Could paramedics use the HEART Pathway to identify patients at low-risk of myocardial infarction in the prehospital setting?

In the Emergency Department, patients with suspected myocardial infarction can be risk stratified using the HEART pathway, which has recently been amended for prehospital use and modified for the incorporation of a high-sensitivity cardiac troponin test. In a prospective analysis, the performance of both HEART pathways in the prehospital setting, with a high-sensitivity cardiac troponin test using 3 different thresholds, was evaluated for major adverse cardiac events at 30 days. We found that both low-risk HEART pathways, when using the most conservative cardiac troponin thresholds, approached but did not reach accepted rule-out performance in the Emergency Department.

[Correlation between serum growth differentiation factor 11 level and severity of coronary artery disease in patients with acute myocardial infarction].

Objective: To investigate the correlation between serum growth differentiation factor 11 (GDF11) level and coronary artery lesions in patients with ST-segment elevation myocardial infarction (STEMI), and the predictive efficacy of nomogram risk prediction model based on GDF11 combined with traditional risk factors on the occurrence of STEMI. Methods: This study was a retrospective cross-sectional study. Patients hospitalized in the Department of Cardiology of the 904th Hospital of Joint Logistic Support Force of People's Liberation Army of China from 2016 to 2018 were selected and divided into control group and STEMI group. The demographic data, blood lipid level, laboratory indicators of blood and GDF11 level were collected. Logistic regression analysis screened out independent correlated factors for the occurrence of STEMI. Spearman correlation analysis clarified the correlation of each indicator with the SYNTAX or Gensini scores. A nomogram risk prediction model for the risk of STEMI occurrence and the receiver operating characteristic curve was used to compare the prediction efficiency of each model. Results: A total of 367 patients were enrolled, divided into control group (n=172) and STEMI group (n=195), age (66.5±11.8), male 222 (60.49%). The serum GDF11 level of STEMI group was significantly lower than that of the control group (36.20 (16.60, 70.75) µg/L vs. 85.00 (53.93, 117.10) µg/L, P<0.001). The results of multivariate logistic regression analysis showed serum GDF11(OR=0.98, 95%CI: 0.97-0.99) and traditional independent risk factors such as smoking, diabetes, C-reactive protein, homocysteine, lipoprotein (a) and apolipoprotein A1/B were independent correlate factors for the occurrence of STEMI (P<0.05). Spearman correlation analysis showed that serum GDF11 was negatively correlated with SYNTAX score and Gensini score (P<0.05). The nomogram model constructed by serum GDF11 combined with traditional independent risk factors (AUC=0.85, 95%CI: 0.81-0.89) had better predictive value for the occurrence of STEMI than the traditional nomogram model constructed by independent risk factors(AUC=0.80, 95%CI:0.75-0.84) or serum GDF11 (AUC=0.76, 95%CI: 0.72-0.81), all P<0.01. Conclusions: Serum GDF11 is an independent correlate factor in the occurrence of STEMI and is negatively correlated with the severity of coronary artery lesions in patients with STEMI. The nomogram model constructed based on GDF11 combined with traditional risk factors can be a good predictor for the occurrence of STEMI.

Remnant Cholesterol, Not LDL Cholesterol, Explains Peripheral Artery Disease Risk Conferred by apoB: A Cohort Study.

