Left Atrial Strain for assessment of left ventricle diastolic dysfunction in acute coronary syndrome patients.

INTRODUCTION: Patients with acute coronary syndrome (ACS) have a high incidence of Left ventricle diastolic dysfunction (DD). Latest algorithms for the assessment of DD lay on 2D parameters and describe a grading to quantify its severity. However, there persists a "gray zone" of values in which DD remains indeterminate. AIM: to analyze the diagnostic value of Left atrium strain (LAS) for categorization of LV DD and assessment of LV filling pressures in ACS patients. METHODS: Cross-sectional study that prospectively evaluated 105 patients presenting ACS with preserved LV ejection fraction (LVEF). Patients were divided in 4 groups according to the DD grade. Mean values of LAS, corresponding to three phases of atrial function: reservoir (LASr), conduit (LAScd) and contraction (LASct), were obtained by speckle-tracking echocardiography. RESULTS: Mean age was 60±10 years, with a gender ratio of 6.14. LASr and LASct were significantly lower according to DD severity (p combined=0.021, p combined=0.034; respectively). E/e' ratio was negatively correlated to LASr (r= - 0.251; p= 0.022) and LASct (r= -0.197; p=0.077). Left atrial volume index (LAVI) was also negatively correlated to LASr (r= -0.294, p= 0.006) and LASct (r= -0.3049, p=0.005). Peak tricuspid regurgitation was negatively correlated to LASr (r=-0.323, p=0.017) and LASct (r=-0.319, p=0.020). Patients presenting elevated LV filling pressures had lower LASr and LASct (p=0.049, p=0.022, respectively) compared to patients witn normal LV filling pressures. ROC curve analysis showed that a LASr < 22% (Se= 75%, Sp= 73%) and a LASct < 13% (Se= 71%, Sp=58%) can increase the likelihood of DD grade II or III by 4.6 (OR= 4.6; 95% CI: 1.31-16.2; p=0.016) and 3.7 (OR= 3.7; 95% CI: 1.06-13.1; p= 0.047), respectively. CONCLUSION: LAS is a valuable tool, which can be used to categorize DD in ACS patients.

Exercise response in post-acute coronary syndrome patients survived to COVID-19 infection.

AIMS: Many studies evaluated the functional response in post-Covid-19 patients; however, they systematically excluded patients with concomitant acute coronary syndrome (ACS). We evaluated the long-term functional capacity assessed by cardiopulmonary exercise test (CPET) in patients hospitalized for ACS and concomitant SARS-CoV2 infection. The secondary aim was to investigate the functional response in patients with symptoms related to "long COVID-19 syndrome" (LCS). METHODS: This cross-sectional case-control study compared 20 patients with ACS and concomitant SARS-COV2 infection with 20 patients without COVID-19. At the follow-up visit (between 6 and 12 months after revascularization procedure) all patients underwent a CPET. RESULTS: Patients with previous ACS and concomitant COVID-19 showed a reduced O2 consumption than controls (predicted peak V̇O2 74.00% vs 86.70%; p = 0.01) with a high degree of ventilatory inefficiency (VE/ V̇CO2 slope 38.04 vs 30.31; p = 0.002). 50% of subjects with previous COVID-19 disease showed symptoms related to "LCS"; this subgroup demarcates the characteristic reduced exercise capacity found in the entire COVID + group. CONCLUSIONS: This study is the first in literature having analyzed the long-term functional capacity phenotype in a population of ACS patients and concomitant SARS-CoV2 infection. Severe ventilatory inefficiency emerged as the functional signature of these patients. Moreover, the subset of patients with symptoms related to LCS has the most compromised long term reduced exercise capacity and an altered ventilation control.

Effect of Oral Care on Endothelial Dysfunction in Patients with Acute Coronary Syndrome.

