Relation of White Blood Cell Count to Bleeding and Ischemic Events in Patients With Acute Coronary Syndrome (from the ATLAS ACS 2-TIMI 51 Trial)

Non-vitamin-K-antagonist oral anticoagulants (NOACs) after acute myocardial infarction: a network meta-analysis

BACKGROUND

Balancing the risk of bleeding and thrombosis after acute myocardial infarction (AMI) is challenging, and the optimal antithrombotic therapy remains uncertain. The potential of non-vitamin K antagonist oral anticoagulants (NOACs) to prevent ischaemic cardiovascular events is promising, but the evidence remains limited.

OBJECTIVES

To evaluate the efficacy and safety of non-vitamin-K-antagonist oral anticoagulants (NOACs) in addition to background antiplatelet therapy, compared with placebo, antiplatelet therapy, or both, after acute myocardial infarction (AMI) in people without an indication for anticoagulation (i.e. atrial fibrillation or venous thromboembolism).

SEARCH METHODS

We searched CENTRAL, MEDLINE, Embase, the Conference Proceedings Citation Index - Science, and two clinical trial registers in September 2022 with no language restrictions. We checked the reference lists of included studies for any additional trials.

SELECTION CRITERIA

We searched for randomised controlled trials (RCTs) that evaluated NOACs plus antiplatelet therapy versus placebo, antiplatelet therapy, or both, in people without an indication for anticoagulation after an AMI.

DATA COLLECTION AND ANALYSIS

Two review authors independently checked the results of searches to identify relevant studies, assessed each included study, and extracted study data. We conducted random-effects pairwise analyses using Review Manager Web, and network meta-analysis using the R package 'netmeta'. We ranked competing treatments by P scores, which are derived from the P values of all pairwise comparisons and allow ranking of treatments on a continuous 0-to-1 scale.

MAIN RESULTS

We identified seven eligible RCTs, including an ongoing trial that we could not include in the analysis. Of the six RCTs involving 33,039 participants, three RCTs compared rivaroxaban with placebo, two RCTs compared apixaban with placebo, and one RCT compared dabigatran with placebo. All participants in the six RCTs received concomitant antiplatelet therapy. The available evidence suggests that rivaroxaban compared with placebo reduces the rate of all-cause mortality (risk ratio (RR) 0.82, 95% confidence interval (CI) 0.69 to 0.98; number needed to treat for an additional beneficial outcome (NNTB) 250; 3 studies, 21,870 participants; high certainty) and probably reduces cardiovascular mortality (RR 0.83, 95% CI 0.69 to 1.01; NNTB 250; 3 studies, 21,870 participants; moderate certainty). There is probably little or no difference between apixaban and placebo in all-cause mortality (RR 1.09, 95% CI 0.88 to 1.35; number needed to treat for an additional harmful outcome (NNTH) 334; 2 studies, 8638 participants; moderate certainty) and cardiovascular mortality (RR 0.99, 95% CI 0.77 to 1.27; number needed to treat not applicable; 2 studies, 8638 participants; moderate certainty). Dabigatran may reduce the rate of all-cause mortality compared with placebo (RR 0.57, 95% CI 0.31 to 1.06; NNTB 63; 1 study, 1861 participants; low certainty). Dabigatran compared with placebo may have little or no effect on cardiovascular mortality, although the point estimate suggests benefit (RR 0.72, 95% CI 0.34 to 1.52; NNTB 143; 1 study, 1861 participants; low certainty). Two of the investigated NOACs were associated with an increased risk of major bleeding compared to placebo: apixaban (RR 2.41, 95% CI 1.44 to 4.06; NNTH 143; 2 studies, 8544 participants; high certainty) and rivaroxaban (RR 3.31, 95% CI 1.12 to 9.77; NNTH 125; 3 studies, 21,870 participants; high certainty). There may be little or no difference between dabigatran and placebo in the risk of major bleeding (RR 1.74, 95% CI 0.22 to 14.12; NNTH 500; 1 study, 1861 participants; low certainty). The results of the network meta-analysis were inconclusive between the different NOACs at all individual doses for all primary outcomes. However, low-certainty evidence suggests that apixaban (combined dose) may be less effective than rivaroxaban and dabigatran for preventing all-cause mortality after AMI in people without an indication for anticoagulation.

