Blood Platelet Count at Hospital Admission Impacts Long-Term Mortality in Patients with Acute Coronary Syndrome

Association of platelet distribution width with all-cause and cause-specific mortality in US adults

BACKGROUND

Platelet distribution width (PDW) indicates heterogeneity in circulating platelet sizes. Studies reporting PDW association with mortality were limited by small sample sizes. Therefore, we examined the relationship between PDW and all-cause and cause-specific mortality in a large representative cohort.

METHODS

The NHANES III data were linked to mortality files to examine the association between PDW and mortality. We excluded participants <18 years old and had a history of myocardial infarction. Since the hazards violated the proportionality assumption, we used piece-wise spline with 5-year time intervals in Cox models without and with adjustment for age, gender, race, smoking history, diabetes mellitus, hypertension, eGFR and total cholesterol.

RESULTS

Of 15,688 participants, 53.2% were females, 36.2% had a history of hypertension, and 6368(40.6%) died during follow-up (range 0 to 31 years). The mean (SD) age of the participants was 47(20) years, platelet count was 275.0(71.7) 109/L, and PDW 16.5(0.5). In multivariable analyses, PDW was associated with all-cause mortality at 0-5 years (HR = 1.44; 95%CI = 1.21, 1.72; P < 0.001) and at 5-10 years (HR = 1.23; 95%CI =1.03, 1.46; P = 0.02). Similarly, PDW association was significant for the first 0-5 years in cardiovascular mortality (HR = 1.58, 95%CI = 1.10, 2.25; P = 0.013) and for cancer mortality (HR = 1.48 (1.15, 95%CI = 1.15, 1.91, P = 0.003). For other-cause mortality, PDW remained significantly associated for 0-5 years (HR = 1.35, 95%CI =1.05, 1.74; P = 0.02) and for 5-10 years (HR = 1.38, 95%CI = 1.05, 1.83; P = 0.023).

CONCLUSIONS

PDW is an independent, but time-dependent, predictor of all-cause, cardiovascular, cancer and other-cause mortality up to 5 years. The mechanisms underlying this association need further study.

Low platelet count at admission has an adverse impact on outcome in patients with acute coronary syndromes: from the START Antiplatelet registry

Some previous observations suggest that a low platelet count is associated with an increased risk of adverse outcomes in patients with acute coronary syndromes (ACS). However, most of the data come from post-hoc analyses of randomized controlled trials and from studies including thrombocytopenia developed during hospital stay. Our aim was to assess the impact of low platelet count at admission on cardiovascular outcomes and treatment approach in patients hospitalized for ACS in a current real-life setting in Italy. Patients admitted to Italian coronary care units for ACS were enrolled in the START-ANTIPLATELET registry. Baseline clinical characteristics and treatment at discharge were recorded. Patients were followed-up at 6 months, 1 year and yearly thereafter. Low platelet count was defined as a count at admission < 150 > 100 k/µl or < 100 k/µL. Among 1894 enrolled patients, 157 (8.3%) had a platelet count < 150 > 100 k/µl and 30 (1.6%) < 100 k/µl. The median follow-up was 12.3 months (0.4-50.1). patients with low platelets were older (72 ± 10.4 vs 66 ± 12.4 years, p = 0.006), more frequently males (82.9 vs 72.1%, p = 0.001), hypertensive (90.0% vs 70.4%, p = 0.03), with non-valvular atrial fibrillation (NVAF) (17.1 vs 8.6%, p = 0.02), and peripheral arterial disease (11.5 vs 6.2% p = 0.01) and/or had a previous myocardial infarction (40 vs 18.7%, p = 0.008) and/or a PCI (14.6 vs 7.8%, p = 0.001) than patients with normal platelets. A slightly, but significantly, lower percentage of thrombocytopenic patients were treated with primary PCI (78.1 vs 84.4%, p = 0.04) and they were more frequently discharged on aspirin plus clopidogrel rather than aspirin plus newer P2Y12 antagonists (51.9 vs 65.4%, p = 0.01). MACE-free survival was significantly shorter in thrombocytopenic patients compared to patients with normal platelets (< 150 > 100 k/µl: 37.6 vs 41.8 months, p = 0.002; HR = 2.7, 95% CIs 1.4-5.2; < 100 k/µl: 31.7 vs 41.8 months, p = 0.01; HR = 6.5, 95% CIs 1.5-29.1). At multivariate analysis, low platelet count, age at enrollment, low glomerular filtration rate, low ejection fraction, a previous ischemic stroke and NVAF were independent predictors of MACE. A low platelet count at admission identifies a subgroup of ACS patients with a significantly increased risk of MACE and these patients should be managed with special care to prevent excess adverse outcomes.

