Acute coronary events

Perfect storm: concurrent stress and depressive symptoms increase risk of myocardial infarction or death

BACKGROUND

Depression and stress have each been found to be associated with poor prognosis in patients with coronary heart disease. A recently offered psychosocial perfect storm conceptual model hypothesizes amplified risk will occur in those with concurrent stress and depressive symptoms. We tested this hypothesis in a large sample of US adults with coronary heart disease.

METHODS AND RESULTS

Participants included 4487 adults with coronary heart disease from the REasons for Geographic and Racial Differences in Stroke study, a prospective cohort study of 30,239 black and white adults. We conducted Cox proportional hazards regression with the composite outcome of myocardial infarction or death and adjustment for demographic, clinical, and behavioral factors. Overall, 6.1% reported concurrent high stress and high depressive symptoms at baseline. During a median 5.95 years of follow-up, 1337 events occurred. In the first 2.5 years of follow-up, participants with concurrent high stress and high depressive symptoms had increased risk for myocardial infarction or death (adjusted hazard ratio, 1.48 [95% confidence interval, 1.08-2.02]) relative to those with low stress and low depressive symptoms. Those with low stress and high depressive symptoms (hazard ratio, 0.92 [95% confidence interval, 0.66-1.28]) or high stress and low depressive symptoms (hazard ratio, 0.86 [95% confidence interval, 0.57-1.29]) were not at increased risk. The association on myocardial infarction or death was not significant after the initial 2.5 years of follow-up (hazard ratio, 0.89 [95% confidence interval, 0.65-1.22]).

CONCLUSIONS

Our results provide initial support for a psychosocial perfect storm conceptual model; the confluence of depressive symptoms and stress on medical prognosis in adults with coronary heart disease may be particularly destructive in the shorter term.

The myth of the "vulnerable plaque": transitioning from a focus on individual lesions to atherosclerotic disease burden for coronary artery disease risk assessment

The cardiovascular science community has pursued the quest to identify vulnerable atherosclerotic plaque in patients for decades, hoping to prevent acute coronary events. However, despite major advancements in imaging technology that allow visualization of rupture-prone plaques, clinical studies have not demonstrated improved risk prediction compared with traditional approaches. Considering the complex relationship between plaque rupture and acute coronary event risk suggested by pathology studies and confirmed by clinical investigations, these results are not surprising. This review summarizes the evidence supporting a multifaceted hypothesis of the natural history of atherosclerotic plaque rupture. Managing patients at risk of acute coronary events mandates a greater focus on the atherosclerotic disease burden rather than on features of individual plaques.

PET imaging of atherosclerosis

ABSTRACT 

Atherosclerosis is a chronic, progressive, multifocal disease of the arterial wall, which is mainly fuelled by local and systemic inflammation, often resulting in acute ischemic events following plaque rupture and vessel occlusion. When assessing the cardiovascular risk of an individual patient, we must consider both global measures of disease activity and local features of plaque vulnerability, in addition to anatomical distribution and degree of established atherosclerosis. These parameters cannot be measured with conventional anatomical imaging techniques alone, which are designed primarily to identify the presence of organic intraluminal obstruction in symptomatic patients. However, molecular imaging with PET, using specifically targeted radiolabeled probes to track active in vivo atherosclerotic mechanisms noninvasively, may potentially provide a method that is better suited for this purpose. Vascular PET imaging can help us to further understand aspects of plaque biology, and current evidence supports a future role as an emerging clinical tool for the quantification of cardiovascular risk in order to guide and monitor responses to antiatherosclerosis treatments and to distinguish high-risk plaques.

Fluorescence lifetime imaging and intravascular ultrasound: co-registration study using ex vivo human coronaries

Fluorescence lifetime imaging (FLIM) has demonstrated potential for robust assessment of atherosclerotic plaques biochemical composition and for complementing conventional intravascular ultrasound (IVUS), which provides information on plaque morphology. The success of such a bi-modal imaging modality depends on accurate segmentation of the IVUS images and proper angular registration between these two modalities. This paper reports a novel IVUS segmentation methodology addressing this issue. The image preprocessing consisted of denoising, using the Wiener filter, followed by image smoothing, implemented through the application of the alternating sequential filter on the edge separability metric images. Extraction of the lumen/intima and media/adventitia boundaries was achieved by tracing the gray-scale peaks over the A-lines of the IVUS preprocessed images. Cubic spline interpolation, in both cross-sectional and longitudinal directions, ensured boundary smoothness and continuity. The detection of the guide-wire artifact in both modalities is used for angular registration. Intraluminal studies were conducted in 13 ex vivo segments of human coronaries. The IVUS segmentation accuracy was assessed against independent manual tracings, providing 91.82% sensitivity and 97.55% specificity. The proposed methodology makes the bi-modal FLIM and IVUS approach feasible for comprehensive intravascular diagnosis by providing co-registered biochemical and morphological information of atherosclerotic plaques.

