central to the prevention of ischemic events following acute coronary syndrome (ACS). However, response to therapy can vary due to several factors including CYP2C19 gene variation, which shows increased prevalence in East Asian populations. DAPT responsiveness can be assessed using techniques such as light transmission aggregometry (LTA), VerifyNow^® and thromboelastography with the PlateletMapping^® assay, and there is increasing focus on the utility of platelet function testing to guide individualized treatment. This systematic literature review of one English and three Chinese language databases was conducted to evaluate the evidence for the utility of thromboelastography in ACS/PCI in East Asia. The search identified 42 articles from the English language and 71 articles from the Chinese language databases which fulfilled the pre-determined inclusion criteria, including 38 randomized controlled trials (RCTs). The identified studies explored the use of thromboelastography compared to LTA and VerifyNow in monitoring patient responsiveness to DAPT, as well as predicting ischemic risk, with some studies suggesting that thromboelastography is better able to detect low DAPT response than LTA. Other studies, including one large RCT, described the use of thromboelastography in guiding the escalation of DAPT, with some evidence suggesting that such protocols reduce ischemic events without increasing the risk of bleeding. There was also evidence suggesting that thromboelastography can be used to identify individuals with DAPT hyporesponsiveness genotypes and could potentially guide treatment by adjusting therapy in patients depending on responsiveness.

Impact of Ticagrelor vs. Clopidogrel in Patients With Acute Coronary Syndrome Undergoing Percutaneous Coronary Intervention After Risk Stratification With the CHA2DS2-VASc Score

Backgrounds

The clinical benefit of ticagrelor vs. clopidogrel in unselected patients with acute coronary syndrome (ACS) after percutaneous coronary intervention (PCI) remains controversial in the real world. This study was aimed to investigate the impact of ticagrelor vs. clopidogrel in subjects with ACS without atrial fibrillation or flutter (AF) after PCI based on risk stratification using the CHA₂DS₂-VASc score.

Methods

In 2016–2019, patients who underwent PCI with at least one stent implanted in the General Hospital of Northern Theater Command were classified as low- or high-risk groups according to the CHA₂DS₂-VASc score. Incidences of 12-month ischemia [cardiac death, myocardial infarction (MI), or stroke], all-cause death, Bleeding Academic Research Consortium (BARC) 2,3,5 bleeding, BARC 3,5 bleeding, and net adverse clinical events (NACEs) (all-cause death, MI, stroke, or BARC 3, 5 bleeding) with aspirin plus different P2Y₁₂ inhibitors (clopidogrel or ticagrelor) were appraised among different risk groups. Propensity score matching (PSM) and Cox multivariate analysis were used to balance the groups.

Results

A total of consecutive 17,037 patients with ACS were enrolled. The optimal cut-off value of the CHA₂DS₂-VASc score for ischemic events by the Youden test was 3 points. Among patients with high risk (CHA₂DS₂-VASc ≥ 3, n = 6,151), ticagrelor was associated with slightly lower risks of ischemic events (2.29% vs. 3.54%, P = 0.02) and stroke (0.39% vs. 1.08%, P = 0.01) without excessive risk of BARC 3, 5 bleeding events (2.16% vs. 2.11%, P = 0.92) compared to clopidogrel within 12 months after PCI. For patients with low risk (CHA₂DS₂-VASc < 3, n = 10,886), a statistically significant difference was seen in the incidence of overall 12-month BARC 2, 3, 5 bleeding events by P2Y₁₂ receptor inhibitor (4.00% vs. 3.26%) with a similar incidence of the ischemic events (1.40% vs. 1.52%). Results in the PSM cohort and the adjustment with Cox multivariate analysis were consistent with the main outcomes.

Conclusion

Higher CHA₂DS₂-VASc scores were associated with a higher incidence of 1-year ischemic events for the patients with ACS after PCI. Compared with clopidogrel, ticagrelor was associated with lower ischemic events within 12 months after PCI without excessive risk of bleeding in high-risk patients but shows poor safety with excess bleeding in low-risk patients.