Haematological Indices in Acute Coronary Syndrome Patients in Ethiopia: A Comparative Cross-Sectional Study

Background

Numerous biomarkers are used as diagnostic, prognostic, and predictive indicators of myocardial ischemia. The most commonly used biomarkers are cardiac troponin I (Tn-I) and creatinine kinase (CK-MB). However, in developing nations, their availability in primary care settings is extremely limited. In such situations, easily available assays such as complete blood count (CBC) should be investigated as prognostic indicators in individuals with acute coronary syndrome (ACS).

Objective

This study aimed to compare the pattern of haematological indices and blood cell ratios of ACS patients compared with apparently healthy controls.

Methods

Patients diagnosed with ACS were recruited consecutively between 01 May 2022 and 31 October 2023 at Jimma Medical Center (JMC). Biochemical analyses and complete blood counts were performed. Analysis of variance was performed to compare the continuous variables. Spearman correlation coefficient tests were performed to correlate hematologic parameters with high sensitive troponin-I (hs-Tn-I) levels.

Results

This study enrolled 220 participants (110 patients with ACS and age, sex, and place of residence matched 110 non-ACS controls). From ACS group 99 (90%) were diagnosed with ST-elevated myocardial infarction. The ACS group had a significantly greater mean platelet volume (MPV), white blood cell count, red cell distribution width (RDW), neutrophil-to-lymphocyte ratio, and platelet-to-lymphocyte ratio. The RDW (r = 0.248, p = 0.009) and MPV (r = 0.245, p = 0.009) were significantly positively correlated with hs-Tn-I levels in the ACS group. MPV, RDW, and monocyte count were significantly higher in non-survivor ACS patients (p <0.05).

Conclusion

The significant differences observed in haematological parameters between individuals with ACS and healthy controls suggest the potential utility of these easily accessible and cost-effective diagnostics in predicting future morbidity and ACS risk. Incorporating these routine evaluations into clinical practice could enhance risk assessment and improve patient outcomes.

Red blood cell distribution width/platelet ratio on admission as a predictor for in-hospital mortality in patients with acute myocardial infarction: a retrospective analysis from MIMIC-IV Database

BACKGROUND

Red blood cell distribution width (RDW) to platelet ratio (RPR) is a novel inflammatory indicator. It integrates the risk prediction of RDW and platelet, which is associated with adverse outcomes. However, the predictive power of RPR in mortality for patients with acute myocardial infarction (AMI) remains uncertain. Thus, we aimed to explore the association between RPR and 180-day in-hospital mortality in patients with AMI.

METHODS

Data on patients with AMI were extracted from the Medical Information Mart for Intensive Care IV (MIMIC-IV) database. Patients were divided into two groups according to the optimal RPR cut-off value. The survival curve between high and low RPR groups was plotted via the Kaplan-Meier (KM) method. Univariate and multivariate Cox regression analyses were performed to determine the association between RPR on admission and 180-day in-hospital mortality.

RESULTS

A total of 1266 patients were enrolled, of which 83 (6.8%) died within 180 days during the hospitalization. Compared with the survivor group, the non-survivor group had higher RPR on admission (0.11 ± 0.07 vs. 0.08 ± 0.06, P < 0.001). The KM curve indicated that the survival probability of low RPR group was higher than that of high RPR group. Multivariate Cox regression analysis demonstrated that higher RPR on admission was an independent and effective predictor of 180-day mortality in patients with AMI (hazard ratio [HR]: 2.677, 95% confidence interval [CI]: 1.159-6.188, P = 0.021).

CONCLUSION

Higher RPR was associated with higher in-hospital 180-day mortality in patients with AMI.

Association between Platelet Count and Treatment Effect of Ticagrelor or Prasugrel in Patients with Acute Coronary Syndromes

BACKGROUND

 The relative efficacy and safety of ticagrelor and prasugrel based dual antiplatelet therapy strategies according to the platelet count (PC) in patients with acute coronary syndromes (ACS) have not been defined.

METHODS

 This is a posthoc analysis of the ISAR-REACT 5 trial, in which patients presenting with ACS were randomized to treatment with ticagrelor versus prasugrel. Patients were divided into quartiles according to PC. The primary endpoint was incidence of death, myocardial infarction, or stroke, and the safety endpoint was incidence of BARC (Bleeding Academic Research Consortium) type 3 to 5 bleeding at 12 months.