BACKGROUND: Elevated apoB-containing lipoproteins (=remnants+LDLs [low-density lipoproteins]) are a major risk factor for atherosclerotic cardiovascular disease, including peripheral artery disease (PAD) and myocardial infarction. We tested the hypothesis that remnants and LDL both explain part of the increased risk of PAD conferred by elevated apoB-containing lipoproteins. For comparison, we also studied the risk of chronic limb-threatening ischemia and myocardial infarction. METHODS: apoB, remnant cholesterol, and LDL cholesterol were measured in 93 461 individuals without statin use at baseline from the Copenhagen General Population Study (2003-2015). During up to 15 years of follow-up, 1207 had PAD, 552 had chronic limb-threatening ischemia, and 2022 had myocardial infarction in the Danish National Patient Registry. Remnant and LDL cholesterol were calculated from a standard lipid profile. Remnant and LDL particle counts were additionally measured with nuclear magnetic resonance spectroscopy in 25 347 of the individuals. Results were replicated in 302 167 individuals without statin use from the UK Biobank (2004-2010). RESULTS: In the Copenhagen General Population Study, multivariable adjusted hazard ratios for risk of PAD per 1 mmol/L (39 mg/dL) increment in remnant and LDL cholesterol were 1.9 (95% CI, 1.5-2.4) and 1.1 (95% CI, 1.0-1.2), respectively; corresponding results in the UK Biobank were 1.7 (95% CI, 1.4-2.1) and 0.9 (95% CI, 0.9-1.0), respectively. In the association from elevated apoB to increased risk of PAD, remnant and LDL cholesterol explained 73% (32%-100%) and 8% (0%-46%), respectively; corresponding results were 63% (30%-100%) and 0% (0%-33%) for risk of chronic limb-threatening ischemia and 41% (27%-55%) and 54% (38%-70%) for risk of myocardial infarction; results for remnant and LDL particle counts corroborated these findings. CONCLUSIONS: PAD risk conferred by elevated apoB-containing lipoproteins was explained mainly by elevated remnants, while myocardial infarction risk was explained by both elevated remnants and LDL.

Restrictive or Liberal Transfusion Strategy in Myocardial Infarction and Anemia.

BACKGROUND: A strategy of administering a transfusion only when the hemoglobin level falls below 7 or 8 g per deciliter has been widely adopted. However, patients with acute myocardial infarction may benefit from a higher hemoglobin level. METHODS: In this phase 3, interventional trial, we randomly assigned patients with myocardial infarction and a hemoglobin level of less than 10 g per deciliter to a restrictive transfusion strategy (hemoglobin cutoff for transfusion, 7 or 8 g per deciliter) or a liberal transfusion strategy (hemoglobin cutoff, <10 g per deciliter). The primary outcome was a composite of myocardial infarction or death at 30 days. RESULTS: A total of 3504 patients were included in the primary analysis. The mean (±SD) number of red-cell units that were transfused was 0.7±1.6 in the restrictive-strategy group and 2.5±2.3 in the liberal-strategy group. The mean hemoglobin level was 1.3 to 1.6 g per deciliter lower in the restrictive-strategy group than in the liberal-strategy group on days 1 to 3 after randomization. A primary-outcome event occurred in 295 of 1749 patients (16.9%) in the restrictive-strategy group and in 255 of 1755 patients (14.5%) in the liberal-strategy group (risk ratio modeled with multiple imputation for incomplete follow-up, 1.15; 95% confidence interval [CI], 0.99 to 1.34; P = 0.07). Death occurred in 9.9% of the patients with the restrictive strategy and in 8.3% of the patients with the liberal strategy (risk ratio, 1.19; 95% CI, 0.96 to 1.47); myocardial infarction occurred in 8.5% and 7.2% of the patients, respectively (risk ratio, 1.19; 95% CI, 0.94 to 1.49). CONCLUSIONS: In patients with acute myocardial infarction and anemia, a liberal transfusion strategy did not significantly reduce the risk of recurrent myocardial infarction or death at 30 days. However, potential harms of a restrictive transfusion strategy cannot be excluded. (Funded by the National Heart, Lung, and Blood Institute and others; MINT ClinicalTrials.gov number, NCT02981407.).

Stability of exosomes in the postmortem serum and preliminary study on exosomal miRNA expression profiling in serum from myocardial infarction cadavers.

