Influence of symptomatic status on the prevalence of obstructive coronary artery disease in patients with zero calcium score
Department of Internal Medicine-Graduate Medical Education, Atlanta Medical Center, GA, United States. Atherosclerosis
(Impact Factor: 3.99).
07/2008; 203(2):533-7. DOI: 10.1016/j.atherosclerosis.2008.07.008
CAC has been used to predict obstructive CAD on invasive coronary angiography. However, it is unknown how the prevalence of obstructive CAD in patients with zero CAC is influenced by the presence or absence of chest pain.
210 consecutive patients referred for CAC and CorCTA were included in this analysis. Chest pain was defined based on the Diamond-Forrester classification.
134 patients (64%) were symptomatic and 76 (36%) were asymptomatic. Seventy patients had negative (33%); 140 had positive CAC (67%). In the symptomatic group with zero CAC, 8.2% (4/49) had an obstructive, non-calcified plaque; of these, 3 were <45 years. Sensitivity, specificity, positive predictive value (PPV) and negative predictive value (NPV) of CAC in the symptomatic population for detection of obstructive CAD were 0.86 (0.66-0.95), 0.42 (0.33-0.52), 0.28 (0.19-0.39) and 0.92 (0.8-0.97), respectively (p=0.007). No asymptomatic subject with zero CAC had obstructive CAD. Sensitivity, specificity, PPV and NPV of CAC in the asymptomatic population for detection of obstructive CAD were 1.00 (0.66-1.00), 0.32 (0.21-0.45), 0.18 (0.10-0.31) and 1.00 (0.80-1.00), respectively (p=0.05). Optimal cut-points to predict obstructive CAD and AUC were significantly different in symptomatic versus asymptomatic subjects (91 and 0.78 vs. 296 and 0.89, respectively) (p=0.005). CAC performed much better in symptomatic patients >45 years compared to younger patients to exclude obstructive CAD (AUC: 0.83 vs. 0.5, p<0.001; NPV=0.98).
CAC is better in asymptomatic compared to symptomatic subjects, especially in patients <age 45, to exclude obstructive CAD. Symptoms and age should be considered when interpreting CAC.
Available from: Ali Khawaja
- "However, around 5% of our patients in this sub group had severe stenosis. Werkhoven et.al observed significant CAD in 4% of patients with a CCS of 0 compared to 8% detected by Cademartiri et al. and Akram et al. [16,20,21]. Presence of stenosis in the absence of CCS is due to early atherosclerosis which contains lipid-rich plaques which have not calcified. "
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ABSTRACT: The need of having feasible screening tools like Coronary Calcium Scoring (CCS) and CT Coronary Artery (CTCA) for Coronary Artery Disease (CAD) has become paramount. We aimed to evaluate the accuracy of CCS in determining the degree of stenosis of coronary vessels as compared to that determined by CTCA in a South Asian population.
A retrospective study was conducted at The Aga Khan University Hospital. A total of 539 patient records were reviewed who had undergone CCS and CTCA between 2008 and 2010. Patient records were reviewed by comparing their CCS and CTCA results.
About 268 out of 301 (89%) patients with a CCS of 0--9 were found to be free of stenosis on CTCA. On a CCS of 10--99, 110 out of 121 (91%) patients were either free of stenosis or had mild stenosis. About 66 out of 79 (84%) patients had moderate or severe stenosis with a calcium score of 100--400 while none of the patients were free of stenosis. Around 28 out of 38 (74%) patients with a CCS of more than 400 had severe stenosis. However, only 04 patients (11%) were found to have mild stenosis. Spearman's rho revealed a correlation coefficient of 0.791 with a p-value of <0.001.
Our study reaffirms that in South Asian population, low CCS (<100) is associated with no or minimal stenosis while high CCS warrants further investigation; hence, making it a reliable tool for screening patients with CAD.
Available from: Sang Il Choi
- "The outstanding diagnostic accuracy of CCTA has been demonstrated by prospective multicenter studies using coronary angiography (CA) as the reference standard.11)12) Widespread use of CCTA revealed a non-negligible prevalence of non-calcified plaque (NCP) in subjects with CACS of zero, who have very low probability of future cardiac adverse events.13-15) In symptomatic patients, NCPs are predictive of myocardial hypoperfusion and future coronary events.16-18) "
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ABSTRACT: Non-calcified plaque (NCP) identified by coronary CT angiography (CCTA) has been reported in up to 10% of individuals with coronary artery calcium score (CACS) of zero. However, clinical risk factors and the prognostic value of NCP in asymptomatic subjects with CACS of zero are unknown.
The study population consisted of consecutive asymptomatic subjects (48±8 years, 57% men) who underwent CCTA from December 2005 to January 2008 as part of a general health evaluation.
Among 4491 of overall asymptomatic individuals with CACS of zero, 313 subjects (7%) had NCP: 279 patients (6%) with non-obstructive and 34 (1%) with obstructive. In multivariable analyses, age, male gender, diabetes, hypertension, and dyslipidemia were significantly associated with presence of NCP (all p<0.05). During the median follow-up duration of 22 months (interquartile percentile: 18 to 28 months) of subjects with NCP (n=313) and age, gender, and CCTA date matched individuals without NCP (n=313), there was no clinical event including all-cause death nor composite outcome of cardiac death, myocardial infarct, unstable angina requiring hospitalization, and revascularization after 90 days from index CCTA in both groups.
In the largest series of asymptomatic individuals with CACS of zero undergoing CCTA, age, male gender, diabetes, hypertension, and dyslipidemia were independently associated with NCP. However, a future risk of exclusive NCP in asymptomatic subjects with CACS of zero was negligible.
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ABSTRACT: The convergence of statistical (random) search for the minimization of an arbitrary function Q(w) is treated. It is shown that random search can be regarded as a gradient algorithm in the q-domain. Using this gradient to define the minimum of the function, the convergence is discussed at length-including convergence WP1, convergence in the mean and ¿-optimality. The proof of convergence is based upon the theorems of convergence of random processes of Braverman and Rozonoer. The relationship between random search and order statistics is explained. Finally, emphasis is put on the applicability of the theorems for the design of hierarchical search systems and statistical search with a mixture.
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