P. J. Jenkins

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.

Coronary artery calcification correlates with the presence and severity of valve calcification

AIM To investigate the prevalence of coronary artery calcification (CAC) in symptomatic individuals with CT evidence for left heart valve calcification, aortic valve (AVC), mitral valve (MAC) or both. METHODS This is a retrospective study of 282 consecutive patients with calcification in either the aortic valve or mitral annulus. Calcium scoring of the coronary artery, aortic and mitral valve was measured using the Agatston score. RESULTS AVC was more prevalent than MAC (64% vs. 2.5%, p < 0.001), with 34% having both. Absence of CAC was noted in 12.7% of the study population. AVC + CAC were observed in 53.5%, MAC and CAC in 2.1%, and combined AVC, MAC and CAC in 31.6%. The median CAC score was higher in individuals with combined AVC+MAC, followed by those with AVC and lowest was in the MAC group. The majority (40%) of individuals with AVC had CAC score >400, and only in 16% had CAC = 0. The same pattern was more evident in individuals with AVC + MAC, where 70% had CAC score >400 and only 6% had CAC score of 0. These results were irrespective of gender. There was no correlation between AVC and MAC but there was modest correlation between CAC score and AVC score (r = 0.28, p = 0.0001), MAC (r = 0.36, p = 0.0001) and with combined AVC + MAC (r = 0.5, p = 0.0001). AVC score of 262 had a sensitivity of 78% and specificity of 92% for the prediction of presence of CAC. CONCLUSION The presence and extent of calcification in the aortic valve or/and mitral valves are associated with severe coronary artery calcification.

Coronary Artery Calcification Progression in Asymptomatic Individuals With Initial Score of Zero

The aim of this study is to determine the progression of coronary artery calcification (CAC) using electron beam computed tomography (CT) when the initial CAC score (CACS) is zero and to determine the best interval to repeat a CAC scan. We studied 388 individuals with zero CACS (308 males; mean age: 48.8 ± 8.26 years) who underwent 2 consecutive CT scans in a period of at least 12 months apart. The interscan period was 2.99 ± 1.35 years (range: 1-6 years). Three-quarters of the individuals (75%) did not develop any CAC progression, 20.87% presented CAC progression of 1 to 10, 3.6% had 11 to 50, whereas only 0.51% had >50. The average time of new CAC development was 4.2 ± 1.1 years. Individuals with CAC progression presented higher incidence of hypertension, diabetes mellitus, hypercholesterolaemia and higer frequency of male gender than those with without CAC changes (p<0.02). No cardiac events occurred during the follow-up period.

Prevalence and Distribution of Coronary Artery Calcification in Asymptomatic British Population

Figure 1. Coronary artery calcification score (CACS) in male and female subjects according to age group. To the Editor: Coronary artery disease (CAD) remains a leading cause of death in western industrialized countries. It is often clinically silent until a life-threating event occurs, therefore there is a need for screening markers, and coronary artery calcification (CAC) has been introduced as 1 of them. We report initial data on CAC prevalence in a large British cohort of 16,222 consecutive asymptomatic individuals without documented CAD or chronic kidney disease (mean age, 52.6 6.5 years; 75.2% male). Scans were performed with electron beam computed tomography (Imatron C300 Ultrafast computed tomography scanner; GE Healthcare, London, UK), between January 2002 and December 2009. Hypertension, hypercholesterolemia, and diabetes mellitus were present in 4293 (24.5%), 2893 (17.8%), and 984 (6.1%), respectively; 2703 (16.6%) had family history of CAD and 2084 (12.8%) were smokers. Most were Caucasians (87.6%), followed by South Asians (5.6%), AfricanCaribbean (1.8%), Chinese (0.3%), and mixed race (4.5%). Male participants were younger compared with female (51.7 0.7 years vs 55.2 9.6 years); a greater number of male participants were smokers, had diabetes, and family history of CAD and hypercholesterolemia (P < 0.0001). CAC was present in 50.5% of the overall population (55.5% male, 35.5% female). In the entire cohort, the prevalence of CAC score (CACS) 0, 1-10, 11-100, 101-400, 4011000, and >1000 was 49.5%, 12%, 18.3%, 12%, 5.1%, and 3%, respectively. In male subjects the prevalence of CACS 0, 1-10, 11-100, 101-400, and >1000 was 44.5%, 13.1%, 19.3%, 13.4%, 6.1%, and 3.6%, respectively; and in female subjects the relevant prevalence was respectively 64.3%, 9.2%, 15%, 7.7%, 2.2%, and 1.5%. In all age groups, except those younger than 40 years (P 1⁄4 0.15), CACS was significantly higher in male subjects than female subjects (P < 0.001) (Fig. 1). The presence of CAC was associated with male sex, age, hypertension, diabetes mellitus, family history of CAD, and hypercholesterolemia (P < 0.0001). Our data show that the range of calcification is broad. In both sexes, CAC prevalence increases with age, although higher in men after the age of 40. Furthermore, CACS increased rapidly after the age of 50 in both sexes and

