Likelihood Of Coronary Artery Disease Research Articles

Clinical Likelihood Prediction of Hemodynamically Obstructive CoronaryArtery Disease in Patients WithStable Chest Pain.

Selection for invasive angiography is recommended to be based on pretest probabilities (PTPs), and physiological measures of hemodynamical impairment by, for example, fractional flow reserve (FFR) should guide revascularization. The risk factor-weighted clinical likelihood (RF-CL) and coronary artery calcium score-weighted clinical likelihood (CACS-CL) models show superior discrimination of patients with suspected obstructive coronary artery disease (CAD), but validation against hemodynamic impairment is warranted. The aim of this study was to validate the RF-CL and CACS-CL models against hemodynamically obstructive CAD. Stable de novo chest pain patients (N=4,371) underwent coronary computed tomography angiography and subsequently invasive coronary angiography with FFR measurements. Hemodynamically obstructive CAD was defined as invasive FFR≤0.80 or high-grade stenosis by visual assessment (>90% diameter stenosis). For comparison, a guideline-endorsed basic PTP model was calculated based on age, sex, and symptom typicality. The RF-CL model additionally included the number of risk factors, and the CACS-CL model incorporated the coronary artery calcium score into the RF-CL. In total, 447 of 4,371 (10.9%) patients had hemodynamically obstructive CAD. Both the RF-CL and CACS-CL models classified more patients with a very low clinical likelihood (≤5%) of obstructive CAD compared to the basic PTP model (33.0% and 53.7% vs 12.0%; P< 0.001) with a preserved low prevalence of hemodynamically obstructive CAD (<5% for all models). Against hemodynamically obstructive CAD, calibration and discrimination of the RF-CL and CACS-CL models were superior to the basic PTP model. The RF-CL and CACS-CL models are well calibrated and superior to a currently recommended basic PTP model to predict hemodynamically obstructive CAD. (Danish Study of Non-Invasive Diagnostic Testing in Coronary Artery Disease [Dan-NICAD]; NCT02264717; Danish Study of Non-Invasive Diagnostic Testing in Coronary Artery Disease 2 [Dan-NICAD 2]; NCT03481712, Danish Study of Non-Invasive Diagnostic Testing in Coronary Artery Disease 3 [Dan-NICAD 3]; NCT04707859).

Coronary atherosclerosis among symptomatic patients with zero coronary artery calcium score in computed tomography coronary angiography

BackgroundComputed tomographic coronary angiography has been recognized as a reliable imaging modality with excellent negative predictive value and a good negative likelihood ratio to exclude coronary artery disease in stable, symptomatic patients with intermediate or high risk. 1) Coronary calcium scoring has been extensively shown to be an invaluable tool to exclude the presence of coronary artery disease in low-risk patients. 2) Our aim was to identify the presence and extent of coronary atherosclerosis in computed tomographic coronary angiography in stable symptomatic patients with a zero Coronary Calcium score. ResultsThree hundred and eighty-three (383) consecutive patients aged ≥ 18 years fulfilling the criteria were enrolled as of January 1, 2021; 165 (43.1%) were male and 218 (56.9%) were female, with a mean age of 57.8 ± 4.9 years and a zero coronary artery calcium score. Two hundred and twenty-six (226) (59.0%) were hypertensive, followed by 125 (32.6%) who were smokers, and 117 (30.5%) who were diabetic. The frequency of atherosclerotic plaque in coronary arteries was 34 (8.9%), with 16 (47.1%) being male and 18 (52.9%) being female. The mean age of patients with atherosclerosis was 54.9 ± 3.3 years; among them, 13 (38.2%) were between the ages of 45 and 54, and 10 (29.4%) were between the ages of 55 and 64. Nineteen (19) (55.9%) were hypertensive, followed by 10 (29.4%) with dyslipidemia. Twenty-three (23) (67.6%) had non-obstructive plaque, and 11 (32.3%) had obstructive plaque. In the subgroup of patients with non-obstructive plaque, 13 (56.5%) were hypertensive, 8 (34.8%) were diabetic, and 16 (69.6%) had single vessel disease, while among patients with obstructive plaque, 6 (54.5%) were hypertensive, 5 (45.5%) were smokers, and all of them had single vessel disease. The most affected artery was the left anterior descending artery. ConclusionAs the frequency of atherosclerotic plaque in patients with a zero coronary calcium score is relatively high, computed tomographic coronary angiography is indicated in stable, symptomatic patients with a lower likelihood of coronary artery disease.

