Prognostic Value of 64-Slice Cardiac Computed Tomography

Clinical utility of systolic left ventricular ejection fraction in atrial fibrillation: Role of prospective ECG-triggered cardiac CT

BACKGROUND

The assessment of left ventricular (LV) systolic function and quantification of LV ejection fraction (LVEF) in patients with atrial fibrillation (AF) can be difficult. We previously demonstrated that LV volume changes over the 100 ms of systole (LVEF100ms) can be used as a measure of LV systolic function.

OBJECTIVE

We sought to evaluate the applicability of LVEF100ms in patients with AF.

METHODS

We screened patients with AF who underwent prospective systolic electrocardiogram-triggered cardiac computed tomography from January 2015 to June 2023. The correlation between LVEF100ms and echocardiography-derived LVEF was assessed. Patients were categorized into 3 groups on the basis of echocardiographic LVEF (≤40%, 40%-55%, and ≥55%), and LVEF100ms was compared among these groups. Receiver operating characteristic curve analysis and Cox proportional hazards models were used to determine the optimal LVEF100ms cutoff for predicting LVEF ≤ 40% and major adverse cardiovascular events (MACE), defined as a composite of cardiac death, myocardial infarction, heart failure hospitalization, and stroke.

RESULTS

Of the total 123 patients, 62 (50.4%) had an LVEF of ≥55%, 40 (32.5%) had an LVEF of 40%-50%, and 21 (17.1%) had an LVEF of ≤40%. LVEF100ms correlated with echocardiography-derived LVEF (P < .001) and differed significantly among groups (P < .001). LVEF100ms ≤ 3.3% predicted LVEF ≤ 40% (area under the curve 0.809; sensitivity 87%; specificity 67%). Patients with an LVEF100ms of ≤3.3% had a higher rate of MACE than did those without (P = .030), and LVEF100ms ≤ 3.3% was an independent predictor of MACE.

CONCLUSION

LVEF100ms can provide a useful indicator of LV dysfunction in patients with AF undergoing prospective electrocardiogram-triggered cardiac computed tomography.

Prognostic value of systolic left ventricular ejection fraction using prospective ECG-triggered cardiac CT

BACKGROUND

Prospective ECG-triggered cardiac computed tomography (CT) imaging limits the ability to assess left ventricular (LV) ejection fraction (EF). We previously developed a new index derived from LV volume changes over 100 ​ms during systole (LVEF100msec) as a surrogate of LV function in patients undergoing prospective ECG-triggered cardiac CT. We sought to evaluate the prognostic value of LVEF100msec.

METHODS

Patients undergoing prospective systolic ECG-triggered cardiac CT were enrolled between January 2015 and September 2022. Each CT was analyzed for LVEF100msec. Area under the curve analysis and Cox proportional hazards models were used to define the best LVEF100msec cut-off and to predict major adverse cardiovascular events (MACE), defined as a composite of all-cause death, cardiac death/arrest, non-fatal myocardial infarction, and stroke.

RESULTS

The study enrolled 313 patients (median age ​= ​58 years, male ​= ​52.4 ​%). During a median follow-up of 924 (660-1365) days, 24 (7.7 ​%) patients had MACE. LVEF100msec was significantly lower in the MACE group compared to the non-MACE group (4.8 ​% vs. 8.3 ​%, p ​= ​0.002). Optimal LVEF100msec cut-off for predicting MACE was 6.3 ​%. MACE-free survival rate was significantly lower in patients with LVEF100msec ≤6.3 ​% than those with >6.3 ​% (p ​< ​0.001). LVEF100msec ≤6.3 ​% was an independent predictor of MACE, with an adjusted hazard ratio of 3.758 (95 ​% CI, 1.543-9.148; p ​= ​0.004). The prognostic value of LVEF100msec was consistent across the various severities of coronary artery disease.

CONCLUSION

LVEF100msec was an independent predictor of adverse events. The implementation of LVEF100msec may improve the prognostic value of prospective ECG-triggered cardiac CT.

Racial referral bias in cardiac computed tomography: Differences, disparities or discrimination?

BACKGROUND

Disparities exist in medicine and can affect patient care. We sought to understand influences of racial biases in diagnostic testing within a Cardiac CT (CCT) population.

METHODS

Race of CCT patients, referring physicians and the population in the catchment area were captured between February 2006 and November 2021. The frequency of CCT referrals for each race was indexed to the catchment population.

RESULTS

Of 21,241 CCT patients, 17,514 (82.5 ​%) patients were White. The Non-White population was comprised of 467(2.2 ​%) Indigenous, 656(3.1 ​%) Black, 932(4.4 ​%) Asian, 276(1.3 ​%) South Asian, 1100(5.2 ​%) Middle Eastern and 296(1.4 ​%) Latin American races. The catchment population was 907,675, with 619,514 individuals of whom 69.7 ​% identified as White. Compared to the catchment population, there was a disproportionately higher referral rate for Whites than Non-Whites. The referral index for Whites was higher than Non-Whites (1.2 versus 0.6, p ​< ​0.001)). This pattern was consistent across all racial minorities and age categories. A total of 356 physicians (236(66.3 ​%) White, 4(1.2 ​%) Black, 39(12.0 ​%) Asian, 30(9.2 ​%) South Asian, 43(13.2 ​%), Middle Eastern and 4 (1.2 ​%) Latin American) made referrals to CCT. The racial difference in referral patterns was independent of physician race and was independent of their years in practice.

CONCLUSIONS

Racial differences exist in CCT referrals. These differences are independent of prevalence of disease, physician race or years in practice. This study supports the need to better understand reasons for disparity and strategies to mitigate potential bias.

Quantitative plaque characteristics and pericoronary fat attenuation index enhance risk prediction of unstable angina in nonobstructive lesions

AIM

The role of quantitative plaque characterization and pericoronary fat attenuation index (FAI) in nonobstructive lesions is uncertain. Hence, this study aimed to investigate artificial intelligence (AI)-based plaque characterization and pericoronary FAI in patients with nonobstructive lesions to enhance risk prediction of unstable angina.

MATERIALS AND METHODS

This study was conducted using the clinical data of 408 patients with cardiovascular disease diagnosed with angina pectoris. A coronary computed tomography angiography examination was performed, and quantitative plaque characteristics and pericoronary FAI were analyzed.

RESULTS

Of the 408 patients with angina, 130 had nonobstructive lesions and 278 had obstructive ones. No significant difference in pericoronary FAI was observed between patients with nonobstructive and obstructive lesions. In patients with nonobstructive lesions, the plaque length and pericoronary FAI were significantly higher in patients with unstable angina than in those with stable angina. In patients with obstructive lesions, the plaque fibrolipid volume and percentage were significantly higher in patients with unstable angina than in those with stable angina, and the narrowest lumen area was significantly smaller. Left anterior descending peripheral (peri-LAD) FAI > -83 HU or total plaque length >20.17 mm were independent predictors of unstable angina in patients with nonobstructive lesions. In patients with obstructive lesions, peri-LAD FAI > -77 HU, total lipid volume >12.6 mm3, and narrowest lumen area ≤2.25 mm2 were independent predictors of unstable angina.

CONCLUSION

Pericoronary FAI and total plaque length may be suitable imaging biomarkers for AI-based prediction of the occurrence of unstable angina in patients with nonobstructive lesions.

Computed Tomography Evaluation of Coronary Atherosclerosis: The Road Travelled, and What Lies Ahead

Coronary CT angiography (CCTA) is now endorsed by all major cardiology guidelines for the investigation of chest pain and assessment for coronary artery disease (CAD) in appropriately selected patients. CAD is a leading cause of morbidity and mortality. There is extensive literature to support CCTA diagnostic and prognostic value both for stable and acute symptoms. It enables rapid and cost-effective rule-out of CAD, and permits quantification and characterization of coronary plaque and associated significance. In this comprehensive review, we detail the road traveled as CCTA evolved to include quantitative assessment of plaque stenosis and extent, characterization of plaque characteristics including high-risk features, functional assessment including fractional flow reserve-CT (FFR-CT), and CT perfusion techniques. The state of current guideline recommendations and clinical applications are reviewed, as well as future directions in the rapidly advancing field of CT technology, including photon counting and applications of artificial intelligence (AI).

