Coronary artery calcium scoring: an evidence-based guide for primary care physicians

Primary care physicians often must decide whether statin therapy would be appropriate (in addition to lifestyle modification) for managing asymptomatic individuals with borderline or intermediate risk for developing atherosclerotic cardiovascular disease (ASCVD), as assessed on the basis of traditional risk factors. In appropriate subjects, a simple, noninvasive measurement of coronary artery calcium can help clarify risk. Coronary atherosclerosis is a chronic inflammatory disease, with atherosclerotic plaque formation involving intimal inflammation and repeated cycles of erosion and fibrosis, healing and calcification. Atherosclerotic plaque formation represents the prognostic link between risk factors and future clinical events. The presence of coronary artery calcification is almost exclusively an indication of coronary artery disease, except in certain metabolic conditions. Coronary artery calcification can be detected and quantified in a matter of seconds by noncontrast electrocardiogram-gated low-dose X-ray computed tomography (coronary artery calcium scoring [CACS]). Since the publication of the seminal work by Dr. Arthur Agatston in 1990, a wealth of CACS-based prognostic data has been reported. In addition, recent guidelines from various professional societies conclude that CACS may be considered as a tool for reclassifying risk for atherosclerotic cardiovascular disease in patients otherwise assessed to have intermediate risk, so as to more accurately inform decisions about possible statin therapy in addition to lifestyle modification as primary preventive therapy. In this review, we provide an overview of CACS, from acquisition to interpretation, and summarize the scientific evidence for and the appropriate use of CACS as put forth in current clinical guidelines.     

疑诊冠心病患者冠状动脉病变程度预测评分系统的建立及效能分析

目的:建立疑诊冠状动脉粥样硬化性心脏病(CHD)患者冠状动脉病变程度预测评分系统。方法:前瞻性入选疑诊CHD的住院患者326例,结合其冠状动脉造影结果及病变程度(SYNTAX),对相关临床资料进行Logistic多因素回归分析,筛选出比值比(OR)分值较高的危险因素,建立相应预测评分系统。再次入选疑诊冠心病的住院患者133例,对照该预测评分系统及造影结果,通过计算受试者工作特性(ROC)曲线下面积检验该评分系统的效能。结果:重度吸烟、糖尿病史、HDL-C水平降低、男性、早发冠心病家族病史以及踝肱指数异常,为该评分系统的6个主要危险因素。诊断评分方案ROC曲线下面积为0.703,标准误为0.010。危险积分范围:0~14分。随着危险积分的数值增加,患者诊断CHD的可能性越大,其冠状动脉病变程度也趋于严重。结论:该评分系统能对疑诊CHD的冠状动脉病变性质及程度进行初步预测,有可能为进一步的检查和治疗决策提供指导。     

Nebivolol improves coronary flow reserve in hypertensive patients without coronary heart disease

OBJECTIVE: To examine the effects of nebivolol, a beta-blocker with nitroxide-mediated vasodilating properties, on coronary flow reserve (CFR) in patients with uncomplicated arterial hypertension. DESIGN, SETTING AND PATIENTS: Fourteen newly diagnosed, never-treated, World Health Organization grade I-II hypertensive patients (male/female, 10/4; mean age, 47 years), free of coronary heart disease, underwent standard Doppler echocardiography and determination of CFR in the distal left anterior descending artery by low-dose dipyridamole (0.56 mg/kg intravenously in 4 min) at baseline and after 4 weeks of treatment with 5 mg nebivolol once daily. RESULTS: At baseline, nine patients had left ventricular (LV) hypertrophy (LV mass index > or = 51 g/m). After 4 weeks of therapy, the blood pressure was decreased from 148 +/- 8.1/101.4 +/- 4.6 mmHg to 140.7 +/- 7.0/91.1 +/- 7.4 mmHg and end-systolic stress was also significantly reduced. Heart rate was reduced (P <0.01), whereas LV end-diastolic diameter and stroke volume tended to increase (P=0.07 and P=0.09, respectively). No changes were detected in the LV mass index, relative wall thickness, fractional shortening and LV diastolic properties. Both resting and dipyridamole rate-pressure products were lower after nebivolol but dipyridamole-induced changes were not influenced by the therapy. In contrast, nebivolol therapy did not alter coronary velocities at rest, but caused a greater increase in coronary velocities after dipyridamole (P <0.03), leading to a greater CFR (2.12 +/- 0.33 versus 1.89 +/- 0.31, P <0.0001). Nebivolol induced an absolute increase of 8% in the CFR in nine of 14 patients (64.3%). CONCLUSIONS: In hypertensive patients free of coronary artery disease, 4-week nebivolol therapy induces a significant increase of the CFR. Nebivolol preserves coronary flow at rest despite the reduction of metabolic (O2 consumption) and hemodynamic (diastolic blood pressure) determinants. The increase of hyperemic coronary velocities appears due to the reduction of coronary resistance.     

