Increased burden of coronary artery disease in South-Asians living in North America. Need for an aggressive management algorithm

Despite improvements in cardiovascular outcomes, coronary artery disease (CAD) continues to be a major cause of death worldwide. South-Asians (SAs) show an increased risk of atherosclerosis and have the highest mortality rates from CAD than any other ethnic group. The greater susceptibility of SAs to CAD cannot be explained entirely by conventional risk factors alone. Other factors are involved, such as genetic predisposition and high prevalence of the metabolic syndrome and type-2 diabetes. CAD is more severe, extensive and malignant among SAs. It is often unsuspected and associated with adverse outcome requiring a more aggressive management strategy. With the growing SA population in North America, physicians need to be aware of the epidemiology, conventional causes, associated contributors, and adverse outcomes of CAD in this group. Importantly, physicians need a structured approach and an aggressive management algorithm for the optimal care of the high-risk SA patient population.     

Obesity, body fat distribution, and coronary artery disease

Obesity is an independent risk factor for the development of coronary artery disease (CAD). Obesity also increases risk for CAD indirectly through its association with insulin resistance, hyperlipidemia, and hypertension. An increased accumulation of fat in the intraabdominal cavity, termed visceral adiposity, is highly correlated with an adverse coronary risk profile. In patients at risk for coronary artery disease, the treatment of obesity results in an improved coronary risk profile. The prevalence of obesity is extremely high in coronary populations, yet the effect of weight loss on cardiovascular outcomes in CAD patients has received relatively little attention. Observational studies in the cardiac rehabilitation setting showed that patients who lose weight and exercise show an improvement in coronary risk profile. Further research is needed to better define the clinical effectiveness of weight loss programs and their benefits in coronary patients.     

Prevalence of, and risk factors for, angiographically determined coronary artery disease in type I-diabetic patients with nephropathy.

BACKGROUND--Thirty-five percent of type I-diabetic patients are dead of coronary artery disease by age 55 years, and the risk of death is increased eightfold to 15-fold in patients with nephropathy. However, the prevalence of coronary artery disease with respect to age is unknown and few risk factors have been identified. METHODS--One hundred ten insulin-dependent diabetic patients underwent routine pretransplant coronary angiography and cardiac risk factor assessment. Angiograms were evaluated by two angiographers for presence or absence of coronary artery disease (CAD, defined as one or more coronary artery stenoses of 50% or greater in diameter, and no CAD, defined as no stenosis of 25% or greater in diameter, respectively). Prevalence of CAD by age was determined, and associated risk factors were defined. RESULTS--Fifty-two of 110 patients had CAD. Coronary artery disease prevalence increased significantly with age; 13 of 16 patients older than 45 years of age had CAD. For patients 35 years of age or younger, associated risk factors included a family history of premature myocardial infarction, higher hemoglobin A1c level, hypertension for more than 5 years, lower high-density lipoprotein level, and smoking for more than 5 pack-years. For patients between 35 and 45 years of age, associated risk factors included number of years of diabetes, higher hemoglobin A1c levels, and smoking more than 5 pack-years. CONCLUSIONS--In type I-diabetic patients with nephropathy, CAD prevalence increased significantly with age and was found in the majority of patients older than 45 years of age. Coronary artery disease risk factors operative in the general population were significantly associated with CAD in this high-risk group. In addition, a role for hyperglycemia in accelerated atherogenesis was supported by the association of both higher hemoglobin A1c levels and number of years of diabetes with CAD.     

多层螺旋CT在冠状动脉疾病诊断中的应用

冠心病是严重影响人类健康的一种常见的重大疾病。在临床症状出现之前及早诊断冠状动脉疾病有着重要的意义。尽管常规冠状动脉造影术仍然是诊断冠心病的“金标准” ,但一些其它非介入技术的应用具有代替常规冠脉造影术的潜在可能性。这样 ,冠状动脉疾病的非介入诊断成为当今医学关心的问题。新一代的多层螺旋CT具有高的分辨率 ,可以对心脏及冠状动脉进行显像评价。它不仅可以直接检测冠脉管腔狭窄 ,而且可以检测冠脉粥样硬化斑块。虽然由于冠脉运动尤其是右冠和回旋支中、远段造成的伪影 ,限制了MSCT的应用 ,但在获得足够的冠脉显像质量的情况下 ,多层螺旋CT冠脉管腔显像诊断明确狭窄的敏感性及特异性达 90 %左右。近几年来 ,CT技术的进步和显像质量的提高为冠脉显像诊断提供了日益增加的临床价值。另一方面 ,多层螺旋CT通过对冠脉钙化的评价 ,进行冠脉斑块负荷的测量 ,可评价、预测心血管病的危险性。通过钙化斑块负荷和造影剂管腔显像结合可增加诊断的准确性。总之 ,MSCT作为评价冠状动脉疾病的非介入方法正在快速发展 ,将来可能成为一种有前途的诊断方法。     