Cardiac CT: Competition, complimentary or confounder

Coronary CT angiography (CCTA) has been gradually adopted into clinical practice over the last two decades. CCTA has high diagnostic accuracy, prognostic value, and unique features such as assessment of plaque composition. CCTA-derived functional assessment techniques such as fractional flow reserve and CT perfusion are also available and can increase the diagnostic specificity of the modality. These properties propound CCTA as a competitor of functional testing in diagnosis of obstructive CAD, however, utilizing CCTA in a concomitant fashion to potentiate the performance of the latter can lead to better patient care and may provide more accurate prognostic information. Although multiple diagnostic challenges such as evaluation of calcified segments, stents, and small distal vessels still exist, the technologic developments in hardware as well as growing incorporation of artificial intelligence to daily practice are all set to augment the diagnostic and prognostic role of CCTA in cardiovascular disorders.

Association between severity of nonalcoholic fatty liver disease and major adverse cardiovascular events in patients assessed by coronary computed tomography angiography

BACKGROUND

The effect of nonalcoholic fatty liver disease (NAFLD) on major adverse cardiovascular events (MACEs) can be influenced by the degree of coronary artery stenosis. However, the association between the severity of NAFLD and MACEs in patients who underwent coronary computed tomography angiography (CCTA) is unclear.

METHODS

A total of 341 NAFLD patients who underwent CCTA were enrolled. The severity of NAFLD was divided into mild NAFLD and moderate-severe NAFLD by abdominal CT results. The degree of coronary artery stenosis was evaluated by using Coronary Artery Disease Reporting and Data System (CAD-RADS) category. Cox regression analysis and Kaplan-Meier analysis were used to assess poor prognosis.

RESULTS

During the follow-up period, 45 of 341 NAFLD patients (13.20%) who underwent CCTA occurred MACEs. The severity of NAFLD (hazard ratio [HR] = 2.95[1.54-5.66]; p = 0.001) and CAD-RADS categories 3-5 (HR = 16.31[6.34-41.92]; p < 0.001) were independent risk factors for MACEs. The Kaplan-Meier analysis showed that moderate to severe NAFLD patients had a worsen prognosis than mild NAFLD patients (log-rank p < 0.001). Moreover, the combined receiver operating characteristic curve of the severity of NAFLD and CAD-RADS category showed a good predicting performance for the risk of MACEs, with an area under the curve of 0.849 (95% CI = 0.786-0.911).

CONCLUSION

The severity of NAFLD was independent risk factor for MACEs in patients with obstructive CAD, having CAD-RADS 3-5 categories on CCTA.

The estimation of left ventricular function using prospective ECG-triggered coronary CT angiography

BACKGROUND

Coronary computed tomography angiography (CCTA) is vital for diagnosing coronary artery disease; however, prospective ECG-triggered acquisition, minimizing radiation exposure, limits left ventricular (LV) ejection fraction (EF) evaluation. We aimed to assess the feasibility and utility of LVEF100msec, a new index for estimating LV function using volumetric changes during 100 msec within systole.

METHODS

This retrospective study analyzed patients who underwent prospective ECG-triggered CCTA with systolic acquisition between January 2015 and June 2022. The LVEF100msec was calculated using the maximum and minimum LV volumes among the three phases (300, 350, and 400 msec post-QRS) and expressed as a percentage. Patients were classified into normal, mild-moderately reduced, or severely reduced LV function categories based on the reference test. The LVEF100msec was compared among groups, and the optimal cutoff value of LVEF100msec for predicting severe LV dysfunction was investigated.

RESULTS

The study included 271 patients (median age ​= ​58 years, 52% male). LVEF was normal in 188 (69.4%), mild-moderately reduced in 57 (21.0%), and severely reduced in 26 (9.6%) patients. Median LVEF100msec value was 9.0 (6.7-12.6) for normal LV function, 4.7 (3.1-8.8) for mild-moderately reduced, and 2.9 (1.5-3.8) for severely reduced LV function. LVEF100msec values significantly differed among categories (p ​< ​0.001). The optimal LVEF100msec cutoff for severe LV dysfunction was 4.3%, with an AUC of 0.924, sensitivity of 88%, and specificity of 89%.

CONCLUSION

The LVEF100msec may serve as a valuable indicator of severe LV dysfunction.

Pre-screening for non-diagnostic coronary computed tomography angiography

Aims

Indiscriminate coronary computed tomography angiography (CCTA) referrals for suspected coronary artery disease could result in a higher rate of equivocal and non-diagnostic studies, leading to inappropriate downstream resource utilization or delayed time to diagnosis. We sought to develop a simple clinical tool for predicting the likelihood of a non-diagnostic CCTA to help identify patients who might be better served with a different test.

Methods and results

We developed a clinical scoring system from a cohort of 21 492 consecutive patients who underwent CCTA between February 2006 and May 2021. Coronary computed tomography angiography study results were categorized as normal, abnormal, or non-diagnostic. Multivariable logistic regression analysis was conducted to produce a model that predicted the likelihood of a non-diagnostic test. Machine learning (ML) models were utilized to validate the predictor selection and prediction performance. Both logistic regression and ML models achieved fair discriminate ability with an area under the curve of 0.630 [95% confidence interval (CI) 0.618-0.641] and 0.634 (95% CI 0.612-0.656), respectively. The presence of a cardiac implant and weight >100 kg were among the most influential predictors of a non-diagnostic study.

Conclusion

We developed a model that could be implemented at the 'point-of-scheduling' to identify patients who would be best served by another non-invasive diagnostic test.

Coronary computed tomography plaque-based scores predict long-term cardiovascular events

OBJECTIVES

Coronary computed tomography angiography (coronary CTA) scores based on luminal obstruction, plaque burden, and characteristics are used for prognostication in coronary artery disease (CAD), such as segmental stenosis and plaque extent involvement and Gensini and Leaman scores. The use of coronary CTA scores for the long-term prognosis remains not completely defined. We sought to evaluate the long-term prognosis of CTA scores for cardiovascular events in symptomatic patients with suspected CAD.

METHODS

The presence and extent of CAD were evaluated by coronary CTA in patients from two multicenter prospective studies, which were classified according to several coronary CTA scores. The primary endpoint was major adverse cardiac events (MACE). Two hundred and twenty-two patients were followed up for a median of 6.8 (6.3-9.1) years, and 73 patients met the composite endpoints of MACE.

RESULTS

Compared to the clinical prediction model, the highest model improvement was observed when added obstructive CAD. After adjustment for the presence of obstructive CAD, the segment involvement score for non-calcified plaque (SISNoncalc) was independently associated with MACE, presenting incremental prognostic value over clinical data and CAD severity (χ2 39.5 vs 21.2, p < 0.001 for comparison with a clinical model; and χ2 39.5 vs 35.6, p = 0.04 for comparison with clinical + CAD severity). Patients with obstructive CAD and SISNoncalc > 3 were likely to experience events (HR 4.27, 95% CI 2.17-4.40, p < 0.001).

CONCLUSIONS

Coronary CTA plaque-based scores provide incremental long-term prognostic value for up to 7 years. Among patients with obstructive CAD, the presence of extensive non-calcified disease (> 3 coronary segments) is associated with increased cardiovascular risk for late events independently of the presence of obstructive CAD.

KEY POINTS

• Coronary CTA plaque-based scores are long-term prognostic markers in patients with stable CAD. • Besides obstructive CAD, the segment involvement score of non-calcified disease of 3 or more independently increased the risk of cardiovascular events.

Can HDL cholesterol be replaced by paraoxonase 1 activity in the prediction of severe coronary artery disease in patients with type 2 diabetes?

BACKGROUND AND AIMS

Novel biomarkers are required to improve cardiovascular disease prediction in patients with type 2 diabetes (T2D) as a high-risk population. This study was conducted to examine whether coronary artery disease (CAD) risk assessment can be improved by substituting high-density lipoprotein (HDL)-bound paraoxonase 1 (PON1) activity for HDL cholesterol (HDL-C) concentration in patients with T2D.

METHODS AND RESULTS

In this study, we studied 139 patients with T2D (mean age 64.12 ± 8.17 years) who underwent coronary angiographic examination. The initial rate of substrate hydrolysis was spectrophotometrically assayed in kinetic mode for measuring PON1 activity. Receiver operating characteristic (ROC) graphs are created by plotting true positivity versus false positivity. In patients with HbA_1c ≥ 7%, PON1 (AUC = 0.7, p = 0.029) and nonHDL-C/PON1 (AUC = 0.75, p = 0.013) were significantly more capable of differentiating patients with CAD from those without CAD compared to HDL-C and nonHDL-C/HDL-C. Also, the predictive power of PON1 (AUC = 0.64, p = 0.029) and nonHDL-C/PON1 (AUC = 0.71, p = 0.004) were significantly higher in comparison with HDL-C and nonHDL-C/HDL-C for CAD characterization in patients aged ≥50 years. Moreover, PON1 and nonHDL-C/PON1 are associated with the incidence of CAD with an AUC of 0.7 (p = 0.026) and AUC of 0.64 (p = 0.087), respectively, among subjects with low HDL-C.