Performance of the 2019 ESC pre-test probability model in predicting obstructive coronary artery disease in a Chinese population using coronary computed tomography angiography outcomes

BackgroundThe 2019 European Society of Cardiology (ESC) guidelines proposed a pre-test probability (PTP) model to determine the likelihood of coronary artery disease (CAD). However, the prediction accuracy of this model has not yet been evaluated in Chinese populations. This study aimed to validate the 2019 ESC-PTP model in predicting CAD using coronary computed tomography angiography (CCTA) outcomes in a Chinese population. MethodsA total of 26,346 consecutive patients with suspected CAD who underwent CCTA were included. The 2019 ESC-PTP model and 2013 ESC-PTP model were calculated for each patient, considering age, sex, and the symptom of chest pain, and the patients were categorized into low-, intermediate-, and high-risk groups. The predictive performance of the 2019 ESC-PTP model was evaluated by comparing it with the 2013 ESC-PTP model and the observed prevalence of CAD from CCTA. ResultsAmong the 11,234 patients analyzed in the study, 1896 (16.9%) patients were found to have obstructive CAD from CCTA. The 2019 ESC-PTP model had better calibration compared to the 2013 ESC-PTP model. After categorization, 80.9% of patients (67.9% in men and 94.4% in women) were in the same risk category as in the 2019 ESC-PTP model, but the risks of younger patients (7.5% versus 2.5%; P ​< ​0.001) and patients with non-anginal chest pain (13.7% versus 8.2%; P ​< ​0.001) were underestimated in the 2019 ESC-PTP model. ConclusionThe 2019 ESC-PTP model demonstrated a good calibration in predicting CAD in a Chinese population who underwent CCTA, but it exhibited an underestimation of CAD probability in younger patients and patients with non-anginal chest pain.

Deep learning approach for cardiovascular disease risk stratification and survival analysis on a Canadian cohort.

The quantification of carotid plaque has been routinely used to predict cardiovascular risk in cardiovascular disease (CVD) and coronary artery disease (CAD). To determine how well carotid plaque features predict the likelihood of CAD and cardiovascular (CV) events using deep learning (DL) and compare against the machine learning (ML) paradigm. The participants in this study consisted of 459 individuals who had undergone coronary angiography, contrast-enhanced ultrasonography, and focused carotid B-mode ultrasound. Each patient was tracked for thirty days. The measurements on these patients consisted of maximum plaque height (MPH), total plaque area (TPA), carotid intima-media thickness (cIMT), and intraplaque neovascularization (IPN). CAD risk and CV event stratification were performed by applying eight types of DL-based models. Univariate and multivariate analysis was also conducted to predict the most significant risk predictors. The DL's model effectiveness was evaluated by the area-under-the-curve measurement while the CV event prediction was evaluated using the Cox proportional hazard model (CPHM) and compared against the DL-based concordance index (c-index). IPN showed a substantial ability to predict CV events (p < 0.0001). The best DL system improved by 21% (0.929 vs. 0.762) over the best ML system. DL-based CV event prediction showed a ~ 17% increase in DL-based c-index compared to the CPHM (0.86 vs. 0.73). CAD and CV incidents were linked to IPN and carotid imaging characteristics. For survival analysis and CAD prediction, the DL-based system performs superior to ML-based models.

Calcium Scoring Improves Clinical Management in Patients With Low Clinical Likelihood of Coronary Artery Disease

BackgroundCoronary artery calcium scoring (CACS) improves management of chest pain patients. However, it is unknown whether the benefit of CACS is dependent on the clinical likelihood (CL). ObjectivesThis study aims to investigate for which patients CACS has the greatest benefit when added to a CL model. MethodsBased on data from a clinical database, the CL of obstructive coronary artery disease (CAD) was calculated for 39,837 patients referred for cardiac imaging due to symptoms suggestive of obstructive CAD. Patients were categorized according to the risk factor–weighted (RF-CL) model (very low, ≤5%; low, >5 to ≤15%; moderate >15 to ≤50%; high, >50%). CL was then recalculated incorporating the CACS result (CACS-CL). Reclassification rates and the number needed to test with CACS to reclassify patients were calculated and validated in 3 independent cohorts (n = 9,635). ResultsIn total, 15,358 (39%) patients were down- or upclassified after including CACS. Reclassification rates were 8%, 75%, 53%, and 30% in the very low, low, moderate, and high RF-CL categories, respectively. Reclassification to very low CACS-CL occurred in 48% of reclassified patients. The number needed to test to reclassify 1 patient from low RF-CL to very low CACS-CL was 2.1 with consistency across age, sex, and cohorts. CACS-CL correlated better to obstructive CAD prevalence than RF-CL. ConclusionsAdded to an RF-CL model for obstructive CAD, CACS identifies more patients unlikely to benefit from further testing. The number needed to test with CACS to reclassify patients depends on the pretest RF-CL and is lowest in patients with low (>5% to ≤15%) likelihood of CAD.