The effect of type 1 diabetes mellitus on the gender difference in coronary artery calcification

OBJECTIVES

To examine whether the gender difference in coronary artery calcification, a measure of atherosclerotic plaque burden, is lost in type 1 diabetic patients, and whether abnormalities in established coronary heart disease risk factors explain this.

BACKGROUND

Type 1 diabetes abolishes the gender difference in coronary heart disease mortality because it is associated with a greater elevation of coronary disease risk in women than men. The pathophysiological basis of this is not understood.

METHODS

Coronary artery calcification and coronary risk factors were compared in 199 type 1 diabetic patients and 201 nondiabetic participants of similar age (30 to 55 years) and gender (50% female) distribution. Only one subject had a history of coronary disease. Calcification was measured with electron beam computed tomography.

RESULTS

In nondiabetic participants there was a large gender difference in calcification prevalence (men 54%, women 21%, odds ratio 4.5, p < 0.001), half of which was explained by established risk factors (odds ratio after ADJUSTMENT = 2.2). Diabetes was associated with a greatly increased prevalence of calcification in women (47%), but not men (52%), so that the gender difference in calcification was lost (p = 0.002 for the greater effect of diabetes on calcification in women than men). On adjustment for risk factors, diabetes remained associated with a threefold higher odds ratio of calcification in women than men (p = 0.02).

CONCLUSIONS

In type 1 diabetes coronary artery calcification is greatly increased in women and the gender difference in calcification is lost. Little of this is explained by known coronary risk factors.     

Detailed angiographic analysis of women with suspected ischemic chest pain (pilot phase data from the NHLBI-sponsored Women's Ischemia Syndrome Evaluation [WISE] Study Angiographic Core Laboratory)

The purpose of this study is to provide a contemporary qualitative and quantitative analysis of coronary angiograms from a large series of women enrolled in the Women's Ischemia Syndrome Evaluation (WISE) study who had suspected ischemic chest pain. Previous studies have suggested that women with chest pain have a lower prevalence of significant coronary artery disease (CAD) compared with men. Detailed analyses of angiographic findings relative to risk factors and outcomes are not available. All coronary angiograms were reviewed in a central core laboratory. Quantitative measurement of percent stenosis was used to assess the presence and severity of disease. Of the 323 women enrolled in the pilot phase, 34% had no detectable, 23% had measurable but minimal, and 43% had significant ( > 50% diameter stenosis) CAD. Of those with significant CAD, most had multivessel disease. Features suggesting complex plaque were identified in < 10%. Age, hypertension, diabetes mellitus, prior myocardial infarction (MI), current hormone replacement therapy, and unstable angina were all significant, independent predictors of presence of significant disease (p < 0.05). Subsequent hospitalization for a cardiac cause occurred more frequently in those women with minimal and significant disease compared with no disease (p = 0.001). The common findings of no and extensive CAD among symptomatic women at coronary angiography highlight the need for better clinical noninvasive evaluations for ischemia. Women with minimal CAD have intermediate rates of rehospitalization and cardiovascular events, and thus should not be considered low risk.     

