Clinical and therapeutic profile of patients presenting with acute coronary syndromes who do not have significant coronary artery disease.The Platelet Glycoprotein IIb/IIIa in Unstable Angina: Receptor Suppression Using Integrilin Therapy (PURSUIT) Trial Investigators

Unstable Angina Risk Stratification Using High-Sensitivity Cardiac Troponin and Coronary Angiography

Patients formerly diagnosed with unstable angina (UA) are being reclassified as non-ST-elevation myocardial infarction with the widespread adoption of high-sensitivity troponin (hsTn) assays, leading to significant changes in the incidence and prognosis of UA. This study aimed to evaluate the value of hsTn and the presence of significant obstructive coronary artery disease (CAD) in the risk stratification of patients with UA. We conducted a retrospective, single-center study of 742 patients hospitalized for UA between 2016 and 2021. The primary end point of this study was all-cause mortality. The secondary outcome (major adverse cardiac events [MACEs]) was defined as a composite of nonfatal myocardial infarction (MI), hospitalization for heart failure (hHF), and repeated coronary angiography because of recurring UA (rUA) after the index event. The outcomes were assessed within 1 month, 1 year, and up to 5 years of follow-up. The average follow-up duration was 45 ± 24 months, and 37.2% (n = 276) of patients completed a 5-year follow-up. No in-hospital death was observed, and 6.9% of patients died during follow-up, which was more commonly a late event (>12 months). The composite secondary end point (MI+hHF+rUA) was observed in 16.7% of the patients. There were 3.2% nonfatal MI, 2.3% hHF, and 11.6% rUA during follow-up. We developed a risk model (UA mortality risk) using variables with the highest discriminatory power: age, hsTn, and ST-segment deviation. Our model performed well against the Global Registry of Acute Coronary Events and Thrombolysis in Myocardial Infarction risk scores in predicting death during follow-up. Obstructive CAD on coronary angiography was the only independent predictor of MACEs during follow-up. In conclusion, a contemporary cohort of patients with UA presented with favorable prognosis, particularly, within the first year after the index event. Nonsignificant increases in hsTn levels add to the risk stratification of patients with UA, and the presence of obstructive CAD was the only independent predictor of MACEs, highlighting the potential importance of assessing coronary anatomy.

The invasive investigation of INOCA in the coronary catheterization lab

Over half of all patients with angina have no angiographically demonstratable obstructive coronary disease, with a significant proportion of these patients having undiagnosed microvascular dysfunction and/or vasospastic angina. In chronic coronary syndrome, ischemia with non-obstructive coronary artery disease (INOCA) often remains undiagnosed, or uninvestigated. INOCAmay occur due to vasospastic angina and microvascular dysfunction and require invasive assessment in the coronary catheterization lab. To evaluate INOCA coronary flow reserve (CFR) and the index of microcirculatory resistance (IMR) are used to assess microvascular dysfunction before acetylcholine provocation testing for coronary spasm. This review provides an overview of the invasive investigation of INOCA in the coronary catheterization lab for patients with angina to be optimally managed.

Unstable Angina: Risk Stratification for Significant Coronary Artery Disease in The Era of High-Sensitivity Cardiac Troponin

Introduction

High-sensitivity troponin (hsTn) has a very high diagnostic accuracy for myocardial infarction (MI), and patients who were formerly diagnosed with unstable angina (UA) are being reclassified as having NSTEMI in the era of hsTn. This paradigm shift has changed the clinical features of UA, which remain poorly characterized, specifically the occurrence of obstructive coronary artery disease (CAD) and the need for myocardial revascularization. The main purpose of this study was to clinically characterize contemporary UA patients, assess predictors of obstructive CAD, and develop a risk model to predict significant CAD in this population.

Methods

We conducted a retrospective cohort study of 742 patients admitted to the hospital with UA. All patients underwent coronary angiography. The endpoint of the study was the presence of obstructive CAD on angiography. The cohort was divided into two groups: patients with significant coronary artery disease (CAD+) and those without CAD (CAD-). We developed a score (UA CAD Risk) based on the multivariate model and compared it with the GRACE, ESC, and TIMI risk scores using ROC analysis.

Results

Obstructive CAD was observed on angiography in 53% of the patients. Age, dyslipidemia, troponin level, male sex, ST-segment depression, and wall motion abnormalities on echocardiography were independent predictors of obstructive CAD. hsTn levels (undetectable vs. nonsignificant detection) had a negative predictive value of 81% to exclude obstructive CAD. We developed a prediction model with obstructive CAD as the outcome (AUC: 0.60).

Conclusions

In a contemporary UA cohort, approximately 50% of the patients did not have obstructive CAD on angiography. Commonly available cardiac tests at hospital admission show limited discrimination power in identifying patients at risk of obstructive CAD. A revised diagnostic and etiology algorithm for patients with UA is warranted.

Comparison of Long-Term Outcomes of Patients With Myocardia Infarction (MI) With Non-obstructive Coronary Arteries and MI With Obstructive Coronary Arteries: A Systematic Review and Meta-Analysis

The aim of this study was to compare long-term outcomes in patients with myocardial infarction with non-obstructive coronary arteries (MINOCA) and patients with myocardial infarction with obstructive coronary arteries (MIOCA). This meta-analysis was conducted according to the recommendations of the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA). The literature search was conducted in online databases including PubMed and Web of Science from 2010 onwards. Primary outcomes assessed in this meta-analysis included major adverse cardiovascular events (MACE) and all-cause mortality. Secondary outcomes included cardiovascular mortality and myocardial infarction. A total of 16 studies were included in the meta-analysis. Pooled analysis showed that the risk of MACE was higher in MIOCA patients (risk ratio (RR): 1.47, 95%CI: 1.43-1.52, p-value: 0.001) compared to MINOCA patients. Additionally, the risk of all-cause mortality was also significantly higher in MIOCA patients compared to MINOCA (RR: 1.33, 95%CI: 1.14-1.56, p-value: 0.001). Our findings also indicate that patients with MIOCA are at a significantly higher risk of recurrent myocardial infarction and cardiovascular-related mortality compared to patients with MINOCA. Overall, the insights gained from this meta-analysis have significant clinical implications, guiding decision-making in the management of patients with MINOCA.

Temporal Trends of the Prevalence of Angina With No Obstructive Coronary Artery Disease (ANOCA)

BACKGROUND

Angina with no obstructive coronary artery disease (ANOCA) is a common entity. There is still under-recognition of this condition, but it is unclear if the referral patterns for chest pain diagnosis have changed. We aimed to determine if the prevalence of patients diagnosed with ANOCA by means of coronary angiography has changed over time.

METHODS

A population-based cohort of patients who had their first coronary angiogram for a chest pain syndrome in Alberta from 1995 to 2020 was extracted retrospectively from the Alberta Provincial Project for Outcome Assessment in Coronary Heart Disease (APPROACH) database. A temporal trend analysis was performed to compare patients with ANOCA vs obstructive coronary artery disease (CAD), and the predictors of ANOCA were investigated.

RESULTS

In our analysis, 121,066 patients were included (26% ANOCA, 31% female, overall mean age 62 years). The percentages of ANOCA vs obstructive CAD ranged from 24.2% to 26.7% in all patients (P < 0.001), from 19.4% to 21.4% in patients with acute coronary syndromes (P = 0.002), and from 30.6% to 37.5% in patients with stable angina (P < 0.001). Independent predictors of ANOCA were female sex (odds ratio [OR] 3.34, 95% confidence interval [CI] 3.05-3.66), younger age (OR 0.96, 95% CI 0.95-0.96), history of atrial fibrillation (OR 2.18, 95% CI 1.73-2.73), and stable angina (vs myocardial infarction: OR 0.25, 95% CI 0.23-0.28; vs unstable angina: OR 0.79, 95% CI 0.70-0.89). Traditional cardiovascular risk factors were associated with obstructive CAD.