Altered Gut Microbiota as a Potential Risk Factor for Coronary Artery Disease in Diabetes: A Two-Sample Bi-Directional Mendelian Randomization Study.

The current body of research points to a notable correlation between an imbalance in gut microbiota and the development of type 2 diabetes mellitus (T2D) as well as its consequential ailment, coronary artery disease (CAD). The complexities underlying the association, especially in the context of diabetic coronary artery disease (DCAD), are not yet fully understood, and the causal links require further clarification. In this study, a bidirectional Mendelian randomization (MR) methodology was utilized to explore the causal relationships between gut microbiota, T2D, and CAD. By analyzing data from the DIAGRAM, GERA, UKB, FHS, and mibioGen cohorts and examining GWAS databases, we sought to uncover genetic variants linked to T2D, CAD, and variations in gut microbiota and metabolites, aiming to shed light on the potential mechanisms connecting gut microbiota with DCAD. Our investigation uncovered a marked causal link between the presence of Oxalobacter formigenes and an increased incidence of both T2D and CAD. Specifically, a ten-unit genetic predisposition towards T2D was found to be associated with a 6.1% higher probability of an increase in the Oxalobacteraceae family's presence (β = 0.061, 95% CI = 0.002-0.119). In a parallel finding, an augmented presence of Oxalobacter was related to an 8.2% heightened genetic likelihood of CAD (β = 0.082, 95% CI = 0.026-0.137). This evidence indicates a critical pathway by which T2D can potentially raise the risk of CAD via alterations in gut microbiota. Additionally, our analyses reveal a connection between CAD risk and Methanobacteria, thus providing fresh perspectives on the roles of TMAO and carnitine in the etiology of CAD. The data also suggest a direct causal relationship between increased levels of certain metabolites - proline, lysophosphatidylcholine, asparagine, and salicylurate - and the prevalence of both T2D and CAD. Sensitivity assessments reinforce the notion that changes in Oxalobacter formigenes could pose a risk for DCAD. There is also evidence to suggest that DCAD may, in turn, affect the gut microbiota's makeup. Notably, a surge in serum TMAO levels in individuals with CAD, coinciding with a reduced presence of methanogens, has been identified as a potentially significant factor for future examination.

Simplified Approach to Predicting Obstructive Coronary Disease With Integration of Coronary Calcium: Development and External Validation.

The Diamond-Forrester model was used extensively to predict obstructive coronary artery disease (CAD) but overestimates probability in current populations. Coronary artery calcium (CAC) is a useful marker of CAD, which is not routinely integrated with other features. We derived simple likelihood tables, integrating CAC with age, sex, and cardiac chest pain to predict obstructive CAD. The training population included patients from 3 multinational sites (n=2055), with 2 sites for external testing (n=3321). We determined associations between age, sex, cardiac chest pain, and CAC with the presence of obstructive CAD, defined as any stenosis ≥50% on coronary computed tomography angiography. Prediction performance was assessed using area under the receiver-operating characteristic curves (AUCs) and compared with the CAD Consortium models with and without CAC, which require detailed calculations, and the updated Diamond-Forrester model. In external testing, the proposed likelihood tables had higher AUC (0.875 [95% CI, 0.862-0.889]) than the CAD Consortium clinical+CAC score (AUC, 0.868 [95% CI, 0.855-0.881]; P=0.030) and the updated Diamond-Forrester model (AUC, 0.679 [95% CI, 0.658-0.699]; P<0.001). The calibration for the likelihood tables was better than the CAD Consortium model (Brier score, 0.116 versus 0.121; P=0.005). We have developed and externally validated simple likelihood tables to integrate CAC with age, sex, and cardiac chest pain, demonstrating improved prediction performance compared with other risk models. Our tool affords physicians with the opportunity to rapidly and easily integrate a small number of important features to estimate a patient's likelihood of obstructive CAD as an aid to clinical management.

A Posteriori Dietary Patterns and Coronary Artery Disease in a Greek Case-Control Study.

