Coronary artery calcium testing in low-intermediate risk symptomatic patients with suspected coronary artery disease: An effective gatekeeper to further testing?

Relationship Between Coronary Artery Calcium Score and Vulnerability of Culprit Plaque Assessed by OCT in Patients With Established Coronary Artery Disease

BACKGROUND

Coronary artery calcium score (CACS) is widely used for risk stratification. However, in patients with established coronary artery disease, its clinical implication and relationship with plaque vulnerability are unclear. We sought to correlate the CACS and plaque vulnerability assessed by optical coherence tomography.

METHODS

Patients with coronary artery disease who had CACS and optical coherence tomography before percutaneous coronary intervention were included. Patients were divided into 5 groups based on CACS: CACS of 0, 1 to 99, 100 to 399, 400 to 999, and ≥1000. Optical coherence tomography-derived vulnerable features in culprit plaque were compared between the groups.

RESULTS

In 460 patients, the prevalence of lipid-rich plaque, macrophage, and cholesterol crystal significantly differed among the 5 groups, being lowest in the patients with a CACS of 0. The prevalence of thin-cap fibroatheroma tended to be lower in those with a CACS of 0. No significant difference in vulnerable features was observed between the 4 groups with CACS >0. In the 2-group comparison between the group with a CACS of 0 and the other 4 groups combined, the prevalence of lipid-rich plaque (60.5% versus 85.9%; P<0.001), macrophage (48.8% versus 74.1%; P<0.001), thin-cap fibroatheroma (16.3% versus 35.0%; P=0.013), and cholesterol crystal (11.6% versus 32.9%; P=0.004) was significantly lower in the patients with CACS of 0. CACS of 0 was independently negatively associated with lipid-rich plaque, macrophage, thin-cap fibroatheroma, and cholesterol crystal after adjustment for patient characteristics.

CONCLUSIONS

Patients with a CACS of 0 have a significantly lower prevalence of vulnerable plaque features compared with those with CACS >0 in patients with established coronary artery disease.

REGISTRATION

URL: https://www.clinicaltrials.gov; Unique identifier: NCT04523194.

Diagnostic utility of coronary artery calcium score percentiles and categories to exclude abnormal scans and relevant ischemia in rubidium positron emission tomography

Background

Despite clinical suspicion, most non-invasive ischemia tests for coronary artery disease (CAD) reveal unremarkable results. Patients with a coronary artery calcium score (CACS) of zero rarely have an abnormal positron emission tomography (PET) and could be deferred from further testing. However, most patients have some extent of coronary calcification.

Objectives

CACS percentiles could be useful to exclude abnormal perfusion in patients with CACS >0, but data from patients with 82Rb PET are lacking. The aim of this study was to assess the diagnostic utility of CACS percentiles in comparison to zero calcium and absolute CACS classes.

Methods

Consecutive patients with suspected CAD (n = 1,792) referred for 82Rb PET were included and analyzed for abnormal PET (SSS ≥4) and relevant ischemia (>10% myocardium). Test characteristics were calculated.

Results

The mean age was 65 ± 11 years, 43% were female, and typical angina was reported in 21%. Abnormal PET/relevant ischemia (>10%) were observed in 19.8%/9.3%. Overall, the sensitivity/negative predictive value (NPV) of a <25th percentile CACS to rule out abnormal PET and relevant ischemia were 93.0%/95.7% and 98.2%/99.5%, respectively. The sensitivity/NPV of CACS 1-9 to rule out abnormal PET and relevant ischemia were 96.0%/91.8% and 97.6%/97.6%, respectively. Except for patients <50 years old, sensitivity for abnormal PET was >90.9% in all age groups.

Conclusion

In patients >50 years, the <25th percentile and CACS 1-9 had good test characteristics to rule out abnormal PET and relevant ischemia (>10%). They could be used to extend the scope of application of CACS 0 by 8%-10% to 32%-34% overall of patients who could be deferred from further testing.

Defining preventive cardiology: A clinical practice statement from the American Society for Preventive Cardiology

Remarkable transformations in science and healthcare have resulted in declines in mortality from cardiovascular disease over the past several decades, largely driven by progress in prevention and treatment of persons at risk. However, these trends are now beginning to stall, as our county faces increases in cardiovascular risk factors including overweight and obesity, type 2 diabetes mellitus, and metabolic syndrome. Furthermore, poor long-term adherence to a healthy lifestyle and lifesaving pharmacotherapy have exacerbated these trends, with recent data suggesting unprecedented increases in cardiovascular morbidity and mortality. A paradigm shift is needed to improve the cardiovascular health of our nation. Preventive cardiology, a growing subspecialty of cardiovascular medicine, is the practice of primordial, primary, and secondary prevention of all cardiovascular diseases. Preventive cardiologists and preventive cardiology specialists are well equipped with the knowledge and skill-set necessary to reduce deaths related to the growing burden of heart disease and its risk factors. Despite dedicated efforts, cardiovascular disease remains the leading killer of men and women in the United States. Although there is little debate regarding the importance of prevention, many healthcare professionals question the need for preventive cardiology as a distinct subspecialty. Additionally, the field's growth has been hampered by a lack of organization and standardization, and variability of training within programs across the country. The purpose of this document is to delineate the key attributes that define the field of preventive cardiology according to the American Society for Preventive Cardiology.