Exosome-encapsulated miRNAs could potentially be sensitive biomarkers of human diseases. Since a lipid bilayer membrane surrounds exosomes, the exosomal miRNA may stably exist in body fluids with diseases as well as biological fluids. Therefore, exosomal miRNA may be helpful for autopsy diagnosis. Assuming cadaver blood would be most useful, we initially examined serum exosome stability with regard to storage temperatures and periods. Characteristic analyses of the exosome revealed that exosomes and the content, miRNA, were stably preserved until at least three days when stored at below 20 °C. Subsequently, exosomal miRNA expression profiling was performed on the serum of acute myocardial infarction (AMI, 4 cases) autopsy bodies and on hemorrhagic shock bodies used as the control (CT, 3 cases). Results showed that significant twofold up- and downregulations of expression of 18 and 16 miRNAs were detectable in AMI as compared to the CT, respectively. miR-126-3p, which has been reported to be increased in serum of AMI patients and a mouse model, was one of the significantly upregulated miRNAs. Furthermore, dysregulation of exosomal miRNAs, such as miR-145-5p, miR-143-3p, and miR-222-3p, which are involved in cardioprotection, may be associated with AMI pathogenesis. These findings provide a novel perspective on the potential role of exosomal miRNA in determining the cause of death.

[Effects of hemoglobin level on the risk of acute kidney injury in patients with acute myocardial infarction].

OBJECTIVE: To investigate the effect of preoperative hemoglobin (Hb) level on the risk of developing acute kidney injury (AKI) after percutaneous coronary intervention (PCI) in patients with acute myocardial infarction (AMI). METHODS: A retrospective study was conducted. The hospitalized patients diagnosed with AMI who underwent PCI from May 2015 to May 2020 in the department of cardiology in the Affiliated Changzhou No.2 People's Hospital of Nanjing Medical University were enrolled. According to the serum creatinine (SCr) level before and after interventional therapy, the patients were divided into an AKI group and a non-AKI group. The difference in patients' Hb levels between the AKI and non-AKI groups was compared. Univariate and multivariate Logistic regression analyses were used to analyze the effects of Hb levels on the risk of AKI after interventional therapy in patients with AMI. Kaplan-Meier survival curve was used to evaluate the effects of Hb levels on patients with AMI in all-cause death in the hospital. RESULTS: A total of 922 AMI patients were enrolled in this study, of which 165 patients (17.9%) developed AKI. Compared with the non-AKI group, female patients in the AKI group had a higher proportion [35.8% (59/165) vs. 26.9% (204/757)], older (age: 69.78±14.56 vs. 66.61±13.44), with a lower rate of smoking [42.4% (70/165) vs. 51.7% (391/757)] and a higher prevalence of hypertension [73.3% (121/165) vs. 63.5% (481/757)], however, the patients in AKI group also had a worse cardiac function [the proportion of Killip grade 3 or above was higher: 33.9% (56/165) vs. 13.9% (105/757)], lower Hb level (g/L: 127.61±22.18 vs. 132.79±19.45), and there were less patients using angiotensin converting enzyme inhibitor/angiotensin II receptor blocker [ACEI/ARB, 60.0% (99/165) vs. 74.5% (564/757)] and more patients using diuretics [24.8% (41/165) vs. 17.7% (134/757)] in AKI group, the differences were statistically significant (all P < 0.05). Compared with non-AKI group, patients in AKI group had a longer operation time [operation time > 60 minutes: 4.2% (7/165) vs. 1.5% (11/757)] and received more contrast media during the operative procedure [contrast media > 100 mL: 16.4% (27/165) vs. 3.6% (27/757)], the individuals had a higher rate of intra-operative hypotension [16.4% (27/165) vs. 8.2% (62/757)], and more patients were implanted more than 2 stents [8.5% (14/165) vs. 3.6% (27/757), all P < 0.05]. Univariate Logistic regression analysis suggested that each 1 g/L increase in preoperative Hb level was associated with a 1.2% decrease in the risk of postoperative AKI [odds ratio (OR) = 0.988, 95% confidence interval (95%CI) was 0.980-0.996, P = 0.003]. Meanwhile, for every 1 standard deviation increase in preoperative Hb level, the risk of postoperative AKI decreased by 22.1% (OR = 0.779, 95%CI was 0.661-0.918, P = 0.003). The patients were divided into low, medium and high concentration groups according to Hb levels (Hb levels were < 110 g/L, 110-150 g/L, ≥ 150 g/L, respectively), and multivariate Logistic regression analysis showed that the risk of AKI was significantly reduced in the high concentration group compared with that in the low concentration group (OR = 0.463, 95%CI was 0.241-0.888, P = 0.020). The Kaplan-Meier survival curve analysis indicated that the short term survival after coronary intervention in AMI patients with low Hb concentration was significantly lower than that in patients with medium and high Hb concentration (Log-Rank: χ2 = 23.215, P < 0.001). CONCLUSIONS: Preoperative lower Hb level is an independent risk factor for postoperative AKI in AMI patients. AMI patients with lower Hb levels have an increased risk of all-cause mortality within 1 month after AMI.