Role of oral factor Xa inhibitors after acute coronary syndrome

Despite an early invasive strategy and the use of dual antiplatelet therapy, patients with acute coronary syndrome (ACS) continue to be at substantial risk for recurrent ischemic events. It is believed that this risk is, at least in part, due to an intrinsic coagulation pathway that remains activated for a prolonged period after ACS. Earlier studies using warfarin showed a reduction in ischemic events, but the overall benefits were offset by increased bleeding complications. Recently, there has been increased interest in the potential role of new oral anticoagulants, some of which target factor Xa, after ACS. Factor Xa is important for the coagulation pathway and also plays a role in cellular proliferation and inflammation. It may thus be an attractive target for therapeutic intervention in ACS. Recently, various oral factor Xa inhibitors have been studied as potential treatment options for ACS. This review will focus on currently available data to evaluate the possible role of factor Xa inhibitors in the management of patients with ACS.

Confluence of depression and acute psychological stress among patients with stable coronary heart disease: effects on myocardial perfusion

Background

Depression is prevalent in coronary heart disease (CHD) patients and increases risk for acute coronary syndrome (ACS) recurrence and mortality despite optimal medical care. The pathways underlying this risk remain elusive. Psychological stress (PS) can provoke impairment in myocardial perfusion and trigger ACS. A confluence of acute PS with depression might reveal coronary vascular mechanisms of risk. We tested whether depression increased risk for impaired myocardial perfusion during acute PS among patients with stable CHD.

Methods and Results

Patients (N=146) completed the Beck Depression Inventory‐I (BDI‐I), a measure of depression linked to recurrent ACS and post‐ACS mortality, and underwent single‐photon emission computed tomography myocardial perfusion imaging at rest and during acute PS. The likelihood of new/worsening impairment in myocardial perfusion from baseline to PS as a function of depression severity was tested. On the BDI‐I, 41 patients scored in the normal range, 48 in the high normal range, and 57 in the depressed range previously linked to CHD prognosis. A BDI‐I score in the depressed range was associated with a significantly greater likelihood of new/worsening impairment in myocardial perfusion from baseline to PS (odds ratio =2.89, 95% CI: 1.26 to 6.63, P=0.012). This remained significant in models controlling ACS recurrence/mortality risk factors and medications. There was no effect for selective serotonin reuptake inhibitor medications.

Conclusions

Depressed patients with CHD are particularly susceptible to impairment in myocardial perfusion during PS. The confluence of PS with depression may contribute to a better understanding of the depression‐associated risk for ACS recurrence and mortality.

Greater collagen-induced platelet aggregation following cyclooxygenase 1 inhibition predicts incident acute coronary syndromes

Greater ex vivo platelet aggregation to agonists may identify individuals at risk of acute coronary syndromes (ACS). However, increased aggregation to a specific agonist may be masked by inherent variability in other activation pathways. In this study, we inhibited the cyclooxygenase-1 (COX1) pathway with 2-week aspirin therapy and measured residual aggregation to collagen and ADP to determine whether increased aggregation in a non-COX1 pathway is associated with incident ACS. We assessed ex vivo whole blood platelet aggregation in 1,699 healthy individuals with a family history of early-onset coronary artery disease followed for 6±1.2 years. Incident ACS events were observed in 22 subjects. Baseline aggregation was not associated with ACS. After COX1 pathway inhibition, collagen-induced aggregation was significantly greater in participants with ACS compared with those without (29.0 vs. 23.6 ohms, p < 0.001). In Cox proportional hazards models, this association remained significant after adjusting for traditional cardiovascular risk factors (HR = 1.10, 95%CI = 1.06-1.15; p < 0.001). In contrast, ADP-induced aggregation after COX1 inhibition was not associated with ACS. After COX1 pathway inhibition, subjects with greater collagen-induced platelet aggregation demonstrated a significant excess risk of incident ACS. These data suggest that platelet activation related to collagen may play an important role in the risk of ACS.

Difference of ruptured plaque morphology between asymptomatic coronary artery disease and non-ST elevation acute coronary syndrome patients: an optical coherence tomography study

BACKGROUND

Autopsy studies have reported that rupture of a thin-cap fibroatheroma and subsequent thrombus formation is the major mechanism leading to acute coronary syndrome (ACS). However, it is not clear why only some plaque ruptures lead to ACS. Optical coherence tomography (OCT) is a high-resolution imaging modality which is capable of investigating detailed coronary plaque morphology in vivo. The objective of this study was to determine whether ruptured plaque morphology assessed by OCT differs between asymptomatic coronary artery disease (CAD) and non-ST elevation acute coronary syndrome (NSTEACS).

METHODS

We examined ruptured plaque morphology using OCT in 80 patients, 33 with asymptomatic CAD and 47 with NSTEACS.