CONCLUSIONS

There remained a high prevalence of ANOCA detected during invasive coronary angiography, which remained stable over time. This study demonstrates an opportunity to exclude obstructive CAD with less invasive testing, particularly in women.

Antiplatelet agents for chronic kidney disease

BACKGROUND

Antiplatelet agents are widely used to prevent cardiovascular events. The risks and benefits of antiplatelet agents may be different in people with chronic kidney disease (CKD) for whom occlusive atherosclerotic events are less prevalent, and bleeding hazards might be increased. This is an update of a review first published in 2013.

OBJECTIVES

To evaluate the benefits and harms of antiplatelet agents in people with any form of CKD, including those with CKD not receiving renal replacement therapy, patients receiving any form of dialysis, and kidney transplant recipients.

SEARCH METHODS

We searched the Cochrane Kidney and Transplant Register of Studies up to 13 July 2021 through contact with the Information Specialist using search terms relevant to this review. Studies in the Register are identified through searches of CENTRAL, MEDLINE, and EMBASE, conference proceedings, the International Clinical Trials Register (ICTRP) Search Portal and ClinicalTrials.gov.

SELECTION CRITERIA

We selected randomised controlled trials of any antiplatelet agents versus placebo or no treatment, or direct head-to-head antiplatelet agent studies in people with CKD. Studies were included if they enrolled participants with CKD, or included people in broader at-risk populations in which data for subgroups with CKD could be disaggregated.

DATA COLLECTION AND ANALYSIS

Four authors independently extracted data from primary study reports and any available supplementary information for study population, interventions, outcomes, and risks of bias. Risk ratios (RR) and 95% confidence intervals (CI) were calculated from numbers of events and numbers of participants at risk which were extracted from each included study. The reported RRs were extracted where crude event rates were not provided. Data were pooled using the random-effects model. Confidence in the evidence was assessed using the Grading of Recommendations Assessment, Development and Evaluation (GRADE) approach.

MAIN RESULTS

We included 113 studies, enrolling 51,959 participants; 90 studies (40,597 CKD participants) compared an antiplatelet agent with placebo or no treatment, and 29 studies (11,805 CKD participants) directly compared one antiplatelet agent with another. Fifty-six new studies were added to this 2021 update. Seven studies originally excluded from the 2013 review were included, although they had a follow-up lower than two months. Random sequence generation and allocation concealment were at low risk of bias in 16 and 22 studies, respectively. Sixty-four studies reported low-risk methods for blinding of participants and investigators; outcome assessment was blinded in 41 studies. Forty-one studies were at low risk of attrition bias, 50 studies were at low risk of selective reporting bias, and 57 studies were at low risk of other potential sources of bias. Compared to placebo or no treatment, antiplatelet agents probably reduces myocardial infarction (18 studies, 15,289 participants: RR 0.88, 95% CI 0.79 to 0.99, I² = 0%; moderate certainty). Antiplatelet agents has uncertain effects on fatal or nonfatal stroke (12 studies, 10.382 participants: RR 1.01, 95% CI 0.64 to 1.59, I² = 37%; very low certainty) and may have little or no effect on death from any cause (35 studies, 18,241 participants: RR 0.94, 95 % CI 0.84 to 1.06, I² = 14%; low certainty). Antiplatelet therapy probably increases major bleeding in people with CKD and those treated with haemodialysis (HD) (29 studies, 16,194 participants: RR 1.35, 95% CI 1.10 to 1.65, I² = 12%; moderate certainty). In addition, antiplatelet therapy may increase minor bleeding in people with CKD and those treated with HD (21 studies, 13,218 participants: RR 1.55, 95% CI 1.27 to 1.90, I² = 58%; low certainty). Antiplatelet treatment may reduce early dialysis vascular access thrombosis (8 studies, 1525 participants) RR 0.52, 95% CI 0.38 to 0.70; low certainty). Antiplatelet agents may reduce doubling of serum creatinine in CKD (3 studies, 217 participants: RR 0.39, 95% CI 0.17 to 0.86, I² = 8%; low certainty). The treatment effects of antiplatelet agents on stroke, cardiovascular death, kidney failure, kidney transplant graft loss, transplant rejection, creatinine clearance, proteinuria, dialysis access failure, loss of primary unassisted patency, failure to attain suitability for dialysis, need of intervention and cardiovascular hospitalisation were uncertain. Limited data were available for direct head-to-head comparisons of antiplatelet drugs, including prasugrel, ticagrelor, different doses of clopidogrel, abciximab, defibrotide, sarpogrelate and beraprost.

AUTHORS' CONCLUSIONS

Antiplatelet agents probably reduced myocardial infarction and increased major bleeding, but do not appear to reduce all-cause and cardiovascular death among people with CKD and those treated with dialysis. The treatment effects of antiplatelet agents compared with each other are uncertain.

The Role of Antiplatelet Therapy in Patients With MINOCA

Myocardial infarction with non-obstructive coronary arteries (MINOCA) is a heterogeneous group of clinical entities characterized by the common clinical evidence of myocardial infarction (MI) with non-obstructive coronary arteries on coronary angiography and without an overt cause for the MI. Platelets play a cornerstone role in the pathophysiology of MI with obstructive coronary arteries. Accordingly, antiplatelet therapy is recommended for treating patients with MI and obstructive coronary disease. However, the role of platelets in the pathophysiology of MINOCA patients is not fully defined, questioning the role of antiplatelet therapy in this setting. In this review, we will assess the role of antiplatelet therapy in MINOCA with a focus on the pathophysiology, therapeutic targets, current evidence, and future directions according to its different etiologies.

Long-term outcomes of early-onset myocardial infarction with non-obstructive coronary artery disease (MINOCA)

BACKGROUND

Acute myocardial infarction with non-obstructive coronary artery disease (MINOCA) is frequent in patients experiencing an early-onset MI, but data concerning its long-term prognosis are limited and conflicting.

METHODS

The Italian Genetic Study on Early-onset MI enrolled 2000 patients experiencing a first MI before the age of 45 years, and had a median follow-up of 19.9 years. The composite primary endpoint was cardiovascular (CV) death, non-fatal MI, and non-fatal stroke (MACE); the secondary endpoint was rehospitalisation for coronary revascularisation.

RESULTS

MINOCA occurred in 317 patients (15.9%) and, during the follow-up, there was no significant difference in MACE rates between them and the patients with obstructive coronary artery disease (MICAD: 27.8% vs 37.5%; adjusted hazard ratio [HR] 0.79, 95% confidence interval [CI] 0.57-1.09;p = 0.15). The CV death rate was lower in the MINOCA group (4.2% vs 8.4%, HR 0.26, 95%CI 0.08-0.86;p = 0.03), whereas the rates of non-fatal reinfarction (17.3% vs 25.4%; HR 0.76, 95%CI 0.52-1.13;p = 0.18), non-fatal ischemic stroke (9.5% vs 3.7%; HR 1.79, 95%CI 0.87-3.70;p = 0.12), and all-cause mortality (14.1% vs 20.7%, HR 0.73, 95%CI 0.43-1.25;p = 0.26) were not significantly different in the two groups. The rate of rehospitalisation for coronary revascularisation was lower among the MINOCA patients (6.7% vs 27.7%; HR 0.27, 95% CI 0.15-0.47;p < 0.001).

