Cardiac Imaging in the Diagnosis of Coronary Artery Disease

Clinical Efficacy of Gadobutrol: Review of Over 25 Years of Use Exceeding 100 Million Administrations

BACKGROUND

Gadobutrol has been administered more than 100 million times worldwide, since February 1998, that is, over the last 25 years. Numerous clinical studies in a broad range of indications document the long-term experience with gadobutrol.

OBJECTIVE

The aim of this study was to provide a literature-based overview on gadobutrol's efficacy in 9 approved indications and use in children.

MATERIALS AND METHODS

Efficacy results in patients of all age groups including sensitivity, specificity, accuracy, and positive/negative predictive values were identified by a systematic literature search on Embase until December 31, 2022. Nine approved indications were considered: central nervous system (CNS), magnetic resonance angiography (MRA), breast, heart, prostate, kidney, liver, musculoskeletal, whole body, and various indications in children.

RESULTS

Sixty-five publications (10 phase III, 2 phase IV, 53 investigator-initiated studies) reported diagnostic efficacy results obtained from 7806 patients including 271 children, at 369 centers worldwide. Indication-specific sensitivity ranges were 59%-98% (CNS), 53%-100% (MRA), 80%-100% (breast), 64%-90% (heart), 64%-96% (prostate), 71-85 (kidney), 79%-100% (liver), 53%-98% (musculoskeletal), and 78%-100% (children). Indication-specific specificity ranges were 75%-100% (CNS), 64%-99% (MRA), 58%-98% (breast), and 47%-100% (heart).

CONCLUSIONS

The evaluated body of evidence, consisting of 65 studies with 7806 patients, including 271 children and 7535 adults, showed that gadobutrol is an efficacious magnetic resonance imaging contrast agent for all age groups in various approved indications throughout the whole body.

Association of postsystolic shortening on stress echocardiography and significant coronary artery stenosis: A single-centre retrospective cohort study

BACKGROUND

Postsystolic shortening (PSS) is one of the proposed quantitative measures to predict myocardial ischaemia in the stress echocardiographic (SE) evaluation. It is previously known that hypo-/akinesia (HA) correlates well with coronary stenosis. However, some patients undergoing SE only present with PSS, and their risk of significant coronary stenosis is less clear. This study aimed to evaluate the association between PSS and significant coronary stenosis compared with HA.

METHODS

This was a retrospective cohort study at the hospital of S:t Görans, Stockholm, Sweden. All patients who underwent SE to investigate inducible ischaemia between 1 January 2018 and 15 October 2021 were eligible for inclusion. Exclusion criteria were normal SE and inconclusive test. Pathological SE were divided into two groups, patients with HA and those with PSS. Outcome was significant coronary artery stenosis visualized by invasive coronary angiography.

RESULTS

The final study population consisted of 108 patients (73 PSS, 35 HA). The presence of HA was associated with a higher risk of significant stenosis compared to those with PSS (63% vs. 23%, p < 0.001). This relationship was observed among males (p < 0.001), but not among females (p = 0.133). Nonsignificant stenosis trended to be more common among patients with PSS (21% vs. 6%, p = 0.053) CONCLUSIONS: The finding of PSS without HA was associated with a lower risk of significant coronary stenosis than HA. However, patients with PSS still often had nonsignificant coronary stenosis and PSS in the evaluation for nonobstructive coronary artery disease (CAD) should be further investigated.

Virtual Hemodynamic Assessment of Coronary Lesions: The Advent of Functional Angiography and Coronary Imaging

The fractional flow reserve (FFR) is well recognized as a gold standard measure for the estimation of functional coronary stenosis. Technological progressions in image processing have empowered the reconstruction of three-dimensional models of the coronary arteries via both non-invasive and invasive imaging modalities. The application of computational fluid dynamics (CFD) techniques to coronary 3D anatomical models allows the virtual evaluation of the hemodynamic significance of a coronary lesion with high diagnostic accuracy.

METHODS

Search of the bibliographic database for articles published from 2011 to 2023 using the following search terms: invasive FFR and non-invasive FFR. Pooled analysis of the sensitivity and specificity, with the corresponding confidence intervals from 32% to 94%. In addition, the summary processing times were determined.

RESULTS

In total, 24 studies published between 2011 and 2023 were included, with a total of 13,591 patients and 3345 vessels. The diagnostic accuracy of the invasive and non-invasive techniques at the per-patient level was 89% (95% CI, 85-92%) and 76% (95% CI, 61-80%), respectively, while on the per-vessel basis, it was 92% (95% CI, 82-88%) and 81% (95% CI, 75-87%), respectively.

CONCLUSION

These opportunities providing hemodynamic information based on anatomy have given rise to a new era of functional angiography and coronary imaging. However, further validations are needed to overcome several scientific and computational challenges before these methods are applied in everyday clinical practice.

An initiative to promote value-based stress test selection in primary care and cardiology clinics: A mixed methods evaluation

OBJECTIVES

Exercise stress echocardiograms (stress echos) are overused, whereas exercise stress electrocardiograms (stress ECGs) can be an appropriate, lower-cost substitute. In this post hoc, mixed methods evaluation, we assessed an initiative promoting value-based, guideline-concordant ordering practices in primary care (PC) and cardiology clinics.