Periodontitis is a common chronic infection and is associated with cardiovascular disease. This study evaluated whether basic oral care for periodontal disease could improve endothelial function in patients with acute coronary syndrome (ACS).This study enrolled 54 patients with acute coronary syndrome admitted to Kagoshima City Hospital and who had undergone percutaneous coronary intervention. Flow-mediated endothelium-dependent dilatation (FMD) was measured before discharge (initial FMD) and at 8 months after percutaneous coronary intervention (follow-up FMD). The following periodontal characteristics were measured: periodontal pocket depth (PPD, mm), plaque control record (%), and bleeding on probing (%). All patients received basic oral care instructions from dentists. The oral health condition was generally poor in the participants and there were 24 patients (44.4%) who had severe PPD. Despite the intervention of basic oral care, the periodontal characteristics did not improve during the study period; initial FMD and follow-up FMD did not significantly differ (4.38 ± 2.74% versus 4.56 ± 2.51%, P = 0.562). However, the follow-up FMD was significantly lower in patients with severe PPD (≥ 6.0 mm, n = 24) than in patients without severe PPD (≤ 5.0 mm, n = 30) (FMD: 3.58 ± 1.91% versus 5.37 ± 2.67%, P = 0.007). FMD tended to be worse in patients with severe PPD than in patients without severe PPD (ΔFMD: -0.55 ± 2.12 versus 0.81 ± 2.77 %, P = 0.055). In conclusion, during the use of basic oral care, endothelial function improved in patients without severe PPD, while it worsened in patients with severe PPD.

Plaque Ruptures Are Related to High Plaque Stress and Strain Conditions: Direct Verification by Using In Vivo OCT Rupture Data and FSI Models.

BACKGROUND: While it has been hypothesized that high plaque stress and strain may be related to plaque rupture, its direct verification using in vivo coronary plaque rupture data and full 3-dimensional fluid-structure interaction models is lacking in the current literature due to difficulty in obtaining in vivo plaque rupture imaging data from patients with acute coronary syndrome. This case-control study aims to use high-resolution optical coherence tomography-verified in vivo plaque rupture data and 3-dimensional fluid-structure interaction models to seek direct evidence for the high plaque stress/strain hypothesis. METHODS: In vivo coronary plaque optical coherence tomography data (5 ruptured plaques, 5 no-rupture plaques) were acquired from patients using a protocol approved by the local institutional review board with informed consent obtained. The ruptured caps were reconstructed to their prerupture morphology using neighboring plaque cap and vessel geometries. Optical coherence tomography-based 3-dimensional fluid-structure interaction models were constructed to obtain plaque stress, strain, and flow shear stress data for comparative analysis. The rank-sum test in the nonparametric test was used for statistical analysis. RESULTS: Our results showed that the average maximum cap stress and strain values of ruptured plaques were 142% (457.70 versus 189.22 kPa; P=0.0278) and 48% (0.2267 versus 0.1527 kPa; P=0.0476) higher than that for no-rupture plaques, respectively. The mean values of maximum flow shear stresses for ruptured and no-rupture plaques were 145.02 dyn/cm2 and 81.92 dyn/cm2 (P=0.1111), respectively. However, the flow shear stress difference was not statistically significant. CONCLUSIONS: This preliminary case-control study showed that the ruptured plaque group had higher mean maximum stress and strain values. Due to our small study size, larger scale studies are needed to further validate our findings.

Prospective Bidirectional Relationship Between Sleep Duration and Posttraumatic Stress Disorder Symptoms After Suspected Acute Coronary Syndrome.

