Harmony R. Reynolds

Cardiogenic Shock Current Concepts and Improving Outcomes

Cardiogenic shock (CS) occurs in ≈5% to 8% of patients hospitalized with ST-elevation myocardial infarction (STEMI). Recent research has suggested that the peripheral vasculature and neurohormonal and cytokine systems play a role in the pathogenesis and persistence of CS. Early revascularization for CS improves survival substantially. New mechanical approaches to treatment are available, and clinical trials are feasible even in this high-risk population. Most importantly, hospital survivors have an excellent chance for long-term survival with good quality of life. This review will outline the causes, pathophysiology, and treatment of CS with a focus on CS complicating myocardial infarction (MI.) The case will be made for viewing CS as a serious disorder with a high early death rate, but one that is treatable and that, if approached aggressively, can result in full recovery. CS is a state of end-organ hypoperfusion due to cardiac failure. The definition of CS includes hemodynamic parameters: persistent hypotension (systolic blood pressure 18 mm Hg or right ventricular [RV] end-diastolic pressure >10 to 15 mm Hg). The diagnosis is usually made with the help of pulmonary artery (PA) catheterization; however, Doppler echocardiography may also be used to confirm elevation of LV filling pressures.1 Hypoperfusion may be manifest clinically by cool extremities, decreased urine output, and/or alteration in mental status. Hemodynamic abnormalities form a spectrum that ranges from mild hypoperfusion to profound shock, and the short-term outcome is directly related to the severity of hemodynamic derangement. MI with LV failure remains …

Mechanisms of Myocardial Infarction in Women Without Angiographically Obstructive Coronary Artery Disease

Background— There is no angiographically demonstrable obstructive coronary artery disease (CAD) in a significant minority of patients with myocardial infarction, particularly women. We sought to determine the mechanism(s) of myocardial infarction in this setting using multiple imaging techniques. Methods and Results— Women with myocardial infarction were enrolled prospectively, before angiography, if possible. Women with ≥50% angiographic stenosis or use of vasospastic agents were excluded. Intravascular ultrasound was performed during angiography; cardiac magnetic resonance imaging was performed within 1 week. Fifty women (age, 57±13 years) had median peak troponin of 1.60 ng/mL; 11 had ST-segment elevation. Median diameter stenosis of the worst lesion was 20% by angiography; 15 patients (30%) had normal angiograms. Plaque disruption was observed in 16 of 42 patients (38%) undergoing intravascular ultrasound. There were abnormal myocardial cardiac magnetic resonance imaging findings in 26 of 44 patients (59%) undergoing cardiac magnetic resonance imaging, late gadolinium enhancement (LGE) in 17 patients, and T2 signal hyperintensity indicating edema in 9 additional patients. The most common LGE pattern was ischemic (transmural/subendocardial). Nonischemic LGE patterns (midmyocardial/subepicardial) were also observed. Although LGE was infrequent with plaque disruption, T2 signal hyperintensity was common with plaque disruption. Conclusions— Plaque rupture and ulceration are common in women with myocardial infarction without angiographically demonstrable obstructive coronary artery disease. In addition, LGE is common in this cohort of women, with an ischemic pattern of injury most evident. Vasospasm and embolism are possible mechanisms of ischemic LGE without plaque disruption. Intravascular ultrasound and cardiac magnetic resonance imaging provide complementary mechanistic insights into female myocardial infarction patients without obstructive coronary artery disease and may be useful in identifying potential causes and therapies. Clinical Trial Registration— URL: http://www.clinicaltrials.gov. Unique identifier: NCT00798122.

Characterization and outcomes of women and men with non–ST-segment elevation myocardial infarction and nonobstructive coronary artery disease: Results from the Can Rapid Risk Stratification of Unstable Angina Patients Suppress Adverse Outcomes with Early Implementation of the ACC/AHA Guidelines (CRUSADE) Quality Improvement Initiative