Coronary artery calcification and risk factors for atherosclerosis in patients with venous thromboembolism

BACKGROUND: Venous thromboembolism (VTE) and atherosclerosis may be associated and may share common risk factors. We conducted a retrospective case-control study to investigate the association between VTE and coronary atherosclerotic disease (CAD) by means of measuring coronary artery calcification and evaluating clinical risk factors. METHODS: From 385 consecutive patients suspected of VTE, we randomly selected 89 cases with idiopathic VTE and 89 controls without VTE, frequency matched on gender and age. Risk factors for atherosclerosis were noted for both groups. Coronary artery calcification was quantified on pulmonary computed tomography (CT) angiographic images. The coronary artery calcification and risk factors were compared between the case and control groups. The associations between VTE and the presence of coronary artery calcium and risk factors were assessed with logistic regression analysis. RESULTS: A higher prevalence of coronary artery calcium was found in the case group (51.7%) than in the control group (28.1%) (p=0.001). The presence of coronary artery calcium was significantly associated with VTE with an odds ratio of 4.3 (95% confidence interval, 1.9-10.1) in a multivariable model. Diabetes mellitus and hypertension were also significantly associated with VTE. CONCLUSION: A significant association between VTE and CAD suggests that CAD is an independent risk factor for VTE. Diabetes and hypertension are also independent risk factors for VTE.     

Ultrasonic correlates of common carotid atherosclerosis in patients with coronary artery disease

Increased intima-media thickness and plaque development in the extracranial carotid arteries reportedly correlate well with the prevalence of coronary artery diseases. The location of these atherosclerotic lesions in the carotid artery varies with age in patients with coronary artery atherosclerosis. Intima-media thickness, plaque, and calcification in the common carotid artery and bifurcation were assessed with high-resolution B-mode ultrasonography. Forty patients with severe atherosclerosis of the coronary artery and 56 healthy control subjects with no risk factors for coronary atherosclerosis were included in this study. The subjects were divided into a middle-age group (40-59 yr) and an old-age group (60-79 yr). In both groups, the intimamedia thickness in the patients was significantly higher than that in the controls. Intima-media thickness of at least 0.7 mm in the middle-age group and at least 1.0 mm in the old-age group was specific and positively predictive of coronary artery disease. Plaque (> 1.0 mm) and calcification were more significant in patients than in controls. In the middle-age group, intimamedia thickness in the common carotid artery was correlated with coronary atherosclerotic severity. Conversely, in the old-age group, the presence of plaque and calcification at the bifurcation was correlated with coronary atherosclerotic severity. The characteristic manifestation of the atherosclerotic lesion in the carotid artery varied with age in patients with coronary artery disease.     

miRNA-146a and miRNA-126 as Potential Biomarkers in Patients with Coronary Artery Disease and Generalized Periodontitis

The present study aims to compare the levels of micro-RNA-146a and micro-RNA-126 in oral subgingival plaque and coronary plaque from artery walls in patients with coronary artery disease who suffer from generalized periodontitis. A total of 75 participants were selected and grouped into three categories of 25 patients each: GP+CAD, GP, and HP groups. GP+CAD consisted of patients diagnosed with generalized periodontitis (GP) and coronary artery disease (CAD). The GP+CAD group was further divided into two groups—GP+CADa: where subgingival plaque samples were collected; GP+CADb group: where coronary plaque samples were collected while the patient underwent a coronary artery bypass grafting surgery. The GP group consisted of 25 patients diagnosed with only generalized periodontitis. The HP group consisted of 25 systemically and periodontally healthy controls. miRNA-146a and miRNA126 levels were assessed in subgingival plaque (SP) samples from all groups. Results revealed that miRNA-146a was expressed at higher levels and miRNA-126 was downregulated in the GP+CAD group. microRNAs in subgingival plaque samples showed a significant correlation with the coronary plaque samples in the GP+CAD group. miRNA-146a and miRNA-126 were present in coronary artery disease patients with periodontitis. These micro-RNAs may serve as risk biomarkers for coronary artery disease and generalized periodontitis.     

Coronary Artery Disease in Patients with Chronic Kidney Disease: A Clinical Update