Fatal Adverse Events of Dabigatran Combined With Aspirin in Elderly Patients: An Analysis Using Data From VigiBase

Introduction: The elderly are vulnerable to cardiovascular diseases and the incidence of atrial fibrillation (AF) and venous thromboembolism (VTE) increases significantly with age. Dabigatran is a commonly used new oral anticoagulant approved by the FDA for stroke prevention in patients with non-valvular AF and VTE treatment and prevention. Aspirin is commonly used as a preventive drug for cardiovascular diseases. AF and coronary heart disease share many risk factors, so these two diseases often coexist and thus dabigatran and aspirin are often combined in those people. The aim of this study was to analyze the clinical characteristics of fatal adverse events of dabigatran combined with aspirin in elderly patients, and to provide references for clinical rational use of drugs.

Materials and Methods: Fatal adverse events related to the combined use of dabigatran and aspirin in elderly patients aged over 75 were extracted from the WHO global database of individual case safety reports (VigiBase). Well-documented reports, vigiGrade completeness score ≥0.80, or with an informative narrative, were analyzed with a focus on the clinical features of the cases.

Results: From 1968 up to January 19, 2020, there were 112 eligible reports in VigiBase from 13 countries, of which 33 were identified as well-documented. Of these 33, 19 were male (58%) and 14 were female (42%), the average age of the patients was 84 (75–95 years), with five cases of extreme weights (&gt;100 kg in one case, &lt;50 kg in four cases). There were 31 cases of death by internal bleeding (mainly 15 of gastrointestinal hemorrhage and 12 of intracranial hemorrhage) and two cases of the sudden death of unknown cause. Medication errors existed in 15 patients. The times to onset (TTO) was provided in 24 cases, ranging from 2 days to 4 years, and in 12 patients occurred within a month. Of the 31 patients with fatal bleeding events, 29 were associated with other factors that increase the risk of bleeding, such as diseases (hypertension, renal impairment, stroke, gastrointestinal related diseases, hypothyroidism, and cancer), drugs (antiplatelets, anticoagulants, thrombolytics, P glycoprotein substrates, non-steroidal anti-inflammatory drugs, hormones, selective serotonin reuptake inhibitors, and acetaminophen) and other factors (low body weights and alcohol consumption), and 21 of these contained two or more risk factors.

Conclusion: The fatal adverse events associated with the combined use of dabigatran and aspirin in elderly patients were mainly serious bleeding events, which often occurred within 1 month. Most of these cases had medication errors and most of the patients had multiple diseases, medications, or other conditions at the same time that increase the risk of bleeding. It is suggested that prescription of dabigatran and aspirin in elderly patients should go along with alertness for medication errors, care for correct dose or control of other bleeding risk factors, and the combined medication time should be as short as possible to minimise serious adverse events.

The association between platelet indices and cardiovascular events in chronic kidney disease patients without dialysis

PURPOSE

Previous studies have indicated that platelet indices are related to the pathogenesis of cardiovascular diseases (CVD). However, it is unclear which platelet-related indicators are associated with CVD events in patients with chronic kidney disease (CKD) without dialysis.

METHODS

We performed a single-center prospective cohort study involved 1391 CKD patients to explore the relationship between platelet indices and CVD events in CKD patients. A nomogram was generated to predict CVD-free survival after 3 and 5 years of follow-up in terms of the fitted Cox regression model. And the time-dependent receiver-operating characteristic (ROC) curves were applied to evaluate the prediction accuracy of platelet indices on CVD events.

RESULTS

During a median follow-up of 3.41 years, 211 (15.2%) patients experienced CVD events. Results showed that platelet counts (PLT), plateletcrit (PCT), platelet-large cell ratio (P-LCR), and platelet distribution width (PDW) among 5 platelet indices were significantly lower in advanced CKD stages. Cox regression model showed that PLT, PDW, and PCT were associated with CVD events. However, after multivariable-adjusted, low level of PLT, hazard ratio (HR) 0.994 and 95% confidence interval (95% CI 0.989-1.000, p = 0.04), and PDW, HR 0.936 (95% CI 0.878-0.998, p = 0.044) predicted CVD events. The area under the ROC curve (AUC) of platelet indices assessed by time-dependent ROC curve analysis showed that only PLT and PDW were significant for predicting CVD events for 5 years.

CONCLUSIONS

We demonstrated that PLT and PDW among 5 platelet indices were independently associated with CVD events in patients with CKD.