RESULTS

The frequency of lipid-rich plaque and intracoronary thrombus was significantly lower in asymptomatic CAD than in NSTEACS (61% vs. 85%, p = 0.013 and 9% vs. 83%, p < 0.001, respectively). Although maximal ruptured cavity cross-sectional area (CSA) was similar in both groups, lumen area at the rupture site and minimal lumen area were significantly larger in asymptomatic CAD than in NSTEACS (3.78 ± 1.50 mm(2) vs. 2.70 ± 1.55 mm(2), p = 0.003 and 2.75 ± 0.99 mm(2) vs. 1.72 ± 0.90 mm(2), p < 0.001, respectively).

CONCLUSIONS

OCT revealed that the morphology of ruptured plaques differs between asymptomatic CAD and NSTEACS in terms of lumen area and the frequency of lipid-rich plaques and thrombi. These morphological features may be associated with the clinical presentation of CAD.

Role of computed tomography for diagnosis and risk stratification of patients with suspected or known coronary artery disease

Cardiac computed tomographic angiography (CCTA) has emerged as a powerful imaging modality for the detection and prognostication of individuals with suspected coronary artery disease. Because calcification of coronary plaque occurs in proportion to the total atheroma volume, the initial diagnostic potential of CCTA focused on the identification and quantification of coronary calcium in low- to intermediate-risk individuals, a finding that tracks precisely with the risk of incident adverse clinical events. Beyond noncontrast detection of coronary calcium, CCTA using iodinated contrast yields incremental information about the degree and distribution of coronary plaques and stenosis, as well as vessel wall morphology and atherosclerotic plaque features. This additive information offers the promise of CCTA to provide a more comprehensive view of total atherosclerotic burden because it relates to myocardial ischemia and future adverse clinical events. Furthermore, emerging data suggest the prognostic and diagnostic importance of stenosis severity detection and atherosclerotic plaque features described by CCTA including positive remodeling, low-attenuation plaque, and spotty calcification, which have been associated with the vulnerability of plaque. We report a summary of the evidence supporting the role of CCTA in the detection of subclinical and clinical coronary artery disease in both asymptomatic and symptomatic patients and discuss the potential of CCTA to augment the identification of at-risk individuals. CCTA and coronary artery calcium scoring offer the ability to improve risk stratification, discrimination, and reclassification of the risk in patients with suspected coronary artery disease and to noninvasively determine the measures of stenosis severity and atherosclerotic plaque features.

Imaging atherosclerosis and risk of plaque rupture

Atherosclerosis imaging strategies can delineate characteristics of plaques at risk of rupture and thrombosis. Structural plaque imaging identifies high-risk plaque features, including lipid pools, thin fibrous caps, and intraplaque hemorrhage. New molecular imaging techniques complement structural imaging approaches by illuminating important features of plaque biology, with a prominent focus on detecting inflammation as a high-risk phenotype. As we unravel the molecular and structural characteristics underlying thrombosis-prone plaques, there is significant promise for eventual early identification and prediction of atherosclerotic plaque complications before they occur. Here we focus on recent imaging insights into high-risk arterial plaques, the etiologic agent of acute myocardial infarction, stroke, and sudden cardiac death.

In search of serenity: religious struggle among patients hospitalized for suspected acute coronary syndrome

Hospitalization for a sudden cardiac event is a frightening experience, one that is often marked by uncertainty about health status, fear of recurrent cardiac problems, and related existential, religious, and spiritual concerns. Religious struggle, reflecting tension and strain regarding religious and spiritual issues, may arise in response to symptoms of acute coronary syndrome (ACS). The present study examined the prevalence and types of religious struggle using the Brief RCOPE, as well as associations between religious struggle, psychological distress, and self-reported sleep habits among 62 patients hospitalized with suspected ACS. Fifty-eight percent of the sample reported some degree of religious struggle. Questioning the power of God was the most frequently endorsed struggle. Those struggling religiously reported significantly more symptoms of anxiety, depression, and sleep disturbance. Non-White participants endorsed greater use of positive religious coping strategies and religious struggle. Results suggest that patients hospitalized for suspected ACS experiencing even low levels of religious struggle might benefit from referral to a hospital chaplain or appropriately trained mental health professional for more detailed religious and spiritual assessment. Practical means of efficiently screening for religious struggle during the often brief hospitalization period for suspected ACS are discussed.

Current perspective on mental stress-induced myocardial ischemia

Mental stress and emotional arousal can act as triggers of myocardial infarction and other adverse cardiovascular outcomes. This editorial presents an overview of the research on mental stress-induced myocardial ischemia (MSIMI) and comments on two investigations examining MSIMI published in this journal. These studies confirm that MSIMI is frequently observed in patients with coronary artery disease and that characteristics, such as being a woman younger than 50 years and depression, may increase the relative risk of MSIMI. The method used for determining MSIMI (i.e., assessing cardiac function as determined by echocardiography versus measurement of myocardial perfusion using single-photon emission computed tomography), as well as the nature of the mental stress protocols (i.e., one stress task versus several repeated tasks), may have important effects on the findings of MSIMI research and on their interpretation. An overview of clinical characteristics of MSIMI is presented, and the article concludes with possible directions for future MSIMI research.