Comparison of coronary calcification among South Asians and Caucasians in the UK.

Most of the published studies have shown racial differences in the prevalence and severity of coronary artery calcification (CAC) [1–3]. Although individuals of South Asian origin (India, Pakistan, Sri Lanka, Nepal & Bangladesh) represent 20% of the world population and considered as one of the largest ethnic groups at risk of coronary heart disease (CHD), they are under-represented in studies investigating the presence of CAC [4,5]. Therefore, we compared the prevalence of CAC in Caucasians and South Asians who underwent electron beam computed tomography (EBCT) at the European Scanning Centre, London, UK. CAC score (CACS) was performed on an Imatron C300 Ultrafast EBCT scanner (GE Healthcare), using a standard method with calcium deposition scored according to Agatston method [6]. Demographic information and the presence of risk factors were abstracted from referral letters and questionnaires completed by the patients prior to their test. Individuals with previously documented CHD or chronic kidney disease were not included in the study. CACSwas assessed in 935 South Asians (739males and 196 females) and 13,501 Caucasians (10,232 males and 3269 females). Gender distribution between Caucasians and South Asians was similar (p= 0.1); conversely, the Caucasians group was older to its South Asians counterpart (52.8 ± 9.6 vs. 50.6 ± 10.3, respectively; p b 0.001); while on the other hand, South Asians appeared to have a higher prevalence of diabetes mellitus (17.5% vs. 4.3%; p b 0.0001). Interestingly, therewas no difference in the prevalence of smoking between the 2 groups (15% vs. 12.1%; p = 0.06), of hypertension (31.3% vs. 25.3%; p b 0.4), family history of CHD (22.8% vs. 16.1%; p = 0.3), and hyperlipidemia (24.5% vs. 17.3%; p = 0.3). The prevalence of CAC (CACS N 0) was similar between Caucasians and South Asians (50.9% vs. 50.8%; p= 0.9), although a statistically significant difference in the prevalence of CAC in South Asians N50 years should be noted (p= 0.01). South Asian males showed a higher mean CACS as compared to Caucasians (179.6 ± 545.1 vs. 144.1 ± 420.1; p= 0.03). Although, in malesb50 years, therewasno statistically significantlydifference inmean CACS between South Asians and Caucasians (36.1 ± 277.8 vs. 23.8 ± 104.2; p= 0.06), inmales N50 years old thedifference inmeanCACSwas significant (South Asians, 339.1 ± 702.9 vs. Caucasians 232.3 ± 528.7; p b 0.0001). On the other hand, no difference was observed in the mean CACS between South Asian and Caucasian females (South Asians 59.2 ± 224.9 vs. Caucasians 56.6 ± 219.2; p = 0.86). South Asian females b50 years and South Asian females N50 years had similar mean CACS compared to Caucasians. CACS subgroups for age, gender and racial subgroups are tabulated in Table 1. We observe that in South Asian males N50 years old, the mean CACS was significantly higher than the Caucasians (p b 0.0003) and there was significant difference in the proportion of the population in any CACS range (p= 0.01). South Asians seem more prone to extensive calcification, as South Asians had higher mean CACS than Caucasians in both sex and all age groups (Fig. 1). Furthermore, age seems to play an important