OBJECTIVE: Sleep disturbance is a "hallmark" symptom of posttraumatic stress disorder (PTSD). Poor sleep (including short sleep) after combat-related trauma can also predict subsequent PTSD. Less is known about the association between sleep duration and PTSD symptoms when PTSD is induced by acute coronary syndrome (ACS). We examined the bidirectional relationship between sleep duration and PTSD symptoms over the year after hospital evaluation for ACS. METHODS: Participants were enrolled in this observational study after emergency department evaluation for ACS. Sleep duration ("During the past month, how many hours of actual sleep did you get at night?") and cardiac event or hospitalization-induced PTSD symptoms (PTSD Checklist) were assessed at 1, 6, and 12 months after hospital discharge. Cross-lagged path analysis was used to model the effects of sleep duration and PTSD symptoms on each other. Covariates included age, sex, race/ethnicity, cardiac severity, baseline depression symptoms, and early acute stress disorder symptoms. RESULTS: The sample included 1145 participants; 16% screened positive for probable PTSD (PTSD Checklist score ≥33). Mean sleep duration across time points was 6.1 hours. Higher PTSD symptoms predicted shorter sleep duration at the next time point (i.e., 1-6 and 6-12 months; B = -0.14 hours/10-point difference, SE = 0.03, p < .001). Shorter sleep duration was associated with higher PTSD symptoms at the next time point (B = -0.25 points/hour, SE = 0.12, p = .04). CONCLUSIONS: Short sleep duration and PTSD symptoms are mutually reinforcing across the first year after ACS evaluation. Findings suggest that sleep, PTSD symptoms, and their relationship should be considered in the post-ACS period.

Pseudo precordial ST-segment depression.

We present a case with acute coronary syndrome and very unusual QRS widening in the acute phase. The case highlights that non-specific intraventricular conduction delay should be considered as a high risk ECG pattern predicting poor prognosis.

An update on the mechanisms of Takotsubo syndrome: "At the end an acute coronary syndrome".

Takotsubo syndrome (TTS) is an acute reversible form of myocardial dysfunction, often preceded by a physical or emotional stressful event, that acts as a trigger. Despite, recent advances in the comprehension of the mechanisms leading to TTS, its pathophysiology is far from being completely understood. However, several studies seem to suggest that an acute coronary microvascular dysfunction may represent a crucial pathogenic mechanism involved in TTS occurrence. In this article, we aim to review the complex pathophysiology of TTS and the possible different mechanisms underlying this clinical condition, focusing on the role of coronary microvascular dysfunction and the remaining knowledge's gaps in the field.

Atrial fibrillation de novo in acute coronary syndrome.

One of the complications during an acute coronary syndrome event is the presence of arrhythmias. Among them, those of the supraventricular type, especially atrial fibrillation, carry a poor prognosis both in the short and long term, being the cause of situations such as cerebrovascular event, ventricular arrhythmias, and increased mortality. The arrhythmia tends to appear in a certain population group with particular risk factors during the index event in approximately 10% of cases. Appropriate treatment at the time of its onset, thanks to the use of drugs that modulate heart rate, rhythm, and anticoagulant management in the most vulnerable groups, will lead to a less bleak outcome for these patients.

Una de las complicaciones durante un evento de síndrome coronario agudo es la presencia de arritmias. Dentro de ellas, las de tipo supraventricular, en especial fibrilación auricular, acarrea un mal pronóstico tanto a corto como a largo plazo y es la causa de situaciones como evento vascular cerebral, arritmias ventriculares y aumento de la mortalidad. Dicha arritmia tiende a aparecer en cierto grupo de población con particulares factores de riesgo durante el evento índice en aproximadamente 10% de los casos. Un tratamiento apropiado en el momento de su aparición, gracias al uso de fármacos que modulan la frecuencia cardiaca, el ritmo y el manejo anticoagulante en los grupos más vulnerables conllevará un desenlace menos sombrío para estos pacientes.

Baseline coronary artery stenosis severity is an independent predictor of subsequent poor sleep quality in patients with acute coronary syndrome.