Diet is one of the most important modifiable risk factors associated with cardiovascular health (CH). Research identifying dietary patterns (DPs) through data-driven analysis and reporting associations between DPs and coronary artery disease (CAD) outcomes is rather limited. The aim of the present report was to generate DPs through factor analysis (FA) and to examine their association with CAD risk. Participants (n = 1017) consisted of cases diagnosed with CAD (n = 356) and controls (n = 661) drawn from the THISEAS study. Demographic, anthropometric and lifestyle data were collected. Dietary components were generated through FA. Logistic regression analysis was performed to estimate CAD relative risks. FA generated seven dietary components, explaining 53.5% of the total variation in intake. The Western-type DP showed a modest significant association with CAD risk, after controlling for confounders (OR = 1.20; 95% CI = 1.09-1.32, p < 0.001). The vegetarian-type DP was not significantly associated with the likelihood of CAD (OR = 0.95; 95% CI = 0.84-1.04, p = 0.259). The Western-type DP was positively associated with CAD risk and the odds were further increased after controlling for confounders. This finding is in concordance with previously reported positive associations between Western patterns and CAD risk. Limited data exist regarding a posteriori DPs and their effect on CAD risk.

Reduction of perivascular inflammation following long-term statin treatment - a coronary CT follow-up study using Fat Attenuation Index

Abstract Background Perivascular fat attenuation index (FAI) assessed by coronary computed tomography (CCTA) has been demonstrated to represent a reliable marker of coronary inflammation. Several studies have explored the potential anti-inflammatory effects of statins in reducing the risk of plaque rupture and subsequent cardiovascular events. However, the effect of statin therapy on FAI has not been clearly demonstrated so far. Purpose Our objective was to investigate the changes in perivascular FAI at the level of coronary lesions, as measured by coronary computed tomography (CCTA), following long-term high-dose statin therapy. Methods This study includes 23 patients who presented with typical chest pain, had a low to intermediate likelihood of coronary artery disease, and underwent a CCTA examination which revealed the existence of at least one coronary atheromatous plaque. Statin therapy was initiated in all patients according to guidelines. The CCTA was repeated after a time interval ranging from 1.5 to 3 years. Lesion-specific perivascular FAI, together with different plaque characteristics, were measured at both baseline and follow-up using a new AI-powered medical device called CaRi-Heart®. Results The mean age of the participants was 61.72 ± 8.86 at the time of the first scan, and 65.21% (n = 15) of them were male. At baseline, the CT density of the adipose tissue (ranging from -190 to -30 HU), was not significantly different between the two groups. A significant decrease in serum lipids following statin therapy was recorded during follow-up: from 193.4 ± 47.09 to 145.2 ± 34.7, p = 0.04 for total cholesterol, and from 101.77 ± 25.20 to 86.41 ± 21.09, p = 0.02 for LDL cholesterol. The FAI-score consistently decreased from baseline to follow-up, especially in the left anterior descending artery: from 15.87 ± 9.32 vs. 12.40 ± 7.55, p = 0.04, while there was no significant decrease in coronary inflammation at the level of left circumflex artery (13.98 ± 6.16 vs. 13.10 ± 6.59, p = ns), or right coronary artery (20.53 ± 13.74 vs. 19.96 ± 16.24, p = ns). Similarly, the FAI-Score Centile values were lower during the second scan, specifically for LAD (0.51 ± 0.28 vs. 0.69 ± 0.29, p = 0.04), while there were no significant differences of FAI score centile in the LCX (0.72 ± 0.28 vs. 0.74 ± 0.26, p = ns) and RCA (0.71 ± 0.32 vs. 0.78 ± 0.21, p = ns). Conclusion CaRi-Heart® mapping technology revealed a significant decrease of coronary inflammation, as expressed by the FAI-score, as a result of high-dose statin treatment especially at the level of the LAD. This indicates a potential role of local factors related to coronary circulation in the complex process of plaque inflammation. The perivascular FAI-score and FAI-score centile may serve as promising imaging biomarkers for monitoring the anti-inflammatory response to statin treatments.Color-coded FAI MappingPVAT-FAI Score of Coronary Inflammation

Stress computed tomography perfusion versus stress cardiac magnetic resonance for the management of suspected or known coronary artery disease: resources and outcomes impact (STRATEGY II Study)