Prevalence of Noncalcified Coronary Plaque in Patients With Calcium Score of 0 : The Silent Enemy

Noncalcified coronary artery plaques (NCAPs) are susceptible to rupture, resulting in coronary artery thrombosis. Using computer tomography coronary angiography (CTCA), we evaluated the prevalence and degree of stenosis caused by NCAP in patients without coronary artery calcification (CAC). A retrospective analysis of 447 symptomatic patients with 0 CAC score revealed negative CTCA in 400 (89.5%). Noncalcified coronary artery plaques were demonstrated in 47 (10.5%), with 4 presenting stenosis >50%. Patients with positive CTCA, compared to those with normal CTCA, had significantly higher mean age (56.2 years vs 50.6 years, P < .004) and higher pretest coronary artery disease (CAD) probability (26% vs 34%, P < .0001). Noncalcified coronary artery plaque was predominantly developed in the proximal segment of the left anterior descending artery. Noncalcified coronary artery plaque is present in up to 10% of patients with a CAC score of 0. Computer tomography coronary angiography could be of diagnostic value in symptomatic patients with multiple risk factors for CAD, even in the absence of CAC.

Differences in clinical profile of individuals with severe and markedly elevated coronary artery calcification detected by electron beam computed tomography.

Although several studies have demonstrated the association between coronary artery calcification (CAC) and coronary artery disease events, the underlying mechanism has not been fully elucidated. Furthermore, extensive CAC still remains a poorly understood phenomenon. The objective of this study is to determine the clinical characteristics and differences between 831 asymptomatic individuals with very high CAC scores (CACS ≥1000) and 497 asymptomatic individuals with CAC scores of 400 to 999. Individuals with CACS ≥1000 were more likely to have hypertension ([HTN]; P = .0004), hypercholesterolemia (P = .0001), diabetes mellitus ([DM] P = .005), and high body mass index ([BMI]; P = .03) compared with individuals with CACS = 400-999. On multivariable analysis, age (P < .0001) and BMI (P = .01) were found to be significant risk factors for the presence of very high CAC. While for males, age (P < .0001), hypercholesterolemia (P = .001), DM (P = .002), and obesity (P = .003) were independent risk factors; in females only HTN (P = .04) was independent risk factor.

Coronary artery calcification is not related to coronary heart disease isolated family history

Coronary artery calcification is not related to coronary heart disease isolated family history

The prevalence of non-calcified plaques in symptomatic patients with zero calcium score

Introduction Atheromatous plaque rupture is the most common cause of coronary artery thrombosis. Non-calcified plaques, with thin fibrous cap and large thrombogenic lipid core, are predominantly the most susceptible to rupture. Aims To investigate, with a 640-slice, 320-row CT scanner, the non-calcified coronary artery plaques (NCAP) prevalence and the degree of caused obstruction, in a cohort of symptomatic subjects, without coronary calcification. Methods and Results Out of 1806 patients, who underwent coronary CT angiography (CTCA), we retrospectively identified 447 symptomatic patients with coronary artery calcification (CAC) score of 0. Standard cardiovascular risk factors were assessed prior to the CTCA study. From the 447 subjects, 400 (89.48%) had a negative CTCA, while in 47 (10.51%) NCAP were depicted on CTCA. Four of these (4/47) had stenosis more than 50%. Mean age of patients with positive CTCA was 56.21 years, significantly higher than those of patients with negative CTCA (50.6 years, p<0.004). Additionally, when compared to patients with normal CTCA, those with NCAP were in higher risk of developing CAD, as derived from the pre CTCA assessment (26% vs 34.04%, p<0.0001). The Left Anterior Descending artery (LAD), and especially the proximal segment, was the predominant location for the development of NCAP. Conclusion Absence of coronary calcification does not exclude the presence of atherosclerosis; NCAP is present in up to 10% of patients with CAC score of 0. Symptomatic patients, who older in age, with multiple factors and high probability of CAD, would benefit from CTCA even in the absence of CAC.