The prognostic significance of the presence of tenascin-C in patients with stable coronary heart disease.

BACKGROUND: We investigated the prognostic value of tenascin-C in patients with stable coronary heart disease. METHODS: A total of 666 patients were enrolled and followed for 72 months. The primary outcome was a composite of cardiac events. The secondary outcomes were all-cause death, cardiovascular death, acute myocardial infarction (AMI), and heart failure hospitalization. RESULTS: The area under the curve of tenascin-C to discriminate the occurrence of composite cardiac events was 70 % (95 % CI: 64.2 % to 75.8 %), and the corresponding optimal cutoff value was 19.91 ng/ml. A higher concentration of tenascin-C was associated with a greater risk of composite cardiac events (P trend < 0.001). Similar results were observed in all-cause death, AMI, and heart failure hospitalization. CONCLUSION: Tenascin-C was found to be an independent predictor of total cardiovascular events in patients with stable coronary heart disease at 72 months, and also for all-cause death, AMI, and heart failure hospitalization.

The Use of Lipoprotein-Associated Phospholipase A2 in a Chinese Population to Predict Cardiovascular Events.

Objective: To explore associations between lipoprotein-associated phospholipase A2 (Lp-PLA2) and the risk of cardiovascular events in a Chinese population, with a long-term follow-up. Methods: A random sample of 2,031 participants (73.6% males, mean age = 60.4 years) was derived from the Asymptomatic Polyvascular Abnormalities Community study (APAC) from 2010 to 2011. Serum Lp-PLA2 levels were determined by enzyme-linked immunosorbent assay (ELISA). The composite endpoint was a combination of first-ever stroke, myocardial infarction (MI) or all-cause death. Lp-PLA2 associations with outcomes were assessed using Cox models. Results: The median Lp-PLA2 level was 141.0 ng/mL. Over a median follow-up of 9.1 years, we identified 389 events (19.2%), including 137 stroke incidents, 43 MIs, and 244 all-cause deaths. Using multivariate Cox regression, when compared with the lowest Lp-PLA2 quartile, the hazard ratios with 95% confidence intervals for developing composite endpoints, stroke, major adverse cardiovascular events, and all-cause death were 1.77 (1.24-2.54), 1.92 (1.03-3.60), 1.69 (1.003-2.84), and 1.94 (1.18-3.18) in the highest quartile, respectively. Composite endpoints in 145 (28.6%) patients occurred in the highest quartile where Lp-PLA2 (159.0 ng/mL) was much lower than the American Association of Clinical Endocrinologists recommended cut-off point, 200 ng/mL. Conclusion: Higher Lp-PLA2 levels were associated with an increased risk of cardiovascular event/death in a middle-aged Chinese population. The Lp-PLA2 cut-off point may be lower in the Chinese population when predicting cardiovascular events.

High-sensitivity cardiac troponin and the diagnosis of myocardial infarction in patients with kidney impairment.