BACKGROUND Women with non-ST-segment elevation myocardial infarction (NSTEMI) who undergo coronary angiography have no obstructive coronary lesions more often than men. Sex-specific characteristics and outcomes of patients without obstructive coronary artery disease (CAD) have not been described previously. METHODS Using data from NSTEMI patients enrolled in CRUSADE from 2001 to 2005, we evaluated differences in clinical features and in-hospital outcomes between men and women with no obstructive CAD. RESULTS After excluding patients with missing catheterization and sex data (n = 1,494), previous coronary artery bypass grafting or percutaneous coronary intervention (47,907), catheterization contraindications (n = 6,588), and missing obstructive CAD status (n = 1,565), there were 55,514 patients (68.4%) with NSTE acute coronary syndromes (ACS) who underwent angiography (among women, 62.1% [21,294/34,290], and among men, 73% [34,220/46,875]; P < .001). Among these, a total of 5,538 patients (10.0%) had nonnonobstructive CAD-15.1% (3,221/21,294) of women and 6.8% (2,317/34,220) of men (P < .0001). In patients without obstructive CAD, women were as likely as men to have MI (troponin elevation in 89% vs 87%, P = .37). Women and men were equally likely to have larger troponin elevations (58.9% vs 58.6% with troponin >5x upper limit of normal, P = .69, respectively). In NSTEMI patients without obstructive CAD, in-hospital death (0.6% women vs 0.7% men) and cardiogenic shock (1.0% women vs 0.7% men) were infrequent. CONCLUSIONS Among NSTE ACS patients undergoing coronary angiography, absence of obstructive CAD is more common in women than men. Although nonobstructive CAD was twice as common among women with NSTEMI, sex differences in characteristics and outcomes were similar to those found with obstructive CAD. Unadjusted in-hospital outcomes of NSTEMI patients with nonobstructive CAD are favorable in both sexes. Whether the underlying pathophysiology of NSTE ACS without documentation of obstructive CAD is different between women and men requires further study.

Comparative Definitions for Moderate-Severe Ischemia in Stress Nuclear, Echocardiography, and Magnetic Resonance Imaging

The lack of standardized reporting of the magnitude of ischemia on noninvasive imaging contributes to variability in translating the severity of ischemia across stress imaging modalities. We identified the risk of coronary artery disease (CAD) death or myocardial infarction (MI) associated with ≥10% ischemic myocardium on stress nuclear imaging as the risk threshold for stress echocardiography and cardiac magnetic resonance. A narrative review revealed that ≥10% ischemic myocardium on stress nuclear imaging was associated with a median rate of CAD death or MI of 4.9%/year (interquartile range: 3.75% to 5.3%). For stress echocardiography, ≥3 newly dysfunctional segments portend a median rate of CAD death or MI of 4.5%/year (interquartile range: 3.8% to 5.9%). Although imprecisely delineated, moderate-severe ischemia on cardiac magnetic resonance may be indicated by ≥4 of 32 stress perfusion defects or ≥3 dobutamine-induced dysfunctional segments. Risk-based thresholds can define equivalent amounts of ischemia across the stress imaging modalities, which will help to translate a common understanding of patient risk on which to guide subsequent management decisions.

ESC working group position paper on myocardial infarction with non-obstructive coronary arteries

The management of acute myocardial infarction (AMI)1 has evolved over the past century and particularly in the past 50 years. Important milestones include the development of the electrocardiogram, coronary care units, coronary angiography, reperfusion therapies, and troponin assays. These innovations are the foundation of contemporary AMI management strategies that include a diagnosis centred on elevated troponin values associated with corroborative clinical evidence,1 early use of coronary angiography, and reperfusion therapies.2–4 Pivotal in the evolution of these contemporary strategies were the early AMI coronary angiography studies undertaken by DeWood et al. These pioneering studies demonstrated that, in patients presenting with ST elevation myocardial infarction (STEMI), almost 90% had an occluded coronary artery provided that angiography was undertaken within 4 h of chest pain onset.5 In contrast, in AMI patients who did not present with ST elevation (non-ST elevation myocardial infarction or NSTEMI), only 26% had an occluded coronary artery when angiography was performed within 24 h of symptom onset.6 In both of these landmark studies,5,6 >90% of the acute MI patients had angiographic evidence of obstructive coronary artery disease (CAD), underscoring the importance of the atherosclerotic process in the pathogenesis of AMI. Although DeWoods studies underscore the importance of obstructive CAD in AMI, it is fascinating that ∼10% had no significant CAD on coronary angiography. This is confirmed in several large AMI registries7–9 where 1–13% of AMIs occurred in the absence of obstructive CAD thereby eliciting an important set of questions—what is the mechanism of the myocardial damage in these patients? Do these patients differ from those with obstructive CAD? Should they be …

Predictors of 30-day mortality in patients with refractory cardiogenic shock following acute myocardial infarction despite a patent infarct artery