Abstract Background Non-invasive techniques have evolved as "gatekeepers" to invasive coronary angiography (ICA) for symptomatic patients with suspected or known coronary artery disease (CAD). Evaluation of myocardial ischemia with functional tests represents a milestone in CAD detection with proved diagnostic and prognostic power. Coronary computed tomography angiography (CCTA), a non-invasive anatomical assessment, intrinsically lacks physiologic data to categorize the downstream hemodynamic significance of lesions. Stress CT perfusion (stress-CTP) is a recently evolved imaging modality able to assess inducible myocardial perfusion defects. The aim of this study is to compare resources and outcomes Impact of combined CCTA+stress-CTP versus stress cardiovascular magnetic resonance (stress-CMR) in consecutive symptomatic patients with suspected CAD and intermediate to high pre-test likelihood of disease or known CAD or previous history of revascularization. Methods 624 symptomatic patients with intermediate to high risk pre-test likelihood for CAD or previous history of revascularization referred to our hospital for clinically indicated CCTA+stress-CTP or stress-CMR were enrolled. Stress-CTP scans were performed in 223 patients using 256-row whole heart-coverage scanner, static protocol acquisition and vasodilation induced by adenosine. 401 patients with clinically indicated stress-CMR were evaluated in a 1.5-T scanner after vasodilatation induced with dipyridamole. Patient follow-up was performed at 1 year after index test performance. Endpoints were as follow: 1) all cardiac events as a combined endpoint of revascularization, non-fatal MI and death; 2) hard cardiac events as combined endpoint of non-fatal MI and death. Results Stress-CMR group showed lower age, higher prevalence of male gender and higher prevalence of previous revascularization, while CCTA+CTP group showed higher prevalence of family history of CAD and statin use. CCTA was defined positive for obstructive disease in 62% of patients while the addition of CTP on top of CCTA reduced the number of positive patients to 46%. Stress-CMR resulted positive in 23% of subjects. Patients who underwent CCTA+CTP underwent more revascularization (29% versus 7%, p: 0.001) while no differences were found in terms of non-fatal MI and death between the two strategies. According to the predefined endpoints, CCTA+CTP group showed higher rate of all cardiac events (29% vs 8%, p: 0.001) and lower rate of hard cardiac events (0.4% vs 3%, p: 0.033), respectively. Stratifying the baseline characteristics by all cardiac events and hard cardiac events, left ventricle volume and index test strategy predicted all cardiac events while only index test strategy predicted hard cardiac events. Conclusions The use of CCTA+CTP strategy was associated with higher referral to revascularization but with a protective trend in terms of hard cardiac events as compared to the usual strategy with lone functional evaluation.

Abstract 12423: CAD Polygenic Risk Score, a Novel Screening Tool for Predicting Likelihood of Coronary Artery Disease, Was Not Superior to Coronary Calcium Score in Predicting MACE

Introduction: Coronary artery calcium (CAC) score is a well-established tool for risk assessment of coronary artery disease (CAD). Alternatively, CAD polygenic risk score (PRS) is an emerging modality for assessing risk of CAD. Our study aims to compare the sensitivity and specificity of the above scores in predicting major adverse cardiovascular events (MACE). Hypothesis: CAD PRS is a better predictor of MACE than CAC score. Methods: Adult patients had CAD PRS, CAC and baseline characteristics documented through the Sanford Heart Screening Program from 2011 to 2021. Incidence of MACE, defined as myocardial infarction, stroke, death, and revascularization, was analyzed. Chi-squared tests were used to examine the impact of stratified risk scores and MACE. A logistic regression model was trained on 70% of the data to assess prediction accuracy on 30% of the data. Results: A total of 1,380 patients were analyzed. Mean age was 63, with female (65%) and Caucasian (99%) predominance. The prevalence of diabetes mellitus, hyperlipidemia, and hypertension was 8%, 32%, and 7%, respectively. The incidence of MACE was 6.6%. Patients with MACE had higher CAC (527.1±856.2 vs. 98.3±294.3) and CAD PRS (15.5±.62 vs. 15.24±.61). Sensitivity and specificity are represented by the receiver operating characteristic curve, which was used to assess prediction accuracy whereby area under the curve (AUC) was used as a measure of fit ranging from 0 to 1. The curves showed that CAC had better AUC than PRS (Figure 1). Conclusions: In our study CAD PRS failed to be a better predictor of MACE compared to CAC score.

Integrated myocardial flow reserve (iMFR) assessment: optimized PET blood flow quantification for diagnosis of coronary artery disease.