The benefit and utility of high-sensitivity cardiac troponin (hs-cTn) in the diagnosis of myocardial infarction in patients with kidney impairment is unclear. Here, we describe implementation of hs-cTnI testing on the diagnosis, management, and outcomes of myocardial infarction in patients with and without kidney impairment. Consecutive patients with suspected acute coronary syndrome enrolled in a stepped-wedge, cluster-randomized controlled trial were included in this pre-specified secondary analysis. Kidney impairment was defined as an eGFR under 60mL/min/1.73m2. The index diagnosis and primary outcome of type 1 and type 4b myocardial infarction or cardiovascular death at one year were compared in patients with and without kidney impairment following implementation of hs-cTnI assay with 99th centile sex-specific diagnostic thresholds. Serum creatinine concentrations were available in 46,927 patients (mean age 61 years; 47% women), of whom 9,080 (19%) had kidney impairment. hs-cTnIs were over 99th centile in 46% and 16% of patients with and without kidney impairment. Implementation increased the diagnosis of type 1 infarction from 12.4% to 17.8%, and from 7.5% to 9.4% in patients with and without kidney impairment (both significant). Patients with kidney impairment and type 1 myocardial infarction were less likely to undergo coronary revascularization (26% versus 53%) or receive dual anti-platelets (40% versus 68%) than those without kidney impairment, and this did not change post-implementation. In patients with hs-cTnI above the 99th centile, the primary outcome occurred twice as often in those with kidney impairment compared to those without (24% versus 12%, hazard ratio 1.53, 95% confidence interval 1.31 to 1.78). Thus, hs-cTnI testing increased the identification of myocardial injury and infarction but failed to address disparities in management and outcomes between those with and without kidney impairment.

High-Sensitivity Troponin I after Cardiac Surgery and 30-Day Mortality.

BACKGROUND: Consensus recommendations regarding the threshold levels of cardiac troponin elevations for the definition of perioperative myocardial infarction and clinically important periprocedural myocardial injury in patients undergoing cardiac surgery range widely (from >10 times to ≥70 times the upper reference limit for the assay). Limited evidence is available to support these recommendations. METHODS: We undertook an international prospective cohort study involving patients 18 years of age or older who underwent cardiac surgery. High-sensitivity cardiac troponin I measurements (upper reference limit, 26 ng per liter) were obtained 3 to 12 hours after surgery and on days 1, 2, and 3 after surgery. We performed Cox analyses using a regression spline that explored the relationship between peak troponin measurements and 30-day mortality, adjusting for scores on the European System for Cardiac Operative Risk Evaluation II (which estimates the risk of death after cardiac surgery on the basis of 18 variables, including age and sex). RESULTS: Of 13,862 patients included in the study, 296 (2.1%) died within 30 days after surgery. Among patients who underwent isolated coronary-artery bypass grafting or aortic-valve replacement or repair, the threshold troponin level, measured within 1 day after surgery, that was associated with an adjusted hazard ratio of more than 1.00 for death within 30 days was 5670 ng per liter (95% confidence interval [CI], 1045 to 8260), a level 218 times the upper reference limit. Among patients who underwent other cardiac surgery, the corresponding threshold troponin level was 12,981 ng per liter (95% CI, 2673 to 16,591), a level 499 times the upper reference limit. CONCLUSIONS: The levels of high-sensitivity troponin I after cardiac surgery that were associated with an increased risk of death within 30 days were substantially higher than levels currently recommended to define clinically important periprocedural myocardial injury. (Funded by the Canadian Institutes of Health Research and others; VISION Cardiac Surgery ClinicalTrials.gov number, NCT01842568.).

Diagnostic performance and predictive value of D-dimer testing in patients referred to the emergency department for suspected myocardial infarction.

