Circulation: Clinical Summaries
Original Research Put Into Perspective for the Practicing Clinician
- Coronary Heart Disease Mortality Declines in the United States From 1979 Through 2011: Evidence for Stagnation in Young Adults, Especially Women
- Inducing Persistent Flow Disturbances Accelerates Atherogenesis and Promotes Thin Cap Fibroatheroma Development in D374Y-PCSK9 Hypercholesterolemic Minipigs
- Risk of Cardiomyopathy in Younger Persons With a Family History of Death from Cardiomyopathy: A Nationwide Family Study in a Cohort of 3.9 Million Persons
- Incidence and Clinical Significance of Poststent Optical Coherence Tomography Findings: One-Year Follow-Up Study From a Multicenter Registry
- Association Between Chest Compression Interruptions and Clinical Outcomes of Ventricular Fibrillation Out-of-Hospital Cardiac Arrest
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Coronary Heart Disease Mortality Declines in the United States From 1979 Through 2011: Evidence for Stagnation in Young Adults, Especially Women
This article reports for the first time national trends in coronary heart disease (CHD) mortality by sex and age for the past 30 years, from 1979 to 2011. The analysis reveals significant heterogeneity in CHD mortality rates over time by sex and age. Older adults, especially men ≥55 years of age and women ≥65 years of age, have shown robust CHD mortality reductions over the past 2 decades with an acceleration over the past decade. In contrast, young adults <55 years old have shown sluggish improvements in the same time period; the gains in CHD mortality reduction have been especially weak for young women. These data suggest that attention should be given to the young population, especially women, whose cardiovascular risk profile may have worsened disproportionally in recent decades, which may potentially explain their less favorable trends in CHD mortality reduction. See p 997.
Inducing Persistent Flow Disturbances Accelerates Atherogenesis and Promotes Thin Cap Fibroatheroma Development in D374Y-PCSK9 Hypercholesterolemic Minipigs
Atherosclerosis is a multifocal lipid-driven inflammatory process. The precise environmental cues leading to plaque initiation, progression, and development of final lesion phenotype are not yet fully elucidated, but disturbed blood flow, which can be quantified by using metrics of shear stress, is thought to play a central role. In the current study, we evaluated whether inducing disturbed flow caused the development of advanced coronary plaques, including thin cap fibroatheroma, by implanting intracoronary shear-modifying stents in D374Y-PCSK9 hypercholesterolemic minipigs. We developed computational fluid dynamic models of local hemodynamics by using frequency-domain optical coherence tomography–derived coronary geometries and coregistered histology of the same vessel to these 3-dimensional reconstructions (3-dimensional histology). Our data support a causal role for lowered and multidirectional shear stress in the initiation of advanced coronary atherosclerotic plaques. Persistently lowered shear stress appears to be the principal flow disturbance needed for the formation of human-like thin cap fibroatheroma. This model, combined with frequency-domain optical coherence tomography–derived fluid dynamics and 3-dimensional histology, provides a new means of studying the biomechanics and mechanobiology of human-like advanced coronary plaques. Our data suggest that specific hemodynamic signatures may determine the development of specific coronary atherosclerotic plaque types. These observations provide the rationale for further exploring whether the metrics quantifying perturbation of normal (ie, nonatherogenic) flow, which evaluate changes in magnitude and direction of wall shear stress, may serve as biomarkers that predict the development of different types of advanced plaque, including those at increased risk of causing future clinical events. See p 1003.
Risk of Cardiomyopathy in Younger Persons With a Family History of Death from Cardiomyopathy: A Nationwide Family Study in a Cohort of 3.9 Million Persons
This is the first nationwide study to confirm familial accumulation of cardiomyopathies previously mainly reported from tertiary referral centers. Our general population-based results strongly support that additional first and second degree relatives of persons with cardiomyopathies are at risk of developing cardiomyopathy and associated complications, including ventricular arrhythmia. Considering the recommendations for primary prophylactic treatment in patients with cardiomyopathies in order to reduce morbidity and mortality by early interventions, our findings significantly support the rational for presymptomatic screening of relatives of patients with cardiomyopathy. In these families, identification of a disease-causing mutation in the proband allows to tailor the follow up of relatives to those carrying that gene mutation and follow up of noncarriers can be ceased. In this context, the strong scientific argument provided by our findings for systematic utilization of family history is crucial for identification of families to be offered screening. It highlights the importance of the old-fashioned, clinically-careful assessment of a detailed family history, a simple, but truly powerful diagnostic tool in cardiology, to potentially save lives. See p 1013.
Incidence and Clinical Significance of Poststent Optical Coherence Tomography Findings: One-Year Follow-Up Study From a Multicenter Registry
Optical coherence tomography was recently introduced to optimize percutaneous coronary intervention. Because of its unprecedented resolution, poststent abnormal vascular response, such as stent edge dissection, instent dissection, incomplete stent apposition, instent tissue, and thrombus, is frequently observed. However, the clinical significance of these findings remains unknown. In this study, we analyzed 900 lesions treated with 1001 stents. Stent edge dissection and instent dissection were detected in one-quarter and two-thirds of lesions. Incomplete stent apposition was detected in more than one-third of lesions. Among these poststent optical coherence tomography findings, irregular protrusion and small minimal stent area were predictive of device-oriented clinical end points at 1 year, which was primarily driven by target lesion revascularization. These 2 optical coherence tomography features showed >95% negative predictive value, which is helpful for risk stratification after stenting. Further studies are needed to evaluate longer-term outcomes and to find optimal treatment for the patients with these abnormal optical coherence tomography findings after stenting. See p 1020.
Association Between Chest Compression Interruptions and Clinical Outcomes of Ventricular Fibrillation Out-of-Hospital Cardiac Arrest
During cardiopulmonary resuscitation, prolonged pauses of chest compressions for defibrillation have been associated with worse survival. Guidelines for cardiopulmonary resuscitation strongly emphasize minimizing such pauses. The relationship between prolonged interruption of chest compressions for reasons other than defibrillation and survival has not been clinically evaluated. In 319 consecutive patients with out-of-hospital cardiac arrest and a shockable initial rhythm, we evaluated the association between survival to hospital discharge and the duration of chest compression interruptions, regardless of their cause. ECG and impedance recordings from defibrillators (automated external defibrillators and monitors) were used to identify the longest interruptions for defibrillation (perishock pauses) and for any other reason (nonshock pauses). The longest perishock pause was a median of 23 seconds; the longest nonshock pause, 24 seconds; and the longest pause regardless of reason, 32 seconds. Increasing duration of all pauses was associated with significantly worse survival. If the longest overall pause was a nonshock pause, there was an even lower survival than when the longest pause was a perishock pause (27% versus 44%; P<0.01), despite a higher chest compression fraction (0.74 versus 0.71; P=0.04). Long preshock pauses were not associated with less termination of ventricular fibrillation by the defibrillation shock. The emphasis placed on minimizing pauses for defibrillation should therefore be broadened to long pauses for other interventions. During resuscitation, avoiding long pauses that are not associated with defibrillation (such as pauses for intubation, rhythm check, or otherwise) is as important as avoiding long pauses for defibrillation. See p 1030.
- © 2015 American Heart Association, Inc.
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