CONCLUSIONS

MINOCA is frequent and not benign in patients with early-onset MI. Although there is a lower likelihood of CV death,the long-term risk of MACE and overall mortality is not significantly different from that of MICAD patients.

MINOCA: a heterogenous group of conditions associated with myocardial damage

Myocardial infarction with non-obstructive coronary arteries (MINOCA) was first described over 80 years ago. The term has been widely and inconsistently used in clinical practice, influencing various aspects of disease classification, investigation and management. MINOCA encompasses a heterogenous group of conditions that include both atherosclerotic and non-atherosclerotic disease resulting in myocardial damage that is not due to obstructive coronary artery disease. In many ways, it is a term that describes a moment in the diagnostic pathway of the patient and is arguably not a diagnosis. Central to the definition is also the distinction between myocardial infarction and injury. The universal definition of myocardial infarction distinguishes acute myocardial infarction, including those with MINOCA, from other causes of myocardial injury by the presence of clinical evidence of ischaemia. However, these ischaemic features are often non-specific causing diagnostic confusion, and can create difficulties for patient management and follow-up. The purpose of this review is to summarise our current understanding of MINOCA and highlight important issues relating to the diagnosis, investigation and management of patients with MINOCA.

ANMCO POSITION PAPER: Prognostic and therapeutic relevance of non-obstructive coronary atherosclerosis

Atherosclerosis often affects the coronary arterial tree. Frequently the disease does not translate in significant narrowing of the vessels, thus determining only a non-obstructive disease. This condition that is described as non-obstructive coronary artery disease (NobsCAD) should be distinguished from the absence of disease (i.e. smooth coronary arteries) as it carries a specific prognostic value. The detection and reporting of NobsCAD should prompt preventive measures that can be individualized upon the degree of the underlying burden of disease. The accompanying clinical condition, the other cardiovascular risk factors present, and the description of the severity and extent of NobsCAD should provide the framework for an individualized treatment that should also consider the best available scientific evidence and guidelines. The description of NobsCAD represents important information to be collected whenever a coronary angiogram (both invasive and non-invasive) is performed. Treating the patient according to the presence and extent of NobsCAD offers prognostic benefits well beyond those offered by considering only the traditional cardiovascular risk factors. In order to reach this goal, NobsCAD should not be confused with the absence of coronary atherosclerosis or even ignored when detected as if it was a trivial information to provide.

ST-segment elevation myocardial infarction with non-obstructive coronary arteries: Score derivation for prediction based on a large national registry

BACKGROUND

Acute myocardial infarction with ST-segment elevation (STEMI) and obstructive coronary arteries (MI-CAD) are treated with primary percutaneous coronary interventions (pPCI), while patients with STEMI and non-obstructive coronary arteries (MINOCA), usually require non-invasive therapy. The aim of the study is to design a score for predicting suspected MINOCA among an overall group of STEMI patients.

MATERIALS AND METHODS

Based on the Polish national registry of PCIs, we evaluated patients between 2014 and 2019, and selected 526,490 subjects treated with PCI and 650,728 treated using only coronary angiography. These subjects were chosen out of 1,177,218 patients who underwent coronary angiography. Then, we selected 124,663 individuals treated with pPCI due to STEMI and 5,695 patients with STEMI and MINOCA. The score for suspected MINOCA was created using the regression model, while the coefficients calculated for the final model were used to construct a predictive model in the form of a nomogram.

RESULTS

Patients with MINOCA differ significantly from those in the MI-CAD group; they were significantly younger, less often males and demonstrated smaller burden of concomitant diseases. The model allowed to show that patients who scored more than 600 points had a 19% probability of MINOCA, while for those scoring more than 650 points, the likelihood was 71%. The other end of the MINOCA probability scale was marginal for patients who scored less than 500 points (< .2%).

CONCLUSIONS

Based on the created MINOCA score presented in the current publication, we are able to distinguish MINOCA from MI-CAD patients in the STEMI group.

Cost-effectiveness Analysis of Anatomic vs Functional Index Testing in Patients With Low-Risk Stable Chest Pain

IMPORTANCE

Both noninvasive anatomic and functional testing strategies are now routinely used as initial workup in patients with low-risk stable chest pain (SCP).

OBJECTIVE

To determine whether anatomic approaches (ie, coronary computed tomography angiography [CTA] and coronary CTA supplemented with noninvasive fractional flow reserve [FFRCT], performed in patients with 30% to 69% stenosis) are cost-effective compared with functional testing for the assessment of low-risk SCP.

DESIGN, SETTING, AND PARTICIPANTS

This cost-effectiveness analysis used an individual-based Markov microsimulation model for low-risk SCP. The model was developed using patient data from the Prospective Multicenter Imaging Study for Evaluation of Chest Pain (PROMISE) trial. The model was validated by comparing model outcomes with outcomes observed in the PROMISE trial for anatomic (coronary CTA) and functional (stress testing) strategies, including diagnostic test results, referral to invasive coronary angiography (ICA), coronary revascularization, incident major adverse cardiovascular event (MACE), and costs during 60 days and 2 years. The validated model was used to determine whether anatomic approaches are cost-effective over a lifetime compared with functional testing.

EXPOSURE

Choice of index test for evaluation of low-risk SCP.

MAIN OUTCOMES AND MEASURES

Downstream ICA and coronary revascularization, MACE (death, nonfatal myocardial infarction), cost, quality-adjusted life-years (QALYs), and incremental cost-effectiveness ratio (ICER) of competing strategies.

RESULTS

The model cohort included 10 003 individual patients (median [interquartile range] age, 60.0 [54.4-65.9] years; 5270 [52.7%] women; 7693 [77.4%] White individuals), who entered the model 100 times. The Markov model accurately estimated the test assignment, results of anatomic and functional index testing, referral to ICA, revascularization, MACE, and costs at 60 days and 2 years compared with observed data in PROMISE (eg, coronary CTA: ICA, 12.2% [95% CI, 10.9%-13.5%] vs 12.3% [95% CI, 12.2%-12.4%]; revascularization, 6.2% [95% CI, 5.5%-6.9%] vs 6.4% [95% CI, 6.3%-6.5%]; functional strategy: ICA, 8.1% [95% CI, 7.4%-8.9%] vs 8.2% [95% CI, 8.1%-8.3%]; revascularization, 3.2% [95% CI, 2.7%-3.7%] vs 3.3% [95% CI, 3.2%-3.4%]; 2-year MACE rates: coronary CTA, 2.1% [95% CI, 1.7%-2.5%] vs 2.3% [95% CI, 2.2%-2.4%]; functional strategy, 2.2% [95% CI, 1.8%-2.6%] vs 2.4% [95% CI, 2.3%-2.4%]). Anatomic approaches led to higher ICA and revascularization rates at 60 days, 2 years, and 5 years compared with functional testing but were more effective in patient selection for ICA (eg, 60-day revascularization-to-ICA ratio, CTA: 53.7% [95% CI, 53.3%-54.0%]; CTA with FFRCT: 59.5% [95% CI, 59.2%-59.8%]; functional testing: 40.7% [95% CI, 40.4%-50.0%]). Over a lifetime, anatomic approaches gained an additional 6 months in perfect health compared with functional testing (CTA, 25.16 [95% CI, 25.14-25.19] QALYs; CTA with FFRCT, 25.14 [95% CI, 25.12-25.17] QALYs; functional testing, 24.68 [95% CI, 24.66-24.70] QALYs). Anatomic strategies were less costly and more effective; thus, CTA with FFRCT dominated and CTA alone was cost-effective (ICERs ranged from $1912/QALY for women and $3,559/QALY for men) compared with functional testing. In probabilistic sensitivity analyses, anatomic approaches were cost-effective in more than 65% of scenarios, assuming a willingness-to-pay threshold of $100 000/QALY.

