Project description:It is assumed that platelets in diseased conditions share similar properties to platelets in healthy conditions, although this has never been examined in detail for myocardial infarction (MI). We examined platelets from patients with ST-segment elevation myocardial infarction (STEMI) and non-ST-segment elevation myocardial infarction (NSTEMI) compared with platelets from healthy volunteers to evaluate for differences in platelet phenotype and function. Platelet activation was examined and postreceptor signal transduction pathways were assessed. Platelet-derived plasma biomarkers were evaluated by receiver operator characteristic curve analysis. Maximum platelet activation through the thromboxane receptor was greater in STEMI than in NSTEMI but less through protease-activated receptor 1. Extracellular-signal related-kinase 5 activation, which can activate platelets, was increased in platelets from subjects with STEMI and especially in platelets from patients with NSTEMI. Matrix metalloproteinase 9 (MMP9) protein content and enzymatic activity were several-fold greater in platelets with MI than in control. Mean plasma MMP9 concentration in patients with MI distinguished between STEMI and NSTEMI (area under curve [AUC] 75% [confidence interval (CI) 60-91], P = 0.006) which was superior to troponin T (AUC 66% [CI 48-85, P = 0.08), predicting STEMI with 80% sensitivity (95% CI 56-94), 90% specificity (CI 68-99), 70% AUC (CI 54-86, P < 0.0001), and NSTEMI with 50% sensitivity (CI 27-70), 90% specificity (CI 68-99), 70% AUC (CI 54-86, P = 0.03). Platelets from patients with STEMI and NSTEMI show differences in platelet surface receptor activation and postreceptor signal transduction, suggesting the healthy platelet phenotype in which antiplatelet agents are often evaluated in preclinical studies is different from platelets in patients with MI.
Project description:Acute myocardial infarction (AMI) complicated by cardiogenic shock has high mortality and remains challenging even in the revascularization era. We conducted this study to understand patients' outcomes. We retrospectively analyzed electronic medical records data from 1175 patients with AMI complicated by cardiogenic shock that developed within 3 days of admission to a multicenter medical care system between January 1, 2000, and July 31, 2018. Patients with AMI were classified into the ST-segment elevation MI (STEMI) group or the non-ST-segment elevation MI (NSTEMI) group. The short-term and 1-year mortality and adverse events after index admission were analyzed via logistic regression and a Cox proportional hazards model. When compared with NSTEMI, patients with STEMI tended to be younger (65.68 ± 14.05 years vs 70.70 ± 12.99 years, P < .001), men (73.29% vs 60.87%, P < .001), and have fewer underlying chronic diseases. Short-term mortality at index hospitalization was 14.83% in the STEMI group and 21.30% in the NSTEMI group; long-term mortality was 17.06% for the STEMI group and 24.13% for the NSTEMI group. No difference was observed between the 2 groups for patients who developed a cerebral vascular accident during the admission period. However, the major and gastrointestinal bleeding rates were higher in the STEMI group (2.66% vs 0.22%, P = .014; 3.36% vs 0.22%, P = .007, respectively). Age and respiratory failure were the most significant risk factors for short-term mortality. Revascularization may be beneficial for the short-term outcome but did not reach significance in multivariable analysis. In patients with AMI with cardiogenic shock, NSTEMI was associated with a significantly higher mortality rate in short-term results.
Project description:ObjectiveTo investigate the relationship between ST-segment resolution (STR) and myocardial scar thickness after percutaneous coronary intervention (PCI) in patients with ST-segment elevation myocardial infarction (STEMI).MethodsForty-two STEMI patients with single-branch coronary artery stenosis or occlusion were enrolled. ST-segment elevations were measured at emergency admission and at 24 h after PCI. Late gadolinium-enhanced cardiac magnetic resonance imaging (CMR-LGE) was performed 7 days after PCI to evaluate myocardial scars. Statistical analyses were performed to assess the utility of STR to predict the development of transmural (> 75%) or non-transmural (< 75%) myocardial scars, according to previous study.ResultsThe sensitivity and specificity of STR for predicting transmural scars were 96% and 88%, respectively, at an STR cut-off value of 40.15%. The area under the curve was 0.925. Multivariate logistic proportional hazards regression analysis disclosed that patients with STR < 40.15% had a 170.90-fold higher probability of developing transmural scars compared with patients with STR ≥ 40.15%. Pearson correlation and linear regression analyses showed STR percentage was significantly associated with myocardial scar thickness and size.ConclusionSTR < 40.15% at 24 h after PCI may provide meaningful diagnostic information regarding the extent of myocardial scarification in STEMI patients.