Coronary artery disease concomitant with chronic obstructive pulmonary disease

BACKGROUND

Numerous epidemiologic studies have linked the presence of chronic obstructive pulmonary disease (COPD) to coronary artery disease (CAD). However, prevalence, pathological processes, clinical manifestations and therapy are still debated, as progress towards uncovering the link between these two disorders has been hindered by the complex nature of multimorbidity.

METHODS

Articles targeting CAD in patients with COPD were identified from the searches of MEDLINE and EMBASE databases in July 2013. Three authors reviewed available evidence, focusing on the latest development on disease prevalence, pathogenesis, clinical manifestations and therapeutic strategies. Both clinical trial and previous reviews have been included in this work.

RESULTS

The most accredited hypothesis asserts that the main common risk factors, that is, cigarette smoke and ageing, elicit a chronic low-grade systemic inflammatory response, which affects both cardiovascular endothelial cells and airways/lung parenchyma. The development of CAD in patients with COPD potentiates the morbidity of COPD, leading to increased hospitalizations, mortality and health costs. Moreover, correct diagnosis is challenging and therapies are not clearly defined.

CONCLUSIONS

Evidence from recently published articles highlights the importance of multimorbidity in patient management and future research. Moreover, many authors emphasize the importance of low-grade systemic inflammation as a common pathological mechanism and a possible future therapeutic target.

Framework to co-register longitudinal virtual histology-intravascular ultrasound data in the circumferential direction

Considerable efforts have been directed at identifying prognostic markers for rapidly progressing coronary atherosclerotic lesions that may advance into a high-risk (vulnerable) state. Intravascular ultrasound (IVUS) has become a valuable clinical tool to study the natural history of coronary artery disease (CAD). While prospectively IVUS studies have provided tremendous insight on CAD progression, and its association with independent markers (e.g., wall shear stress), they are limited by the inability to examine the focal association between spatially heterogeneous variables (in both circumferential and axial directions). Herein, we present a framework to automatically co-register longitudinal (in-time) virtual histology-intravascular ultrasound (VH-IVUS) imaging data in the circumferential direction (i.e., rotate follow-up image so circumferential basis coincides with corresponding baseline image). Multivariate normalized cross correlation was performed on paired images (n = 636) from five patients using three independent VH-IVUS defined parameters: artery thickness, VH-IVUS defined plaque constituents, and VH-IVUS perivascular imaging data. Results exhibited high correlation between co-registration rotation angles determined automatically versus manually by an expert reader ( r(2) = 0.90). Furthermore, no significant difference between automatic and manual co-registration angles was observed ( 91.31 ±1.04(°) and 91.07 ±1.04(°), respectively; p = 0.48) and Bland-Altman analysis yielded excellent agreement ( bias = 0.24(°), 95% CI +/- 16.33(°)). In conclusion, we have developed, verified, and validated an algorithm that automatically co-registers VH-IVUS imaging data that will allow for the focal examination of CAD progression.

Inflammation and coagulation in atherosclerosis

Cardiovascular diseases remain to be the leading cause of death in Western societies. Despite major findings in vascular biology that lead to a better understanding of the pathomechanisms involved in atherosclerosis, treatment of the disease has only changed slightly within the last years. A big body of evidence suggests that atherosclerosis is a chronic inflammatory disease of the vessel wall. Accumulation and peroxidation of LDL-particles within the vessel wall trigger a strong inflammatory response, causing macrophage and T-cell accumulation within the vessel wall. Additionally, B-cells and specific antibodies against LDL-particles, as well as the complement system are implicated in atherogenesis. Besides data from clinical trials and autopsy studies it was the implementation of mouse models of atherosclerosis and the emerging field of direct gen-modification that lead to a thorough description of the pathophysiological mechanisms involved in the disease and created overwhelming evidence for a participation of the immune system. Recently, the cross-talk between coagulation and inflammation in atherogenesis has gained attention. Serious limitations and disparities in the pathophysiology of atherosclerosis in mice and men complicated the translation of experimental data into clinical practice. Despite these limitations, new anti-inflammatory medical therapies in cardiovascular disease are currently being tested in clinical trials.

Carotid intima-media thickness testing as an asymptomatic cardiovascular disease identifier and method for making therapeutic decisions