CONCLUSIONS AND RELEVANCE

The results of this study suggest that anatomic strategies may present a more favorable initial diagnostic option in the evaluation of low-risk SCP compared with functional testing.

Risk of Myocardial Infarction in Patients Without Angiographic Coronary Artery Disease Compared With the General Population

We examined the 10-year risk of myocardial infarction (MI) and death in patients without obstructive coronary artery disease (CAD) compared with the general population. We conducted a cohort study of every patient without obstructive CAD by coronary angiography (CAG) between 2003 and 2016 in Western Denmark. Patients were matched by gender and age with individuals from the general population of Western Denmark with no history of CAD. End points were MI and death. Ten-year risk differences in cumulative incidence proportions were computed, accounting for the competing risk of death in the case of MI. Unadjusted and adjusted incidence rate ratios (aIRRs) were estimated using conditional Poisson regression. We included 46,467 patients and 234,654 individuals from the general population. Median follow-up was 7.7 years. The 10-year cumulative incidence of MI was 2.40% (95% confidence interval [CI] 2.24 to 2.57) in patients without obstructive CAD in the CAG and 2.70% (95% CI 2.62 to 2.78) in the general population, with a reduced absolute 10-year risk (risk difference -0.30%, 95% CI -0.49 to -0.12) and a reduced aIRR (aIRR 0.70, 95% CI 0.63 to 0.77). Ten-year mortality was higher in patients without obstructive CAD in the CAG (21.44%, 95% CI 20.99 to 21.89) compared with the general population (17.25%, 95% CI 17.06 to 17.44). However, mortality rates were similar after adjustment (aIRR 1.00, 95% CI 0.96 to 1.02). In conclusion, the absence of obstructive CAD according to CAG is associated with a lower risk of MI than in the general population, and similar 10-year mortality.

A review of diagnosis, etiology, assessment, and management of patients with myocardial infarction in the absence of obstructive coronary artery disease

Myocardial infarction (MI) in the absence of obstructive coronary artery disease (MINOCA) is prevalent in around 5% of acute myocardial infarction (AMI) presentations. MINOCA is a heterogeneous entity with many different etiologies. It is important for health care providers to familiarize themselves with the disease process, presentation, and possible underlying causes in order to guide appropriate management strategies. In this article, the authors review the contemporary definition, etiologies and assessment, and management for AMI patients with MINOCA.

Clinical Characteristics, Treatments, and Outcomes of Patients with Myocardial Infarction with Non-Obstructive Coronary Arteries (MINOCA): Results from a Multicenter National Registry

BACKGROUND

Diagnosis of myocardial infarction with non-obstructive coronary arteries (MINOCA) requires both clinical evidence of acute myocardial infarction (AMI) and demonstration of non-obstructive coronary arteries using angiography. We compared the clinical features, treatments, and three-year outcomes in patients with MINOCA and myocardial infarction with obstructive coronary artery disease (MI-CAD).

METHODS

We retrospectively analyzed data for 205,606 hospitalized patients with AMI. MINOCA was indicated as a working diagnosis in 6063 patients (2.94% of all AMI patients). For the control group we included 160,886 patients with MI-CAD. We evaluated the baseline characteristics, medication management options, outcomes, and readmission causes at 36 months follow-up.

RESULTS

Patients in the MINOCA group were younger. Females constituted a greater proportion of patients in the MINOCA group when compared to MI-CAD patients. STEMI during admission was diagnosed less frequently in the MINOCA group when compared to the MI-CAD group. All-cause mortality at 12 months was higher in the MINOCA group (10.94% vs. 9.54%, p < 0.001). At 36 months, there was no difference in the all-cause mortality rates (MINOCA 16.18% vs. MI-CAD 14.93%, p = 0.081). All-cause readmission rates were lower in the MINOCA group when compared to the MI-CAD group at both 12 months (45.19% vs. 54.33%, p < 0.001) and 36 months follow-up (56.42% vs. 66.66%, p < 0.001).

CONCLUSIONS

This is the first description of the clinical features, treatments, and three-year outcomes in a large population of Polish patients. The main finding of this study was a relatively low rate of MINOCA, with high rates of adverse events both at 12 and 36 months follow-up.

Optical Coherence Tomography for the Diagnosis of Exercise-Related Acute Cardiovascular Events and Inconclusive Coronary Angiography

Objectives

The aim of this study is to assess the utility of optical coherence tomography (OCT) in patients with exercise-related acute coronary syndrome (ACS) presenting with inconclusive angiographic findings.

Background

Regular physical activity reduces the incidence of cardiovascular events. Nevertheless, the risk of ACS or sudden cardiac death (SCD) increases during sport. In adults older than 35 years, exercise-related ACS or SCD is associated with plaque rupture, but not infrequently patients present ambiguous angiographic findings.

Methods

Between September 2015 and January 2020, patients admitted for ACS or SCD triggered by physical exertion and with coronary stenosis ≤50% were included in this prospective observational study. OCT was performed on the artery deemed to be responsible of the event.

Results

Ten patients were enrolled, predominantly men (80%) of middle age (51 years old, IQR 41–63) with low cardiovascular risk burden. Cycling was the most frequent (50%) exercise-related trigger, 8 patients were regular sport practitioners, and 7 had the clinical event during strenuous exertion. Five patients presented with non-ST-elevation ACS, two with ST-elevation ACS, and three with SCD. Angiographic analysis showed nonsignificant stenosis in all patients (42% stenosis, IQR 36–46). OCT identified the etiology of the event in 9 patients (4 plaque erosion, 3 plaque rupture, 1 eruptive calcific nodule, and 1 coronary dissection). Treatment was adjusted according to OCT findings.

Conclusions

OCT is a valuable technique to identify the etiology of exercise-related ACS or SCD in patients with nonobstructive coronary arteries and, as a result, may lead to a more specific treatment.

Associations of antithrombotic agent use with clinical outcomes in critically ill patients with troponin I elevation in the absence of acute coronary syndrome

Introduction

To evaluate efficacy of antithrombotic agents in critically ill patients with elevated troponin I level during intensive care unit (ICU) admission.

Methods and results

It was a retrospective observational study which was conducted in a tertiary teaching hospital in Taipei, Taiwan. All patients hospitalized in ICU for >3 days and with available serum troponin I data from December 2015 to July 2017 were included. Patients with definite diagnosis of acute myocardial infarction (AMI) were excluded. We divided patients with troponin I elevation into three groups; no prescription, chronic prescription and new prescription of antithrombotic agents during ICU admission. We defined new prescription when patients were on antithrombotic agents, including antiplatelet agents, direct oral anticoagulants, and warfarin after troponin I was found to be elevated at ICU admission and chronic prescription, if antithrombotic agents were on medication list more than 30 days before ICU admission. Primary outcomes were 30-day and one-year all-cause mortality. Of 597 subjects who met inclusion criteria, 407 (68%) patients had elevated troponin I (>0.1 ng/mL) on ICU admission. These patients had increased 30-day [hazard ratio (HR), 1.679; 95% confidence interval (CI), 1.132–2.491; p = 0.009] and one-year (HR, 1.568; 95% CI, 1.180–2.083; p = 0.002) all-cause mortality compared with those without elevated troponin I. In patients with elevated troponin I, there was no significant difference of 30-day all-cause mortality among three groups (p = 0.051) whereas patients on chronic prescription showed significant survival benefit in one-year all-cause mortality when compared to those without or with new prescription (p = 0.008).