Distinguishing obstructive epicardial coronary artery disease (CAD) from microvascular dysfunction and diffuse atherosclerosis would be of immense benefit clinically. However, quantitative measures of absolute myocardial blood flow (MBF) integrate the effects of focal epicardial stenosis, diffuse atherosclerosis, and microvascular dysfunction. In this study, MFR and relative perfusion quantification were combined to create integrated MFR (iMFR) which was evaluated using data from a large clinical registry and an international multi-center trial and validated against invasive coronary angiography (ICA). This study included 1,044 clinical patients referred for 82Rb rest/stress positron emission tomography myocardial perfusion imaging and ICA, along with 231 patients from the Flurpiridaz 301 trial (clinicaltrials.gov NCT01347710). MFR and relative perfusion quantification were combined to create an iMFR map. The incremental value of iMFR was evaluated for diagnosis of obstructive stenosis, adjusted for patient demographics and pre-test probability of CAD. Models for high-risk anatomy (left main or three-vessel disease) were also constructed. iMFR parameters of focally impaired perfusion resulted in best fitting diagnostic models. Receiver-operating characteristic analysis showed a slight improvement compared to standard quantitative perfusion approaches (AUC 0.824 vs. 0.809). Focally impaired perfusion was also associated with high-risk CAD anatomy (OR 1.40 for extent, and OR 2.40 for decreasing mean MFR). Diffusely impaired perfusion was associated with lower likelihood of obstructive CAD, and, in the absence of transient ischemic dilation (TID), with lower likelihood of high-risk CAD anatomy. Focally impaired perfusion extent derived from iMFR assessment is a powerful incremental predictor of obstructive CAD while diffusely impaired perfusion extent can help rule out obstructive and high-risk CAD in the absence of TID.

Peripheral Artery Disease Diagnosed by Pulse Palpation as a Predictor of Coronary Artery Disease in Patients with Chronic Kidney Disease.

There is a need of simple, inexpensive, and reliable noninvasive testing to predict coronary artery disease (CAD) in patients with chronic kidney disease (CKD), where the prevalence of cardiovascular (CV) events and death is elevated. We analyzed the association between peripheral artery disease (PAD) and CAD in 201 patients with stage 5 CKD on dialysis using a prospective observational cohort. Diagnosis of PAD by both palpation and USD were significantly correlated. In patients with PAD diagnosed by palpation, CAD was observed in 80%, while in those diagnosed by USD, CAD was present in 79.1%. The absence of a pulse by palpation predicted CAD with a sensitivity of 55% and a specificity of 76%; USD showed a sensitivity of 62% and specificity of 60% to predict CAD. The risk of combined serious CV events and death was significantly higher in subjects with PAD diagnosed by palpation, but not by USD. PAD assessed by palpation also correlated with the occurrence of multivessel CAD and with the probability of coronary intervention. Both methods are moderately useful for predicting CAD, but PAD diagnosis by palpation was a better predictor of combined CV events and death and was also associated with CAD severity and likelihood of intervention.

Using Coronary Artery Calcium Score as Diagnostic Tool in Symptomatic Chronic Coronary Syndrome Patients in a Real-Life Setting.

The coronary artery calcium (CAC) score can be used to increase (CAC score > 0) or decrease (CAC score = 0) the likelihood of coronary artery disease (CAD). We compared the CAC score with the pre-test probability (PTP) for CAD (low, intermediate, and high). Furthermore, we compared the CAC score with exercise electrocardiography (ECG) and compared both tests with coronary angiography. We retrospectively identified patients with angina and/or dyspnea for whom CAC score was used to increase or decrease the likelihood of CAD. Of 882 patients, majority had low (45%) or intermediate (44%) PTP. Patients with higher PTP had significantly higher CAC scores (Cramer's V = 0.29, p < 0.0001). Most patients (57%) had a CAC score of zero, especially those with low (73%) and intermediate (49%) PTP. However, 20% of patients with high PTP had CAC score of zero. Higher CAC scores were observed in patients with abnormal exercise ECG, but association was weak and not significant (Cramer's V = 0.13, p = 0.08). Moreover, more than 40% of patients with an abnormal exercise ECG had CAC score of zero. Higher CAC scores were associated with more severe abnormalities on coronary angiography (Cramer's V = 0.43, p < 0.0001), whereas there was no association between results of exercise ECG and coronary angiography (Cramer's V = 0.11, p = 0.91). CAC score can be used in addition to PTP to increase or decrease the likelihood of CAD, and it might be more useful than exercise ECG in the diagnostic work-up of chest pain.

Normal physiologic coronary flow velocity gradient across the left anterior descending artery in healthy asymptomatic subjects

