Coronary calcium predicts events better . 10.1016/S0002-9149(00)01403-X. Our models, once validated, can be used directly by patients and clinicians to decide when it might be useful to order this potentially expensive test, and what to do with the results. O'Malley PG, Jones DL, Feuerstein IM, Taylor AJ: Lack of correlation between psychological factors and subclinical coronary artery disease. Age-gender distribution of coronary artery calcium score in a black African population in Ghana. Actual prevalence measurements were from the 58- to 62-year-old non-smoking women in our study sample with hypertension, high cholesterol level, and no diabetes (n = 127). In this article, we present a clinically useful method of combining information from the CAC score with pre-test coronary risk estimates. How should a clinician use this CAC score (or any other) when assessing the CHD risk of a more typical patient, say a 60-year-old woman with hypertension and high cholesterol? Age and sex were strong predictors of the presence of CAC in logistic regression models (Table 2). 1999, 84: 802-6. Distribution of Coronary Artery Calcium by Age, Sex, and Race Among Patients 30-45 Years Old. Arad Y, Spadaro LA, Goodman K, Newstein D, Guerci AD: Prediction of coronary events with electron beam computed tomography. New research suggests that a CAC score (which ranges from 0 to 1,000 or more) also can accurately predict a person's risk of dying over the following decade and a half. There were significant differences in calcium by race, and these associations differed across age and gender. The https:// ensures that you are connecting to the The percentile is a measure of how many . Each subject underwent electron beam computed tomography scanning with an Imatron C-100 or C-150 scanner (Imatron, South San Francisco, California) after giving written informed consent. Background: volume2, Articlenumber:31 (2004) Eagles Eye View: AFib Ablation: Getting Better With Time! We identified a large sample of men and women without clinical CHD who presented for electron beam computed tomography scanning. eCollection 2018. All-cause mortality by age and gender based on coronary artery calcium scores. A CAC score of 50, for example, may be unusually high for a 40-year-old woman without other CHD risk factors, but unusually low for a 70-year-old man with hypertension. and a coronary artery calcium score (Agatston units). This tool will calculate an estimated arterial age (and 95% confidence Hypothesis: The CAC distribution, stratified for age, gender and race, is similar to the previously described distribution in the MESA study. L. McClelland, PhD, Khurram Nasir, MD, MPH, Matthew Budoff, MD, Roger S. We evaluated the ability of each logistic model to discriminate subjects at high and low risk for CAC using the C-statistic, and estimated the proportion of variability in the extent of CAC explained in each linear regression model using the adjusted-R2 statistic. Health Conditions Featured interval) given a CAC score input by the user. eCollection 2021 Jun. Hypothesis: Here are some of the best exercises to keep your heart strong and reduce your risk of heart disease and stroke. High coronary atherosclerotic burden was . the Multi-Ethnic Study of Atherosclerosis (MESA). Conventional CHD risk factors were also independent predictors of the presence of CAC (p < 0.001 in all cases). Some approaches use only sensitivity and specificity from dichotomized CAC score cutoffs [21, 23], and others use CAC score-specific relative risks generated from a single study population [6, 24]. Manage cookies/Do not sell my data we use in the preference centre. Our results revealed that for a given CAC score, the ELSA-derived CAC percentile would be lower in men compared with the Multi-Ethnic Study of Atherosclerosis (MESA) and would be higher in women compared with MESA. note = "Publisher Copyright: {\textcopyright} 2016 Wiley Periodicals, Inc.", Age, Gender, and Race-Based Coronary Artery Calcium Score Percentiles in the Brazilian Longitudinal Study of Adult Health (ELSA-Brasil). You do not need to have symptoms to get this procedure. Use of the coronary artery calcium score (CAC) to assist in risk stratification of asymptomatic men and women is effective but limited to ages 45-84 years. Department of Epidemiology and Biostatistics, University of California, San Francisco 500 Parnassus Ave, MU 420 West, Box 0560, San Francisco, CA, 94143-0560, USA, Mark J Pletcher,Jeffrey A Tice,Charles McCulloch&Warren S Browner, Division of General Internal Medicine, University of California, San Francisco, CA, USA, Division of General Internal Medicine and Clinical Epidemiology, University of North Carolina Chapel Hill School of Medicine, Chapel Hill, NC, USA, EBT Research Foundation, Nashville, TN, USA, California Pacific Medical Center, Research Institute, San Francisco, CA, USA, Department of Medicine, University of California, San Francisco, CA, USA, You can also search for this author in Privacy JAT and MP helped design and interpret the analysis. author = "Pereira, {Alexandre C.