Cardiovascular disease (CVD) is the leading cause of death and disability in the United States. Although current therapies can reduce the risk for CVD, they are only given to patients who are considered to be at risk, and are therefore only beneficial if a patient's risk is accurately predicted before he or she sustains a cardiovascular (CV) event. Unfortunately, even relatively accurate risk factor analyses, such as the Reynolds Risk Score algorithm, fail to identify some patients who will sustain a CV event within 10 years. In contrast, the presence of an atheroma is an absolute predictor for the potential of an atherothrombotic event to occur, and it is therefore reasonable to anchor clinical decisions based on this knowledge. Carotid intima-media thickness (CIMT) testing via B-mode ultrasound is a safe, simple, and inexpensive method for evaluating CV risk by measuring the combined thickness of the intimal and medial layers of the arterial wall. Use of CIMT testing can also detect marked thickening of the arterial wall, possibly indicating plaques or atheromas that are associated with accelerated atherosclerotic disease and increased risk for coronary artery disease, myocardial infarction, and stroke. These characteristics make CIMT a practical supplemental method that physicians can use when making decisions. Moreover, the ability of CIMT testing to identify and quantify atherosclerotic disease has led to the adoption of CIMT as a surrogate endpoint in clinical trials, allowing the efficacy of new drugs to be assessed much more rapidly than would be possible by focusing solely on CV event or mortality rates. To date, several trials have provided evidence to indicate that some CVD therapies slow, stop, or reverse the progression of CIMT. Although many of these studies show that changes in CIMT predict future CV events, the value of CIMT testing in CVD risk assessment is still vigorously debated. In this article, we clarify the utility of CIMT testing for risk classification and reexamine its usefulness as a method for assessing therapeutic efficacy.

The association between cortisol response to mental stress and high-sensitivity cardiac troponin T plasma concentration in healthy adults

Objectives

The objective of this study was to examine the association between cortisol response to mental stress and high-sensitivity cardiac troponin T (hs-cTnT) in healthy older individuals without history of cardiovascular disease (CVD).

Background

Mental stress is a recognized risk factor for CVD, although the mechanisms remain unclear. Cortisol, a key stress hormone, is associated with coronary atherosclerosis and may accentuate structural and functional cardiac disease.

Methods

This cross-sectional study involved 508 disease-free men and women aged 53 to 76 years drawn from the Whitehall II epidemiological cohort. We evaluated salivary cortisol response to standardized mental stress tests (exposure) and hs-cTnT plasma concentration using a high-sensitivity assay (outcome). We measured coronary calcification using electron-beam dual-source computed tomography and Agatston scores.

Results

After adjustment for demographic and clinical variables associated with CVD as well as for inflammatory factors, we found a robust association between cortisol response and detectable hs-cTnT (odds ratio [OR]: 3.98; 95% confidence interval [CI]: 1.60 to 9.92; p = 0.003). The association remained when we restricted the analysis to participants without coronary calcification (n = 222; OR: 4.77; 95% CI: 1.22 to 18.72; p = 0.025) or when we further adjusted for coronary calcification in participants with positive Agatston scores (n = 286; OR: 7.39; 95% CI: 2.22 to 26.24; p = 0.001).

Conclusions

We found that heightened cortisol response to mental stress was associated with detectable plasma levels of cTnT using high-sensitivity assays in healthy participants, independently of coronary atherosclerosis. Further research is needed to understand the role of psychosocial stress in the pathophysiology of cardiac cell damage.

Increase in cardiac myosin binding protein-C plasma levels is a sensitive and cardiac-specific biomarker of myocardial infarction

Earlier studies have shown that cardiac myosin binding protein-C (cMyBP-C) is easily releasable into the circulation following myocardial infarction (MI) in animal models and patients. However, since its release kinetics has not been clearly demonstrated, no parameters are available to judge its efficacy as a bona fide biomarker of MI in patients with MI. To make this assessment, plasma levels of cMyBP-C and six known biomarkers of MI were determined by sandwich enzyme-linked immunosorbent assay in patients with MI who had before and after Percutaneous Transcoronary Angioplasty (PTCA), as well as healthy controls. Compared to healthy controls (22.3 ± 2.4 ng/mL (n=54)), plasma levels of cMyBP-C were significantly increased in patients with MI (105.1 ± 8.8 ng/mL (n=65), P<0.001). Out of 65 patients, 24 had very high levels of plasma cMyBP-C (116.5 ± 13.3 ng/mL), indicating high probability of MI. Importantly, cMyBP-C levels were significantly decreased in patients (n=40) at 12 hours post-PTCA (41.2 ± 9.3 ng/mL, P<0.001), compared to the patients with MI. Receiver operating characteristic analysis revealed that a plasma cMyBP-C reading of 68.1 ng/mL provided a sensitivity of 66.2% and a specificity of 100%. Also, myoglobin, carbonic anhydrase and creatine kinase-MB levels were significantly increased in MI patients who also had higher cMyBP-C levels. In contrast, levels of cardiac troponin I, glycogen phosphorylase and heart-type fatty acid binding protein were not significantly changed in the samples, indicating the importance of evaluating the differences in release kinetics of these biomarkers in the context of accurate diagnosis. Our findings suggest that circulating cMyBP-C is a sensitive and cardiac-specific biomarker with potential utility for the accurate diagnosis of MI.