Aim: Coronary flow velocity (CFV) can be obtained with transthoracic echocardiography (TTE) in the left anterior descending coronary artery (LAD). The physiologic flow velocity gradient across the different segments of LAD has not been established. This study aims to assess the normal values of resting CFV in proximal, mid, and distal LAD. Methods: In a single center, prospective, observational study design, TTE was attempted on 110 consecutive, asymptomatic middle-aged subjects (age = 55 years, 46% males) with a low likelihood of coronary artery disease (&lt; 5%). Resting CFV in the LAD was assessed with high-end machines, dedicated coronary pre-set, and high-frequency transducers by pulsed-wave Doppler under color-Doppler guidance in the proximal, mid, and distal segments. Results: The technical success rate for CFV imaging was lowest for the proximal (101/110, 92%), intermediate for mid (106/110, 96%), and highest for the distal segment (108/110, 98%). All 3 segments were interpretable in 101 subjects. CFV was highest in proximal segments (38.6 cm/s ± 3.9 cm/s), intermediate in mid segments (34.3 cm/s ± 6.04 cm/s, P &lt; 0.01 vs. proximal), and lowest in distal segments (28.1 cm/s ± 1.7 cm/s, P &lt; 0.01 vs. proximal and vs. mid). Conclusions: A resting evaluation of CFV-LAD can be obtained by TTE in the large majority of consecutive subjects referred to the echocardiography laboratory. Feasibility is highest for distal and lowest for proximal-LAD segments. There is a clear physiologic gradient of CFV with decreasing values, of about 10% for each step, going from proximal to mid and distal segments of LAD. When resting CFV is considered, the site of the sampling is important to obtain comparable and physiologically meaningful data.

Exercise electrocardiography for pre-test assessment of the likelihood of coronary artery disease

ObjectivesTo develop a tool including exercise electrocardiography (ExECG) for patient-specific clinical likelihood estimation of patients with suspected obstructive coronary artery disease (CAD).MethodsAn ExECG-weighted clinical likelihood (ExECG-CL) model was developed in...

Diagnostic and prognostic value of cardiac stress testing before major noncardiac surgery—A cohort study

ObjectiveTo assess the incremental contribution of preoperative stress test results toward a diagnosis of obstructive coronary artery disease (CAD), prediction of mortality, or prediction of perioperative myocardial infarction in patients considering noncardiac, nonophthalmologic surgery. Design, setting, participantsA retrospective cohort study of visits to a preoperative risk assessment and optimization clinic in a large health system between 2008 and 2018. MeasurementsTo assess diagnostic information of preoperative stress testing, we used the Begg and Greenes method to calculate test characteristics adjusted for referral bias, with a gold standard of angiography. To assess prognostic information, we first created multiply-imputed logistic regression models to predict 90-day mortality and perioperative myocardial infarction (MI), starting with two tools commonly used to assess perioperative cardiac risk, Revised Cardiac Risk Index (RCRI) and Myocardial Infarction or Cardiac Arrest (MICA). We then added stress test results and compared the discrimination for models with and without stress test results. Main resultsAmong 136,935 visits by patients without an existing diagnosis of CAD, the decision to obtain preoperative stress testing identified around 4.0% of likely new diagnoses. Stress testing increased the likelihood of CAD (likelihood ratio: 1.31), but for over 99% of patients, stress testing should not change a decision on whether to proceed to angiography. In 117,445 visits with subsequent noncardiac surgery, stress test results failed to improve predictions of either perioperative MI or 90-day mortality. Reweighting the models and adding hemoglobin improved the prediction of both outcomes. ConclusionsCardiac stress testing before noncardiac, nonophthalmologic surgery does not improve predictions of either perioperative mortality or myocardial infarction. Very few patients considering noncardiac, nonophthalmologic surgery have a pretest probability of CAD in a range where stress testing could usefully select patients for angiography. Better use of existing patient data could improve predictions of perioperative adverse events without additional patient testing.

Stress computed tomography perfusion versus stress cardiac magnetic resonance for the management of suspected or known coronary artery disease: resources and outcomes impact (STRATEGY II Study)