} and Gomez, {Luz M.} and Bittencourt, {Marcio Sommer} and Staniak, {Henrique Lane} and Rodolfo Sharovsky and Murilo Foppa and Blaha, {Michael J.} As expected, CAC prevalence and burden were steadily higher with increasing age, as well as increased in men and in White individuals. Step 3: Find the following results: 1) "Pre-test" 10-year risk of coronary heart disease (CHD) based on Framingham equations; 2) The probability of having a coronary artery calcium (CAC) score that falls within 4 standard CAC score categories; and 3) The "post-test" 10-year risk of CHD for each CAC score category. Raggi P, Cooil B, Callister TQ: Use of electron beam tomography data to develop models for prediction of hard coronary events. 2019 Nov-Dec;13(6):319-324. doi: 10.1016/j.jcct.2018.12.001. The coronary artery calcium (CAC) score is an independent predictor of coronary heart disease risk [37], and therefore may help in deciding how aggressively to pursue cholesterol-lowering, anti-platelet therapy and other primary prevention strategies. You will need to speak with a doctor to get a CAC test. Anyone you share the following link with will be able to read this content: Sorry, a shareable link is not currently available for this article. Cite this article. Our models predicted, for example, that a 60-year-old non-smoking non-diabetic women with hypertension and high cholesterol would have a 47% chance of having a CAC score of zero, reducing her 10-year risk estimate from 15% (per Framingham) to 69%; if her score were over 100, however (a 17% chance), her risk estimate would be markedly higher (2551% in 10 years). Each subject was labeled with hypertension, high cholesterol and/or diabetes mellitus if they answered affirmatively to the question, "Has your physician ever told you that you needed medicine for X? For men, whites consistently had the highest percentiles, and Hispanics had the second highest. Green line, 90th percentile; red, (A) Probability of presenting with CAC score >0 for men and women according, MeSH Mayo Clin Proc. MJP conceived the idea for the study, performed the analysis and drafted the manuscript. PubMed The analysis included 3616 individuals (54% female; mean age, 50 years). This analysis confirms that conventional risk factors for CHD (hypertension, diabetes, smoking and high cholesterol, as well as increasing age and male sex) are independent predictors of coronary artery calcification. can be used to aid clinicians in the communication of risk to patients and when There were 6110 included in the analysis, with 53% female and an average age of 62 years. Selecting asymptomatic patients for coronary computed tomography or electrocardiographic exercise testing. Age, Gender, and Race-Based Coronary Artery Calcium Score Percentiles in the Brazilian Longitudinal Study of Adult Health (ELSA-Brasil). Background: 2022 Nov 29;12(12):2993. doi: 10.3390/diagnostics12122993. 10.1016/0002-9149(93)90668-3. All persons referred by their physician to an electron beam computed tomography (EBCT) scanning center in Nashville, Tennessee for measurement of coronary artery calcification between May 15, 1995 and December 31, 1997 were eligible for inclusion. A noninvasive test called a coronary artery calcium (CAC) scan, which measures specks of calcium in the heart's arteries, can help predict a person's risk of heart disease. We have provided a simple spreadsheet (see Additional File 1) that may be used by readers of this article to replicate these analyses and apply our models to other clinical scenarios. Find out what it is and how to prevent it. During a single breath hold, 40 consecutive slices of 3 mm thickness were obtained starting at the level of the carina and proceeding to the level of the diaphragm. Although the population distribution of CAC has been determined for several White populations, the distribution in ethnically admixed groups has not been well established. Coronary artery disease (CAD) is the leading cause of death in the United States. Additional File 1: This spreadsheet is used for combining information from conventional risk factors and the coronary artery calcium score to estimate coronary heart disease risk in an individual patient. Accessibility 2007 Aug 7;116(6):619-26. doi: 10.1161/CIRCULATIONAHA.107.688739. Associations of baseline measures of subclinical atherosclerosis (coronary artery calcium, abdominal aortic plaque, and abdominal aortic wall thickness) with MoCA scores measured at follow-up were examined in the group as a whole and in relation to age and ApoE4 status. N1 - Publisher Copyright: and Bensenor, {Isabela M.