AUTHORS' CONCLUSIONS

Compared with placebo, rivaroxaban reduces all-cause mortality and probably reduces cardiovascular mortality after AMI in people without an indication for anticoagulation. Dabigatran may reduce the rate of all-cause mortality and may have little or no effect on cardiovascular mortality. There is probably no meaningful difference in the rate of all-cause mortality and cardiovascular mortality between apixaban and placebo. Moreover, we found no meaningful benefit in efficacy outcomes for specific therapy doses of any investigated NOACs following AMI in people without an indication for anticoagulation. Evidence from the included studies suggests that rivaroxaban and apixaban increase the risk of major bleeding compared with placebo. There may be little or no difference between dabigatran and placebo in the risk of major bleeding. Network meta-analysis did not show any superiority of one NOAC over another for our prespecified primary outcomes. Although the evidence suggests that NOACs reduce mortality, the effect size or impact is small; moreover, NOACs may increase major bleeding. Head-to-head trials, comparing NOACs against each other, are required to provide more solid evidence.

Factors associated with early, late, and very late stent thrombosis among patients with acute coronary syndrome undergoing coronary stent placement: analysis from the ATLAS ACS 2-TIMI 51 trial

Background

Stent thrombosis (ST) is an uncommon but serious complication of stent implantation. This study aimed to explore factors associated with early, late, and very late ST to help guide risk assessment and clinical decision-making on ST.

Methods

The analysis included patients who received stent placement for the index acute coronary syndrome (ACS). Cumulative incidence of ST was assessed at 30 days (early ST), 31-360 days (late ST), 361-720 days (very late ST), and up to 720 days. Cox proportional hazards models were used to assess associations between ST and various factors, including patient characteristics [i.e., age, sex, ACS presentation, history of hypertension, smoking, diabetes, prior myocardial infarction (MI), heart failure, prior ischemic stroke, and cancer], laboratory tests [i.e., positive cardiac biomarker, hemoglobin, platelet count, white blood cell (WBC) count], and treatment [i.e., drug-eluting stent (DES) vs. bare-metal stent (BMS) and anticoagulant with rivaroxaban vs. placebo].

Results

Among the 8,741 stented patients, 155 ST events (2.25%) occurred by Day 720. The cumulative incidences of early, late, and very late ST were 0.80%, 0.81%, and 0.77%, respectively. After multivariable adjustment, age ≥ 75 [hazard ratio (HR) = 2.13 (95% confidence interval, CI: 1.26-3.60)], a history of prior MI [HR = 1.81 (95% CI: 1.22-2.68)], low hemoglobin level [HR = 2.34 (95% CI: 1.59-3.44)], and high WBC count [HR = 1.58 (95% CI: 1.02-2.46)] were associated with a greater risk of overall ST, whereas DES [HR = 0.56 (95% CI: 0.38-0.83)] and rivaroxaban therapy [HR = 0.63 (95% CI: 0.44-0.88)] were associated with a lower risk of overall ST up to 720 days. Low hemoglobin level and high WBC count were associated with early ST (low hemoglobin: HR = 2.35 [95% CI: 1.34-4.12]; high WBC count: HR = 2.11 [95% CI: 1.17-3.81]). Low hemoglobin level and prior MI were associated with a greater risk of late ST (low hemoglobin: HR = 2.32 [95% CI: 1.26-4.27]; prior MI: HR = 2.98 [95% CI: 1.67-5.31]), whereas DES was associated with a lower risk of late ST [HR = 0.33 (95% CI: 0.16-0.67)]. Age ≥75 years was associated with very late ST.

Conclusion

The study identified positive and negative associations with early, late, and very late ST. These variables may be useful in constructing risk assessment models for ST.

Clinical Trial Registration

http://www.clinicaltrials.gov, identifier NCT00809965.