Chronic kidney disease (CKD) is an independent risk factor for coronary artery disease (CAD). Coronary artery disease is the leading cause of morbidity and mortality in patients with CKD. The outcomes of CAD are poorer in patients with CKD. In addition to traditional risk factors, several uremia-related risk factors such as inflammation, oxidative stress, endothelial dysfunction, coronary artery calcification, hyperhomocysteinemia, and immunosuppressants have been associated with accelerated atherosclerosis. A number of uremia-related biomarkers are identified as predictors of cardiac outcomes in CKD patients. The symptoms of CAD may not be typical in patients with CKD. Both dobutamine stress echocardiography and radionuclide myocardial perfusion imaging have moderate sensitivity and specificity in detecting obstructive CAD in CKD patients. Invasive coronary angiography carries a risk of contrast nephropathy in patients with advanced CKD. It should be reserved for those patients with a high risk for CAD and those who would benefit from revascularization. Guideline-recommended therapies are, in general, underutilized in renal patients. Medical therapy should be considered the initial strategy for clinically stable CAD. The effects of statins in patients with advanced CKD have been neutral despite a lipid-lowering effect. Compared to non-CKD population, percutaneous coronary intervention (PCI) is associated with higher procedure complications, restenosis, and future cardiac events even in the drug-eluting stent era in patients with CKD. Compared with PCI, coronary artery bypass grafting (CABG) reduces repeat revascularizations but is associated with significant perioperative morbidity and mortality. Screening for CAD is an important part of preoperative evaluation for kidney transplant candidates.     

冠状动脉钙化研究进展

冠状动脉钙化(CAC)是导致一般人群和冠状动脉性心脏病患者不良结局的危险因素。CAC的发病机制和骨形成有共同的途径,目前已经确定了一些导致CAC发生和发展的危险因素。用药物治疗控制CAC的努力没有取得成功,而冠状动脉钙化的患者经皮冠脉介入术和冠状动脉搭桥术后的无事件生存率也较低。虽然应用药物洗脱支架和斑块修饰装置对钙化血管的预后有一定改善,但不良事件发生率仍然很高。在未来,仍需创新的药物和器械治疗来改善CAC患者的不良预后。     

冠状动脉钙化积分预测老年冠心病的相关研究

目的进一步探讨预测老年冠心病的新指标,预防心血管事件的发生。方法对≥60岁老年人66例(冠心病48例,非冠心病18例)进行多层螺旋CT(MSCT)冠状动脉扫描和计算机自动测定冠状动脉钙化积分(CACS),对CACS结果进行分析。结果老年冠心病组的CACS明显高于非冠心病组(P<0·01)。3支血管钙化者CACS明显高于1支及2支血管钙化者,且钙化发生在任意血管段都有明确意义(P<0·01,P<0·05)。结论CACS优于传统危险因子,可作为预测冠心病的新指标之一。     

主动脉瓣钙化与冠心病的相关性研究

目的 探讨珠海地区汉族人群主动脉瓣钙化（AVC）与冠心病的相关性.方法 回顾性研究心内科住院患者1140例.所有患者均同期行超声心动图和冠状动脉造影检查,分析AVC与冠心病的相关性.结果 冠心病组中检出AVC的比率明显高于非冠心病组（32.3％比13.8％,P＜0.01）.冠心病组AVC患者冠脉受累严重程度高于无AVC患者.多因素分析显示,AVC、年龄、性别、高脂血症和糖尿病为全组冠心病的独立预测因子（P＜0.05）.结论 AVC与冠心病之间存在显著的相关性,对预测冠心病有一定参考价值.     

Angiographic prevalence and pattern of coronary artery disease in women

Background

There are not many studies describing the prevalence and pattern of “coronary artery disease” (CAD) in women undergoing “coronary angiography” (CAG). Hence, uncertainty thrives with regard to the angiographic prevalence and pattern of CAD in women.

Objective

Our objective was to study the prevalence and pattern of CAD among women undergoing CAG.

Methods

Data of 500 women who underwent CAG for suspected CAD over 3 years were retrospectively analyzed. They were classified into young group (age < 55 years) and elderly group (age ≥ 55 years). Angiographic profile of “left main disease” (LMD) was also studied.

Results

There was greater prevalence of obstructive CAD especially double vessel disease and triple vessel disease in elderly group while normal coronaries were more prevalent in young group. There was equal distribution of non-significant lesions and intermediate lesions between the two groups. The prevalence of LMD is 3.4%, obstructive CAD is 45.4%, and multivessel disease is 28%. The prevalence of LMD and multivessel disease is 31.4%. The pattern of involvement of coronary arteries was same between the two groups; left anterior descending artery is the most commonly affected vessel. Chronic total occlusion mostly involved right coronary artery. Bifurcation lesion involving distal left main coronary artery is the most prevalent pattern of LMD.