AIM: To investigate the relationship between coronary artery lesion severity determined using the baseline SYNTAX score and sleep problems that might occur after discharge determined using the Pittsburgh Sleep Quality Index (PSQI). METHODS: This prospective study included patients with first acute coronary syndrome (ACS) who underwent percutaneous coronary angiography between February 2019 and August 2019. The severity of coronary artery stenosis was classified according to coronary angiography and SYNTAX scores. Patients were grouped as those with a SYNTAX score of ≤22 and >22. Sleep quality after discharge was classified according to the PSQI. PSQI ≤5 represented good sleep quality, and PSQI >5 represented poor sleep quality. Univariate and multivariate logistic regression was used to investigate the relationship between sleep quality and coronary artery stenosis severity. RESULTS: A total of 424 patients were included in the study. Of these, 294 (69.34%) had a SYNTAX score of ≤22 and 130 (30.66%) had a SYNTAX score of >22. The mean age of all patients was 60.37 ±â€…12.23 years, 59.69 ±â€…11.85 years in the SYNTAX ≤22 groups and 61.90 ±â€…12.98 years in the SYNTAX >22 group (P = 0.086). The majority (78.54%) of the patients were male and there was no significant difference between the SYNTAX ≤22 group and the SYNTAX >22 group in terms of sex distribution (P = 0.383). According to the univariate logistic regression analysis, age (P = 0.014), diabetes (P = 0.027), left ventricular ejection fraction (P = 0.001), estimated glomerular filtration rate (P = 0.039), creatine kinase MB (P = 0.040) and SYNTAX scores (P < 0.001) were significantly associated with high PSQI global scores (>5). However, according to the multivariate logistic regression analysis results, high (>22) SYNTAX scores were the only factor independently associated with the high (>5) PSQI global scores [odds ratio, 3.477; 95% confidence interval (CI), (2.190-5.522); P < 0.001]. Complete revascularization group had significantly higher sleep latency and sleep duration time, sleep efficiency and the percentage of patients with PSQI global score of ≤5 than the incomplete revascularization group (P < 0.001 for all). CONCLUSION: Among patients with ACS, those with high SYNTAX scores should be monitored more carefully for sleep disorders that may occur later.

Non-invasive vascular measures as prognostic predictors for older patients with non-ST elevation acute coronary syndrome.

BACKGROUND: Adverse cardiac events are common in older patients with non-ST elevation acute coronary syndrome (NSTEACS), yet prognostic predictors are still lacking. This study investigated the long-term prognostic significance of non-invasive measures including endothelial function, carotid intima-media thickness (CIMT), and vascular stiffness in older NSTEACS patients referred for invasive treatment. METHODS: NSTEACS patients aged 75 years and older recruited to a multicentre cohort study (NCT01933581) were assessed for baseline endothelial function using endoPAT logarithm of reactive hyperemia index (LnRHI), CIMT using B-mode ultrasound, and vascular stiffness using carotid-femoral pulse wave velocity (cfPWV). Long-term outcomes included major adverse cardiovascular events (MACE), a composite of death, reinfarction, urgent revascularization, stroke/transient ischemic attack, and significant bleeding. RESULTS: Recruitment resulted in 214 patients assessed for LnRHI, 190 patients assessed for CIMT and 245 patients assessed for cfPWV. For LnRHI group (median follow-up 4.73 years [IQR: 1.41-5.00]), Cox regression analysis revealed a trend towards increased risk of MACE (HR: 1.24 [95% CI: 0.80-1.93]; P  = 0.328) and mortality (HR: 1.49 [95% CI: 0.86-2.59]; P  = 0.157), but no significance was reached. No difference for other components of MACE was found. For CIMT group (median follow up 4.74 years [IQR: 1.55-5.00]), no statistically significant difference in MACE was found (HR: 0.92 [95% CI: 0.53-1.59]; P  = 0.754). Similarly, for cfPWV group (median follow-up 4.96 years [IQR: 1.55-5.00]), results did not support prognostic significance (for MACE, HR: 0.95 [95% CI: 0.65-1.39]; P  = 0.794). CONCLUSION: Endothelial function, CIMT and vascular stiffness were proven unsuitable as strong prognostic predictors in older patients with NSTEACS. CLINICAL TRIAL REGISTRATION: NCT01933581.

Electrocardiographic patterns and clinical outcomes of acute coronary syndrome cardiogenic shock in patients undergoing percutaneous coronary intervention - A propensity score analysis.