BACKGROUND Little is known about predictors of survival in patients with persistent shock following acute myocardial infarction (MI) despite a patent infarct artery. METHODS We examined data from TRIUMPH, a multicenter randomized clinical trial of the nitric oxide synthase inhibitor, L-N(G)-monomethyl-arginine, in patients with persistent vasopressor-dependent cardiogenic shock complicating acute MI at least 1 hour after established infarct-related artery patency. Patients who died within 30 days were compared with those who survived. Continuous variables were assessed using the Wilcoxon rank sum and categorical variables using the chi(2) test. Prespecified baseline variables were included in a multivariable logistic regression model to predict mortality. A second model incorporating baseline vasopressors and dosages and a third model including change in systolic blood pressure at 2 hours were also developed. Bootstrapping was used to assess the stability of model variables. RESULTS Of 396 patients, 180 (45.5%) died within 30 days. Systolic blood pressure (SBP), measured on vasopressor support, and creatinine clearance were significant predictors of mortality in all models. The number of vasopressors and norepinephrine dose were also predictors of mortality in the second model, but the latter was no longer significant when change in SBP at 2 hours was added as a covariate in the third model. CONCLUSIONS The SBP, creatinine clearance, and number of vasopressors are significant predictors of mortality in patients with persistent vasopressor-dependent cardiogenic shock following acute MI despite a patent infarct artery. These prognostic variables may be useful for risk-stratification and in selecting patients for investigation of additional therapies.

A severity scoring system for risk assessment of patients with cardiogenic shock: A report from the SHOCK Trial and Registry

BACKGROUND Early revascularization (ERV) is beneficial in the management of cardiogenic shock (CS) complicating myocardial infarction. The severity of CS varies widely, and identification of independent risk factors for outcome is needed. The effect of ERV on mortality in different risk strata is also unknown. We created a severity scoring system for CS and used it to examine the potential benefit of ERV in different risk strata using data from the SHOCK Trial and Registry. METHODS Data from 1,217 patients (294 from the randomized trial and 923 from the registry) with CS due to pump failure were included in a Stage 1 severity scoring system using clinical variables. A Stage 2 scoring system was developed using data from 872 patients who had invasive hemodynamic measurements. The outcome was in-hospital mortality at 30 days. RESULTS In-hospital mortality at 30 days was 57%. Multivariable modeling identified 8 risk factors (Stage 1): age, shock on admission, clinical evidence of end-organ hypoperfusion, anoxic brain damage, systolic blood pressure, prior coronary artery bypass grafting, noninferior myocardial infarction, and creatinine > or = 1.9 mg/dL (c-statistic = 0.74). Mortality ranged from 22% to 88% by score category. The ERV benefit was greatest in moderate- to high-risk patients (P = .02). The Stage 2 model based on patients with pulmonary artery catheterization included age, end-organ hypoperfusion, anoxic brain damage, stroke work, and left ventricular ejection fraction <28% (c-statistic = 0.76). In this cohort, the effect of ERV did not vary by risk stratum. CONCLUSIONS Simple clinical predictors provide good discrimination of mortality risk in CS complicating myocardial infarction. Early revascularization is associated with improved survival across a broad range of risk strata.

Impact of Collateral Flow to the Occluded Infarct-Related Artery on Clinical Outcomes in Patients With Recent Myocardial Infarction: A Report From the Randomized Occluded Artery Trial

Background— Collateral flow to the infarct artery territory after acute myocardial infarction may be associated with improved clinical outcomes and may also impact the benefit of subsequent recanalization of an occluded infarct-related artery. Methods and Results— To understand the association between baseline collateral flow to the infarct territory on clinical outcomes and its interaction with percutaneous coronary intervention of an occluded infarct artery, long-term outcomes in 2173 patients with total occlusion of the infarct artery 3 to 28 days after myocardial infarction from the randomized Occluded Artery Trial were analyzed according to angiographic collaterals documented at study entry. There were important differences in baseline clinical and angiographic characteristics as a function of collateral grade, with generally lower-risk characteristics associated with higher collateral grade. Higher collateral grade was associated with lower rates of death (P=0.009), class III and IV heart failure (P<0.0001) or either (P=0.0002) but had no association with the risk of reinfarction. However, by multivariate analysis, collateral flow was neither an independent predictor of death nor of the primary end point of the trial (composite of death, reinfarction, or class IV heart failure). There was no interaction between angiographic collateral grade and the results of randomized treatment assignment (percutaneous coronary intervention or medical therapy alone) on clinical outcomes. Conclusions— In recent myocardial infarction, angiographic collaterals to the occluded infarct artery are correlates but not independent predictors of major clinical outcomes. Late recanalization of the infarct artery in addition to medical therapy shows no benefit compared with medical therapy alone, regardless of the presence or absence of collaterals. Therefore, revascularization decisions in patients with recent myocardial infarction should not be based on the presence or grade of angiographic collaterals. Clinical Trial Registration— URL: http://www.clinicaltrials.gov. Unique identifier: NCT00004562.