Abstract Funding Acknowledgements Type of funding sources: None. Background Non-invasive techniques have evolved as "gatekeepers" to invasive coronary angiography (ICA) for symptomatic patients with suspected or known coronary artery disease (CAD). Evaluation of myocardial ischemia with functional tests represents a milestone in CAD detection with proved diagnostic and prognostic power. Coronary computed tomography angiography (CCTA), a non-invasive anatomical assessment, intrinsically lacks physiologic data to categorize the downstream hemodynamic significance of lesions. Stress CT perfusion (stress-CTP) is a recently evolved imaging modality able to assess inducible myocardial perfusion defects. The aim of this study is to compare resources and outcomes Impact of combined CCTA+stress-CTP versus stress cardiovascular magnetic resonance (stress-CMR) in consecutive symptomatic patients with suspected CAD and intermediate to high pre-test likelihood of disease or known CAD or previous history of revascularization. Methods 624 symptomatic patients with intermediate to high risk pre-test likelihood for CAD or previous history of revascularization referred to our hospital for clinically indicated CCTA+stress-CTP or stress-CMR were enrolled. Stress-CTP scans were performed in 223 patients using 256-row whole heart-coverage scanner, static protocol acquisition and vasodilation induced by adenosine. 401 patients with clinically indicated stress-CMR were evaluated in a 1.5-T scanner after vasodilatation induced with dipyridamole. Patient follow-up was performed at 1 year after index test performance. Endpoints were as follow: 1) all cardiac events as a combined endpoint of revascularization, non-fatal MI and death; 2) hard cardiac events as combined endpoint of non-fatal MI and death. Results Stress-CMR group showed lower age, higher prevalence of male gender and higher prevalence of previous revascularization, while CCTA+CTP group showed higher prevalence of family history of CAD and statin use. CCTA was defined positive for obstructive disease in 62% of patients while the addition of CTP on top of CCTA reduced the number of positive patients to 46%. Stress-CMR resulted positive in 23% of subjects. Patients who underwent CCTA+CTP underwent more revascularization (29% versus 7%, p: 0.001) while no differences were found in terms of non-fatal MI and death between the two strategies. According to the predefined endpoints, CCTA+CTP group showed higher rate of all cardiac events (29% vs 8%, p: 0.001) and lower rate of hard cardiac events (0.4% vs 3%, p: 0.033), respectively. Stratifying the baseline characteristics by all cardiac events and hard cardiac events, left ventricle volume and index test strategy predicted all cardiac events while only index test strategy predicted hard cardiac events. Conclusions The use of CCTA+CTP strategy was associated with higher referral to revascularization but with a protective trend in terms of hard cardiac events as compared to the usual strategy with lone functional evaluation.

CORONARY ARTERY DISEASE IN PATIENTS OF PERIPHERAL ARTERIAL DISEASE: AN OBSERVATIONAL STUDY

This study assessed the frequency of coronary artery disease in patients with peripheral arterial disease undergoing angiography. The study was carried out between January 2019 and June 2019, at the Department of Cardiology, MTI-KTH, Peshawar, on 149 patients who met the operational characteristics of PAD as stated were enrolled in the study through the outpatient and accident and emergency departments before being admitted to the cardiology ward for additional assessment. The patients were informed of the study's goals and advantages, and written informed consent was taken. Patients underwent coronary angiography in the same setting through the femoral or radial artery approach electively. The mean and SDs for age were 51 ±10.92, whereas the disease duration was 4±1.58. The mean and SDs for BMI were 29.4±1.07. 114 (76.51%) patients were found to be hypertensive, whereas 35 (23.48%) patients had normal blood pressure. 133 (89.26%) patients had diabetes, while 17 (10.73%) patients were non-diabetic. 91 (61.07%) patients were found to be smokers, whereas 58 (38.92%) patients were nonsmokers. 80 (53.69%) patients were recorded with coronary artery disease (CAD). It is concluded that scrutiny must be concentrated on the concomitant likelihood of coronary artery disease in patients with diagnosed severe peripheral arterial disease. Moreover, non-invasive coupled with invasive investigation must also be carried out to lessen the burden of this condition regarding morbidity and mortality.

PROTEUS Study: A Prospective Randomized Controlled Trial Evaluating the Use of Artificial Intelligence in Stress Echocardiography

Stress echocardiography (SE) is one of the most commonly used diagnostic imaging tests for coronary artery disease (CAD) but requires clinicians to visually assess scans to identify patients who may benefit from invasive investigation and treatment. EchoGo Pro provides an automated interpretation of SE based on artificial intelligence (AI) image analysis. In reader studies, use of EchoGo Pro when making clinical decisions improves diagnostic accuracy and confidence. Prospective evaluation in real world practice is now important to understand the impact of EchoGo Pro on the patient pathway and outcome. PROTEUS is a randomized, multicenter, 2-armed, noninferiority study aiming to recruit 2,500 participants from National Health Service (NHS) hospitals in the UK referred to SE clinics for investigation of suspected CAD. All participants will undergo a stress echocardiogram protocol as per local hospital policy. Participants will be randomized 1:1 to a control group, representing current practice, or an intervention group, in which clinicians will receive an AI image analysis report (EchoGo Pro, Ultromics Ltd, Oxford, UK) to use during image interpretation, indicating the likelihood of severe CAD. The primary outcome will be appropriateness of clinician decision to refer for coronary angiography. Secondary outcomes will assess other health impacts including appropriate use of other clinical management approaches, impact on variability in decision making, patient and clinician qualitative experience and a health economic analysis. This will be the first study to assess the impact of introducing an AI medical diagnostic aid into the standard care pathway of patients with suspected CAD being investigated with SE. Clinicaltrials.gov registration number NCT05028179, registered on 31 August 2021; ISRCTN: ISRCTN15113915; IRAS ref: 293515; REC ref: 21/NW/0199.