Conclusions

In critically ill patients, elevated troponin I in the absence of AMI was associated with poor prognosis. Newly prescribed antithrombotic agents in ICU didn’t reveal the difference in short and long-term prognosis while chronic antithrombotic agent use was associated with better one-year survival rate, suggesting that these drugs play a protective role in this high-risk population.

A Review of the Evidence for Treatment of Myocardial Infarction With Nonobstructive Coronary Arteries

Myocardial infarction (MI) with non-obstructive coronary arteries (MINOCA) is reported in 6% of patients with acute MI referred for catheterization. Because of the complex etiology and a limited amount of evidence, the treatment of MINOCA remains elusive. The etiology of MINOCA manifests from several causes including plaque disruption or erosion, epicardial coronary artery vasospasm, and coronary microvascular dysfunction. In addition, spontaneous coronary artery dissection, takotsubo, and myocarditis have been identified as contributing to the diagnosis of MINOCA. Patients with MINOCA are frequently young, non-white females with fewer traditional risk factors compared with those with an MI caused by obstructive coronary disease. Moreover, women who suffered an MI are 5 times more likely to be diagnosed with MINOCA with a trend for worse outcomes compared with men. The increased recognition/diagnosis of MINOCA has highlighted a gap in our understanding of the treatment of MINOCA. This review identified that there is a paucity of evidence on treatment strategies for patients clinically diagnosed with MINOCA, but more importantly that MINOCA should be viewed as a "syndrome" with many different pathologic causes. This suggests that a standard protocol may not be useful for patients with MINOCA. Given the ongoing debate over the complexity of MINOCA, the main focus in the management of MINOCA should be to identify the underlying mechanism for targeted therapies that may optimize outcomes.

Guidelines for the management of myocardial infarction/injury with non-obstructive coronary arteries (MINOCA): a position paper from the Dutch ACS working group

Patients with myocardial infarction and non-obstructive coronary arteries (MINOCA), defined as angiographic stenosis <50%, represent a conundrum given the many potential underlying aetiologies. Possible causes of MINOCA can be subdivided into coronary, myocardial and non-cardiac disorders. MINOCA is found in up to 14% of patients presenting with an acute coronary syndrome. Clinical outcomes including mortality, and functional and psychosocial status, are comparable to those of patients with myocardial infarction and obstructive coronary arteries. However, many uncertainties remain regarding the definition, clinical features and management of these patients. This position paper of the Dutch ACS working group of the Netherlands Society of Cardiology aims to stress the importance of considering MINOCA as a dynamic working diagnosis and to guide the clinician in the management of patients with MINOCA by proposing a clinical diagnostic algorithm.

Expanding Access to Lung Cancer Clinical Trials by Reducing the Use of Restrictive Exclusion Criteria: Perspectives of a Multistakeholder Working Group

Low rates of adult patient participation have been a persistent problem in cancer clinical trials and have continued to be a barrier to efficient drug development. The routine use of significant exclusion criteria has contributed to this problem by limiting participation in studies and creating significant clinical differences between the study cohorts and the real-world cancer patient populations. These routine exclusions also unnecessarily restrict opportunities for many patients to access potentially promising new therapies during clinical development. Multiple efforts are underway to broaden eligibility criteria, allowing more patients to enroll in studies and generating more robust data regarding the effect of novel therapies in the population at large. Focusing specifically on lung cancer as an example, a multistakeholder working group empaneled by the LUNGevity Foundation identified 14 restrictive and potentially outdated exclusion criteria that appear frequently in lung cancer clinical trials. As a part of the project, the group evaluated data from multiple recent lung cancer studies to ascertain the extent to which these 14 criteria appeared in study protocols and played a role in excluding patients (screen failures). The present report describes the working group's efforts to limit the use of these routine exclusions and presents clinical justifications for reducing the use of 14 criteria as routine exclusions in lung cancer studies, potentially expanding trial eligibility and improving the generalizability of the results from lung cancer trials.

Long-term health outcomes and cost-effectiveness of coronary CT angiography in patients with suspicion for acute coronary syndrome

BACKGROUND

Randomized trials have shown favorable clinical outcomes for coronary CT angiography (CTA) in patients with suspected acute coronary syndrome (ACS). Our goal was to estimate the cost-effectiveness of coronary CTA as compared to alternative management strategies for ACP patients over lifetime.

METHODS

Markov microsimulation model was developed to compare cost-effectiveness of competitive strategies for ACP patients: 1) coronary CTA, 2) standard of care (SOC), 3) AHA/ACC Guidelines, and 4) expedited emergency department (ED) discharge protocol with outpatient testing. ROMICAT-II trial was used to populate the model with low to intermediate risk of ACS patient data, whereas diagnostic test-, treatment effect-, morbidity/mortality-, quality of life- and cost data were obtained from the literature. We predicted test utilization, costs, 1-, 3-, 10-year and over lifetime cardiovascular morbidity/mortality for each strategy. We determined quality adjusted life years (QALY) and incremental cost-effectiveness ratio. Observed outcomes in ROMICAT-II were used to validate the short-term model.

RESULTS

Estimated short-term outcomes accurately reflected observed outcomes in ROMICAT-II as coronary CTA was associated with higher costs ($4,490 vs. $2,513-$4,144) and revascularization rates (5.2% vs. 2.6%-3.7%) compared to alternative strategies. Over lifetime, coronary CTA dominated SOC and ACC/AHA Guidelines and was cost-effective compared to expedited ED protocol ($49,428/QALY). This was driven by lower cardiovascular mortality (coronary CTA vs. expedited discharge: 3-year: 1.04% vs. 1.10-1.17; 10-year: 5.06% vs. 5.21-5.36%; respectively).

CONCLUSION

Coronary CTA in patients with suspected ACS renders affordable long-term health benefits as compared to alternative strategies.

Prognosis and Predictors of Mortality in Patients Suffering Myocardial Infarction With Non-Obstructive Coronary Arteries

Background Myocardial infarction with nonobstructive coronary arteries ( MINOCA ) is a heterogeneous disease entity. Its prognosis and predictor of mortality remain unclear. This study aimed to compare the prognosis between MINOCA and myocardial infarction with obstructive coronary artery disease and identify factors related to all-cause death in MINOCA using a nation-wide, multicenter, and prospective registry. Methods and Results Among 13 104 consecutive patients enrolled, patients without previous history of significant coronary artery disease who underwent coronary angiography were selected. The primary outcome was 2-year all-cause death. Secondary outcomes were cardiac death, noncardiac death, reinfarction, and repeat revascularization. Patients with MINOCA (n=396) and myocardial infarction with obstructive coronary artery disease (n=10 871) showed similar incidence of all-cause death (9.1% versus 8.8%; hazard ratio [ HR ], 1.04; 95% CI, 0.74-1.45; P=0.83). Risks of cardiac death, noncardiac death, and reinfarction were not significantly different between the 2 groups ( HR , 0.82; 95% CI , 0.53-1.28; P=0.38; HR , 1.55; 95% CI , 0.93-2.56; P=0.09; HR , 1.23; 95% CI , 0.65-2.31; P=0.38, respectively). MINOCA patients had lower incidence of repeat revascularization (1.3% versus 7.2%; HR , 0.17; 95% CI , 0.07-0.41; P<0.001). Results were consistent after multivariable regression and propensity-score matching. In a multivariate model, several significant predictors of all-cause death of MINOCA were found, including the nonuse of renin-angiotensin system blockers ( HR , 2.63; 95% CI , 1.08-6.25; P=0.033) and statins ( HR , 2.17; 95% CI , 1.04-4.54; P=0.039). Conclusions Patients with MINOCA and those with myocardial infarction with obstructive coronary artery disease had comparable clinical outcomes. Use of renin-angiotensin system blockers and statins was associated with lower mortality in patients with MINOCA .