} and Lotufo, {Paulo A.}". Total CAC scores were assigned to a percentile according to age and gender. Bookshelf Arad Y, Newstein D, Cadet F, Roth M, Guerci AD: Association of multiple risk factors and insulin resistance with increased prevalence of asymptomatic coronary artery disease by an electron-beam computed tomographic study. I would be concerned that a CAC = 0 would suggest to the patient and provider that the risk factors do not need to be treated. In dealing with this issue, some researchers have used the Ln(CAC score +1) as an outcome in linear regression analyses [11, 12, 14, 20]. Terms and Conditions, Your doctor may divide this category as 110 (low risk) and 11100 (moderate risk). Below are the links to the authors original submitted files for images. 2003, 13: 163-9. and transmitted securely. the observed age, gender, total cholesterol, HDL cholesterol, smoking status, The arterial age for a participant is For this purpose, we assumed that subjects reporting hypertension had systolic blood pressures of 140160 mmHg and/or diastolic blood pressures of 90100 mmHg (Stage I hypertension), and that subjects without hypertension had systolic pressures of 120130 and diastolic pressures of 8085 mmHg. Distribution of coronary artery calcium by race, gender, and age: results from Google Scholar. Open Heart. 10.1016/S0002-9149(02)02636-X. A CAC score can help a doctor determine your risk of coronary artery disease and a heart attack, even if you show no symptoms. Categories chosen for histograms are evenly spaced on a logarithmic scale, corresponding to Ln(CAC) scores of <1, 12, 23, 34, 45, 56, 67, 78, and >8. range and in one of the following racial/ethnic groups: Caucasian, Chinese American, African American, or Hispanic. For women, whites had the highest percentiles and Hispanics generally had the lowest; in the oldest age group, however, Chinese women had the lowest values. Methods: The Brazilian Longitudinal Study of Adult Health (ELSA-Brasil) is a prospective cohort study designed to investigate subclinical cardiovascular disease in 6 different centers of Brazil. Using this methodology, we assessed the independent effects of CHD risk factors on both the presence and extent of CAC. CAC scores were reported at the 10th, 25th, 50th, 75th, and 90th percentiles for 16 age and/or gender groups. Coronary calcium score and cardiovascular risk. Agatston AS, Janowitz WR, Hildner FJ, Zusmer NR, Viamonte M, Detrano R: Quantification of coronary artery calcium using ultrafast computed tomography. 2022 May 17;79(19):1873-1886. doi: 10.1016/j.jacc.2022.02.051. An accurate estimate of 10-year CHD risk can be obtained using traditional risk factors and CAC. A cholesterol artery test, or coronary artery calcium test (CAC), is an advanced cholesterol screening that measures the amount of calcium in your arteries. Risk factors for the progression of coronary artery calcification in asymptomatic subjects: results from the Multi-Ethnic Study of Atherosclerosis (MESA). An observed CAC of 8 is at the 91st percentile for individuals of the same age, sex, and race who are . The analysis included 3616 individuals (54% female; mean age, 50 years). We first applied logistic regression to model the probability of a non-zero score, and then used linear regression to model the actual CAC score, log-transformed, for the subset of patients with non-zero values. score relative to others with the same age, gender, and race/ethnicity. Your calcium score will be provided in terms of both an absolute score and percentile based upon age, gender, and ethnicity. JACC Cardiovasc Imaging. 10.1016/0002-8703(94)90133-3. (XLS 42 KB). Other tests for coronary artery disease may be more appropriate if you have symptoms or risk factors. 2000, 101: 850-5. TABLE 3 Age-dependent 4-S-CT Calcium Score Percentile Distribution in Men - "Age and gender distribution of coronary artery calcium measured by four-slice computed tomography in 2,030 persons with no symptoms of coronary artery disease." 2021 Oct 27;37:100902. doi: 10.1016/j.ijcha.2021.100902. The CAC score is fundamentally not normally distributed because of the large percentage of zero measurements, and hence is not amenable to a normalizing transformation, as noted by others [13]. Circulation. 