CONCLUSION

PON1 and the ratio of nonHDL-C/PON1 significantly improve the prediction of severe CAD in T2D patients and in patients with HbA_1c ≥ 7%, age ≥50 years, or low HDL-C. PON1 activity and lipid ratios using this enzyme may be valuable as substitutes of HDL-C for increasing clinical efficacies in cardiovascular risk assessment.

Prognostic Value of Coronary Computed Tomography Angiography in Coronary Artery Bypass Graft Patients Systematic Review and Meta-Analysis

We sought to assess the prognostic value of coronary computed tomographic angiography (CCTA) in patients with coronary artery bypass graft (CABG) by meta-analysis. MEDLINE, Embase, Cochrane Central Register of Controlled Trials, and Scopus were searched for relevant original articles published up to July 2021. CCTA prognostic studies enrolling patients with CABG were screened and included if outcomes included all-cause mortality or major adverse cardiac events. Maximally adjusted hazard ratios (HRs) were extracted for CCTA-derived prognostic factors. HRs were log-transformed and pooled across studies using the DerSimonian-Laird random-effects model and statistical heterogeneity was assessed using the I² statistic. Of 1,576 screened articles, 4 retrospective studies fulfilled all inclusion criteria. Collectively, a total of 1,809 patients with CABG underwent CCTA (mean [SD] age 67.0 [8.5] years across 3 studies, 81.5% male across 4 studies). Coronary artery disease severity and revascularization were categorized using 2 models: unprotected coronary territories and coronary artery protection score. The pooled HRs from the random-effects models using the most highly adjusted study estimate were 3.64 (95% confidence interval 2.48 to 5.34, I² = 57.8%, p <0.001; 4 studies) and 4.85 (95% confidence interval 3.17 to 7.43, I² = 39.9%, p <0.001; 2 studies) for unprotected coronary territories and coronary artery protection score, respectively. In conclusion, in a limited number of studies, CCTA is an independent predictor of adverse events in patients with CABG. Larger studies using uniform models and endpoints are needed.

Non-Contrast and Contrast-Enhanced Cardiac Computed Tomography Imaging in the Diagnostic and Prognostic Evaluation of Coronary Artery Disease

In recent decades, cardiac computed tomography (CT) has emerged as a powerful non-invasive tool for risk stratification, as well as the detection and characterization of coronary artery disease (CAD), which remains the main cause of morbidity and mortality in the world. Advances in technology have favored the increasing use of cardiac CT by allowing better performance with lower radiation doses. Coronary artery calcium, as assessed by non-contrast CT, is considered to be the best marker of subclinical atherosclerosis, and its use is recommended for the refinement of risk assessment in low-to-intermediate risk individuals. In addition, coronary CT angiography (CCTA) has become a gate-keeper to invasive coronary angiography (ICA) and revascularization in patients with acute chest pain by allowing the assessment not only of the extent of lumen stenosis, but also of its hemodynamic significance if combined with the measurement of fractional flow reserve or perfusion imaging. Moreover, CCTA provides a unique incremental value over functional testing and ICA by imaging the vessel wall, thus allowing the assessment of plaque burden, composition, and instability features, in addition to perivascular adipose tissue attenuation, which is a marker of vascular inflammation. There exists the potential to identify the non-obstructive lesions at high risk of progression to plaque rupture by combining all of these measures.

Prognostic Value of Machine Learning-based Time-to-Event Analysis Using Coronary CT Angiography in Patients with Suspected Coronary Artery Disease

Purpose

To assess the long-term prognostic value of a machine learning (ML) approach in time-to-event analyses incorporating coronary CT angiography (CCTA)-derived and clinical parameters in patients with suspected coronary artery disease.

Materials and Methods

The retrospective analysis included patients with suspected coronary artery disease who underwent CCTA between October 2004 and December 2017. Major adverse cardiovascular events were defined as the composite of all-cause death, myocardial infarction, unstable angina, or late revascularization (>90 days after index scan). Clinical and CCTA-derived parameters were assessed as predictors of major adverse cardiovascular events and incorporated into two models: a Cox proportional hazards model with recursive feature elimination and an ML model based on random survival forests. Both models were trained and validated by employing repeated nested cross-validation. Harrell concordance index (C-index) was used to assess the predictive power.

Results

A total of 5457 patients (mean age, 61 years ± 11 [SD]; 3648 male patients) were evaluated. The predictive power of the ML model (C-index, 0.74; 95% CI: 0.71, 0.76) was significantly higher than the Cox model (C-index, 0.71; 95% CI: 0.68, 0.74; P = .02). The ML model also outperformed the segment stenosis score (C-index, 0.69; 95% CI: 0.66, 0.72; P < .001), which was the best performing CCTA-derived parameter, and patient age (C-index, 0.66; 95% CI: 0.63, 0.69; P < .001), the best performing clinical parameter.

Conclusion

An ML model for time-to-event analysis based on random survival forests had higher performance in predicting major adverse cardiovascular events compared with established clinical or CCTA-derived metrics and a conventional Cox model.Keywords: Machine Learning, CT Angiography, Cardiac, Arteries, Heart, Arteriosclerosis, Coronary Artery DiseaseSupplemental material is available for this article.© RSNA, 2023.

Underestimated prognostic value of depression in patients with obstructive coronary artery disease

OBJECTIVE

The aim of this study was to explore the different predictive values of depression among patients with different cardiac systolic function levels.

METHODS

Four hundred eighty-three consecutive patients with obstructive coronary artery disease (CAD) were included the depressive state was assessed using the Chinese version of the Patient Health Questionnaire 9 (PHQ-9). Depression was defined as have depressive symptoms with a PHQ-9 score ≥5. The level of cardiac systolic function was classified as left ventricular ejection fraction (LVEF) ≥50 and <50%.

RESULTS

Over a median of 26.2 months, 421 patients completed the follow-up and experienced 101 major adverse cardiovascular events (MACEs), 45 non-cardiac rehospitalizations, and 17 deaths. Predictors for clinical outcomes in patients with different cardiac systolic function levels were not the same. For participants with preserved LVEF, depression was associated with increased risks for cardiovascular events and composite outcomes. However, when focusing the whole population, predictive values of depression for MACEs, non-cardiac rehospitalizations, and composite endpoints all dropped. Receiver operating characteristic (ROC) analyses further confirmed that depression was the one of the main predictors for all clinical outcomes. With the combination of other simple features, area under curve (AUC) could reach 0.64-0.67.

CONCLUSIONS

Inconsistent with the general impression, depression is found to have a closer linkage with clinical outcomes in CAD patients with preserved LVEF rather than in those with decreased LVEF. These findings appeal for more attention on CAD patients with depressive symptoms and comparatively normal LVEF. Including psychological factors may be a good attempt when constructing risk prediction models.

Static CT myocardial perfusion imaging: image quality, artifacts including distribution and diagnostic performance compared to 82Rb PET

Background

Rubidium-82 positron emission tomography (⁸²Rb PET) MPI is considered a noninvasive reference standard for the assessment of myocardial perfusion in coronary artery disease (CAD) patients. Our main goal was to compare the diagnostic performance of static rest/ vasodilator stress CT myocardial perfusion imaging (CT-MPI) to stress/ rest ⁸²Rb PET-MPI for the identification of myocardial ischemia.

Methods

Forty-four patients with suspected or diagnosed CAD underwent both static CT-MPI and ⁸²Rb PET-MPI at rest and during pharmacological stress. The extent and severity of perfusion defects on PET-MPI were assessed to obtain summed stress score, summed rest score, and summed difference score. The extent and severity of perfusion defects on CT-MPI was visually assessed using the same grading scale. CT-MPI was compared with PET-MPI as the gold standard on a per-territory and a per-patient basis.