Systemic Coagulation Inflammation Index Associated With Bleeding in Acute Coronary Syndrome

AIM

Assessment of the inflammatory component of acute coronary syndrome (ACS) and the degree of activation of the coagulation cascade may provide prognostic information. The systemic coagulation-inflammation index (SCI) assesses both inflammation and the coagulation system, and it has also been found to be associated with clinical outcomes. We investigated the relationship between SCI and in-hospital clinical events (acute kidney injury, cardiogenic shock, life-threatening arrhythmia, bleeding) and mortality.

MATERIAL AND METHODS

The study included 396 patients aged ≥18 yrs who were hospitalized with a diagnosis of ACS. The SCI was calculated using the formula: platelet count (103 / µl) X fibrinogen (g / l) / white blood cell (WBC) count (103 / µl). Patients were divided into two groups according to whether their SCI score was >100 or <100, and the relationship between clinical and laboratory characteristics was analyzed accordingly.

RESULTS

The mean age of the patients was 61.4±12.2 years and 78.3 % (n=310) were male. The type of ACS was NSTEMI in 56.1 % (n=222). The responsible vessel was the left anterior descending artery (LAD) in 42.4 % of the patients (n=168). The mean SCI score was 97.5±47.1. WBC, neutrophil, and lymphocyte counts were higher in the SCI <100 group, whereas fibrinogen, C-reactive protein, and platelet count were higher in the SCI >100 group. Bleeding from any cause as an in-hospital complication was significantly higher in patients with SCI >100 (p<0.05). Other in-hospital events were not significantly associated with SCI (p>0.05).

CONCLUSIONS

Bleeding in ACS patients was significantly more common in the group with SCI >100. Thus, SCI may be a useful parameter for predicting in-hospital bleeding complications in ACS. On the other hand, SCI was not associated with mortality and other in-hospital clinical events.

Prognostic impact of white blood cell counts on clinical outcomes in patients with chronic renal insufficiency undergoing percutaneous coronary intervention

Objective

To determine whether the inclusion of white blood cell (WBC) counts in the SYNTAX score (SS) or SS II models could improve the models’ performance for risk stratification in individuals with chronic renal insufficiency (CRI) following percutaneous coronary intervention (PCI).

Methods

In total, 2,313 patients with CRI, who were subjected to PCI and had data available on in-hospital WBC (ih-WBC) counts, were recruited. Patients were divided into 3 groups as per their ih-WBC counts (low, medium, and high). The primary endpoints were all-cause mortality (ACM) and cardiac mortality (CM). The secondary endpoints incorporated myocardial infarction, stroke, unplanned revascularization, and major adverse cardiovascular and cerebrovascular events (MACCEs).

Results

During a median follow-up of 3 years, the high WBC group had the highest incidences of CM (2.4% vs. 2.1% vs. 6.7%; p &lt; 0.001), ACM (6.3% vs. 4.1% vs. 8.2%; p &lt; 0.001), unplanned revascularization (8.4% vs. 12.4% vs. 14.1%; p &lt; 0.001), and MACCEs (19.3% vs. 23.0% vs. 29.2%; p &lt; 0.001) among the three groups. Multivariable Cox regression analysis depicted that the risk of ACM and CM in the high WBC group was 2.577 (95% confidence interval [CI]: 1.504–4.415, p &lt; 0.001) and 3.850 (95% CI: 1.835–8.080, p &lt; 0.001) times that in the low WBC group after adjusting for other confounding factors. A combination of ih-WBC counts with SS or SS II significantly improved the risk assessment and prediction of ACM and CM.

Conclusion

The ih-WBC counts was associated with the risk of occurrence of ACM, CM, unplanned revascularization, and MACCEs in individuals with CRI following PCI. It provides an incremental predictive value for the occurrence of ACM and CM when included in SS or SS II models.