Conclusion

There has been a change with regard to clinical presentation and onset of risk factors for CAD at young age, but the load of atherosclerotic burden and pattern of involvement of coronary arteries have not changed in women.     

Aggressive and diffuse coronary calcification in South Asian angina patients compared to Caucasians with similar risk factors

Background

Ethnic differences in prevalence and severity of coronary artery disease are well established and are usually attributed to risk factors variation. This study investigates the differences in coronary artery narrowing and coronary calcification between two age- and gender-matched cohorts of South Asian and Caucasian symptomatic angina patients.

Methods

We identified 101 symptomatic angina patients of South Asian origin who had undergone CT angiography and calcium scoring, and compared them with 101 age and gender matched Caucasian patients.

Results

South Asians had a greater mean number of arterial segments with both obstructive and non-obstructive plaque than Caucasians (p = 0.006 and p = 0.0003, respectively) and higher prevalence of triple-vessel disease (p = 0.0004). Similarly, South Asians had a higher mean CAC score (p < 0.0001) and the percentage of South Asians with CAC > 0 and in all categories of CAC score 100–1000 were also higher, as was the number of arterial segments with calcified and non-calcified plaque. These results were more marked in patients aged > 50 but in those ≤ 50, Caucasians showed a higher mean number of diseased segments (p = 0.019), with non-obstructive plaque (p = 0.02), possibly suggesting that Caucasians are likely to have more diffuse atherosclerosis at an earlier age. CAC prevalence and severity in this age-group were not significantly different between South Asians and Caucasians.

Conclusion

Despite similar conventional risk factors for CAD, symptomatic South Asians seem to have more aggressive and diffuse arterial calcification compared to Caucasians. These differences are more profound above the age of 50, suggesting potential genetic or other risk factors yet to be determined.     

数字荧光透视检出冠状动脉钙化与冠状动脉造影的对比研究

目的　评价数字荧光透视检出冠状动脉钙化 (CAC)对诊断冠心病的价值。方法　 114例患者于冠状动脉造影前经数字荧光透视检查 CAC,以冠状动脉造影存在 1支以上的管径狭窄≥ 5 0 %为诊断冠心病的标准。结果　 114例患者中 ,冠心病患者 63例 ,无冠心病患者 5 1例。冠心病组 CAC阳性率明显高于造影无冠心病组 (71.4%对13 .7% ) ,P<0 .0 1;以数字荧光透视有无 CAC判断冠心病与冠状动脉造影对比 ,总符合率为 78.1% ;不同年龄、性别患者以及不同类型冠心病之间其符合率无明显差异 ,P>0 .0 5。结论　数字荧光透视检出 CAC简便易行 ,无创伤性 ,与冠状动脉造影对比符合率高 ,可广泛用于临床预测及诊断冠心病     

Prevalence of metabolic syndrome in patients with angiographically proven coronary artery disease presenting to a tertiary care hospital in Delhi,India

BackgroundCoronary artery disease is fast emerging as the major concern for afflicting people across the globe. The Indian subcontinent is highly predisposed to this condition due to distinctive risk factor profile of this population. This fact has led to a condition where the current preventative and management protocols that have worked well in the non-Asian Indian Caucasian populations, have failed to bring about the anticipated control over the incidence and progression of CAD in Asian Indians. Metabolic syndrome has been identified as a major determinant of CAD in this population.Materials and methodsThe prevalence of metabolic syndrome was determined in 431 patients undergoing coronary angiography through various diagnostic algorithms. The Asian modified diagnostic criteria were also implemented to estimate the metabolic syndrome prevalence in patients with different levels of stenosis.ResultsWe observed a high incidence of metabolic syndrome in the patients with coronary artery disease. The prevalence of MS increased with increase in severity of coronary artery involvement. The IDF guideline with Asian modification was the most successful diagnostic algorithm.ConclusionsIt is now imperative to acknowledge the unique pattern of CAD and risk factor profile prevalent among South Asians. This will facilitate more focused and individualized management protocols directed to this population. Metabolic syndrome is a major syndrome prevalent in this population. Hence, effective control of MS may help in reducing the morbidity and mortality due to CAD in a great way.     