Results

On a per-patient basis, there was moderate agreement between CT-MPI and PET-MPI with a weighted 0.49 for detection of stress induced perfusion abnormalities. Using PET-MPI as a reference, static CT-MPI had 89% sensitivity (SS), 58% specificity (SP), 71% accuracy (AC), 88% negative predictive value (NPV), and 59% positive predictive value (PPV) to diagnose stress-rest perfusion deficits on a per-patient basis. On a per-territory analysis, CT-MPI had 73% SS, 65% SP, 67% AC, 90.8% NPV, and 34% PPV to diagnose perfusion deficits.

Conclusions

CT-MPI has high sensitivity and good overall accuracy for the diagnosis of functionally significant CAD using ⁸²Rb PET-MPI as the reference standard. CT-MPI may play an important role in assessing the functional significance of CAD especially in combination with CCTA.

Normalized Subendocardial Myocardial Attenuation on Coronary Computed Tomography Angiography Predicts Postoperative Adverse Cardiovascular Events: Coronary CTA VISION Substudy

BACKGROUND

Abnormalities in computed tomography myocardial perfusion has been associated with coronary artery disease and major adverse cardiovascular events (MACE). We sought to investigate if subendocardial attenuation using coronary computed tomography angiography predicts MACE 30 days postelective noncardiac surgery.

METHODS

Using a 17-segment model, coronary computed tomography angiography images were analyzed for subendocardial and transmural attenuation and the corresponding blood pool. The segment with the lowest subendocardial attenuation and transmural attenuation were normalized to the segment with the highest subendocardial and transmural attenuation, respectively (SUB_normalized, and TRANS_normalized, respectively). We evaluated the independent and incremental value of myocardial attenuation to predict the composite of cardiovascular death or nonfatal myocardial infarction.

RESULTS

Of a total of 995 coronary CTA VISION (Coronary Computed Tomographic Angiography and Vascular Events in Noncardiac Surgery Patients Cohort Evaluation Study) patients, 735 had available images and complete data for these analyses. Among these patients, 60 had MACE. Based on Revised Cardiovascular Risk Index, 257, 302, 138, and 38 patients had scores of 0, 1, 2, and ≥3, respectively. On coronary computed tomography angiography, 75 patients had normal coronary arteries, 297 patients had nonobstructive coronary artery disease, 264 patients had obstructive disease, and 99 patients had extensive obstructive coronary artery disease. SUB_normalized was an independent and incremental predictor of events in the model that included Revised Cardiovascular Risk Index and coronary artery disease severity. Compared with patients in the highest tertile of SUB_normalized, patients in the second and first tertiles had an increased hazards ratio for events (2.23 [95% CI, 1.091-4.551] and 2.36 [95% CI, 1.16-4.81], respectively). TRANS_normalized, as a continuous variable, was also found to be a predictor of MACE (P=0.027).

CONCLUSIONS

Our study demonstrates that SUB_normalized and TRANS_normalized are independent and incremental predictors of MACE 30 days after elective noncardiac surgery. Registration: URL: https://www.clinicaltrials.gov; Unique identifier: NCT01635309.

Comparison of carotid artery ultrasound and Framingham risk score for discriminating coronary artery disease in patients with psoriatic arthritis

Objectives

This study aimed to assess the performance of carotid ultrasound (US) parameters alone or in combination with Framingham Risk Score (FRS) in discriminating patients with psoriatic arthritis (PsA) with and without coronary artery disease (CAD).

Methods

Ninety-one patients with PsA (56 males; age: 50±11 years, disease duration: 9.4±9.2 years) without overt cardiovascular (CV) diseases were recruited. Carotid intima-media thickness (cIMT), the presence of plaque and total plaque area (TPA) was determined by high-resolution US. CAD was defined as the presence of any coronary plaque on coronary CT angiography (CCTA). Obstructive-CAD (O-CAD) was defined as >50% stenosis of the lumen.

Results

Thirty-five (38%) patients had carotid plaque. Fifty-four (59%) patients had CAD (CAD+) and 9 (10%) patients had O-CAD (O-CAD+). No significant associations between the presence of carotid plaque and CAD were found. However, cIMT and TPA were higher in both the CAD+ and O-CAD+ group compared with the CAD− or O-CAD− groups, respectively. Multivariate logistic regression analysis revealed that mean cIMT was an independent explanatory variable associated with CAD and O-CAD, while maximum cIMT and TPA were independent explanatory variables associated with O-CAD after adjusting for covariates. The optimal cut-offs for detecting the presence of CAD were FRS >5% and mean cIMT at 0.62 mm (AUC: 0.71; sensitivity: 67%; specificity: 76%), while the optimal cut-offs for detecting the presence of O-CAD were FRS >10% in combination with mean cIMT at 0.73 mm (AUC: 0.71; sensitivity: 56%; specificity: 85%).

Conclusion

US parameters including cIMT and TPA may be considered in addition to FRS for CV risk stratification in patients with PsA.

Prognostic durability of coronary computed tomography angiography

AIMS

This large prospective cohort study sought to confirm the incremental prognostic value of coronary computed tomographic angiography (CCTA) measured over a prolonged follow-up duration. CCTA has diagnostic and prognostic value but data supporting its long-term prognostic value in a large prospectively recruited cohort with suspected coronary artery disease (CAD) has been limited.

METHODS AND RESULTS

Consecutive patients (without history of myocardial infarction, revascularization, cardiac transplantation, and congenital heart disease) were prospectively enrolled. CCTA was evaluated for CAD severity, total plaque score (TPS), and left ventricular ejection fraction. Patients were followed for major adverse events (MAE) and major adverse cardiac events (MACE).Over a total of 99 months, 8667 consecutive CCTA patients (mean age = 57.1 ± 11.1 years, 52.9% men) were prospectively enrolled and followed for a mean duration of 7.0 ± 2.6 years. At follow-up, there were a total of 723 MAE, 278 MACE, 547 all-cause deaths, 110 cardiac deaths, and 104 non-fatal myocardial infarction. Patients without coronary atherosclerosis at the time of CCTA had a very low annual event rate for both MAE and MACE (0.45%/year and 0.19%/year, respectively). Both MAE and MACE increased with increasing TPS and severity of CAD. In patients with non-obstructive CAD and who were statin-naive, TPS ≥5 had MACE rates >0.75%/year. Patients with high-risk CAD had an annual MAE and MACE rates of 3.52%/year and 2.58%/year, respectively. Adjusted hazard ratio of the severity of CAD based on multivariable analyses indicated that the prognostic values were incremental.

CONCLUSION

CCTA has independent and incremental prognostic value that is durable over time. The absence of coronary atherosclerosis portends an excellent prognosis. Patients with increasing non-obstructive plaque burden have worse prognosis and a TPS threshold ≥5 may identify a population that may benefit from statin therapy.

Coronary Computer Tomography Angiography in 2021-Acquisition Protocols, Tips and Tricks and Heading beyond the Possible

Recent technological advances, together with an increasing body of evidence from randomized trials, have placed coronary computer tomography angiography (CCTA) in the center of the diagnostic workup of patients with coronary artery disease. The method was proven reliable in the diagnosis of relevant coronary artery stenosis. Furthermore, it can identify different stages of the atherosclerotic process, including early atherosclerotic changes of the coronary vessel wall, a quality not met by other non-invasive tests. In addition, newer computational software can measure the hemodynamic relevance (fractional flow reserve) of a certain stenosis. In addition, if required, information related to cardiac and valvular function can be provided with specific protocols. Importantly, recent trials have highlighted the prognostic relevance of CCTA in patients with coronary artery disease, which helped establishing CCTA as the first-line method for the diagnostic work-up of such patients in current guidelines. All this can be gathered in one relatively fast examination with minimal discomfort for the patient and, with newer machines, with very low radiation exposure. Herein, we provide an overview of the current technical aspects, indications, pitfalls, and new horizons with CCTA, providing examples from our own clinical practice.

Are Training Programs Ready for the Rapid Adoption of CCTA?: CBME in CCTA

OBJECTIVES

This study sought to assess training volumes and its relationship to learning and identify potential new thresholds for determining expertise.

BACKGROUND

Competency-based medical education (CBME) is being rapidly adopted and therefore training programs will need to adapt and identify new and novel methods of defining, measuring, and assessing clinical skills.

METHODS

Consecutive cardiac computed tomography (CT) studies were interpreted independently by trainees and expert readers, and their interpretations (Agatston score, coronary artery disease severity, and Coronary Artery Disease Reporting and Data System) were collected. Kappa agreements were measured between trainees and experts for every 50 consecutive cases. Agreements between trainees and experts were tracked and compared with the agreement between expert readers.