PURPOSE: The study sought to assess the performance of D-dimer testing for the diagnosis of acute coronary syndrome (ACS) and prediction of outcomes in patients admitted for suspected myocardial infarction (MI). RESULTS: A total of 3,557 patients with suspected ACS presenting to a single center with a broad range of symptoms including atypical chest pain were retrospectively recruited between 02/2012-01/2019. Of the study cohort, 435 patients had unstable angina (UA), 420 non-ST-segment elevation myocardial infarction (NSTEMI), 22 ST-segment elevation myocardial infarction (STEMI), and 2,680 non-coronary chest pain. Plasma D-dimer concentrations in patients with hs-cTnT > 14 ng/L differed significantly from those with hs-cTnT < 14 ng/L (1.5 ± 3.6 mg/L vs. 0.5 ± 0.8 mg/L; p < 0.0001). Positive predictive value for a final diagnosis of ACS increased proportionally to rising D-dimer concentrations. The area under the curve (AUC) to discriminate STEMI from non-coronary chest pain (AUC 0.729, 95% confidence interval [CI] 0.71-0.75) was moderate and differed not significantly to UA (AUC 0.595, 95% CI 0.58-0.61; p = 0.0653). During a median follow-up of 29 months, higher D-dimer was associated with a significantly increased risk of recurrent MI (quartile 4 vs. 1: hazard ratio [HR], 6.9 [95% CI 1.2-39.9]; p < 0.0001) and higher all-cause mortality (HR, 17.4 [95% CI 4.3-69.9]; p < 0.0001). D-dimer was an independent predictor of all-cause mortality (p < 0.0001) and subsequent MI events (p = 0.0333). CONCLUSIONS: D-dimer testing revealed great potential to provide independent prognostic information on recurrent MI and all-cause mortality. However, D-dimers do not improve the diagnostic performance except if values exceed the 95th percentile.

Circulating Cystatin C Is an Independent Risk Marker for Cardiovascular Outcomes, Development of Renal Impairment, and Long-Term Mortality in Patients With Stable Coronary Heart Disease: The LIPID Study.

Background Elevated plasma cystatin C levels reflect reduced renal function and increased cardiovascular risk. Less is known about whether the increased risk persists long-term or is independent of renal function and other important biomarkers. Methods and Results Cystatin C and other biomarkers were measured at baseline (in 7863 patients) and 1 year later (in 6106 patients) in participants in the LIPID (Long-Term Intervention with Pravastatin in Ischemic Disease) study, who had a previous acute coronary syndrome. Outcomes were ascertained during the study (median follow-up, 6 years) and long-term (median follow-up, 16 years). Glomerular filtration rate (GFR) was estimated using Chronic Kidney Disease Epidemiology Collaboration equations (first GFR-creatinine, then GFR-creatinine-cystatin C). Over 6 years, in fully adjusted multivariable time-to-event models, with respect to the primary end point of coronary heart disease mortality or nonfatal myocardial infarction, for comparison of Quartile 4 versus 1 of baseline cystatin C, the hazard ratio was 1.37 (95% CI, 1.07-1.74; P=0.01), and for major cardiovascular events was 1.47 (95% CI, 1.19-1.82; P<0.001). Over 16 years, the association of baseline cystatin C with coronary heart disease, cardiovascular, and all-cause mortality persisted (each P<0.001) and remained significant after adjustment for estimated GFR-creatinine-cystatin C. Cystatin C also predicted the development of chronic kidney disease for 6 years (odds ratio, 6.61; 95% CI, 4.28-10.20) independently of estimated GFR-creatinine and other risk factors. However, this association was no longer significant after adjustment for estimated GFR-creatinine-cystatin C. Conclusions Cystatin C independently predicted major cardiovascular events, development of chronic kidney disease, and cardiovascular and all-cause mortality. Prediction of long-term mortality was independent of improved estimation of GFR. Registration URL: https://anzctr.org.au; Unique identifier: ACTRN12616000535471.

Frequency and Outcomes of Periprocedural MI in Patients With Chronic Coronary Syndromes Undergoing PCI.