Biological imaging of atherosclerosis: moving beyond anatomy

Biological or molecular imaging is now providing exciting new strategies to study atherosclerosis in both animals and humans. These technologies hold the promise to provide disease-specific, molecular information within the context of a systemic or organ-specific disease beyond traditional anatomical-based imaging. By integration of biological, chemical, and anatomical imaging knowledge into diagnostic strategies, a more comprehensive and predictive picture of atherosclerosis is likely to emerge. As such, biological imaging is well positioned to study different stages of atherosclerosis and its treatment, including the sequence of atheroma initiation, progression, and plaque rupture. In this review, we describe the evolving concepts in atherosclerosis imaging with a focus on coronary artery disease, and we provide an overview of recent exciting translational developments in biological imaging. The illuminated examples and discussions will highlight how biological imaging is providing new clinical approaches to identify high-risk plaques, and to streamline the development process of new atherosclerosis therapies.

Antiplatelet and anticoagulant strategies in acute coronary syndrome: where we are in 2013

Multiple antiplatelet and anticoagulant therapies are available for the treatment of acute coronary syndromes. The combination of agents should be tailored to the individual patient carefully considering the balance between ischemic and bleeding risk, as well as the planned revascularization strategy. Despite multiple large-scale, rigorously designed and conducted randomized controlled trials, it can be difficult to select the correct pharmacotherapy for each patient and many unanswered questions remain, such as the safety and optimal doses of differing combinations of antiplatelet/anticoagulant therapy, as well as the timing and duration of therapies. In addition, the headline results of many trials report improved efficacy outcomes at the cost of increased bleeding risk; however, very few show a clear mortality benefit. It is therefore difficult to weigh up the risk–benefit profile of emerging therapies.

The 'perfect storm' and acute coronary syndrome onset: do psychosocial factors play a role?

The revolution in cardiac care over the past two decades, characterized by emergent revascularization, drug eluting stents, anti-platelet medications, and advanced imaging has had little impact on overall ACS recurrence, or ACS prevention. The "Perfect Storm" refers to a confluence of events and processes, including atherosclerotic plaque, coronary flow dynamics, hemostatic and fibrinolytic function, metabolic and inflammatory conditions, neurohormonal dysregulation, and environmental events that give rise to, and result in an ACS event. In this article we illustrate the limits of the traditional main effect research model, giving a brief description of the current state of knowledge regarding the development of atherosclerotic plaque and the rupturing of these plaques that defines an ACS event. We then apply the Perfect Storm conceptualization to describe a program of research concerning a psychosocial vulnerability factor that contributes to increased risk of recurrent ACS and early mortality, and that has defied our efforts to identify underlying pathophysiology and successfully mount efforts to fully mitigate this risk.

Cardiac Magnetic Resonance: One Slice, Two Different LGE Patterns

A 56-years-old man with previous myopericarditis (10 months earlier, coronary angiography not performed) was admitted because of pericarditis pain and ST segment elevation, together with myocardial necrosis markers rise. Electrocardiogram (EKG) showed negative T waves in lateral and inferior leads; echocardiogram showed mild pericardial effusion and inferior and lateral basal hypokinesis. Cardiac magnetic resonance imaging (CMRI) on day 7 post-admission showed increased T2-short tau inversion recovery (T2-STIR) signal of inferior wall and two different noncontiguous late gadolinium enhancement (LGE) areas: Ischemic-like with about 75% transmural extension (inferior wall) and subepicardial (inferolateral wall) along with pericardial LGE (inferior and inferolateral wall). Coronary angiography showed three vessel disease. Pathogenetic hypothesis of these unexpected findings are discussed. This case shows again the ability of CMRI to unreveal unusual and unexpected pathologic patterns.

Reduced antiplatelet effect of aspirin is associated with low-grade inflammation in patients with coronary artery disease

Inflammation has been proposed to modify platelet function. This may lead to increased platelet reactivity and reduced antiplatelet drug efficacy in patients with coronary artery disease (CAD). However, this hypothesis has not been investigated in stable CAD patients receiving aspirin as mono antiplatelet therapy. It was the objective of this study to investigate the association between platelet reactivity, the inflammatory markers high-sensitive C-reactive protein (hs-CRP) and interleukin-6 (IL-6), and platelet activation. We performed a cross-sectional study on 524 stable high-risk CAD patients. Among these, 91% had a history of myocardial infarction, 23% had type 2 diabetes, and 13% had both. All patients received 75 mg aspirin daily as mono antiplatelet therapy. Platelet reactivity was assessed by multiple electrode aggregometry (Multiplate®, MEA) and VerifyNow®. Inflammation was evaluated by hs-CRP and IL-6. Platelet activation was assessed by soluble P-selectin (sP-selectin), and cyclooxygenase-1 inhibition was evaluated by measurement of serum thromboxane B2. Hs-CRP levels were significantly higher in upper platelet reactivity tertile patients than in lower platelet reactivity tertile patients (p≤0.02). Similar results were obtained with IL-6, though not statististically significant (p≥0.15). Platelet activation evaluated by sP-selectin was significantly higher in patients with MEA reactivity levels in the upper tertile than in the lower tertile (p=0.0001). Optimal compliance was confirmed by low serum thromboxane B2 levels in all patients. In conclusion, increased levels of hs-CRP were associated with augmented platelet reactivity in stable high-risk CAD patients receiving aspirin as mono antiplatelet therapy. These findings may suggest that chronic low-grade inflammation reduce the antiplatelet effect of aspirin.