RESULTS

A total of 36 trainees interpreted 14,432 cardiac CT studies. Agreement between trainees and experts increased with CT case volumes, but trainees learned at different rates. Using a threshold for expertise, skill of measuring coronary calcification was achieved within 50 cases, but expertise for coronary CT angiography appeared to require a mean case volume of 750, comprising 400 abnormal cases.

CONCLUSIONS

Current volume-based training guidelines may be insufficient and higher case volumes may be required. We demonstrate that tracking cardiac CT learners is feasible and that CBME could be incorporated into CT training programs.

LncRNA TONSL-AS1 participates in coronary artery disease by interacting with miR-197

BACKGROUND

It has been reported that high expression levels of miR-197 can predict coronary artery disease (CAD). Our bioinformatics analysis showed that miR-197 may bind to long non-coding RNA (lncRNA) TONSL-AS1. This study aimed to investigate the role of TONSL-AS1 in CAD.

METHODS

This study included 60 CAD patients and 60 healthy controls. Coronary angiography was performed to diagnose CAD. The interaction between TONSL-AS1 and miR-197 was predicted by IntaRNA2.0. Western-blot analysis was performed to illustrate the effect of MTONSL-AS1, miR-197 and BCL2 on human primary coronary artery endothelial cells (HCAECs). Cell migration assay was performed to explore the roles of MTONSL-AS1, miR-197 and BCL2 in regulating cell migration. Cell apoptosis assay was performed to investigate the role of MTONSL-AS1, miR-197 and BCL2 in regulating the apoptosis of HCAECs.

RESULT

Significant differences in high-density lipoprotein cholesterol (HDL-C), low density lipoprotein cholesterol (LDL-C), and gensini score were observed in patients with CAD. In addition, TONSL-AS1 was downregulated in CAD. Follow-up study revealed that low expression levels of TONSL-AS1 and high expression levels of miR-197 predicted poor survival of CAD patients. Overexpression experiments showed that TONSL-AS1 and miR-197 had no significant effect on the expression of each other. We speculated that MAFG-AS1 may sponge miR-145. Moreover, overexpression of TONSL-AS1 increased, while overexpression of miR-197 decreased the expression levels of BCL2. Furthermore, overexpression of TONSL-AS1 attenuated the effects of overexpression of miR-197 on migration and apoptosis of HCAECs.

CONCLUSIONS

Therefore, the expression of TONSL-AS1 predicted the survival of CAD patients and it sponged miR-197 to inhibit the apoptosis of HCAECs.

Coronary CT Angiography Guided Medical Therapy in Subclinical Atherosclerosis

The goals of primary prevention in coronary atherosclerosis are to avoid sudden cardiac death, myocardial infarction or the need for revascularization procedures. Successful prevention will rely on accurate identification, effective therapy and monitoring of those at risk. Identification and potential monitoring can be achieved using cardiac computed tomography (CT). Cardiac CT can determine coronary artery calcification (CAC), a useful surrogate of coronary atherosclerosis burden. Cardiac CT can also assess coronary CT angiography (CCTA). CCTA can identify arterial lumen narrowing and highlight mural atherosclerosis hitherto hidden from other anatomical approaches. Herein we consider the role of CCTA and CAC-scoring in subclinical atherosclerosis. We explore the use of these modalities in screening and discuss data that has used CCTA for guiding primary prevention. We examine therapeutic trials using CCTA to determine the effects of plaque-modifying therapies. Finally, we address the role of CCTA and CAC to guide therapy as defined in current primary prevention documents. CCTA has emerged as an essential tool in the detection and management of clinical coronary artery disease. To date, its role in subclinical atherosclerosis is less well defined, yet with modern CT scanners and continued pharmacotherapy development, CCTA is likely to achieve a more prominent place in the primary prevention of coronary atherosclerosis.

Effectiveness of point-of-care oral ivabradine for cardiac computed tomography

BACKGROUND

Coronary CT angiography (CCTA) is increasing seen as a first line investigation in patients with suspected coronary artery disease. Heart-rate control improves the image quality and diagnostic accuracy of CCTA. Typically, beta-blockers are administered to induce sinus bradycardia. Sinus bradycardia may also be induced by ivabradine. We hypothesized that in a real-world population ivabradine would be an effective alternative to metoprolol at heart rate lowering for CCTA.

METHODS

This was a retrospective analysis of consecutive patients who were exposed to an ivabradine-based (IB) versus a metoprolol-only (MO) protocol to achieve a target heart rate </ = 65bpm. Hemodynamic responses to both strategies were compared along with differences in cost and the time expired from medication administration to CCTA.

RESULTS

5955 consecutive patients were included in the analysis: 3211 were imaged during an era of a metoprolol only strategy (MO) and 2744 CCTA following an ivabradine based (IB) strategy. 2676 patients had heart rates >65 and received heart-rate lowering medication: 1958 patients had MO, and 718 received IB protocol. Target heart rate of </ = 65bpm was achieved in 77% of MO and 89% of IB patients (p < 0.01). The time from initial medication administration to CCTA was longer in the IB versus MO patients (77 versus 48 min, p < 0.01).

CONCLUSIONS

Introduction of a novel single dose ivabradine-based protocol to control heart rate for CCTA was more successful in achieving target heart rate than a metoprolol-only strategy. The use of ivabradine however incurred a 1.6-fold increase in the time delay from medication administration and imaging compared to a metoprolol only protocol.

Prognostic value of coronary computed tomography angiography in patients with prior percutaneous coronary intervention

OBJECTIVE

We sought to determine the prognostic value of coronary computed tomography angiography (CCTA) in patients with a history of percutaneous coronary intervention (PCI).

BACKGROUND

Although the prognostic value of CCTA has been well studied, its incremental value in patients with previous PCI has not been robustly investigated.

METHODS

Consecutive patients with previous PCI were prospectively enrolled and CCTA images were evaluated for coronary artery disease (CAD) severity. Patients were followed for major adverse cardiovascular events (MACE) which was a composite of cardiac death and non-fatal myocardial infarction. All-cause death was assessed as a secondary endpoint.

RESULTS

A total of 501 patients were analyzed with a mean follow-up time of 59.5 ± 32.0 months and 52 patients (10.4%) experienced MACE. Multivariable Cox regression analysis showed that CAD severity was a predictor of MACE with 0, 1, 2, and 3 vessel disease having annual rates of 1.3%, 2.2%, 2.2%, and 5.3%, respectively. All-cause death was similar in all categories of CAD.

CONCLUSIONS

In patients with previous PCI, CAD severity as measured with CCTA has independent and incremental prognostic value.

In Vivo Detection of Lipid-Core Plaques by Coronary CT Angiography: A Head-to-Head Comparison with Histologic Findings

Objective

We sought to distinguish lipid plaques using a CT quantitative pixel density histogram, based on the pathological diagnosis of lipid cores as the gold standard.

Materials and Methods

Eight patients awaiting heart transplantation due to end-stage coronary heart disease underwent coronary CT angiography (CCTA) spectroscopy prior to heart transplantation; coronary artery pathological analysis was performed for all patients. Lipid-core plaques were defined pathologically as manifesting a lipid core diameter > 200 µm, a circumference > 60 degrees, and a cap thickness < 450 µm. The percentage distributions of CT pixel attenuation ≤ 20, 30, 40, and 50 HU were calculated using quantitative histogram analysis.

Results

A total of 271 transverse sections were co-registered between CCTA and pathological analysis. Overall, 26 lipid cores and 16 fibrous plaques were identified by pathological analysis. There was no significant difference in median CT attenuation between the lipid and fibrous plaques (51 HU [interquartile range, 46–63] vs. 57 HU [interquartile range, 50–64], p = 0.659). The median percentage of CT pixel attenuation ≤ 30 HU accounted for 11% (5–17) of lipid-core plaques and 0% (0–2) of fibrous plaques (p < 0.001). The sensitivity and specificity of the method for diagnosing lipid plaques by the average CT pixel attenuation ≤ 30 HU were 80.8% and 87.5%, respectively. The area under the receiver operator characteristics curve was 0.898 (95% confidence interval: 0.765–0.970; 3.0% was the best cut-off value). The diagnostic performance was significantly higher than those of the average pixel CT attenuation percentages ≤ 20, 40, and 50 HU and the mean CT attenuation (p < 0.05).