The Effectiveness of Antiplatelet Therapy and the Factors Influencing It in Patients with Acute Coronary Syndrome before and during the COVID-19 Pandemic

Background and Objectives: Dual antiplatelet therapy (DAPT) is essential in the treatment of patients with acute coronary syndrome (ACS). The objective of this study was to evaluate the effectiveness of antiplatelet medication in our practice and to investigate the factors that influence it. Materials and Methods: A prospective cohort observational study was conducted, in which 193 patients with ACS were enrolled. The patients were stented in the catheterization laboratory between May 2019 and October 2020, before and during the COVID-19 pandemic, and were receiving DAPT. Their platelet functions were tested using a Multiplate Analyzer. In addition to this, clinical data, demographics, laboratory tests, and cardiovascular risk factors were also analyzed. Results: 43.46% of the patients treated with aspirin were found to be resistant to it. This phenomenon was more common in men (48.17% vs. 31.48%, p = 0.036), and it was associated with being under the age of 50 (OR: 2.08; 95% CI: 1.11-3.90) and weighing over 70 kg (OR: 3.00; 95% CI: 1.21-7.40). Most of the patients treated with clopidogrel were in the optimal treatment window, while about half of the patients treated with ticagrelor had an exaggerated pharmacological response. Among the laboratory parameters, leukocytosis and platelet count were found to be determinants of platelet reactivity for both the aspirin and ticagrelor treatments. Conclusions: Many patients treated with antiplatelet agents are outside of the treatment window. The results obtained showed that low doses of gastro-resistant aspirin tablets are ineffective, and their efficacy can be influenced by various clinical and laboratory factors. Patients receiving ticagrelor have significantly reduced platelet reactivity, influenced only by certain laboratory indicators. The pandemic significantly influenced the results of the platelet aggregation tests only in patients treated with clopidogrel.

Leukocyte and its Subtypes as Predictors of Short-Term Outcome in Cardiogenic Shock Complicating Acute Myocardial Infarction: A Cohort Study

BACKGROUND

Patients with cardiogenic shock (CS) complicating acute myocardial infarction (AMI) are at high risk of death. Inflammation is involved in both CS and AMI, and our present study aimed to investigate the changes of leukocyte and its subtypes as well as their prognostic value in patients with CS complicating AMI.

METHODS

Data of 217 consecutive patients with CS complicating AMI were analyzed. The primary endpoint was 30-day all-cause mortality. The secondary endpoint was the composite events of major adverse cardiovascular events (MACE) including 30-day all-cause mortality, ventricular tachycardia/ventricular fibrillation, atrioventricular block, gastrointestinal hemorrhage and nonfatal stroke. The association of leukocyte and its subtypes with the endpoints was analyzed by Cox regression analysis.

RESULTS

Leukocyte and its subtypes including neutrophil, eosinophil, lymphocyte, monocyte and basophil were all statistically significant between survivors and nonsurvivors (all P < 0.05). Among the leukocyte subtypes, eosinophil had the highest predictive value for 30-day all-cause mortality (AUC = 0.799) and the composite of leukocyte and its subtypes improved the predictive power (AUC = 0.834). The 30-day mortality and MACE K-M curves of leukocyte and its subtypes reveal a distinct trend based on the cut-off value determined by Youden Index (all log rank P < 0.001). After multivariable adjustment, high leukocyte (>11.6 × 109/L) (HR 1.815; 95%CI 1.134, 2.903; P = 0.013), low eosinophil (<0.3%) (HR 2.562; 95%CI 1.412, 4.648; P = 0.002) and low basophil (≤0.1%) (HR 1.694; 95%CI 1.106, 2.592; P = 0.015) were independently associated with increased risk of 30-day mortality. Similarly, high leukocyte (>11.6 × 109/L) (HR 1.894; 95%CI 1.285, 2.791; P = 0.001), low eosinophil (<0.3%) (HR 1.729; 95%CI 1.119, 2.670; P = 0.014) and low basophil (≤0.1%) (HR 1.560; 95%CI 1.101, 2.210; P = 0.012) were independently associated with increased risk of 30-day MACE.

CONCLUSIONS

Leukocyte and its subtypes changed significantly in patients with CS complicating AMI. In addition to leukocyte, eosinophil and basophil also served as independent prognostic factors for 30-day outcomes. Moreover, as the composite of leukocyte and its subtypes increased the predictive power, thus leukocyte and its subtypes, especially eosinophil and basophil should be taken into consideration for the current risk stratification model.