BACKGROUND: Definitions of periprocedural myocardial infarction (MI) differ with respect to biomarker threshold as well as ancillary criteria for myocardial ischemia and are limited in terms of validation. OBJECTIVES: This study evaluated the frequency and impact of periprocedural MI by using various MI definitions among patients with chronic coronary syndrome (CCS) undergoing percutaneous coronary intervention (PCI). METHODS: Between 2010 and 2018, periprocedural MIs were assessed according to the third and fourth Universal Definition of Myocardial Infarction (UDMI), Academic Research Consortium-2 (ARC-2), and Society for Cardiovascular Angiography and Interventions (SCAI) criteria based on high-sensitivity troponin in patients with CCS undergoing PCI enrolled into the Bern PCI registry. The primary endpoint was cardiac death at 1 year. RESULTS: Among 4,404 patients with CCS, periprocedural MI defined by the third UDMI, fourth UDMI, ARC-2, and SCAI were observed in 18.0%, 14.9%, 2.0%, and 2.0% of patients, respectively. Among patients with periprocedural MI defined by the third UDMI, fourth UDMI, ARC-2, and SCAI, cardiac mortality at 1 year was 2.9%, 3.0%, 5.8%, and 10.0%. The ARC-2 (HR: 3.90; 95% CI: 1.54-9.93) and SCAI (HR: 7.66; 95% CI: 3.64-16.11) were more relevant compared with the third UDMI (HR: 1.76; 95% CI: 1.04-3.00) and fourth UDMI (HR: 1.93; 95% CI: 1.11-3.37) for cardiac death at 1 year. CONCLUSIONS: Among patients with CCS undergoing PCI, periprocedural MI defined according to the ARC-2 and SCAI criteria was 7 to 9 times less frequent compared with the third and fourth UDMI. Periprocedural MI defined by using the ARC-2 and SCAI were more prognostic for cardiac death at 1 year compared with the third and fourth UDMI. (CARDIOBASE Bern PCI Registry; NCT02241291).

Epigenetic Regulation of F2RL3 Associates With Myocardial Infarction and Platelet Function.

BACKGROUND: DNA hypomethylation at the F2RL3 (F2R like thrombin or trypsin receptor 3) locus has been associated with both smoking and atherosclerotic cardiovascular disease; whether these smoking-related associations form a pathway to disease is unknown. F2RL3 encodes protease-activated receptor 4, a potent thrombin receptor expressed on platelets. Given the role of thrombin in platelet activation and the role of thrombus formation in myocardial infarction, alterations to this biological pathway could be important for ischemic cardiovascular disease. METHODS: We conducted multiple independent experiments to assess whether DNA hypomethylation at F2RL3 in response to smoking is associated with risk of myocardial infarction via changes to platelet reactivity. Using cohort data (N=3205), we explored the relationship between smoking, DNA hypomethylation at F2RL3, and myocardial infarction. We compared platelet reactivity in individuals with low versus high DNA methylation at F2RL3 (N=41). We used an in vitro model to explore the biological response of F2RL3 to cigarette smoke extract. Finally, a series of reporter constructs were used to investigate how differential methylation could impact F2RL3 gene expression. RESULTS: Observationally, DNA methylation at F2RL3 mediated an estimated 34% of the smoking effect on increased risk of myocardial infarction. An association between methylation group (low/high) and platelet reactivity was observed in response to PAR4 (protease-activated receptor 4) stimulation. In cells, cigarette smoke extract exposure was associated with a 4.9% to 9.3% reduction in DNA methylation at F2RL3 and a corresponding 1.7-(95% CI, 1.2-2.4, P=0.04) fold increase in F2RL3 mRNA. Results from reporter assays suggest the exon 2 region of F2RL3 may help control gene expression. CONCLUSIONS: Smoking-induced epigenetic DNA hypomethylation at F2RL3 appears to increase PAR4 expression with potential downstream consequences for platelet reactivity. Combined evidence here not only identifies F2RL3 DNA methylation as a possible contributory pathway from smoking to cardiovascular disease risk but from any feature potentially influencing F2RL3 regulation in a similar manner.

Decreased Iron Ion Concentrations in the Peripheral Blood Correlate with Coronary Atherosclerosis.