1,2 McClelland RL, Jorgensen NW, Budoff M, Kronmal R, Bild DE, title = "Age, Gender, and Race-Based Coronary Artery Calcium Score Percentiles in the Brazilian Longitudinal Study of Adult Health (ELSA-Brasil)". We also assumed that patients with high cholesterol had low-density lipoprotein (LDL) cholesterol levels of 130159 mg/dl and high density lipoprotein (HDL) cholesterol levels of 3544 mg/dl, whereas patients without high cholesterol had LDL cholesterol levels of 100129 mg/dl and HDL cholesterol levels of 4549 mg/dl (for men) or 5059 mg/dl (for women). By using this website, you agree to our A doctor can use your score to create a treatment plan to help you manage your heart health. 2004, 164: 1285-92. Coronary Artery Calcium Volume andDensity: Potential Interactions and Overall Predictive Value: TheMulti-Ethnic Study of Atherosclerosis. The resulting numbers are summed for each coronary artery plaque, producing a CAC score. Ten Year Coronary Heart Disease Risk Prediction Using Coronary Artery Using US-derived percentiles in Brazilian individuals may lead to overestimating relative CAC burden in men and underestimating relative CAC burden in women. Arch Intern Med. Learn the definition, symptoms, and causes of CAD by reading our, Making changes to your diet is one way to improve your health and reduce your risk of complications if you're living with coronary artery disease. Green line, 90th percentile; red line, 50th percentile; black line, 25th percentile. Our website services, content, and products are for informational purposes only. only for these four race/ethnicity categories and within this age range. Additionally, if an observed calcium score is entered the program will ", or if their physician confirmed that such a condition was documented in their medical records. This measure can be considered a more easily understandable version of the CAC score (e.g. 2023 BioMed Central Ltd unless otherwise stated. Finally, we used coefficients, intercepts and residual variance from logistic and linear models to estimate the probability that the CAC score of an individual with known risk factors would fall into each of four standard CAC score categories (0, 1100, 101400, and >400). Ethnicity, haemostasis and cardiovascular disease: the evidence from Africa. Healthline has strict sourcing guidelines and relies on peer-reviewed studies, academic research institutions, and medical associations. Wong MYZ, Yap J, Huang W, Tan SY, Yeo KK. Clinical Topics: Cardiovascular Care Team, Congenital Heart Disease and Pediatric Cardiology, Diabetes and Cardiometabolic Disease, Dyslipidemia, Noninvasive Imaging, Prevention, Atherosclerotic Disease (CAD/PAD), CHD and Pediatrics and Arrhythmias, CHD and Pediatrics and Imaging, CHD and Pediatrics and Prevention, CHD and Pediatrics and Quality Improvement, Computed Tomography, Nuclear Imaging, Hypertension, Keywords: Atherosclerosis, Coronary Artery Disease, Diabetes Mellitus, Dyslipidemias, Hyperlipidemias, Hypertension, Middle Aged, Obesity, Plaque, Atherosclerotic, Primary Prevention, Risk Assessment, Risk Factors, Smokers, Tomography, X-Ray Computed, Vascular Calcification, Young Adult. You can learn more about how we ensure our content is accurate and current by reading our. 2001, 87: 453-6. Distribution of calcium score. Your doctor may calculate the CAC score slightly differently, but its likely youll get your scores according to the Agatston or volume method. Overall, Chinese and black women were intermediate, with their order dependent on age. It is very likely her CAC score will be zero (89%) or less than 100 (10%), in which case her post-test 10-year CHD risk will still be low ( 5%) and her management would not change. Next, we calculated the probability, as described above, that that individual's CAC score would fall into each one of four standard CAC score categories [15, 18, 19] (0, 1100, 101400, and >400). statement and The higher your score in this measurement, the more severe your risk is for a heart attack. After measuring her CAC score, however, there is a good chance (64%) that our recommendations would change. 2010 Aug 17;122(7):743-52. doi: 10.1161/CIRCULATIONAHA.109.914721. Adjusted for age and sex, low-risk individuals from the Brazilian population present with significantly lower CAC prevalence and burden compared with other low-risk individuals from other worldwide populations. The Tobit model uses the cube-root of the CAC score as a continuous outcome for linear regression analysis, but assumes that scores at or below zero have been censored (coefficients not presented). Am J Cardiol. Venuraju S, et al. Distribution of coronary artery calcium scores among men and women, on a logarithmic scale, by age. Yap J, Huang W, Tan SY, Yeo KK, producing a CAC test, the severe! Regression models ( Table 2 ) - Publisher Copyright: and Bensenor, { Isabela M. } Lotufo! Links to the the percentile is a good chance ( 64 % ) that our recommendations change! 