D-Dimer Is Associated With Coronary Microvascular Dysfunction in Patients With Non-obstructive Coronary Artery Disease and Preserved Ejection Fraction.

Background: Coronary microvascular dysfunction (CMVD), an important etiology of ischemic heart disease, has been widely studied. D-dimer is a simple indicator of microthrombosis and inflammation. However, whether an increase in D-dimer is related to CMVD is still unclear. Materials and Methods: This retrospective study consecutively enrolled patients with myocardial ischemia and excluded those with obstructive coronary artery. D-dimer was measured at admission and the TIMI myocardial perfusion grade (TMPG) was used to distinguish CMVD. Patients were divided into the two groups according to whether the D-dimer was elevated (>500 ng/ml). Logistic models and restricted cubic splines were used to explore the relationship between elevated D-dimer and CMVD. Results: A total of 377 patients were eventually enrolled in this study. Of these, 94 (24.9%) patients with CMVD had older age and higher D-dimer levels than those without CMVD. After full adjustment for other potential clinical risk factors, patients with high D-dimer levels (>500 ng/ml) had a 1.89-times (95% CI: 1.09-3.27) higher risk of CMVD than patients with low D-dimer levels. A non-linear relationship was found between concentrations of D-dimer and CMVD. With increased D-dimer level, the incidence of CMVD increased and then remained at a high level. Stratified analysis was performed and showed similar results. Conclusion: Elevated D-dimer level is associated with the incidence of CMVD and potentially serves as a simple biomarker to facilitate the diagnosis of CMVD for patients with angina.

Effects of early myocardial reperfusion and perfusion on myocardial necrosis/dysfunction and inflammation in patients with ST-segment and non-ST-segment elevation acute coronary syndrome: results from the PLATelet inhibition and patients Outcomes (PLATO) trial.

AIMS: Restoration of myocardial blood flow and perfusion during percutaneous coronary intervention (PCI) measured using Thrombolysis in Myocardial Infarction (TIMI) flow grade (TFG) and perfusion grade (TMPG) is associated with improved outcomes in acute coronary syndrome (ACS). Associations between TFG/TMPG and changes in biomarkers reflecting myocardial damage/dysfunction and inflammation is unknown. METHODS AND RESULTS: Among 2606 patients included, TFG was evaluated in 2198 and TMPG in 1874 with ST-segment elevation myocardial infarction (STEMI) or non-ST-segment ACS (NSTE-ACS). Biomarkers reflecting myocardial necrosis [troponin T (TnT)], myocardial dysfunction [N-terminal prohormone brain natriuretic peptide (NT-proBNP)], inflammation [interleukin-6 (IL-6) and C-reactive protein (CRP)], and oxidative stress/ageing/inflammation [growth differentiation factor-15 (GDF-15)] were measured at baseline, discharge, and 1- and 6-month post-randomization. Associations between TFG/TMPG and changes in biomarker levels were evaluated using the Mann-Whitney-Wilcoxon signed test. In total, 1423 (54.6%) patients had STEMI and 1183 (45.4%) NSTE-ACS. Complete reperfusion after PCI with TFG = 3 was achieved in 1110 (85.3%) with STEMI and in 793 (88.5%) with NSTE-ACS. Normal myocardial perfusion with TMPG = 3 was achieved in 475 (41.6%) with STEMI and in 396 (54.0%) with NSTE-ACS. Levels of TnT, NT-proBNP, IL-6, CRP, and GDF-15 were substantially lower at discharge in patients with complete vs. incomplete TFG and STEMI (P < 0.01). This pattern was not observed for patients with NSTE-ACS. Patients with normal vs. abnormal TMPG and NSTE-ACS had lower levels of NT-proBNP at discharge (P = 0.01). CONCLUSIONS: Successful restoration of epicardial blood flow in STEMI was associated with less myocardial necrosis/dysfunction and inflammation. Attainment of normal myocardial perfusion was associated with less myocardial dysfunction in NSTE-ACS.

Temporal changes in biomarkers and their relationships to reperfusion and to clinical outcomes among patients with ST segment elevation myocardial infarction.