OBJECTIVES: To determine the influence of presenting electrocardiographic (ECG) changes on prognosis in acute coronary syndrome cardiogenic shock (ACS-CS) patients undergoing percutaneous coronary angiography (PCI). BACKGROUND: The effect of initial ECG changes such as ST-elevation myocardial infarction (STEMI) versus non-STEMI among patients ACS-CS on prognosis remains unclear. METHODS: We analysed data from consecutive patients with ACS-CS enrolled in the Victorian Cardiac Outcomes registry between 2014 and 2020. Inverse probability of treatment weighting analysis (IPTW) was used to assess the effect of ECG changes on 30-day mortality. RESULTS: Of 1564 patients with ACS-CS who underwent PCI, 161 had non-STEMI and 1403 had STEMI on ECG. The mean age was 66 ± 13 years, and 74 % (1152) were males. Patients with non-STEMI compared to STEMI were older (70 ± 12 vs 65 ± 13 years), had higher rates of diabetes (34 % vs 21 %), prior coronary artery bypass graft surgery (14 % vs 3.3 %), peripheral arterial disease (10.6 % vs 4.1 %, p < 0.01), and lower baseline eGFR (53.8 [37.1, 75.4] vs 65.3 [46.3, 87.8] ml/min/1.73m2), all p ≤ 0.01. Non-STEMI patients were more likely to have a culprit left circumflex artery (29 % vs 20 %) and more often underwent multivessel percutaneous coronary intervention (30 % vs 20 %) but had lower rates of out-of-hospital cardiac arrest (21 % vs 39 %), all p ≤ 0.01. Propensity score analysis with IPTW confirmed that non-STEMI ECG was associated with lower odds for 30-day all-cause mortality (OR 0.47 [0.32, 0.69], p < 0.001), and 30-day major adverse cardiovascular and cerebrovascular events (OR 0.48 [0.33, 0.70]). CONCLUSIONS: In patients undergoing PCI, Non-STEMI as compared to STEMI on index ECG was associated with approximately half the relative risk of both 30-day mortality and 30-day MACCE and could be a useful variable to integrate in ACS-CS risk scores.

Left atrial strain is associated with long-term mortality in acute coronary syndrome patients.

To investigate the long-term prognostic value of the left atrial (LA) strain indices - peak atrial longitudinal strain (PALS), peak conduit strain (PCS), and peak atrial contractile strain (PACS) in acute coronary syndrome (ACS) patients in relation to all-cause mortality. This retrospective study included ACS patients treated with percutaneous coronary intervention (PCI) and examined with echocardiography. Exclusion criteria were non-sinus rhythm during echocardiography, missing images, and inadequate image quality for 2D speckle tracking analysis of the LA. The endpoint was all-cause death. Multivariable Cox regression which included relevant clinical and echocardiographic measures was utilized to assess the relationship between LA strain parameters and all-cause mortality. A total of 371 were included. Mean age was 64 years and 76% were male. Median time to echocardiography was 2 days following PCI. During a median follow-up of 5.7 years, 83 (22.4%) patients died. Following multivariable analysis, PALS (HR 1.04, 1.01-1.06, p = 0.002, per 1% decrease) and PCS (HR 1.05, 1.01-1.09, p = 0.006, per 1% decrease) remained significantly associated with all-cause mortality. PALS and PCS showed a linear relationship with the outcome whereas PACS was associated with the outcome in a non-linear fashion such that the risk of death increased when PACS < 18.22%. All LA strain parameters remained associated with worse survival rate when restricting analysis to patients with left atrial volume index < 34 ml/m2. Reduced LA function as assessed by PALS, PCS, and PACS were associated with an increased risk of long-term mortality in patients with ACS.

The Long-Term Prognostic Role of Nighttime Resting Heart Rate in Obstructive Sleep Apnea in Patients with Acute Coronary Syndrome.