Conclusion

In in vivo conditions, with the pathological lipid core as the gold standard, quantification of the percentage of average CT pixel attenuation ≤ 30 HU in the histogram can be useful for accurate identification of lipid plaques.

Improved long-term prognostic value of coronary CT angiography-derived plaque measures and clinical parameters on adverse cardiac outcome using machine learning

OBJECTIVES

To evaluate the long-term prognostic value of coronary CT angiography (cCTA)-derived plaque measures and clinical parameters on major adverse cardiac events (MACE) using machine learning (ML).

METHODS

Datasets of 361 patients (61.9 ± 10.3 years, 65% male) with suspected coronary artery disease (CAD) who underwent cCTA were retrospectively analyzed. MACE was recorded. cCTA-derived adverse plaque features and conventional CT risk scores together with cardiovascular risk factors were provided to a ML model to predict MACE. A boosted ensemble algorithm (RUSBoost) utilizing decision trees as weak learners with repeated nested cross-validation to train and validate the model was used. Performance of the ML model was calculated using the area under the curve (AUC).

RESULTS

MACE was observed in 31 patients (8.6%) after a median follow-up of 5.4 years. Discriminatory power was significantly higher for the ML model (AUC 0.96 [95%CI 0.93-0.98]) compared with conventional CT risk scores including Agatston calcium score (AUC 0.84 [95%CI 0.80-0.87]), segment involvement score (AUC 0.88 [95%CI 0.84-0.91]), and segment stenosis score (AUC 0.89 [95%CI 0.86-0.92], all p < 0.05). Similar results were shown for adverse plaque measures (AUCs 0.72-0.82, all p < 0.05) and clinical parameters including the Framingham risk score (AUCs 0.71-0.76, all p < 0.05). The ML model yielded significantly higher diagnostic performance compared with logistic regression analysis (AUC 0.96 vs. 0.92, p = 0.024).

CONCLUSION

Integration of a ML model improves the long-term prediction of MACE when compared with conventional CT risk scores, adverse plaque measures, and clinical information. ML algorithms may improve the integration of patient's information to enhance risk stratification.

KEY POINTS

• A machine learning (ML) model portends high discriminatory power to predict major adverse cardiac events (MACE). • ML-based risk stratification shows superior diagnostic performance for MACE prediction over coronary CT angiography (cCTA)-derived risk scores or clinical parameters alone. • A ML model outperforms conventional logistic regression analysis for the prediction of MACE.

From CT to artificial intelligence for complex assessment of plaque-associated risk

The recent technological developments in the field of cardiac imaging have established coronary computed tomography angiography (CCTA) as a first-line diagnostic tool in patients with suspected coronary artery disease (CAD). CCTA offers robust information on the overall coronary circulation and luminal stenosis, also providing the ability to assess the composition, morphology, and vulnerability of atherosclerotic plaques. In addition, the perivascular adipose tissue (PVAT) has recently emerged as a marker of increased cardiovascular risk. The addition of PVAT quantification to standard CCTA imaging may provide the ability to extract information on local inflammation, for an individualized approach in coronary risk stratification. The development of image post-processing tools over the past several years allowed CCTA to provide a significant amount of data that can be incorporated into machine learning (ML) applications. ML algorithms that use radiomic features extracted from CCTA are still at an early stage. However, the recent development of artificial intelligence will probably bring major changes in the way we integrate clinical, biological, and imaging information, for a complex risk stratification and individualized therapeutic decision making in patients with CAD. This review aims to present the current evidence on the complex role of CCTA in the detection and quantification of vulnerable plaques and the associated coronary inflammation, also describing the most recent developments in the radiomics-based machine learning approach for complex assessment of plaque-associated risk.

Computed tomography coronary angiography for patients with heart failure (CTA-HF): a randomized controlled trial (IMAGE-HF 1C)

AIMS

This randomized controlled trial sought to determine the financial impact of an initial diagnostic strategy of coronary computed tomography angiography (CCTA) in patients with heart failure (HF) of unknown aetiology. Invasive coronary angiography (ICA) is used to investigate HF patients. CCTA may be a non-invasive cost-effective alternative to ICA. This randomized controlled trial sought to determine the financial impact of an initial diagnostic strategy of coronary computed tomography angiography (CCTA) in patients with heart failure (HF) of unknown aetiology.

METHODS AND RESULTS

This multicentre, international trial enrolled patients with HF of unknown aetiology. The primary outcome was the cost of CCTA vs. ICA strategies at 12 months. Clinical outcomes were also collected. An 'intention-to-diagnose' analysis was performed and a secondary 'as-tested' analysis was based on the modality received. Two hundred and forty-six patients were randomized (age = 57.8 ± 11.0 years, ejection fraction = 30.1 ± 10.1%). The severity of coronary artery disease was similar in both groups. In the 121 CCTA patients, 93 avoided ICA. Rates of downstream ischaemia and viability testing were similar for both arms. There were no significant differences in the composite clinical outcomes or quality of life measures. The cost of CCTA trended lower than ICA [CDN -$871 (confidence interval, CI -$4116 to $3028)]. Using an 'as-tested' analysis, CCTA was associated with a decrease in healthcare costs (CDN -$2932, 95% CI -$6248 to $746).

CONCLUSION

In patients with HF of unknown aetiology, costs were not statistically different between the CCTA and ICA strategies.

CLINICAL TRIALS.GOV

NCT01283659.

Serum Levels of Cystatin C, N-Terminal Pro-B-Type Natriuretic Peptide (NT-proBNP), and Cardiac Function in Patients with Unstable Angina Pectoris

Background

This study aimed to investigate the association between serum levels of cystatin C, N-terminal pro-B-type natriuretic peptide (NT-proBNP), and cardiac function in patients with unstable angina pectoris (UAP).

Material/Methods

A cross-sectional observational study was conducted at a single center and recruited 300 patients (214 men and 86 women), who were diagnosed with UAP between June 2018 to December 2018. The patients had serum levels of NT-ProBNP measured and were divided into four groups according to the serum levels of cystatin C: Q1, 0.49–0.83 mg/L; Q2, 0.84–1.04 mg/L; Q3, 1.05–1.38 mg/L; Q4, 1.39–4.21 mg/L. Cardiac function was graded according to the New York Heart Association (NYHA) class I to IV criteria.

Results

In the 300 patients with UAP, there were significant differences in cardiac function and NT-ProBNP levels between the four study groups (Q1 to Q4) (p<0.05). Univariate analysis showed that body weight, heart rate, treatment with aspirin, ticagrelor, angiotensin-converting enzyme inhibitor and an angiotensin receptor blocker (ACE/ARB), diuretic use, uric acid level, and serum cystatin C levels were significantly associated with increased levels of NT-ProBNP. After adjusting for confounding factors screened in univariate analysis, multivariate regression analysis showed that increased serum cystatin C levels were significantly associated with increased levels of NT-ProBNP.

Conclusions

Increased serum levels of cystatin C were associated with poor cardiac function and increased levels of NT-ProBNP in patients with UAP.

Diagnostic value of echocardiography on detecting the various types of anomalous origin of the left coronary artery from the pulmonary artery

BACKGROUND

To assess the diagnostic value of echocardiography in detecting the various types of anomalous origin of the left coronary artery from the pulmonary artery (ALCAPA).

METHODS

A total of 30 patients with an established diagnosis of ALCAPA were retrospectively analyzed, and classified into infant- (n=20) and adult-type (n=10) groups according to the age of symptom manifestation and the mode of presentation. All patients underwent echocardiography examination.

RESULTS

Twenty-four out of thirty patients were diagnosed with ALCAPA by echocardiography. The remaining six cases were confirmed by dual-source computed tomography (DSCT) and angiocardiography, respectively. In the infant-type group, there was negligible or no collateral flow between the right coronary artery (RCA) and the left coronary artery (LCA). Eighteen of these patients had enhanced echogenicity of left ventricular (LV) papillary muscles, different degrees of mitral regurgitation (MR) and the RCA to aortic annulus ratio (RCA/AO) was >0.12. In the adult-type group, all ten patients had RCA dilation and significant development of collateralization from the RCA to the dilated LCA. They all had mild MR and RCA/AO was >0.20. Preoperatively, left ventricular ejection fraction (LVEF) was significantly lower in infant-type group than in adult-type group (46.24%±5.47% vs. 61.43%±6.38%, P<0.01). Cardiac surgery significantly improved post-operative LVEF (60.12%±6.02%, P<0.01 vs. pre-operation) in infant-type group.