Association of plasma soluble E-selectin and adiponectin with carotid plaque in patients with systemic lupus erythematosus

BACKGROUND Systemic lupus erythematosus (SLE) is associated with premature atherosclerosis but the mechanisms underlying this association are not understood. The role of endothelial dysfunction is hypothesized. METHODS In predominantly non-Caucasian patients with SLE (N=119) and controls (N=71), carotid ultrasonography was performed and circulating endothelial cells (CECs), soluble endothelial protein C receptor and gene polymorphism at A6936G, soluble E-selectin (sE-selectin), and adiponectin were assessed. RESULTS Carotid plaque was more prevalent among patients than controls (43% vs 17%, p=0.0002). Mean CCA IMT was greater in patients compared to controls (0.59+/-0.19 mm vs 0.54+/-0.11 mm, p=0.03). Among SLE patients, plaque was not associated with smoking, body-mass index, LDL, triglycerides, homocysteine, C-reactive protein, anti-ds DNA antibody, C3, C4, SLE activity, or medications. Age and levels of soluble E-selectin and adiponectin were significantly higher in the SLE patients with plaque compared to those without plaque in univariate and multivariate analyses. sE-selectin and adiponectin were found to serve as independent predictors of carotid plaque and that elevations were persistent over more than one visit. Unexpectedly, these biomarkers were present despite clinical quiescence. CONCLUSION Premature atherosclerosis is a consistent feature of SLE and extends across ethnicities. Higher levels of adiponectin may represent a physiological attempt to limit further endothelial damage already reflected by the elevation in sE-selectin and the observed increase in plaque represents overwhelming of this reparative process by atherogenic stimuli.

Ambient Particulate Matter Air Pollution Exposure and Mortality in the NIH-AARP Diet and Health Cohort

Background: Outdoor fine particulate matter (≤ 2.5 μm; PM2.5) has been identified as a global health threat, but the number of large U.S. prospective cohort studies with individual participant data remains limited, especially at lower recent exposures. Objectives: We aimed to test the relationship between long-term exposure PM2.5 and death risk from all nonaccidental causes, cardiovascular (CVD), and respiratory diseases in 517,041 men and women enrolled in the National Institutes of Health-AARP cohort. Methods: Individual participant data were linked with residence PM2.5 exposure estimates across the continental United States for a 2000–2009 follow-up period when matching census tract–level PM2.5 exposure data were available. Participants enrolled ranged from 50 to 71 years of age, residing in six U.S. states and two cities. Cox proportional hazard models yielded hazard ratio (HR) estimates per 10 μg/m3 of PM2.5 exposure. Results: PM2.5 exposure was significantly associated with total mortality (HR = 1.03; 95% CI: 1.00, 1.05) and CVD mortality (HR = 1.10; 95% CI: 1.05, 1.15), but the association with respiratory mortality was not statistically significant (HR = 1.05; 95% CI: 0.98, 1.13). A significant association was found with respiratory mortality only among never smokers (HR = 1.27; 95% CI: 1.03, 1.56). Associations with 10-μg/m3 PM2.5 exposures in yearly participant residential annual mean, or in metropolitan area-wide mean, were consistent with baseline exposure model results. Associations with PM2.5 were similar when adjusted for ozone exposures. Analyses of California residents alone also yielded statistically significant PM2.5 mortality HRs for total and CVD mortality. Conclusions: Long-term exposure to PM2.5 air pollution was associated with an increased risk of total and CVD mortality, providing an independent test of the PM2.5–mortality relationship in a new large U.S. prospective cohort experiencing lower post-2000 PM2.5 exposure levels. Citation: Thurston GD, Ahn J, Cromar KR, Shao Y, Reynolds HR, Jerrett M, Lim CC, Shanley R, Park Y, Hayes RB. 2016. Ambient particulate matter air pollution exposure and mortality in the NIH-AARP Diet and Health cohort. Environ Health Perspect 124:484–490; http://dx.doi.org/10.1289/ehp.1509676