AIM: A close relationship exists between resting heart rate (RHR) and obstructive sleep apnea (OSA). Still, the prognostic importance of nighttime RHR in patients with acute coronary syndrome (ACS) with or without OSA remains unclear. METHODS: In this prospective cohort study, OSA was defined as an apnea-hypopnea index of ≥ 15 events/h, and the high nighttime RHR (HNRHR) was defined as a heart rate of ≥ 70 bpm. The primary endpoint was a major adverse cardiovascular and cerebrovascular event (MACCE), including cardiovascular death, myocardial infarction, stroke, ischemia-driven revascularization, or hospitalization for heart failure. RESULTS: Among the 1875 enrolled patients, the mean patient age was 56.3±10.5 years, 978 (52.2%) had OSA, and 425 (22.7%) were in HNRHR. The proportion of patients with HNRHR is higher in the OSA population than in the non-OSA population (26.5% vs. 18.5%; P＜0.001). During 2.9 (1.5, 3.5) years of follow-up, HNRHR was associated with an increased risk of MACCE in patients with OSA (adjusted HR: 1.56, 95% CI: 1.09-2.23, P=0.014), but not in patients without OSA (adjust HR: 1.13, 95% CI: 0.69-1.84, P=0.63). CONCLUSIONS: In patients with ACS, a nighttime RHR of ≥ 70 bpm was associated with a higher risk of MACCE in those with OSA but not in those without it. This identifies a potential high-risk subgroup where heart rate may interact with the prognosis of OSA. Further research is needed to determine causative relationships and confirm whether heart rate control impacts cardiovascular outcomes in patients with ACS-OSA.

Leg strength and incidence of heart failure in patients with acute coronary syndrome.

AIMS: The risk of developing heart failure (HF) after acute coronary syndrome (ACS) remains high. It is unclear whether skeletal muscle strength, in addition to existing risk factors, is a predictor for developing HF after ACS. We aimed to clarify the relationship between quadriceps isometric strength (QIS), a skeletal muscle strength indicator, and the risk of developing HF in patients with ACS. METHODS AND RESULTS: We included 1053 patients with ACS without a prior HF or complications of HF during hospitalization. The median (interquartile range) age was 67 (57-74) years. The patients were classified into two groups-high and low QIS-using the sex-specific median QIS. The endpoint was HF admissions. During a mean follow-up period of 4.4 ± 3.7 years, 75 (7.1%) HF admissions were observed. After multivariate adjustment, a high QIS was associated with a lower risk of HF [hazard ratio: 0.52, 95% confidence interval (CI): 0.32-0.87]. Hazard ratio (95% CI) per 5% body weight increment increase of QIS for HF incidents was 0.87 (0.80-0.95). Even when competing risks of death were taken into account, the results did not change. The inclusion of QIS was associated with increases in net reclassification improvement (0.26; 95% CI: 0.002-0.52) and an integrated discrimination index (0.01; 95% CI: 0.004-0.02) for HF. CONCLUSION: The present study showed that a higher level of QIS was strongly associated with a lower risk of developing HF after ACS. These findings suggest that skeletal muscle strength could be one of the factors contributing to the risk of developing HF after ACS.

The risk of developing heart failure (HF) after acute coronary syndrome (ACS) remains high. Basic attributes, coronary risk factors, and cardiac and renal function have been reported as risk factors for developing HF after ACS. However, the association between skeletal muscle strength and the development of HF after ACS is unclear. We included 1053 patients with ACS without a prior HF or complications of HF during hospitalization and used quadriceps isometric strength (QIS) as a measure of skeletal muscle strength. We found that higher QIS was associated with a lower risk of developing HF after ACS. The results of our study suggest the benefit of assessing skeletal muscle strength in addition to basic attributes, coronary risk factors, and cardiac and renal function to assess the risk of developing HF after ACS.

Angiogenic content of microparticles in patients with diabetes and coronary artery disease predicts networks of endothelial dysfunction.