Project description:ImportanceChallenges to improving ST-segment elevation myocardial infarction (STEMI) care are formidable in low- to middle-income countries because of several system-level factors.ObjectiveTo examine access to reperfusion and percutaneous coronary intervention (PCI) during STEMI using a hub-and-spoke model.Design, setting, and participantsThis multicenter, prospective, observational study of a quality improvement program studied 2420 patients 20 years or older with symptoms or signs consistent with STEMI at primary care clinics, small hospitals, and PCI hospitals in the southern state of Tamil Nadu in India. Data were collected from the 4 clusters before implementation of the program (preimplementation data). We required a minimum of 12 weeks for the preimplementation data with the period extending from August 7, 2012, through January 5, 2013. The program was then implemented in a sequential manner across the 4 clusters, and data were collected in the same manner (postimplementation data) from June 12, 2013, through June 24, 2014, for a mean 32-week period.ExposuresCreation of an integrated, regional quality improvement program that linked the 35 spoke health care centers to the 4 large PCI hub hospitals and leveraged recent developments in public health insurance schemes, emergency medical services, and health information technology.Main outcomes and measuresPrimary outcomes focused on the proportion of patients undergoing reperfusion, timely reperfusion, and postfibrinolysis angiography and PCI. Secondary outcomes were in-hospital and 1-year mortality.ResultsA total of 2420 patients with STEMI (2034 men [84.0%] and 386 women [16.0%]; mean [SD] age, 54.7 [12.2] years) (898 in the preimplementation phase and 1522 in the postimplementation phase) were enrolled, with 1053 patients (43.5%) from the spoke health care centers. Missing data were common for systolic blood pressure (213 [8.8%]), heart rate (223 [9.2%]), and anterior MI location (279 [11.5%]). Overall reperfusion use and times to reperfusion were similar (795 [88.5%] vs 1372 [90.1%]; P = .21). Coronary angiography (314 [35.0%] vs 925 [60.8%]; P < .001) and PCI (265 [29.5%] vs 707 [46.5%]; P < .001) were more commonly performed during the postimplementation phase. In-hospital mortality was not different (52 [5.8%] vs 85 [5.6%]; P = .83), but 1-year mortality was lower in the postimplementation phase (134 [17.6%] vs 179 [14.2%]; P = .04), and this difference remained consistent after multivariable adjustment (adjusted odds ratio, 0.76; 95% CI, 0.58-0.98; P = .04).Conclusions and relevanceA hub-and-spoke model in South India improved STEMI care through greater use of PCI and may improve 1-year mortality. This model may serve as an example for developing STEMI systems of care in other low- to middle-income countries.
Project description:Among the diverse populations of myeloid cells that reside within the healthy and diseased heart, C-C chemokine receptor 2 (CCR2) is specifically expressed on inflammatory populations of monocytes and macrophages that contribute to the development and progression of heart failure1-4. Here, we evaluated a peptide-based imaging probe (64Cu-DOTA-ECL1i) that specifically recognizes CCR2+ monocytes and macrophages for human cardiac imaging. Compared to healthy controls, 64Cu-DOTA-ECL1i heart uptake was increased in subjects following acute myocardial infarction, predominately localized within the infarct area, and was associated with impaired myocardial wall motion. These findings establish the feasibility of molecular imaging of CCR2 expression to visualize inflammatory monocytes and macrophages in the injured human heart.
Project description:Background Many communities have implemented systems of regionalized care to improve access to timely care for patients with ST-segment-elevation myocardial infarction. However, patients who are ultimately diagnosed with non-ST-segment-elevation myocardial infarctions (NSTEMIs) may also be affected, and the impact of regionalization programs on NSTEMI treatment and outcomes is unknown. We set out to determine the effects of ST-segment-elevation myocardial infarction regionalization schemes on treatment and outcomes of patients diagnosed with NSTEMIs. Methods and Results The cohort included all patients receiving care in emergency departments diagnosed with an NSTEMI at all nonfederal hospitals in California from January 1, 2005 to September 30, 2015. Data were analyzed using a difference-in-differences approach. The main outcomes were 1-year mortality and angiography within 3 days of the index admission. A total of 293 589 patients with NSTEMIs received care in regionalized and nonregionalized communities. Over the study period, rates of early angiography increased by 0.5 and mortality decreased by 0.9 percentage points per year among the overall population (95% CI, 0.4-0.6 and -1.0 to -0.8, respectively). Regionalization was not associated with early angiography (-0.5%; 95% CI, -1.1 to 0.1) or death (0.2%; 95% CI, -0.3 to 0.8). Conclusions ST-segment-elevation myocardial infarction regionalization programs were not statistically associated with changes in guideline-recommended early angiography or changes in risk of death for patients with NSTEMI. Increases in the proportion of patients with NSTEMI who underwent guideline-directed angiography and decreases in risk of mortality were accounted for by secular trends unrelated to regionalization policies.
Project description:ST segment elevation myocardial infarction remains a significant contributor to morbidity and mortality worldwide, despite a declining incidence and better survival rates. It usually results from thrombotic occlusion of a coronary artery at the site of a ruptured or eroded plaque. Diagnosis is based on characteristic symptoms and electrocardiogram changes, and confirmed subsequently by raised cardiac enzymes. Prognosis is dependent on the size of the infarct, presence of collaterals and speed with which the occluded artery is reopened. Mechanical reperfusion by primary percutaneous coronary intervention is superior to fibrinolytic therapy if delivered by an experienced team in a timely fashion. Post-reperfusion care includes monitoring for complications, evaluation of left ventricular function, secondary preventive therapy and cardiac rehabilitation.
Project description:Infarction of the anterior myocardial wall results in anterior ST-elevation. However, ST-deviation may also appear inferiorly and may aid in localizing the culprit lesion.