Characteristics of patients with myocardial infarction with nonobstructive coronary arteries (MINOCA) from the ARIAM-SEMICYUC registry: development of a score for predicting MINOCA

Background

Acute myocardial infarction (AMI) with no evidence of relevant stenosis of the coronary artery, known as myocardial infarction (MI) with nonobstructive coronary arteries (MINOCA), has a prevalence of up to 14%. The various causes of MINOCA lead to damage of the myocardium, and there are marked differences in diagnoses, prognoses, and treatments. Although the number of patients affected is considerable owing to the high prevalence of acute coronary syndrome (ACS), the causes of MINOCA have received little attention with the result that some patients may not receive appropriate treatment. Awareness of this disease among clinicians has started only to improve since the beginning of the current century. The aim of this study was to develop a score that enables patients with MINOCA to be distinguished from patients with MI with coronary artery disease (MI-CAD) and thus to facilitate appropriate diagnosis and therapy.

Patients and methods

A multicenter observational cohort study was designed. All patients aged ≥18 years from the ARIAM-SEMICYUC (Analysis of Delay in AMI-Spanish Society of Intensive Care Medicine and Coronary Unit) registry, diagnosed with AMI, and admitted to critical care units or coronary care units (CCUs) were included. Patients were classified into two groups: MINOCA, comprising patients with no significant lesions on angiography, and MI-CAD, comprising patients with lesions of the coronary artery tree.

Results

A score based on standard variables to assess the probability of MINOCA on admission was designed, showing a maximum value corresponding to a 40% probability of MINOCA. The discriminative power of the model was 0.756 (P-value for the Hosmer-Lemeshow test was >0.05). At 30-day follow-up, the mortality rate was higher for MI-CAD patients.

Conclusion

Patients with MINOCA constitute a population that differs from other patients with AMI. Their differential characteristics require a certain diagnostic effort to align therapy with the disease causing the ischemic event. This score could prove useful in establishing additional diagnostic procedures.

Chest pain CT in the Emergency Department: evaluating the coronary arteries even when not specifically asked for?

Background Computed tomography (CT) for excluding acute aortic syndrome (AAS) and pulmonary embolism (PE) simultaneously in patients with chest pain could be used to exclude coronary artery disease (CAD). Purpose To evaluate the frequency of further testing for CAD in patients receiving a CT in the emergency department (ED) for simultaneous evaluation for AAS and PE. Material and Methods This retrospective study was conducted over a three-year period including all patients with acute chest pain visiting our ED. All patients were included that received an electrocardiography (ECG)-gated CT of the entire chest enquiring simultaneously for AAS and PE. Those patients were followed up for 30 days after their initial ED visit whether they received further testing for CAD. Results Within the study period, a total of 157 patients with acute chest pain received a chest pain CT for simultaneous evaluation of both AAS and PE. Image quality was deemed sufficient to evaluate the coronary arteries in 80% of the patients. Thirty-seven patients (24%) underwent additional testing for CAD within 30 days of their ED visit, including catheter coronary angiography (n = 25), cardiac-stress single-photon emission-CT (n = 6), and cardiac magnetic resonance imaging (MRI) (n = 6). Conclusion Of patients presenting to the ED with acute chest pain who received a chest pain CT for simultaneous evaluation of AAS and PE, 24% had further imaging for CAD within 30 days of the initial ED visit. Immediate evaluation of the coronary arteries as part of a chest pain CT should be considered here for not delaying diagnosis.

Presentation, Clinical Profile, and Prognosis of Young Patients With Myocardial Infarction With Nonobstructive Coronary Arteries (MINOCA): Results From the VIRGO Study

BACKGROUND

We compared the clinical characteristics and outcomes of young patients with myocardial infarction with nonobstructive coronary arteries (MINOCA) versus obstructive disease (myocardial infarction due to coronary artery disease [MI-CAD]) and among patients with MINOCA by sex and subtype.

METHODS AND RESULTS

Between 2008 and 2012, VIRGO (Variation in Recovery: Role of Gender on Outcomes of Young AMI Patients) prospectively enrolled acute myocardial infarction patients aged 18 to 55 years in 103 hospitals at a 2:1 ratio of women to men. Using an angiographically driven taxonomy, we defined patients as having MI-CAD if there was revascularization or plaque ≥50% and as having MINOCA if there was <50% obstruction or a nonplaque mechanism. Patients who did not have an angiogram or who received thrombolytics before an angiogram were excluded. Outcomes included 1- and 12-month mortality and functional (Seattle Angina Questionnaire [SAQ]) and psychosocial status. Of 2690 patients undergoing angiography, 2374 (88.4%) had MI-CAD, 299 (11.1%) had MINOCA, and 17 (0.6%) remained unclassified. Women had 5 times higher odds of having MINOCA than men (14.9% versus 3.5%; odds ratio: 4.84; 95% confidence interval, 3.29-7.13). MINOCA patients were more likely to be without traditional cardiac risk factors (8.7% versus 1.3%; P<0.001) but more predisposed to hypercoaguable states than MI-CAD patients (3.0% versus 1.3%; P=0.036). Women with MI-CAD were more likely than those with MINOCA to be menopausal (55.2% versus 41.2%; P<0.001) or to have a history of gestational diabetes mellitus (16.8% versus 11.0%; P=0.028). The MINOCA mechanisms varied: a nonplaque mechanism was identified for 75 patients (25.1%), and their clinical profiles and management also varied. One- and 12-month mortality with MINOCA and MI-CAD was similar (1-month: 1.1% and 1.7% [P=0.43]; 12-month: 0.6% and 2.3% [P=0.68], respectively), as was adjusted 12-month SAQ quality of life (76.5 versus 73.5, respectively; P=0.06).

CONCLUSIONS

Young patients with MINOCA were more likely women, had a heterogeneous mechanistic profile, and had clinical outcomes that were comparable to those of MI-CAD patients.

CLINICAL TRIAL REGISTRATION

URL: http://www.clinicaltrials.gov. Unique identifier: NCT00597922.

Editor's Choice- Pathophysiology, diagnosis and management of MINOCA: an update

Myocardial infarction with non-obstructive coronary arteries (MINOCA) is a syndrome with different causes, characterised by clinical evidence of myocardial infarction with normal or near-normal coronary arteries on angiography. Its prevalence ranges between 5% and 25% of all myocardial infarction. The prognosis is extremely variable, depending on the cause of MINOCA. The key principle in the management of this syndrome is to clarify the underlying individual mechanisms to achieve patient-specific treatments. Clinical history, electrocardiogram, cardiac enzymes, echocardiography, coronary angiography and left ventricular angiography represent the first level diagnostic investigations to identify the causes of MINOCA. Regional wall motion abnormalities at left ventricular angiography limited to a single epicardial coronary artery territory identify an 'epicardial pattern'whereas regional wall motion abnormalities extended beyond a single epicardial coronary artery territory identify a 'microvascular pattern'. The most common causes of MINOCA are represented by coronary plaque disease, coronary dissection, coronary artery spasm, coronary microvascular spasm, Takotsubo cardiomyopathy, myocarditis, coronary thromboembolism, other forms of type 2 myocardial infarction and MINOCA of uncertain aetiology. This review aims at summarising the diagnosis and management of MINOCA, according to the underlying physiopathology.

Cardiac CT in the Emergency Department: Contrasting Evidence from Registries and Randomized Controlled Trials

PURPOSE OF REVIEW

To compare outcomes between registries and randomized controlled trials of coronary computed tomographic angiography (CCTA)-based versus standard of care approaches to the initial evaluation of patients with acute chest pain.