CONCLUSIONS

Echocardiography plays a pivotal role in detecting ALCAPA. Imaging and clinical features differ significantly between infant- and adult-type cases.

Prognostic value of normal and non-obstructive coronary artery disease based on CT angiography findings. A 12 month follow up study

Introduction: The advent of multi-slice computed tomography (CT) technology has provided a new promising tool for non-invasive assessment of the coronary arteries. However, as the prognostic outcome of patients with normal or non-significant finding on computed tomography coronary angiography (CTCA) is not well-known, this study was aimed to determine the prognostic value of CTCA in patients with either normal or non-significant CTCA findings.

Methods: This retrospective cohort study was performed on patients who were referred for CTCA to the hospital. 527 patients with known or suspected coronary artery disease (CAD), who had undergone CTCA within one year were enrolled. Among them, data of 465 patients who had normal (no stenosis, n=362) or non-significant CTCA findings (stenosis <50% of luminal narrowing, n=103) were analyzed and prevalence of cardiac risk factors and major adverse cardiac events (MACE) were compared between these groups. In addition, a correlation between these factors and the number of involved coronary arteries was also determined.

Results: After a mean follow-up duration of 13.11±4.63 months, all cases were alive except for three patients who died by non-cardiac events. Prevalence of MACE was 0% and 3% in normal CTCA group and non-significant groups, respectively. There was no correlation found between the number of involved coronary arteries and the prevalence of MACE (P = 0.57).

Conclusion: A normal CTCA could be associated with extremely low risk of MACE over the first year after the initial imaging, whereas non-significant obstruction in coronary arteries may be associated with a slightly higher risk of MACE.

Point of Care Clinical Risk Score to Improve the Negative Diagnostic Utility of an Agatston Score of Zero: Averting the Need for Coronary Computed Tomography Angiography

BACKGROUND

Coronary artery calcification is a marker of underlying atherosclerotic vascular disease. The absence of coronary artery calcification is associated with a low prevalence of obstructive coronary artery disease (CAD), but it cannot be ruled out completely. We sought to develop a clinical tool that can be added to Agatston score of zero to rule out obstructive CAD with high accuracy.

METHODS

We developed a clinical score retrospectively from a cohort of 4903 consecutive patients with an Agatston score of zero. Patients with prior diagnosis of CAD, coronary percutaneous coronary intervention, or surgical revascularization were excluded. Obstructive CAD was defined as any epicardial vessel diameter narrowing of ≥50%. The score was validated using an external cohort of 4290 patients with an Agatston score of zero from a multinational registry.

RESULTS

The score consisted of 7 variables: age, sex, typical chest pain, dyslipidemia, hypertension, family history, and diabetes mellitus. The model was robust with an area under the curve of 0.70 (95% CI, 0.65-0.76) in the derivation cohort and 0.69 (95% CI, 0.65-0.72) in the validation cohort. Patients were divided into 3 risk groups based on the score: low (≤6), intermediate (7-13), and high (≥14). Patients who score ≤6 have a negative likelihood ratio of 0.42 for obstructive CAD, whereas those who score ≥14 have a positive likelihood ratio of >5.5 for obstructive CAD. The outcome was ruled out in >98% of patients with a score ≤6 in the validation cohort.

CONCLUSIONS

We developed a score that may be used to identify the likelihood of obstructive CAD in patients with an Agatston score of zero, which may be used to direct the need for additional testing. However, the results of this retrospective analysis are hypothesis generating and before clinical implementation should be validated in a trial with a prospectively collected data.

Effect of cilostazol, a phosphodiesterase-3 inhibitor, on coronary artery stenosis and plaque characteristics in patients with type 2 diabetes: ESCAPE study

AIM

To perform a prospective study to evaluate the effect of cilostazol (CTZ) compared with aspirin (acetylsalicylic acid; ASA) in Korean people with diabetes and subclinical coronary atherosclerosis.

MATERIALS AND METHODS

A total of 100 people with diabetes who had mild to moderate coronary atherosclerosis, assessed by coronary computed tomographic angiography (CCTA), were randomly assigned to either 200 mg/d CTZ or 100 mg/d ASA (n = 50 each group). The primary outcome was change in coronary artery stenosis assessed by CCTA after 12 months of treatment. Secondary outcomes included changes in plaque composition, coronary artery calcium score and cardiac markers.

RESULTS

The mean age, body mass index and glycated haemoglobin concentration were 61.5 years, 25.0 kg/m² and 56.8 mmol/mol, respectively, and were well matched between the two groups. Coronary artery stenosis decreased in the CTZ group (from 44.0 ± 2.1% to 40.4 ± 2.5%) but remained unchanged in the ASA group (from 38.9 ± 2.1% to 40.6 ± 2.1%). In the CTZ group, the non-calcified portion of plaques decreased significantly (from 20.6 ± 3.0 to 17.3 ± 3.0 mm³ ), whereas it did not change significantly in the ASA group (15.2 ± 2.8 vs 16.6 ± 2.9 mm³ ). Increases in HDL cholesterol, decreases in triglycerides, liver enzyme and high-sensitivity C-reactive protein levels, and reductions in abdominal visceral fat area and insulin resistance were observed only in the CTZ group.

CONCLUSION

CTZ treatment for 12 months decreased coronary artery stenosis and the non-calcified plaque component. These results suggest that CTZ treatment may be an option for preventing the progression of coronary atherosclerosis in people with diabetes.

Association between coronary artery atherosclerosis and plasma glucose levels assessed by dual-source computed tomography

Background

To assess the association between coronary artery atherosclerosis (CAA) and plasma glucose parameters in a randomly selected cohort of asymptomatic, community-dwelling, Chinese adults by dual-source computed tomography (DSCT).

Methods

We randomly selected participants and classified them into three groups based on their plasma glucose levels: normal glucose regulation (NGR), pre-diabetes, and diabetes mellitus (DM). The participants underwent DSCT, and those identified with CAA were divided into four groups according to the severity of their coronary artery stenosis. We analyzed the composition of plaques in all coronary artery segments according to the American Heart Association's (AHA) guidelines. We compared the severity of coronary artery stenosis and the plaque composition with plasma glucose parameters among participants.

Results

Out of a total of 335 participants, 118 were found to have CAA. The prevalence of CAA was highest (P value for trend =0.031) in the diabetic group (67.7%) followed by the pre-diabetic group (35.1%) then the NGR group (27.7%). Both calcified and mixed plaques were found in the coronary arteries of the diabetic group while mixed and non-calcified plaques predominated in the pre-diabetic and the NGR groups. When data from all subjects with CAA were analyzed, blood glucose parameters, fasting plasma glucose (FPG), 2-hr postprandial plasma glucose (PPG), and hemoglobin A1c (HbA1c), exhibited a positive correlation with the severity of coronary stenosis (P<0.05). Multivariable logistic regression models indicated a significantly higher risk of CAA among the diabetic patients. Triglyceride levels were positively correlated with the blood glucose parameters among the three groups while LDL-C was elevated in the DM group but not in the pre-diabetic group compared to the NGR group.

Conclusions

The severity of CAA exhibited a direct correlation with the blood glucose parameters, FPG, PPG, and HbA1c. DSCT can accurately detect the presence and distribution of CAA in asymptomatic, community-dwelling subjects. DSCT is a useful screening tool for coronary artery disease (CAD).

Prognostic Performance of Prospective versus Retrospective Electrocardiographic Gating in Coronary Computed Tomographic Angiography

Coronary computed tomographic angiography (CCTA) with prospective electrocardiographic gating reduces radiation exposure, but its prognostic power for predicting cardiovascular risk in patients with suspected CAD has not been fully validated. To determine whether prospective gating performs as well as retrospective gating in this population, we compared these scan modes in patients undergoing 64-slice CCTA. From January 2009 through September 2011, 1,407 patients underwent CCTA; of these, 915 (mean age, 57.8 ± 13.5 yr; 54% male) had suspected coronary artery disease at the time of CCTA and were included in the study. Prospective gating was used in 195 (21%) and retrospective gating in 720 (79%). The mean follow-up duration was 2.4 ± 0.9 years. Overall, 390 patients (42.6%) had normal results on CCTA, 382 (41.7%) had nonobstructive coronary artery disease, and 143 (15.6%) had obstructive disease. Major adverse cardiac events occurred in 32 patients (3.5%): 11 cardiac deaths, 15 late revascularizations, and 6 nonfatal myocardial infarctions. Total event occurrences were similar in both groups (retrospective, 3.8%; prospective, 2.6%; P=0.42), as were the occurrences of each type of event. On adjusted multivariate analysis, nonobstructive (P=0.015) and obstructive (P <0.001) coronary artery disease were independently associated with major adverse cardiac events. Scan mode was not a predictor of outcome. The mean effective radiation dose was 4 ± 2 mSv for prospective compared with 12 ± 4 mSv for retrospective gating (P <0.01). The prognostic value of CCTA with prospective electrocardiographic gating compares favorably with that of retrospective gating, and it involves significantly less radiation exposure.