(1) Background: Obesity and diabetes continue to reach epidemic levels in the population with major health impacts that include a significantly increased risk of coronary atherosclerosis. The imbalance of trace elements in the body caused by nutritional factors can lead to the progression of coronary atherosclerosis. (2) Methods: We measured the concentrations of sodium (Na), potassium (K), magnesium (Mg), calcium (Ca), Zinc (Zn), and iron (Fe) in peripheral blood samples from 4243 patients and performed baseline analysis and propensity matching of the patient datasets. The patients were grouped into acute myocardial infarction (AMI, 702 patients) and stable coronary heart disease (SCAD1, 253 patients) groups. Both of these groups were included in the AS that had a total of 1955 patients. The control group consisted of 2288 patients. The plasma concentrations of calcium, magnesium, and iron were measured using a colorimetric method. For comparison, 15 external quality assessment (EQA) samples were selected from the Clinical Laboratory Center of the Ministry of Health of China. SPSS software was used for statistical analysis. The average values and deviations of all of the indicators in each group were calculated, and a p-value threshold of <0.05 was used to indicate statistical significance. (3) Results: The iron ion concentrations of the acute myocardial infarction (AMI) group were significantly lower than the control group (p < 0.05, AUC = 0.724, AUC = 0.702), irrespective of tendency matching. Compared to the data from the stable coronary artery disease (SCAD) group, the concentration of iron ions in the acute myocardial infarction group was significantly lower (p < 0.05, AUC = 0.710, AUC = 0.682). Furthermore, the iron ion concentrations in the (AMI + SCAD) group were significantly lower (p < 0.05) than in the control group. (4) Conclusions: The data presented in this study strongly indicate that the concentration of iron ions in the peripheral blood is related to coronary atherosclerosis. Decreases in the levels of iron ions in the peripheral blood can be used as a predictive biomarker of coronary atherosclerosis.

Low-density lipoprotein receptor and apolipoprotein A 5, myocardial infarction biomarkers in plasma-derived exosomes.

OBJECTIVES: Myocardial infarction (MI), a leading cause of death around the world, displays a complex pattern of inheritance. Previously, rare mutations in low-density lipoprotein receptor (LDLR) genes and apolipoprotein A V (APOA5) have been shown to contribute to MI risk in individual families. Exosomes provide a potential source of biomarkers for MI. This study is to determine the role of LDLR and APOA5 as biomarkers for early diagnosis of MI. METHODS: In this study, we detected the levels of LDLR, APOA5, and cardiac troponin T in plasma-derived exosomes in MI patients and age-matched healthy people by enzyme linked immunosorbent assay and observed the morphology and number of exosomes using transmission electron microscope and nanoparticle tracking analysis. Oxygen-glucose deprivation (OGD) method was used to induce MI in H9C2 cardiomyocytes to explore the effect of exosomes. RESULTS: We found that the levels of LDLR and APOA5 in plasma-derived exosomes in MI patients were significantly decreased. Furthermore, exosomes of MI patients were significantly larger in size and the concentration of exosomes was higher than that of age-matched non-MI people. In vitro experiments showed that OGD treatment induced apoptosis of myocardial cells and decreased the expression of LDLR and APOA5, while addition of exosomes isolated from healthy people rescued these phenotypes. CONCLUSION: Exosomal APOA5 and LDLR are intimately associated with MI, and thereby have the potential to function as diagnostic markers of MI.

Serum GDF-15 Predicts In-Hospital Mortality and Arrhythmic Risks in Patients With Acute Myocardial Infarction.

This study aims to evaluate the association of serum growth differentiation factor 15 (GDF-15) with in-hospital mortality and arrhythmic risks in patients with acute myocardial infarction (AMI). A total of 296 consecutive patients with AMI were enrolled in our hospital from Jan. 2018 to Dec. 2020. Serum GDF-15 levels were measured at baseline. The primary endpoint was in-hospital all-cause mortality, and the secondary endpoint was major adverse cardiac events (MACEs) during hospitalization, defined as a composite of cardiovascular death, heart failure, sustained ventricular arrhythmias (ventricular tachycardia or ventricular fibrillation), and bleeding. During hospitalization, patients with a higher GDF-15 level had significantly higher incidences of in-hospital mortality (7.4% vs 1.4%; P = .02) and MACEs (9.5% vs 20.9%, P < .01) than those with a lower GDF-15 level. Multivariate logistic regression analysis showed that a higher GDF-15 level was significantly associated with increased risks of in-hospital mortality (OR = 1.92, 95% CI: 1.44-2.50; P < .01) and MACEs (OR = 2.19, 95% CI: 1.56-2.77; P < .01). In conclusion, GDF-15 was associated with the risks of in-hospital mortality and MACEs, indicating that it should be a prognostic biomarker for patients with AMI.