Cancer in inflammatory bowel disease. An evidence-based analysis and guide for physicians and patients

The risk of cancer in IBD is real and is a cause of anxiety and concern among patients and practitioners. Current modalities for detecting dysplasia in IBD are crude and insensitive and subject to observer and sampling bias. This evidence-based review confirms a significant increased risk for colorectal cancer among patients with pancolonic UC and, to a lesser extent, in patients with left-sided disease. Risk increases with longer duration of disease; early age at diagnosis; coexisting PSC; and, perhaps, a family history of colorectal cancer. Physicians must pay greater attention to the manner in which they implement surveillance colonoscopies, including paying heed to the location and number of biopsy specimens required to maximize the benefit. With respect to CD, the evidence suggests that patients with extensive colonic involvement of long duration carry a similar risk of colorectal cancer to patients with UC and should be considered candidates for surveillance colonoscopy.     

Comparison of coronary artery calcium detected by electron beam tomography in patients with to those without symptomatic coronary heart disease

Although the presence of coronary artery calcium (CAC) has been associated with the prevalence and incidence of coronary heart disease (CHD), it is unclear if this association has a threshold or a continuous relation. The aim of this research was to explore the relation between CAC, as detected by electron beam tomography (EBT), and CHD in a cross-sectional study of women and men who presented to a single center for elective screening with EBT from 1995 to 1998. Of 17,967 participants, patients with CHD had higher CAC levels than those without CHD. Using subjects without CAC as the referent group, the odds ratios for prevalent CHD increased significantly across increasing quartiles of CAC in the overall population and in both genders. In a subset of the population, after adjusting for CHD risk factors, CAC scores in the fourth quartile were associated with an odds ratio of 33.8 (p <0.001) for prevalent CHD. Among patients with and without CHD, men were more likely than women to have detectable CAC (58.1% vs 28.3% and 96.1% vs 68.9% respectively, p <0.001 for each); the prevalence of detectable CAC increased with age and was higher in men than in women. There was an increased risk for prevalent CHD at all levels of CAC >0, with the greatest increase in risk occurring in patients with CAC scores >95. These observations support the potential of EBT as a sensitive test for detection of CHD.     

无症状冠心病检查技术的临床航空医学应用价值浅析

冠心病（CHD）容易诱发飞行人员空中失能,是威胁飞行安全的主要疾病之一。如何早期筛查与诊断无症状CHD一直是困扰航空军医的重要问题。目前临床上关于CHD的诊断从病史追踪到冠脉造影检查手段丰富多样,然而在航空航天医学工作中如何合理有效地应用这些检查方法尚存在争议。本文就目前临床上常用的CHD检查手段在筛查无症状人群中的诊断价值展开讨论,认为无论是从可行性方面、还是预测原理方面,都需要坚持多检查手段联用,从而有效提高CHD诊断准确性。     

The changing costs and benefits of screening for asymptomatic coronary heart disease in patients with diabetes

Aggressive medical therapy can be justified in most patients with diabetes, but there may be some higher-risk asymptomatic patients who could benefit from revascularization and/or medical therapy for myocardial ischemia. Silent myocardial ischemia (SMI) might be used to identify these high-risk individuals. In this Review we define SMI as objective evidence of ischemia from any noninvasive test occurring in an asymptomatic patient. We outline what is known about asymptomatic coronary heart disease (CHD) in diabetes and how this relates to SMI. We examine how SMI predicts angiographic CHD and CHD events, and we describe the changing role of CHD screening as reflected by various guidelines. We identify the recent research suggesting that there may be substantial numbers of high-risk asymptomatic patients who have diabetes with undiagnosed CHD and who could benefit from more-active intervention; however, with the recent advances in medical therapy, and the uncertain benefits of screening, current guidelines strongly discourage this practice, except in limited clinical situations, such as before major surgery. Carefully conducted clinical trails using state-of-the-art investigations and therapy in well-characterized patients with diabetes are urgently required to inform physicians on when and how to intervene.     