RESULTS

 A total of 3,943 patients with known PC (997 patients in quartile 1 (Q1), 1,003 in quartile 2 (Q2) [205 ± 10.3 × 109/L], 961 patients in quartile 3 (Q3) [241 ± 11.7 × 109/L], and 982 patients in quartile 4 (Q4) [317 ± 68.6 × 109/L]). There was no significant interaction between treatment arm (ticagrelor vs. prasugrel) and PC group with respect to primary endpoint (Q1: 8.8 vs. 6.3%, hazard ratio [HR] =1.41, 95% confidence interval [CI]: 0.89-2.23; p = 0.148; Q2: 9.9 vs. 5.8%, HR = 1.68, 95% CI: 1.06-2.66; p = 0.027; Q3: 7.8 vs. 5.5%, HR = 1.43, 95% CI: 0.87-2.37; p = 0.159; Q4: 10.1 vs. 10.1%, HR = 1.05, 95% CI: 0.71-1.57; p = 0.799; p for interaction [p int] = 0.482) and with respect to bleeding endpoint (Q1: 5.8 vs. 4.2%, HR = 1.41, 95% CI: 0.76-2.63; p = 0.279; Q2: 6.4 vs. 3.7%, HR = 1.62, 95% CI: 0.85-2.06; p = 0.140; Q3: 4.4 vs. 3.0%, HR = 1.53, 95% CI: 0.73-3.18; p = 0.258; Q4: 5.6 vs. 8.5%, HR = 0.67, 95% CI: 0.40-1.14; p = 0.138, p int = 0.102).

CONCLUSIONS

 In this analysis, incidences of ischemic and bleeding events at 12 months are comparable across quartiles of platelet count.

Predictive Role of Platelet-Associated Indices on Admission and Discharge in the Long-Term Prognosis of Acute Coronary Syndrome Patients

Our study aimed to investigate the association between platelet indices and their in-hospital change and long-term prognosis in acute coronary syndrome (ACS). Data from a randomized controlled trial (NCT02927808) recruiting ACS patients were analyzed (survival analysis). The examined variables were platelet count (PC), mean platelet volume (MPV), platelet distribution width (PDW), and plateletcrit (PCT) on admission and discharge, as well as their alteration during hospitalization. The primary endpoint was major adverse cardiac events (MACE) (cardiovascular death, non-fatal myocardial infarction, and non-fatal stroke or hospitalization for unstable angina) and all-cause mortality, while secondary endpoints were all-cause hospitalization and bleeding events. The study included 252 patients with a follow-up of 39 (28-45) months. In the univariate analysis, MACE was associated with discharge PC [hazard ratio (HR) 2.20, 95% confidence interval (CI) 1.10-4.40], discharge MPV (HR 0.48, 95% CI 0.25-0.94), and in-hospital PC difference (HR 0.25, 95% CI 0.13-0.51). In the multivariable analysis, only in-hospital PC decrease correlated with lower MACE incidence (adjusted HR .27, 95% CI 0.14-0.54) and lower all-cause hospitalization risk (adjusted HR 0.36, 95% CI 0.19-0.68). PC reduction during hospitalization for ACS is an independent predictor of better prognosis.

Ischemic and Bleeding Events Associated with Thrombocytopenia and Thrombocytosis after Percutaneous Coronary Intervention in Patients with Acute Myocardial Infarction

The early and late ischemic and bleeding clinical outcomes according to baseline platelet count after percutaneous coronary intervention (PCI) in patients with acute myocardial infarction (AMI) remain unclear. Overall, 10,667 patients from the Cardiovascular Risk and identification of potential high-risk population in AMI (COREA-AMI) I and II registries were classified according to the following universal criteria on baseline platelet counts: (1) moderate to severe thrombocytopenia (platelet < 100 K/μL, n = 101), (2) mild thrombocytopenia (platelet = 100~149 K/μL, n = 631), (3) normal reference (platelet = 150~450 K/μL, n = 9832), and (4) thrombocytosis (platelet > 450 K/μL, n = 103). The primary endpoint was the occurrence of major adverse cardiovascular events (MACE). The secondary outcome was Bleeding Academic Research Consortium (BARC) 2, 3, and 5 bleeding. After adjusting for confounders, the moderate to severe thrombocytopenia (HR, 2.03; 95% CI, 1.49-2.78); p < 0.001), mild thrombocytopenia (HR, 1.15; 95% CI, 1.01-1.34; p = 0.045), and thrombocytosis groups (HR, 1.47; 95% CI, 1.07-2.03; p = 0.019) showed higher 5-year MACE rates than the normal reference. In BARC 2, 3, and 5 bleeding outcomes, the bleedings rates were higher than the normal range in the moderate to severe thrombocytopenia (HR, 2.18; 95% CI, 1.36-3.49; p = 0.001) and mild thrombocytopenia (HR, 1.41; 95% CI, 1.12-1.78; p = 0.004) groups. Patients with AMI had higher 5-year MACE rates after PCI if they had lower- or higher-than-normal platelet counts. Thrombocytopenia revealed higher early and late bleeding rates whereas thrombocytosis showed long-term bleeding trends, although these trends were not statistically significant.