BACKGROUND: Elevated endothelial microparticles (EMPs) levels are surrogate markers of vascular dysfunction. We analyzed EMPs with apoptotic characteristics and assessed the angiogenic contents of microparticles in the blood of patients with type 2 diabetes (T2D) according to the presence of coronary artery disease (CAD). METHODS: A total of 80 participants were recruited and equally classified as (1) healthy without T2D, (2) T2D without cardiovascular complications, (3) T2D and chronic coronary artery disease (CAD), and (4) T2D and acute coronary syndrome (ACS). MPs were isolated from the peripheral circulation, and EMPs were characterized using flow cytometry of CD42 and CD31. CD62E was used to determine EMPs' apoptotic/activation state. MPs content was extracted and profiled using an angiogenesis array. RESULTS: Levels of CD42- CD31 + EMPs were significantly increased in T2D with ACS (257.5 ± 35.58) when compared to healthy subjects (105.7 ± 12.96, p < 0.01). There was no significant difference when comparing T2D with and without chronic CAD. The ratio of CD42-CD62 +/CD42-CD31 + EMPs was reduced in all T2D patients, with further reduction in ACS when compared to chronic CAD, reflecting a release by apoptotic endothelial cells. The angiogenic content of the full population of MPs was analyzed. It revealed a significant differential expression of 5 factors in patients with ACS and diabetes, including TGF-ß1, PD-ECGF, platelet factor 4, serpin E1, and thrombospondin 1. Ingenuity Pathway Analysis revealed that those five differentially expressed molecules, mainly TGF-ß1, inhibit key pathways involved in normal endothelial function. Further comparison of the three diabetes groups to healthy controls and diabetes without cardiovascular disease to diabetes with CAD identified networks that inhibit normal endothelial cell function. Interestingly, DDP-IV was the only differentially expressed protein between chronic CAD and ACS in patients with diabetes. CONCLUSION: Our data showed that the release of apoptosis-induced EMPs is increased in diabetes, irrespective of CAD, ACS patients having the highest levels. The protein contents of MPs interact in networks that indicate vascular dysfunction.

Diagnosis and Treatment of Acute Coronary Syndromes: A Review.

IMPORTANCE: Acute coronary syndromes (ACS) are characterized by a sudden reduction in blood supply to the heart and include ST-segment elevation myocardial infarction (STEMI), non-STEMI (NSTEMI), and unstable angina. Each year, an estimated more than 7 million people in the world are diagnosed with ACS, including more than 1 million patients hospitalized in the US. OBSERVATIONS: Chest discomfort at rest is the most common presenting symptom of ACS and affects approximately 79% of men and 74% of women presenting with ACS, although approximately 40% of men and 48% of women present with nonspecific symptoms, such as dyspnea, either in isolation or, more commonly, in combination with chest pain. For patients presenting with possible ACS, electrocardiography should be performed immediately (within 10 minutes of presentation) and can distinguish between STEMI and non-ST-segment elevation ACS (NSTE-ACS). STEMI is caused by complete coronary artery occlusion and accounts for approximately 30% of ACS. ACS without significant ST-segment elevation on electrocardiography, termed NSTE-ACS, account for approximately 70% of ACS, are caused by partial or intermittent occlusion of the artery and are associated with ST-segment depressions (approximately 31%), T-wave inversions (approximately 12%), ST-segment depressions combined with T-wave inversions (16%), or neither (approximately 41%). When electrocardiography suggests STEMI, rapid reperfusion with primary percutaneous coronary intervention (PCI) within 120 minutes reduces mortality from 9% to 7%. If PCI within 120 minutes is not possible, fibrinolytic therapy with alteplase, reteplase, or tenecteplase at full dose should be administered for patients younger than 75 years without contraindications and at half dose for patients 75 years or older (or streptokinase at full dose if cost is a consideration), followed by transfer to a facility with the goal of PCI within the next 24 hours. High-sensitivity troponin measurements are the preferred test to evaluate for NSTEMI. In high-risk patients with NSTE-ACS and no contraindications, prompt invasive coronary angiography and percutaneous or surgical revascularization within 24 to 48 hours are associated with a reduction in death from 6.5% to 4.9%. CONCLUSIONS AND RELEVANCE: Each year, an estimated more than 7 million people are diagnosed with ACS worldwide. For patients with STEMI, coronary catheterization and PCI within 2 hours of presentation reduces mortality, with fibrinolytic therapy reserved for patients without access to immediate PCI. For high-risk patients with NSTE-ACS without contraindications, prompt invasive coronary angiography followed by percutaneous or surgical revascularization is associated with lower rates of death.