Coronary plaque rupture mediating acute ST segment elevation myocardial infarction (STEMI) is associated with a systemic inflammatory response. Whether early temporal changes in inflammatory biomarkers are associated with angiographic and electrocardiographic markers of reperfusion and subsequent clinical outcomes is unclear. In the APEX-AMI biomarker substudy, 376 patients with STEMI had inflammatory biomarkers measured at the time of hospital presentation and 24 h later. The primary outcome was the 90-day composite of death, shock, or heart failure. Secondary reperfusion outcomes were (1) worst least residual ST segment elevation (ST-E: <1 mm, 1 to <2 mm, ≥2 mm) and (2) post-percutaneous coronary intervention (PCI) TIMI flow grade (0/1/2 vs 3) and TIMI myocardial perfusion grade (TMPG 0/1 vs 2/3). The 90-day incidence of death, shock or heart failure was 21.3 % in this cohort. Electrocardiographic reperfusion (worst residual ST-E <1 mm, 1 to <2 mm, ≥2 mm) was associated with differences in 24 h change in N-terminal proB-type natriuretic peptide (NT-proBNP) (1192.8, 1332.5, 1859.0 ng/mL; p = 0.043) and the pro-inflammatory cytokines Interleukin (IL)-6 (14.0, 13.6, 22.1 pg/mL; p = 0.016), IL-12 (-0.5, -0.9, -0.1 pg/mL; p = 0.013), and tumor necrosis factor α (TNFα) (1.0, 0.6, 3.6 pg/mL; p = 0.023). Angiographic reperfusion (TMPG 0/1 vs 2/3) was associated with changes in median NT-proBNP (2649.3, 1382.7 ng/mL; p = 0.002) and IL-6 (28.7, 15.1; p = 0.040). After adjustment for baseline covariates, the 24 h change in the pro-inflammatory cytokine TNFα [hazard ratio (HR) 0.49; 95 % CI 0.26-0.95; p = 0.035] and the anti-inflammatory cytokine IL 10 (HR 1.41; 95 % CI 1.06-1.87; p = 0.018) were independently associated with the primary composite outcome. Successful coronary reperfusion was associated with less systemic inflammatory response and greater temporal inflammatory changes were independently associated with higher 90-day composite of death, shock, or heart failure. These findings provide support for an association between success of reperfusion, an acute STEMI inflammatory response and subsequent clinical outcomes.

Angiographic outcomes in the PLATO Trial (Platelet Inhibition and Patient Outcomes).

OBJECTIVES: The PLATO (Platelet Inhibition and Patient Outcomes) angiographic substudy sought to compare the efficacy of ticagrelor versus clopidogrel with respect to angiographic outcomes before and after PCI in the setting of acute coronary syndrome. BACKGROUND: Greater platelet inhibition has been associated with improved angiographic outcomes before and after percutaneous coronary intervention (PCI). Therefore, it was hypothesized that treatment with ticagrelor, which achieves more rapid, higher, and more consistent platelet inhibition, would be associated with improved angiographic outcomes when compared with those of clopidogrel treatment. METHODS: The angiographic cohort consists of 2,616 patients drawn from the 18,624-patient PLATO trial. Clopidogrel naïve or pre-treated patients were randomized to 180 mg of ticagrelor or 300 mg of clopidogrel (75 mg for clopidogrel pre-treated patients). PCI patients were administered, as per treatment group: 1) an additional 90 mg of ticagrelor if >24 h following the initial loading dose; or 2) an optional further 300 mg of clopidogrel or placebo (total 600 mg) prior to PCI. The substudy primary endpoint was the incidence of post-PCI TIMI (Thrombolysis In Myocardial Infarction) myocardial perfusion grade 3 (TMPG 3) among patients who received a study drug prior to PCI. RESULTS: In total, 21.3% of patients were pretreated with clopidogrel prior to randomization. There was a short time interval between randomization and PCI (median: 0.68 [interquartile range (IQR): 0.30 to 2.21] h) among all patients. Post-PCI TMPG 3 was similar between the ticagrelor and clopidogrel groups (47.1% vs. 46.9%; p = 0.96). Likewise, the following pre-PCI outcomes were similar in the ticagrelor and clopidogrel groups, respectively: TMPG 3 (30.5% vs. 31.2%), TIMI flow grade 3 (37.1% vs. 39.3%), corrected TIMI frame count (median: 100 vs. 71 frames), TIMI thrombus grade 0 (24.1% vs. 27.6%), minimum lumen diameter (median: 0.3 [IQR: 0.0 to 0.6] vs. 0.3 [IQR: 0.0 to 0.6] mm) and percentage of diameter stenosis (median: 89 [IQR: 78 to 100] vs. 89 [IQR: 77 to 100]). CONCLUSIONS: Neither coronary flow nor myocardial perfusion, evaluated on coronary angiograms performed before or following PCI procedures within a few hours after the start of oral antiplatelet treatment in the setting of acute coronary syndromes, demonstrated a difference with ticagrelor versus clopidogrel. (A Comparison of Ticagrelor [AZD6140] and Clopidogrel in Patients With Acute Coronary Syndrome [PLATO]; NCT00391872).