Usefulness of carotid ultrasound to improve the ability of stress testing to predict coronary artery disease

Carotid ultrasound is a useful tool to detect plaque and measure carotid intimal-medial thickness (CIMT), which help identify asymptomatic patients at risk of cardiovascular events. However, the role of carotid ultrasound in stratifying risk in symptomatic patients has not been studied. We prospectively examined the hypothesis that in symptomatic patients undergoing exercise (or pharmacologic) stress testing (EST), CIMT and carotid plaque will improve the ability to identify patients with > or =50% coronary diameter stenosis. Mean and maximal CIMTs were measured in 50 symptomatic patients without known coronary artery disease (CAD) who were scheduled to undergo diagnostic angiography after EST with imaging. Pretest probability of CAD was calculated for each patient based on age, gender, and nature of symptoms. Fifty percent of patients were men, 32% were diabetic, 70% had hypertension, and 58% had dyslipidemia. CAD > or =50% was associated with CIMT in the >75th percentile (74% vs 44%, p = 0.047) and with presence of carotid plaque (96% vs 59%, p = 0.003). Of patients with an equivocal/negative EST result (n = 38), those with carotid plaque had a 46% (13 of 28) prevalence of significant CAD; in the smaller subset of patients without carotid plaque (n = 10), none had luminal stenosis > or =50% (p = 0.007). Pretest probability of CAD, presence of carotid plaque, moderately/severely abnormal EST result, and hypertension were independent predictors of significant CAD. In conclusion, carotid ultrasound appears to offer incremental value to EST in predicting presence or absence of > or =50% coronary diameter stenosis in symptomatic patients with equivocal/negative EST result.     

64层螺旋CT冠状动脉成像与心血管疾病危险分层的相关性

目的 探讨64层螺旋CT(64MSCT)冠状动脉(冠脉)成像与心血管病危险分层的相关性.方法 收集疑诊冠心病患者470例,按64MSCT冠脉成像结果根据冠脉有无病变、病变范围、钙化积分、冠脉狭窄程度、斑块性质分组;其中80例患者同时行冠脉造影术,按冠脉造影结果根据冠脉有无病变、病变范围、冠脉狭窄程度分组.470患者按心血管病危险分层分为极高危、高危、中高危、中危、低危5组,观察各危险分层中冠脉病变情况,并分析相关性.结果 470例患者中同时行MS CT冠脉成像与冠脉造影者80例,判断冠脉病变范围(χ2=3.631,P=0.067)与狭窄程度(χ2=1.639,P=0.200)两种方法间差异无统计学意义.随着危险分层的增高,冠脉病变范围增加(极高危多支血管病变值分别为1.09、高危双支血管病变值分别为0.91、低危单支血管病变值分别为1.07,冠脉狭窄程度也增加、极高危重度狭窄值分别为0.96、高危中度狭窄值分别为1.03、低危.轻度狭窄值分别为0.78,各心血管危险分层之间冠脉病变钙化积分差异有统计学意义(F=256.20、123.76、62.50、98.24、52.36,P＜0.01).在极高危的患者中软斑块比例最高,随着危险分层降低钙化斑块比例增高或无斑块极高危软斑值分别为1.01、低危钙斑值分别为1.17.结论 64MSCT冠脉成像可作为心血管病危险分层的依据,患者冠脉病变复杂,狭窄程度、钙化积分程度严重,软斑块比例较高,危险分层越高;随着危险分层的降低,冠脉病变支数减少,钙化积分降低,狭窄程度减轻,斑块以钙化斑块比例增高或无斑块.     

主动脉瓣钙化与冠心病有关联

目的:探讨中国南方部分汉族人群主动脉瓣钙化与冠心病之间的关系。方法:选取同期行冠状动脉造影检查和超声心动图检查患者1 153例,探讨主动脉瓣钙化与冠心病的相关性。结果:冠心病组主动脉瓣钙化的检出率明显高于非冠心病组(32.6%vs.13.9%,P0.01),多因素Logistic回归分析结果显示,除传统危险因素如年龄、性别、高脂血症、糖尿病外,主动脉瓣钙化也是全组冠心病的一项独立的预测因子(OR=1.53,P0.05)。结论:主动脉瓣钙化与全组冠心病发病之间存在显著的相关性,是冠心病的一项有意义的独立预测因子。