Prediction models as gatekeepers for diagnostic testing in angina patients with suspected chronic coronary syndrome

AIMS

Assessment of pre-test probability (PTP) is an important gatekeeper when selecting patients for diagnostic testing for coronary artery disease (CAD). The 2019 European Society of Cardiology (ESC) guidelines recommend upgrading PTP based on clinical risk factors but provide no estimates of how these affect PTP. We aimed to validate two published PTP models in a contemporary low-CAD-prevalence cohort and compare with the ESC 2019 PTP.

METHODS AND RESULTS

Previously published basic and clinical prediction models and the ESC 2019 PTP were validated in 42 328 patients (54% women) ≥30 years old without previous CAD referred for cardiac computed tomography angiography in a region of Denmark from 2008 to 2017. Obstructive CAD prevalence was 8.8%. The ESC 2019 PTP and basic model included angina symptoms, sex, and age, while the clinical model added diabetes mellitus family history of CAD, and dyslipidaemia. Discrimination was good for all three models [area under the receiver operating curve (AUC) 0.76, 95% confidence interval (CI) (0.75-0.77), 0.74 (0.73-0.75), and 0.76 (0.75-0.76), respectively]. Using the clinically relevant low predicted probability ≤5% of CAD cut-off, the clinical and basic models were well calibrated, whereas the ESC 2019 PTP overestimated CAD prevalence. At a cut-off of ≤5%, the clinical model ruled out 36.2% more patients than the ESC 2019 PTP, n = 23 592 (55.7%) vs. n = 8 245 (19.5%), while missing 824 (22.2%) vs. 132 (3.6%) cases of obstructive CAD.

CONCLUSION

A prediction model for CAD including cardiovascular risk factors was successfully validated. Implementation of this model would reduce the need for diagnostic testing and serve as gatekeeper if accepting a watchful waiting strategy for one-fifth of the patients.

Evaluating the Coronary Artery Disease Consortium Model and the Coronary Artery Calcium Score in Predicting Obstructive Coronary Artery Disease in a Symptomatic Mixed Asian Cohort

Background

The utility of a given pretest probability score in predicting obstructive coronary artery disease (CAD) is population dependent. Previous studies investigating the additive value of coronary artery calcium (CAC) on pretest probability scores were predominantly limited to Western populations. This retrospective study seeks to evaluate the CAD Consortium (CAD2) model in a mixed Asian cohort within Singapore with stable chest pain and to evaluate the incremental value of CAC in predicting obstructive CAD.

Methods and Results

Patients who underwent cardiac computed tomography and had chest pain were included. The CAD2 clinical model comprised of age, sex, symptom typicality, diabetes, hypertension, hyperlipidemia, and smoking status and was compared with the CAD2 extended model that added CAC to assess the incremental value of CAC scoring, as well as to the corresponding locally calibrated local assessment of the heart models. A total of 522 patients were analyzed (mean age 54±11 years, 43.1% female). The CAD2 clinical model obtained an area under the curve of 0.718 (95% CI, 0.668–0.767). The inclusion of CAC score improved the area under the curve to 0.896 (95% CI, 0.867–0.925) in the CAD2 models and from 0.767 (95% CI, 0.721–0.814) to 0.926 (95% CI, 0.900–0.951) in the local assessment of the heart models. The locally calibrated local assessment of the heart models showed better discriminative performance than the corresponding CAD2 models (P<0.05 for all).

Conclusions

The CAD2 model was validated in a symptomatic mixed Asian cohort and local calibration further improved performance. CAC scoring provided significant incremental value in predicting obstructive CAD.

The Diagnostic and Prognostic Value of Coronary Calcium Scoring in Stable Chest Pain Patients: A Narrative Review

Background  Non-contrast computed tomography (CT) scanning allows for reliable coronary calcium score (CCS) calculation at a low radiation dose and has been well established as marker to assess the future risk of coronary artery disease (CAD) events in asymptomatic individuals. However, the diagnostic and prognostic value in symptomatic patients remains a matter of debate. This narrative review focuses on the available evidence for CCS in patients with stable chest pain complaints.

Method  PubMed, Embase, and Web of Science were searched for literature using search terms related to three overarching categories: CT, symptomatic chest pain patients, and coronary calcium. The search resulted in 42 articles fulfilling the inclusion and exclusion criteria: 27 articles (n = 38 137 patients) focused on diagnostic value and 23 articles (n = 44 683 patients) on prognostic value of CCS. Of these, 10 articles (n = 21 208 patients) focused on both the diagnostic and prognostic value of CCS.