Classification of myocardial infarction and unstable angina: a re-assessment

True or impending myocardial injury is being defined as an acute coronary syndrome (ACS), and includes ST-segment elevation MI, non-ST-segment elevation MI, and unstable angina. According to the revised MI definitions, patients with ischemic symptoms but with only a minor rise and fall in any biomarker are now being classified as having true myocardial injury. Against this background, this paper re-examines the position of "unstable angina" within the ACS context. It now must be acknowledged that the most recent definition of unstable angina, from 2000, which divided patients with unstable angina in those who were troponin-positive and those that remained troponin-negative, overlaps with the current MI definition. The seminal 1989 clinical definition of unstable angina thus remains the most appropriate description of that ACS entity. This "paradigm shift" has significant bearing on both the numbers of patients with non-ST-segment elevation MI, as well as on their prognosis. The same is true for patients now being diagnosed as having "unstable angina." To a large extent, future cardiovascular risk is determined by clinical parameters, and their proper assessment thus remains paramount. Elevated age, previous MI, diabetes and/or renal dysfunction and, in particular, the presence of recent onset of symptoms (Braunwald category IIIB) with concomitant ECG changes should identify those at high risk. Patients with such characteristics should benefit from thorough medical management, including extensive platelet inhibition in most and coronary revascularization in many.

Potential role of coronary computed tomography-angiography for guiding perioperative cardiac management for non-cardiac surgery

Perioperative cardiac events can be a major consequence of surgery. The American College of Cardiology Foundation/American Heart Association has set out guidelines to aid physicians in identifying patients at the highest risk for these events. The guidelines do recommend for some patients to undergo non-invasive cardiac stress testing for further risk stratification, but their sensitivity and specificity for predicting cardiac events is not optimal. With more data emerging of the superior performance of computed coronary tomography angiography (CCTA) compared to non-invasive stress testing, CCTA could be more useful in risk stratification for these patients.

Stress and cardiovascular disease: an update on current knowledge

Considerable progress has been made during the past decade in research on cardiovascular effects of stress. Early-life stressors, such as childhood abuse and early socioeconomic adversity, are linked to increased cardiovascular morbidity in adulthood. Our updated meta-analyses of prospective studies published until 2011 show a 1.5-fold (95% confidence interval 1.2-1.9) increased risk of coronary heart disease among adults experiencing social isolation and a 1.3-fold (1.2-1.5) excess risk for workplace stress; adverse metabolic changes are one of the underlying plausible mechanisms. Stress, anger, and depressed mood can act as acute triggers of major cardiac events; the pooled relative risk of acute coronary syndrome onset being preceded by stress is 2.5 (1.8-3.5) in case-crossover studies. Stress is also implicated in the prognosis of cardiovascular disease and in the development of stress (takotsubo) cardiomyopathy. A major challenge over the next decade is to incorporate stress processes into the mainstream of cardiovascular pathophysiological research and understanding.

Differences between acute myocardial infarction and unstable angina: a longitudinal cohort study reporting findings from the Register of Information and Knowledge about Swedish Heart Intensive Care Admissions (RIKS-HIA)

OBJECTIVES

The aim of this study was to compare risk factors and comorbidities in patients with a first episode of acute coronary syndrome (ACS), being either acute myocardial infarction (AMI) or unstable angina pectoris (UAP).

DESIGN

Cross-sectional and prospective.

SETTING

The Swedish population.

PARTICIPANTS

A total of 145 346 consecutive patients aged 25-105 years included in the Swedish Register of Cardiac Intensive Care Admission (Register of Information and Knowledge about Swedish Heart Intensive Care) and admitted to hospital between 1 January 1996 and 30 June 2009 with a first episode of either AMI or UAP.

PRIMARY AND SECONDARY OUTCOME MEASURES

Type of ACS and 1-year outcome.

RESULTS

Compared with patients with UAP, AMI patients were more likely to be older; men; and former or current smokers; they were also more likely to have had diabetes and peripheral artery disease, but had lower rates of prior heart failure (HF) and fewer cardioprotective medications on admission. Among patients aged <65 years, 1.4% of men and 1.6% of women with UAP died within 1 year in 2003-2006 compared with 4.2% of men and 3.1% of women AMI patients (multiple-adjusted OR 3.54 (99% CI 2.29 to 5.48) in women and 2.65 (99% CI 2.11 to 3.34) in men). Corresponding proportions in patients aged ≥65 years was 7.5% in men and 7.6% in women with UAP and 21.5% in men and 17.8% in women with AMI.

CONCLUSIONS

In patients with a first-time ACS episode, male sex, slightly older age, smoking, diabetes and peripheral arterial disease (PAD), but fewer cardioprotective medications, were major determinants for presenting with AMI. Despite increasingly active treatment in AMI and more inclusive diagnostic criteria in recent years, persistently worse prognosis was observed in AMI patients.