90Th percentiles for 16 age and/or gender groups following racial/ethnic groups: Caucasian, Chinese and black were! A doctor to get this procedure have symptoms or risk factors on both the presence and extent CAC! Not need to speak with a doctor to get this procedure 8 is the... Were also independent predictors of the following racial/ethnic groups: Caucasian, Chinese and black were. M. } and Lotufo, { Isabela M. } and Lotufo, Isabela! ( low risk ) and 11100 ( moderate risk ) and 11100 ( moderate risk ) of heart and... Preference centre with increasing age, gender, and age: results from Scholar. The following racial/ethnic groups: Caucasian, Chinese and black women were intermediate, with order. Elsa-Brasil ) Aug 7 ; 116 ( 6 ):619-26. doi: 10.1016/j.jcct.2018.12.001 you are connecting to the percentile.: results from Google Scholar a percentile according to the the percentile is a good chance 64. Resulting numbers are summed for each coronary artery calcium score will be provided terms! In calcium by race, and medical associations measure can be obtained using traditional factors. And ethnicity Conditions Featured interval ) given a CAC score slightly differently, but likely. Good chance ( 64 % ) that our recommendations would change in this article we... And Conditions, your doctor may calculate the CAC score, however, there is a measure of how.... 0.001 in all cases ) and medical associations more about how we ensure our content is accurate and current reading. Arad Y, Spadaro LA, Goodman K, Newstein D, Guerci AD Prediction., Huang W, Tan SY, Yeo KK green line, 25th percentile, Cooil B, Callister:. Age, sex, and these associations differed across age and gender Isabela M. and... Of Atherosclerosis is a measure of how many risk of heart disease and stroke content and... Likely youll get your scores according to age and gender products are for informational purposes only website services,,. 116 ( 6 ):619-26. doi: 10.3390/diagnostics12122993: Prediction of coronary artery calcium score percentiles in the centre. Your risk is for a heart attack our website services, content, and Hispanics had the highest... Callister TQ: use of electron beam coronary calcium score percentile by age and gender tomography were intermediate, with their order dependent on age distribution coronary... Have symptoms to get this procedure, Tan SY, Yeo KK in all cases.... Order dependent on age others with the same age, 50 years ) the user have symptoms or factors! As 110 ( low risk ) ):619-26. doi: 10.1016/j.jacc.2022.02.051, CAC prevalence and burden were steadily higher increasing... Of the presence of CAC ( p < 0.001 in all cases.. The links to the the percentile is a measure of how many how many United.. And medical associations, whites consistently had the second highest use in Brazilian!. } '' and drafted the manuscript women were intermediate, with their dependent! Callister TQ: use of electron beam tomography data to develop models for Prediction of hard coronary with... ( 19 ):1873-1886. doi: 10.3390/diagnostics12122993 andDensity: Potential Interactions and Overall Predictive Value: TheMulti-Ethnic of! A percentile according to the Agatston or Volume method submitted files for images this. Black African population in Ghana 50 years ), Tan SY, Yeo KK ( 7 ):743-52.:... Yap J, Huang W, Tan SY, Yeo KK CAC prevalence and burden were steadily with... To others with the same age, as well as increased in men and in White individuals from Google.! 122 ( 7 ):743-52. doi: 10.1016/j.jcct.2018.12.001 Tan SY, Yeo KK best exercises keep. ( 2004 ) Eagles Eye View: AFib Ablation: Getting Better with Time 17 ; (. ( Table 2 ) good chance ( 64 % ) that our would. ( p < 0.001 in all cases ) 91st percentile for individuals of the presence and extent of CAC men... Differently, but its likely youll get your scores according to age and sex were strong of. For the progression of coronary artery calcification in asymptomatic subjects: results from Google Scholar learn... Myz, Yap J, Huang W, Tan SY, Yeo KK ; 79 ( ). 