A methodology review on the incremental prognostic value of computed tomography biomarkers in addition to Framingham risk score in predicting cardiovascular disease: the use of association, discrimination and reclassification

BACKGROUND

Computed tomography (CT) biomarkers claim to improve cardiovascular risk stratification. This review focuses on significant differences in incremental measures between adequate and inadequate reporting practise.

METHODS

Studies included were those that used Framingham Risk Score as a baseline and described the incremental value of adding calcium score or CT coronary angiogram in predicting cardiovascular risk. Searches of MEDLINE, EMBASE, Web of Science and Cochrane Central were performed with no language restriction.

RESULTS

Thirty five studies consisting of 206,663 patients (men = 118,114, 55.1%) were included. The baseline Framingham Risk Score included the 1998, 2002 and 2008 iterations. Selective reporting, inconsistent reference groupings and thresholds were found. Twelve studies (34.3%) had major and 23 (65.7%) had minor alterations and the respective Δ AUC were significantly different (p = 0.015). When the baseline model performed well, the Δ AUC was relatively lower with the addition of a CT biomarker (Spearman coefficient = - 0.46, p < 0.0001; n = 33; 76 pairs of data). Other factors that influenced AUC performance included exploration of data analysis, calibration, validation, multivariable and AUC documentation (all p < 0.05). Most studies (68.7%) that reported categorical NRI (n = 16; 46 pairs of data) subjectively drew strong conclusions along with other poor reporting practices. However, no significant difference in values of NRI was found between adequate and inadequate reporting.

CONCLUSIONS

The widespread practice of poor reporting particularly association, discrimination, reclassification, calibration and validation undermines the claimed incremental value of CT biomarkers over the Framingham Risk Score alone. Inadequate reporting of discrimination inflates effect estimate, however, that is not necessarily the case for reclassification.

Computed Tomographic Coronary Angiography–Derived Plaque Characteristics Predict Major Adverse Cardiovascular Events

Background—

Computed tomographic coronary angiography is a noninvasive imaging modality that permits identification and characterization of coronary plaques. Despite consensus statements supporting routine reporting of computed tomographic coronary angiography plaque characteristics, there remains uncertainty whether these data convey prognostic information. We performed a systematic review and meta-analysis assessing the strength of association between computed tomographic coronary angiography–derived plaque characterization and major adverse cardiovascular events (MACE).

Methods and Results—

Electronic databases were searched for studies reporting computed tomographic coronary angiography plaque characterization and MACE. Data were gathered on plaque morphology (noncalcified, partially calcified, and calcified) and high-risk plaque (HRP) features, including low-attenuation plaque, napkin-ring sign, spotty calcification, and positive remodeling. Of 5496 citations, 13 studies met inclusion criteria. Five hundred fifty-two (3.9%) MACE occurred in 13 977 patients with mean follow-up ranging between 1.3 and 8.2 years. In terms of plaque morphology, the strongest association was observed for noncalcified plaque (hazard ratio [HR], 1.45; 95% confidence interval [CI], 1.24–1.70; P <0.001), with weaker associations found for partially calcified (HR, 1.37; 95% CI, 1.18–1.60; P <0.001) and calcified plaques (HR, 1.23; 95% CI, 1.16–1.30; P <0.001). All HRP features were strongly associated with MACE, including napkin-ring sign (HR, 5.06; 95% CI, 3.23–7.94; P <0.001), low-attenuation plaque (HR, 2.95; 95% CI, 2.03–4.29; P <0.001), positive remodeling (HR, 2.58; 95% CI, 1.84–3.61; P <0.001), and spotty calcification (HR, 2.25; 95% CI, 1.26–4.04; P =0.006). The presence of ≥2 HRP features had highest risk of MACE (HR, 9.17; 95% CI, 4.10–20.50; P <0.001).

Conclusions—

These data demonstrate that HRP is most likely an independent predictor of MACE, which supports the inclusion of HRP reporting in clinical practice. However, at this point, it remains unclear whether HRP reporting has clinical implications.

Sex Differences in Associations of Arterial Compliance With Coronary Artery Plaque and Calcification Burden

Background

Coronary artery disease is a leading killer of women. Arterial stiffness predicts myocardial infarction, and postmenopausal women have lower arterial compliance (AC) than men. We hypothesized that lower AC would be associated with greater burden of coronary artery plaque and calcification, and that these associations would be stronger in women than men.

Methods and Results

We evaluated 3639 consecutive adults without coronary artery disease history who had coronary computed tomography between 2006 and 2014. Coronary artery calcification was calculated using the Agatston method. Plaque extent was assessed by the number of arterial segments with visible plaque divided by the number of visualized segments ×100 (percent plaque score). Indexed AC was calculated as stroke volume index/central pulse pressure. We used step‐wise multivariable linear regression to assess associations of log indexed AC with log (percent plaque score+1) and log (coronary artery calcification+1). Sex‐specific models were performed if the interaction sex×AC was significant. Mean age was 57±11 years, 53% were men, and 71% were hypertensive. Interaction term sex×AC was significant for both models (P=0.008 for percent plaque score and 0.022 for coronary artery calcification). Lower indexed AC was associated with higher percent plaque score and coronary artery calcification in women (β±SE: −0.231±0.113, P=0.042 and −0.334±0.166, P=0.044, respectively), but not in men (β±SE: −0.062±0.104, P=0.551 and 0.114±0.173, P=0.510, respectively).

Conclusions

Lower AC is associated with greater burden of coronary artery plaque and calcification in women, but not in men. Our findings highlight low AC as a correlate of more‐advanced coronary artery disease and as a potential link to the worse cardiovascular outcomes in women.

Increased prevalence of coronary plaque in patients with psoriatic arthritis without prior diagnosis of coronary artery disease

OBJECTIVES

To evaluate coronary atherosclerosis in patients with psoriatic arthritis (PsA) and control subjects using coronary CT angiography (CCTA).

METHODS

Ninety consecutive patients with PsA (male: 56(62.2%); 50.3±11.1 years) were recruited. 240 controls (male: 137(57.1%); 49.6±10.7 years) without known cardiovascular (CV) diseases who underwent CCTA due to chest pain and/or multiple CV risk factors were recruited for comparison.

RESULTS

Patients with PsA and controls were matched in age, gender and traditional CV risk factors (all p>0.2). The prevalence of overall plaque (54(60%)/84(35%), p<0.001), calcified plaque (CP) (29(32%)/40(17%), p=0.002), mixed plaque (MP) (20(22%)/18(8%), p<0.001), non-calcified plaque (NCP) (39(43%)/53(22%), p<0.001) and combined MP/NCP (46(51%)/62(26%), p<0.001) were all significantly higher in patients with PsA. Three-vessel disease was diagnosed in 12(13%) patients with PsA and 7(3%) controls (p<0.001), while obstructive plaques (>50% stenosis) were observed in 8(9%) patients with PsA and 7(3%) controls (p=0.033). After adjusting for traditional CV risk factors, PsA remained an independent explanatory variable for all types of coronary plaques (OR: 2.730 to 4.064, all p<0.001). PsA was also an independent explanatory variable for three-vessel disease (OR: 10.798, p<0.001) and obstructive plaque (3.939, p=0.024). In patients with PsA, disease duration was the only disease-specific characteristic associated with more vulnerable plaques (MP/NCP) in multivariate analysis (1.063, p=0.031). The other independent explanatory variables were age ≥55 years (5.636, p=0.005) and male gender (8.197, p=0.001).

CONCLUSIONS

Patients with PsA have increased prevalence, burden and severity of coronary atherosclerosis as documented by CCTA. Longer disease duration was independently associated with the presence of vulnerable MP/NCP plaques in patients with PsA.

TRIAL REGISTRATION NUMBER

NCT02232321.