Results  Between 22 and 10 037 patients were included in the studies on the diagnostic and prognostic value of CCS, including 43 % and 51 % patients with CCS 0. The most evidence is available for patients with a low and intermediate pre-test probability (PTP) of CAD. Overall, the prevalence of obstructive CAD (OCAD, defined as a luminal stenosis of ≥ 50 % in any of the coronary arteries) as determined with CT coronary angiography in CCS 0 patients, was 4.4 % (n = 703/16 074) with a range of 0–26 % in individual studies. The event rate for major adverse cardiac events (MACE) ranged from 0 % to 2.1 % during a follow-up of 1.6 to 6.8 years, resulting in a high negative predictive value for MACE between 98 % and 100 % in CCS 0 patients. At increasing CCS, the OCAD probability and MACE risk increased. OCAD was present in 58.3 % (n = 617/1058) of CCS > 400 patients with percentages ranging from 20 % to 94 % and MACE occurred in 16.7 % (n = 175/1048) of these patients with percentages ranging from 6.9 % to 50 %.

Conclusion  Accumulating evidence shows that OCAD is unlikely and the MACE risk is very low in symptomatic patients with CCS 0, especially in those with low and intermediate PTPs. This suggests a role of CCS as a gatekeeper for additional diagnostic testing. Increasing CCS is related to an increasing probability of OCAD and risk of cardiac events. Additional research is needed to assess the value of CCS in women and patient management in a primary healthcare setting.

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Age and the power of zero CAC in cardiac risk assessment: overview of the literature and a cautionary case

The coronary artery calcium (CAC) score is a marker of advanced coronary atherosclerosis. Numerous prospective cohorts have validated CAC as an independent marker that improves prognostication in atherosclerotic cardiovascular disease (ASCVD) beyond traditional risk factors. Accordingly, CAC is now incorporated into international cardiovascular guidelines as a tool to inform medical decision-making. Particular interest concerns the significance of zero CAC score (CAC=0). While many studies report CAC=0 to virtually exclude obstructive coronary artery disease (CAD), non-negligible rates of obstructive CAD despite CAC=0 are reported in certain populations. Overall, the current literature supports the power of zero CAC as a strong downward risk classifier in older patients, whose CAD burden predominantly involves calcified plaque. However, with their higher burden of non-calcified plaque, CAC=0 does not reliably exclude obstructive CAD in patients under 40 years. Illustrating this point, we present a cautionary case of a 31-year-old patient found to have severe two-vessel CAD despite CAC=0. We highlight the value of coronary computed tomography angiography (CCTA) as the gold-standard non-invasive imaging modality when the diagnosis of obstructive CAD is in question.

The Atherosclerotic Profile of a Young Symptomatic Population between 19 and 49 Years: Coronary Computed Tomography Angiography or Coronary Artery Calcium Score?

(1) Background: Whether coronary computed tomography angiography (CTA) or the coronary artery calcium score (CACS) should be used for diagnosis of coronary heart disease, is an open debate. The aim of our study was to compare the atherosclerotic profile by coronary CTA in a young symptomatic high-risk population (age, 19-49 years) in comparison with the coronary artery calcium score (CACS). (2) Methods: 1137 symptomatic high-risk patients between 19-49 years (mean age, 42.4 y) who underwent coronary CTA and CACS were stratified into six age groups. CTA-analysis included stenosis severity and high-risk-plaque criteria (3) Results: Atherosclerosis was more often detected based on CTA than based on CACS (45 vs. 27%; p < 0.001), 50% stenosis in 13.6% and high-risk plaque in 17.7%. Prevalence of atherosclerosis was low and not different between CACS and CTA in the youngest age groups (19-30 y: 5.2 and 6.4% and 30-35 y: 10.6 and 16%). In patients older than >35 years, the rate of atherosclerosis based on CTA increased (p = 0.004, OR: 2.8, 95%CI:1.45-5.89); and was higher by CTA as compared to CACS (34.9 vs. 16.7%; p < 0.001), with a superior performance of CTA. In patients older than 35 years, stenosis severity (p = 0.002) and >50% stenosis increased from 2.6 to 12.5% (p < 0.001). High-risk plaque prevalence increased from 6.4 to 26.5%. The distribution of high-risk plaque between CACS 0 and >0.1 AU was similar among all age groups, with an increasing proportion in CACS > 0.1 AU with age. A total of 24.9% of CACS 0 patients had coronary artery disease based on CTA, 4.4% > 50% stenosis and 11.5% had high-risk plaque. (4) Conclusions: In a symptomatic young high-risk population older than 35 years, CTA performed superior than CACS. In patients aged 19-35 years, the rate of atherosclerosis was similar and low based on both modalities. CACS 0 did not rule out coronary artery disease in a young high-risk population.