RECENT FINDINGS

Randomized trials have demonstrated CCTA to be a safe and efficient tool for triage of low- to intermediate-risk patients presenting to the emergency department with chest pain. Recent studies demonstrate heterogeneous result using different standard of care approaches for evaluation of hard endpoints in comparison with standard evaluation. Also, there has been continued concern for increase in subsequent testing after coronary CTA. Although CCTA improves detection of coronary artery disease, it is uncertain if it will bring improvement of long-term health outcomes at this point of time. Careful analysis of the previous results and further investigation will be required to validate evaluation of hard endpoints.

Two-year Follow-up of Patients With Unstable Angina/Non-ST Segment Elevation Myocardial Infarction Undergoing Early Invasive Strategy: Predictors of Normal or Near-Normal Coronary Angiography and Mortality

BACKGROUND

Predictors of normal or near-normal coronary angiography (NONCAG) in patients with unstable angina/non-ST-elevation myocardial infarction (UA/NSTEMI) and their importance regarding the prognosis are not understood. Accordingly, we determined these predictors as well as mortality risk factors at 2-year follow-up of UA/NSTEMI patients managed by the early invasive strategy.

METHODS

We prospectively studied consecutive patients with UA/NSTEMI managed with the early invasive strategy at Tehran Heart Center, in 1-year period. Echocardiography was performed before coronary angiography (CAG) for all the patients. Baseline characteristics, laboratory parameters, echocardiographic findings, invasive treatment modalities, and survival status after 2 years of follow-up were collected. We identified the predictors of NONCAG in the first phase of the study and then the risk factors of mortality in the second phase.

RESULTS

In the study period, 298 patients including 211 (71%) males, with the age of 59.31 ± 10.72 years were enrolled. The following factors were predictors of NONCAG: the female sex (P < 0.001); negative family history of CAD (P = 0.028); Thrombolysis in Myocardial Infarction (TIMI) risk score (P < 0.001); and early transmitral flow velocity/mean mitral annular velocity (E/E'mean) (P = 0.003). The following items were significant protective factors against mortality: percutaneous coronary intervention (PCI) (P = 0.012), age (P = 0.001), and E/E'mean (P = 0.020).

CONCLUSION

Patients' baseline characteristics as well as echocardiographic data could help in predicting those with NONCAG and PCI can be considered as the treatment of strategy with the most protection against mortality.

Long-term prognosis of patients with non-ST-segment elevation myocardial infarction according to coronary arteries atherosclerosis extent on coronary angiography: a historical cohort study

BACKGROUND

Patients with non-ST-segment elevation myocardial infarction (NSTEMI) without obstructive coronary artery disease (CAD) are often managed differently than those with obstructive CAD, therefore we aimed in this study to examine the long-term prognosis of patients with NSTEMI according to the degree of CAD on coronary angiography (CAG).

METHODS

We examined 8.889 consecutive patients admitted for first time NSTEMI during 2000-2011, to whom CAG was performed. Patients were classified by CAG into: 0-vessel disease (0VD), diffuse atherosclerosis (DA) (0% < stenosis <50%), 1-vessel disease (1VD), 2VD, and 3VD with stenosis ≥50%. Follow-up period: 13 years (median 4.5).

RESULTS

One-year mortality for NSTEMI patients with 0VD was 3.7%, DA 5.7%, 1VD 2.5%, 2VD 4.8%, and 3VD 11.5%. Non-diabetic 0VD patients had higher risk of mortality than 1VD patients (HR:1.59; 95% CI:1.21-2.02; P < 0.001), while those with diabetes mellitus (DM) had not significantly different risk. In addition 0VD group had higher risk of heart failure (HF) (HR 1.61; 95% CI: 1.39-1.88; P < 0.001), and lower risk of recurrent MI (HR:0.55; 95% CI:0.39-0.77; P < 0.001) compared with 1VD. For patients with DA; mortality and HF risks were higher than 1VD and not different than 2VD, while recurrent MI risk was not different than 1VD and lower than 2VD. Finally, the DA group had higher risk of mortality if they had DM, higher risk of recurrent MI, and not different risk of HF and stroke compared with the 0VD group patients.

CONCLUSION

Patients with NSTEMI and non-obstructive CAD (both normal coronaries and diffuse atherosclerosis) have a comparable prognosis to patients with one- or two-vessel disease. Patients with diffuse atherosclerosis have worse prognosis than those with angiographically normal coronary arteries.

GRACE risk score: Sex-based validity of in-hospital mortality prediction in Canadian patients with acute coronary syndrome

BACKGROUND

Although there are sex differences in management and outcome of acute coronary syndromes (ACS), sex is not a component of Global Registry of Acute Coronary Events (GRACE) risk score (RS) for in-hospital mortality prediction. We sought to determine the prognostic utility of GRACE RS in men and women, and whether its predictive accuracy would be augmented through sex-based modification of its components.

METHODS

Canadian men and women enrolled in GRACE and Canadian Registry of Acute Coronary Events were stratified as ST-segment elevation myocardial infarction (STEMI) or non-ST-segment elevation ACS (NSTE-ACS). GRACE RS was calculated as per original model. Discrimination and calibration were evaluated using the c-statistic and Hosmer-Lemeshow goodness-of-fit test, respectively. Multivariable logistic regression was undertaken to assess potential interactions of sex with GRACE RS components.

RESULTS

For the overall cohort (n=14,422), unadjusted in-hospital mortality rate was higher in women than men (4.5% vs. 3.0%, p<0.001). Overall, GRACE RS c-statistic and goodness-of-fit test p-value were 0.85 (95% CI 0.83-0.87) and 0.11, respectively. While the RS had excellent discrimination for all subgroups (c-statistics >0.80), discrimination was lower for women compared to men with STEMI [0.80 (0.75-0.84) vs. 0.86 (0.82-0.89), respectively, p<0.05]. The goodness-of-fit test showed good calibration for women (p=0.86), but suboptimal for men (p=0.031). No significant interaction was evident between sex and RS components (all p>0.25).

CONCLUSIONS

The GRACE RS is a valid predictor of in-hospital mortality for both men and women with ACS. The lack of interaction between sex and RS components suggests that sex-based modification is not required.

Optimal secondary prevention medication use in acute myocardial infarction patients with nonobstructive coronary artery disease is modified by management strategy: insights from the TRIUMPH Registry

BACKGROUND

Patients with acute myocardial infarction (AMI) and nonobstructive coronary artery disease (nonobCAD) may be perceived to be at lower risk for cardiac events, relative to those with obstructive CAD (obCAD), and thus less likely to receive optimal preventive medications in the year following AMI.

HYPOTHESIS

We aimed to determine if AMI patients with nonobCAD, compared to obCAD, received lower rates of prevention medications in the year following AMI.

METHODS

We compared optimal prevention medication use at hospital discharge, 1, 6, and 12 months after hospitalization. Optimal medication use was defined as the receipt of all prevention medications for which that patient was eligible (eg, aspirin, clopidogrel, statins, β-blockers, and angiotensin-converting enzyme inhibitors/angiotensin receptor blockers). We used multivariable logistic regression analyses to determine the association between nonobCAD to medication use and adjusted for potential confounders.

RESULTS

Three thousand six hundred thirty AMI patients were studied, of whom 200 (5.2%) had nonobCAD. Fewer nonobCAD patients received optimal medication use compared to obCAD patients at discharge (31% vs 65%, P < 0.001), driven primarily by lower rates of clopidogrel use (40.5% vs 83.3%, P < 0.001). After adjustment for percutaneous coronary intervention (PCI), differences in medication use were similar at discharge and 1 year after hospitalization. Stratified analyses by receipt of PCI suggested patients confined to medical management had less optimal medication use, regardless of their CAD burden.