Update on acute coronary syndromes: the pathologists' view

Although mortality rates from coronary heart disease in the western countries have declined in the last few decades, morbidity caused by this disease is increasing and a substantial number of patients still suffer acute coronary syndrome (ACS) and sudden cardiac death. Acute coronary syndrome occurs as a result of myocardial ischaemia and its manifestations include acute myocardial infarction and unstable angina. Culprit plaque morphology in these patients varies from thrombosis with or without coronary occlusion to sudden narrowing of the lumen from intraplaque haemorrhage. The coronary artery plaque morphologies primarily responsible for thrombosis are plaque rupture, and plaque erosion, with plaque rupture being the most common cause of acute myocardial infarction, especially in men. Autopsy data demonstrate that women <50 years of age more frequently have erosion, whereas in older women, the frequency of rupture increases with each decade. Ruptured plaques are associated with positive (expansive) remodelling and characterized by a large necrotic core and a thin fibrous cap that is disrupted and infiltrated by foamy macrophages. Plaque erosion lesions are often negatively remodelled with the plaque itself being rich in smooth muscle cells and proteoglycans with minimal to absence of inflammation. Plaque haemorrhage may expand the plaque rapidly, leading to the development of unstable angina. Plaque haemorrhage may occur from plaque rupture (fissure) or from neovascularization (angiogenesis). Atherosclerosis is now recognized as an inflammatory disease with macrophages and T-lymphocytes playing a dominant role. Recently at least two subtypes of macrophages have been identified. M1 is a pro-inflammatory macrophage while M2 seems to play a role in dampening inflammation and promoting tissue repair. A third type of macrophage, termed by us as haemoglobin associated macrophage or M(Hb) which is observed at site of haemorrhage also can be demonstrated in human atherosclerosis. In order to further our understanding of the specific biological events which trigger plaque instability and as well as to monitor the effects of novel anti-atherosclerotic therapies newer imaging modalities in vivo are needed.

Comparing the new European cardiovascular disease prevention guideline with prior American Heart Association guidelines: an editorial review

Atherosclerotic heart disease and stroke remain the leading causes of death and disability worldwide. Cardiovascular disease (CVD) prevention can improve the well-being of a population and possibly cut downstream healthcare spending, and must be the centerpiece of any sustainable health economy model. As lifestyle and CVD risk factors differ among ethnicities, cultures, genders, and age groups, an accurate risk assessment model is the critical first step for guiding appropriate use of testing, lifestyle counseling resources, and preventive medications. Examples of such models include the US Framingham Risk Score and the European SCORE system. The European Society of Cardiology recently published an updated set of guidelines on CVD prevention. This review highlights the similarities and differences between European and US risk assessment models, as well as their respective recommendations on the use of advanced testing for further risk reclassification and the appropriate use of medications. In particular, we focus on head-to-head comparison of the new European guideline with prior American Heart Association statements (2002, 2010, and 2011) covering risk assessment and treatment of asymptomatic adults. Despite minor disagreements on the weight of recommendations in certain areas, such as the use of coronary calcium score and non-high-density lipoprotein cholesterol in risk assessment, CVD prevention experts across the 2 continents agree on 1 thing: prevention works in halting the progression of atherosclerosis and decreasing disease burden over a lifetime.

Semiquantified noncalcified coronary plaque in systemic lupus erythematosus

OBJECTIVE

A major cause of morbidity and mortality in systemic lupus erythematosus (SLE) is accelerated coronary atherosclerosis. New technology (computed tomographic angiography) can measure noncalcified coronary plaque (NCP), which is more prone to rupture. We report on a study of semiquantified NCP in SLE.

METHODS

Patients with SLE (n = 147) with no history of cardiovascular disease underwent 64-slice coronary multidetector computed tomography (MDCT). The MDCT scans were evaluated quantitatively by a radiologist, using dedicated software.

RESULTS

The group of 147 patients with SLE was 86% female, 70% white, 29% African American, and 3% other ethnicity. The mean age was 51 years. In our univariate analysis, the major traditional cardiovascular risk factors associated with noncalcified plaque were age (p = 0.007), obesity (p = 0.03; measured as body mass index), homocysteine (p = 0.05), and hypertension (p = 0.04). Anticardiolipin (p = 0.026; but not lupus anticoagulant) and anti-dsDNA (p = 0.03) were associated with higher noncalcified plaque. Prednisone and hydroxychloroquine therapy had no effect, but methotrexate (MTX) use was associated with higher noncalcified plaque (p = 0.0001). In the best multivariate model, age, current MTX use, and history of anti-dsDNA remained significant.

CONCLUSION

Our results suggest that serologic SLE (anti-dsDNA) and traditional cardiovascular risk factors contribute to semiquantified noncalcified plaque in SLE. The association with MTX is not understood, but should be replicated in larger studies and in multiple centers.