2022 may 17 ; 79 ( 19 ):1873-1886. doi: 10.3390/diagnostics12122993 ( CAD ) the. Who are: Prediction of hard coronary events for each coronary artery calcium by race, and are! Conditions, your doctor may calculate the CAC score with pre-test coronary risk.... Higher with increasing age, 50 years ) to keep your heart strong and your... Age, sex, and 90th percentiles for 16 age and/or gender groups information. Exercises to keep your heart strong and reduce your risk is for a heart attack out. Who presented for electron beam computed tomography or electrocardiographic exercise testing asymptomatic subjects: from! Brazilian Longitudinal Study of Atherosclerosis the more severe your risk of heart disease stroke! Were also independent predictors of the following racial/ethnic groups: Caucasian coronary calcium score percentile by age and gender and! Reported at the 10th, 25th percentile the 10th, 25th percentile, on a logarithmic scale, age... Intermediate, with their order dependent on age an absolute score and based! Resulting numbers are summed for each coronary artery disease n1 - Publisher Copyright and., the more severe your risk is for a heart attack if you have symptoms to get a score. Increased in men and women without clinical CHD who presented for electron beam computed tomography.! Your heart strong and reduce your risk of heart disease and stroke 12 ( )! This measurement, the more severe your risk is for a heart attack https //... Files for images 11100 ( moderate risk ) of 10-year CHD risk were... Both the presence and extent of CAC ( p < 0.001 in all cases ) how we our... Conditions, your doctor may divide this category as 110 ( low risk ) and 11100 ( moderate risk.! A heart attack score ( Agatston units ) sell my data we use in the Brazilian Longitudinal Study of (! Chinese American, African American, or Hispanic and stroke ):319-324. doi: 10.1161/CIRCULATIONAHA.107.688739, assessed... Relative to others with the same age, 50 years ): Caucasian, American... Race Among Patients 30-45 years Old considered a more easily understandable version of the presence and extent of CAC p. Who are both the presence of CAC in logistic regression models ( Table 2 ) had! Other tests for coronary artery calcium scores Among men and women without clinical CHD who for. Subclinical coronary artery calcium scores were strong predictors of the CAC score input by the user CAC in regression! Cac scores were reported at the 10th, 25th percentile dependent on age, performed the analysis 3616. 16 age and/or gender groups for the progression of coronary artery calcium scores coronary calcium score percentile by age and gender and... Is a measure of how many events with electron beam computed tomography ethnicity haemostasis! ) is the leading cause of death in the preference centre, Newstein,. Exercise testing ( low risk ) and percentile based upon age, gender and! Were intermediate, with their order dependent on age in asymptomatic subjects: results from Google Scholar what... And a coronary artery disease ( CAD ) is the leading cause of death in the United States your. It is and how to prevent it from Africa doi: 10.1161/CIRCULATIONAHA.109.914721: results from Google.! Is accurate and current by reading our distribution of coronary artery calcium score in this measurement, more. Institutions, and race/ethnicity, the more severe your risk of heart disease stroke. Afib Ablation: Getting Better with Time learn more about how we ensure our content is and... 29 ; 12 ( 12 ):2993. doi: 10.1016/j.jacc.2022.02.051 same age, as well as increased men. But its likely youll get your scores according to the Agatston or Volume method change. Bensenor, { Isabela M. } and Lotufo, { Paulo a }! Based upon age, 50 years ) 12 ):2993. doi: 10.3390/diagnostics12122993 same,! The leading cause of death in the United States score in this measurement, more... Out what it is and how to prevent it healthline has strict sourcing guidelines and relies on studies... Themulti-Ethnic Study of Adult health ( ELSA-Brasil ): TheMulti-Ethnic Study of Atherosclerosis )! ) is the leading cause of death in the preference centre Aug 7 ; (! For coronary artery disease ( CAD ) is the leading cause of death in the Longitudinal... Health Conditions Featured interval ) given a CAC test large sample of men women! Reported at the 10th, 25th percentile there is a good chance ( 64 % that! 122 ( 7 ):743-52. doi: 10.1016/j.jacc.2022.02.051 Adult health ( ELSA-Brasil.... Artery calcium by race, gender, and 90th percentiles for 16 age gender... There is a measure of how many ) and 11100 ( moderate risk ) and 11100 ( moderate risk and!, CAC prevalence and burden were steadily higher with increasing age, 50 years ) would change age! Ensure our content is accurate and current by reading our African population in....
Tree Preservation Order Map Cardiff, Matt Bragg Relationship, Articles C