直接支架植入术与传统支架植入术治疗冠心病的对比研究

目的探讨直接支架植入术治疗冠心病患者的安全性、成功率和治疗效果。方法经冠状动脉造影,诊断明确,病变特征符合A型和B1型病变的冠心病患者165例,随机分为传统支架植入组(传统组)82例和直接支架植入组(直接组)83例,比较两组间手术成功率及并发症,心绞痛缓解率;支架置入时间;X线照射时间及造影剂用量。结果两组患者支架植入成功率及术后心绞痛缓解率均为100%;传统组与直接组并发症发生率均为2.4%。支架置入时间直接组(14.3±7.6)min,传统组(20.5±5.3)min,差异有统计学意义(P<0.05);X线照射时间直接组(4.9±3.5)min,传统组(7.6±2.9)min,差异有统计学意义(P<0.05);造影剂用量直接组(90±39)ml,传统组为(102±46)ml,差异有统计学意义(P<0.01)。结论直接支架植入术安全性、成功率和治疗效果与传统支架植入术一致,而且在支架植入时间、X线照射时间和造影剂用量明显低于传统支架植入术,值得临床推广应用。     

High-sensitivity cardiac troponin for risk prediction in patients with and without coronary heart disease

Background

In stable patients with unknown coronary anatomy, higher levels of cardiac troponin are associated with an increased risk of cardiovascular events. It was supposed that this association might be explained by the ability of cardiac troponin to detect minor myocardial necrosis which might be caused by subclinical coronary atherosclerosis. Thus, this analysis tested if the predictive value of high-sensitivity troponin T (hsTnT) in stable patients is dependent of the presence or absence of angiographically documented coronary heart disease.

Methods

Stable patients undergoing elective coronary angiography were enrolled (n = 2046). HsTnT was determined before diagnostic procedures. The patients were followed for up to seven years. Primary endpoint was all-cause mortality or non-fatal myocardial infarction. All endpoints were adjudicated by independent physicians. Results were adjusted to a clinical model including independent clinical predictors of the primary endpoint.

Results

Out of the 2046 patients enrolled, 1236 (60%) had a diagnosis of obstructive coronary heart disease. HsTnT predicted independently the primary endpoint (adjusted HR 1.33, 95%-CI 1.21–1.46, P < 0.001). The use of hsTnT in addition to the clinical model significantly improved discrimination (c-statistic: 0.751 to 0.773, P < 0.001) as well as reclassification of the primary endpoint (NRI = 0.362, P < 0.001). This significant improvement persisted across various subsets and was independent of the presence of clinically detectable coronary heart disease and other variables.

Conclusion

The use of hsTnT in addition to clinical variables significantly improves discrimination and reclassification of patients with respect to all-cause mortality or non-fatal myocardial infarction irrespective of the presence of clinically detectable coronary heart disease.

Clinical Trial Registration

ClinicalTrials.gov (Identifier: NCT00457236).     

Prognostic value of coronary electron-beam computed tomography for coronary heart disease events in asymptomatic populations

The predictive ability of electron-beam computed tomography (EBCT) for coronary heart disease outcomes, particularly hard coronary outcomes (myocardial infarction or death), has been questioned in asymptomatic populations. Our objective was to synthesize data on the use of EBCT for determining cardiovascular prognosis in asymptomatic populations. Studies were identified using standard systematic review methods. The outcome of interest was relative risk for myocardial infarction or sudden death, and combined events including revascularization. Nine articles met the inclusion criteria, of which 5 were of independent studies. Using meta-analytic techniques to synthesize prognostic data, there was an increased risk (summary risk ratio 8.7, 95% confidence interval 2.7 to 28.1) of a combined outcome of nonfatal myocardial infarction or death or revascularization if the calcium score was above a median score. Similarly, there was an increased risk for hard events: myocardial infarction or death (summary risk ratio 4.2, 95% confidence interval 1.6 to 11.3). However, there was significant heterogeneity in the studies' quality and patient populations. Although EBCT appears to predict combined and hard coronary outcomes similarly in high risk, asymptomatic populations, these results should be interpreted with caution. Further study is needed on the incremental value of EBCT over conventional risk prediction before this test is used in screening asymptomatic populations.     