CONCLUSIONS

Lower rates of unadjusted optimal medication use were seen in nonobCAD patients, driven by low clopidogrel use among medically managed patients, suggesting improvement efforts should focus on these patients.

Prevalence and Prognosis of Nonobstructive Coronary Artery Disease in Patients Undergoing Coronary Angiography or Coronary Computed Tomography Angiography: A Meta-Analysis

OBJECTIVE

To evaluate the prevalence, clinical characteristics, and risk of cardiac events in patients with nonobstructive coronary artery disease (CAD).

PATIENTS AND METHODS

We searched PubMed, EMBASE, and the Cochrane Library from January 1, 1990, to November 31, 2015. Studies were included if they reported prevalence or prognosis of patients with nonobstructive CAD (≤50% stenosis) among patients with known or suspected CAD. Patients with nonobstructive CAD were further grouped as those with no angiographic CAD (0% or ≤20%) and those with mild CAD (>0% or >20% to ≤50%). Data were pooled using random effects modeling, and annualized event rates were assessed.

RESULTS

Fifty-four studies with 1,395,190 participants were included. The prevalence of patients with nonobstructive CAD was 67% (95% CI, 63%-71%) among patients with stable angina and 13% (95% CI, 11%-16%) among patients with non-ST-segment elevation acute coronary syndrome. The prevalence varied depending on sex, clinical setting, and risk profile of the population investigated. The risk of hard cardiac events (cardiac death or myocardial infarction) in patients with mild CAD was lower than that in patients with obstructive CAD (risk ratio, 0.28; 95% CI, 0.20-0.38) but higher than that in those with no angiographic CAD (risk ratio, 1.85; 95% CI, 1.52-2.26). The annualized event rates of hard cardiac events in patients with no angiographic CAD, mild CAD, and obstructive CAD were 0.3% (95% CI, 0.1%-0.4%), 0.7% (95% CI, 0.5%-1.0%), and 2.7% (95% CI, 1.7%-3.7%), respectively, among patients with stable angina and 1.2% (95% CI, 0.02%-2.3%), 4.1% (95% CI, 3.3%-4.9%), and 17.0% (95% CI, 8.4%-25.7%) among patients with non-ST-segment elevation acute coronary syndrome. The correlation between CAD severity and prognosis is consistent regardless of clinical presentation of all-cause death, myocardial infarction, total cardiovascular events, and revascularization.

CONCLUSION

Nonobstructive CAD is associated with a favorable prognosis compared with obstructive CAD, but it is not benign. The high prevalence and impaired prognosis of this population warrants further efforts to improve the risk stratification and management of patients with nonobstructive CAD.

Outcomes of Women and Men With Acute Coronary Syndrome Treated With and Without Percutaneous Coronary Revascularization

Background

Women hospitalized with a non‐ST segment elevation acute coronary syndrome (ACS) have worse clinical outcomes compared with men. An early invasive strategy with prompt coronary revascularization may mitigate sex differences in outcomes. However, few contemporary studies have evaluated whether clinical outcomes differ between women and men presenting with ACS treated with an early invasive strategy.

Methods and Results

A population‐based cohort of hospitalized ACS patients who received prompt cardiac catheterization from 2008 to 2011 in Ontario, Canada and followed for up to 2 years was studied. Clinical outcomes were compared between men and women, stratified by the use of coronary revascularization. Inverse probability weighting using the propensity score accounted for measured differences in baseline characteristics between men and women. Among the 23 473 ACS patients who received cardiac catheterization during an index hospitalization, 66.1% of men and 51.8% of women received coronary revascularization during the same hospitalization. In the propensity‐weighted cohort of patients who received coronary revascularization, the 1‐year rate of death or recurrent ACS was 10.6% for men (referent) compared with 13.1% for women (hazard ratio 1.24; 95% CI 1.16–1.33). In contrast, outcomes for patients who did not receive coronary revascularization did not differ significantly between women and men at 1 year (17.8% versus 16.9%; hazard ratio 1.06; 95% CI 0.99–1.14) or at longer follow‐up.

Conclusions

An increased risk of adverse clinical outcomes was observed for women with ACS undergoing an early invasive strategy and coronary revascularization compared with men.

Nonobstructive Versus Obstructive Coronary Artery Disease in Acute Coronary Syndrome: A Meta-Analysis

Background

Differences in prognosis and baseline clinical presentation have been documented among patient with acute coronary syndrome and coronary artery disease with obstructive (ObCAD) or nonobstructive arteries (NObCAD), but the rates of events largely varied across single studies. We carried out a meta‐analysis to compare the clinical presentation and prognosis of NObCAD versus ObCAD acute coronary syndrome patients, as well as of the subjects with zero versus mild occlusion.

Methods and Results

Searches were made in MedLine, EMBASE, Cochrane databases, and proceedings of international meetings up to June 30, 2015. We compared the risk of events of NObCAD versus ObCAD patients using random‐effect meta‐analyses. We also performed meta‐analyses to estimate the yearly or monthly outcome rates in each single group. In NObCAD and ObCAD patients, respectively, the combined yearly rates were as follows: 2.4% versus 10.1% (all‐cause mortality); 1.2% versus 6.0% (myocardial infarction), 4.0% versus 12.8% (all‐cause mortality plus myocardial infarction), 1.4% versus 5.9% (cardiac death), and 9.2% versus 16.8% (major cardiovascular events). In the studies directly comparing NObCAD versus ObCAD, all of the above outcomes were significantly less frequent in NObCAD subjects (with risk ratios ranging from 0.33 to 0.66). No differences in any outcome rate were observed between mild occlusion (1–49% stenosis) and zero occlusion patients.

Conclusions

NObCAD in patients with acute coronary syndrome has a significantly lower cardiovascular risk at baseline and a subsequent lower likelihood of death or main cardiovascular events. However, these subjects are still at high risk for cardiovascular mortality and morbidity, suggesting potential undertreatment and calling for specific management.

Highly sensitive troponin and coronary computed tomography angiography in the evaluation of suspected acute coronary syndrome in the emergency department

The evaluation of patients presenting to the emergency department with suspected acute coronary syndrome (ACS) remains a clinical challenge. The traditional assessment includes clinical risk assessment based on cardiovascular risk factors with serial electrocardiograms and cardiac troponin measurements, often followed by advanced cardiac testing as inpatient or outpatient (i.e. stress testing, imaging). Despite this costly and lengthy work-up, there is a non-negligible rate of missed ACS with an increased risk of death. There is a clinical need for diagnostic strategies that will lead to rapid and reliable triage of patients with suspected ACS. We provide an overview of the evidence for the role of highly sensitive troponin (hsTn) in the rapid and efficient evaluation of suspected ACS. Results of recent research studies have led to the introduction of hsTn with rapid rule-in and rule-out protocols into the guidelines. Highly sensitive troponin increases the sensitivity for the detection of myocardial infarction and decreases time to diagnosis; however, it may decrease the specificity, especially when used as a dichotomous variable, rather than continuous variable as recommended by guidelines; this may increase clinician uncertainty. We summarize the evidence for the use of coronary computed tomography angiography (CTA) as the rapid diagnostic tool in this population when used with conventional troponin assays. Coronary CTA significantly decreases time to diagnosis and discharge in patients with suspected ACS, while being safe. However, it may lead to increase in invasive procedures and includes radiation exposure. Finally, we outline the opportunities for the combined use of hsTn and coronary CTA that may result in increased efficiency, decreased need for imaging, lower cost, and decreased radiation dose.