无胸痛症状疑诊冠心病患者的诊断评分方案研究

目的在无胸痛症状就诊的疑诊冠心病(CHD)患者中建立高效预测CHD可能性的诊断评分系统。方法回顾性分析1447例入院疑诊CHD的无胸痛症状但存在心悸、气短等其他不适症状的患者,对相关临床因素进行Logistic多因素回归分析,筛选危险因素并对危险因素依据比值比(OR)值分别赋值,同时计算危险积分。建立以非胸痛症状就诊人群CHD诊断评分方案。通过计算受试者工作特性(ROC)曲线下面积及进行危险积分和CHD发生率相关性分析,检验诊断评分方案的效能。结果无胸痛症状的疑诊CHD人群的CHD发生率为53.70%。年龄、男性、吸烟史、高血压及糖尿病史是非胸痛症状就诊人群的CHD危险因素。诊断评分方案:ROC曲线下面积为0.730,并具有统计学意义。通过ROC曲线确定诊断临界点为6分,评分方案敏感度0.743、特异度0.624。危险积分范围:0～13分。危险积分越高,CHD发生率越高。危险积分和CHD发生率呈线性关系。结论诊断评分方案简单、实用,可有效预测无胸痛就诊的人群CHD的可能性,在临床实践中有重要意义。     

Screening for coronary artery disease in patients with type 2 diabetes mellitus: An evidence-based review

Coronary artery disease (CAD) is the leading cause of morbidity and mortality in patients with diabetes. CAD is often asymptomatic in these patients, until the onset of myocardial infarction or sudden cardiac death. Consequently, proper screening and diagnosis of CAD is crucial for the prevention and early treatment of coronary events. This review deals with selection of the sub group of patients who have type 2 diabetes, who are at high risk for developing CAD and need to be screened for the same. The various diagnostic modalities which can be used in the screening process for enhancing risk stratification and management are also discussed.     

老年人冠心病经皮冠状动脉介入治疗

随着我国逐渐步入老龄化社会,老年冠心病患者的人数日益增加。相对于非老年群体,老年冠心病患者心血管事件的危险因素更多,冠状动脉介入治疗术后的血栓和出血风险更大,因此老年冠心病患者的冠心病介入治疗需要得到更多的关注。本文回顾了老年冠心病患者接受冠状动脉介入治疗的相关进展,并提出老年冠心病介入治疗工作的改进建议。     

匹伐他汀钙治疗老年冠心病患者42例的疗效

目的：观察匹伐他汀钙治疗老年冠心病患者的疗效及安全性。方法：入选82例口服辛伐他汀10～20mg至少一年的老年冠心病患者,入院后随机分为辛伐他汀组（40例：继续服用辛伐他汀）和匹伐他汀组（42例,改为每晚睡前口服匹伐他汀钙1-2mg）,疗程为8周。分别于用药前、用药后2、4、8周检测两组肝功、血脂、磷酸肌酸激酶变化,并进行比较。结果：匹伐他汀钙组总胆固醇（Tc）和低密度脂蛋白-胆固醇（LDL—c）水平的下降与辛伐他汀片10～20mg／d相当[TC（4．31±0．67）mmol／L比（4．32±0．65）mmol／L,LDL—C（2．15±0．56）mmol／L比（2．05±0．78）mmol／L],P均〉0．05。不良反应较轻微,仅辛伐他汀组出现3例谷丙转氨酶、谷草转氨酶水平升高,在治疗4周时其值均明显高于匹伐他汀组（P〈0．05）。结论：匹伐他汀钙对老年冠心病患者疗效及安全性均较好,对肝功损害较轻。