METHODS

Change in percent of stress ECGs ordered of all exercise stress tests (stress ECGs and echos) was calculated between three periods: baseline (January 2019-February 2020); Period 1 with reduced stress ECG report turnaround time + PC-targeted education (began June 2020); and Period 2 with the addition of electronic health record-based alternative alert (AA) providing point-of-care clinical decision support. The AA was deployed in two of five PC clinics in July 2020, two additional PC clinics in January 2021, and one of four cardiology clinics in February 2021. Nineteen primary care providers (PCPs) and five cardiologists were interviewed in Period 2.

RESULTS

Clinicians reported reducing ECG report turnaround time was crucial for adoption. PCPs specifically reported that value-based education helped change their practice. In PC, the percent of stress ECGs ordered increased by 38% ± 6% (SE) (p < 0.0001) from baseline to Period 1. Most PCPs identified the AA as the most impactful initiative, yet stress ECG ordering did not change (6% ± 6%; p = 0.34) between Periods 1 and 2. In contrast, cardiologists reportedly relied on their expertise rather than AAs, yet their stress ECGs orders increased from Period 1 to 2 to a larger degree in the cardiology clinic with the AA (12% ± 5%; p = 0.01) than clinics without the AA (6% ± 2%; p = 0.01). The percent of stress ECGs ordered was higher in Period 2 than baseline for both specialties (both p < 0.0001).

CONCLUSIONS

This initiative influenced ordering behaviour in PC and cardiology clinics. However, clinicians' perceptions of the initiative varied between specialties and did not always align with the observed behaviour change.

Myocardial Bridging of Mid-left Anterior Descending Artery (LAD) Presenting As Transient Left Bundle Branch Block During Nuclear Stress Test

Transient left bundle branch block occurring during a nuclear stress test in the setting of myocardial bridging is a relatively rare finding. We report a case of a 75-year-old male who presented with typical stable angina. Serial troponins were negative, and the electrocardiogram revealed normal sinus rhythm with left ventricular hypertrophy and T-wave inversions in the lateral leads. The nuclear stress test was non-ischemic but showed a transient left bundle branch block associated with chest pain and shortness of breath that occurred right after the administration of regadenoson. Coronary angiography revealed non-obstructive coronary artery disease and a mid-LAD myocardial bridge.

Multimodality Imaging in Advanced Heart Failure for Diagnosis, Management and Follow-Up: A Comprehensive Review

Advanced heart failure (AHF) presents a complex landscape with challenges spanning diagnosis, management, and patient outcomes. In response, the integration of multimodality imaging techniques has emerged as a pivotal approach. This comprehensive review delves into the profound significance of these imaging strategies within AHF scenarios. Multimodality imaging, encompassing echocardiography, cardiac magnetic resonance imaging (CMR), nuclear imaging and cardiac computed tomography (CCT), stands as a cornerstone in the care of patients with both short- and long-term mechanical support devices. These techniques facilitate precise device selection, placement, and vigilant monitoring, ensuring patient safety and optimal device functionality. In the context of orthotopic cardiac transplant (OTC), the role of multimodality imaging remains indispensable. Echocardiography offers invaluable insights into allograft function and potential complications. Advanced methods, like speckle tracking echocardiography (STE), empower the detection of acute cell rejection. Nuclear imaging, CMR and CCT further enhance diagnostic precision, especially concerning allograft rejection and cardiac allograft vasculopathy. This comprehensive imaging approach goes beyond diagnosis, shaping treatment strategies and risk assessment. By harmonizing diverse imaging modalities, clinicians gain a panoramic understanding of each patient's unique condition, facilitating well-informed decisions. The aim is to highlight the novelty and unique aspects of recently published papers in the field. Thus, this review underscores the irreplaceable role of multimodality imaging in elevating patient outcomes, refining treatment precision, and propelling advancements in the evolving landscape of advanced heart failure management.

Diagnostic accuracy of coronary artery stenosis and thrombosis assessment using unenhanced multiplanar 3D post-mortem cardiac magnetic resonance imaging

BACKGROUND

A 3D sequence was introduced to unenhanced post-mortem cardiac magnetic resonance imaging (PMCMR) to enable multiplanar coronary artery image analysis and to investigate its diagnostic accuracy for the diagnosis of coronary artery stenosis and thrombosis.

MATERIALS AND METHODS

N = 200 forensic cases with suspected coronary artery pathology underwent 3 Tesla PMCMR (sequence used: T2 weighted transversal 3D turbo spin echo) before autopsy. Main coronary artery stenosis and thrombosis were assessed in PMCMR by multiplanar image analysis by two observers. Coronary artery histology was determined as the gold standard and compared to PMCMR. Sensitivity, specificity, negative (NPV) and positive predictive values (PPV) with 95% confidence intervals were calculated.

RESULTS

For all coronary arteries combined, sensitivity was 75% (PPV 73%) for the diagnosis of stenosis and 72% (PPV 71%) for the diagnosis of thrombosis. Specificity was 92% (NPV 90%) for correct diagnosis of non-existing stenosis and 97% (NPV 97%) for non-existing thrombosis. Sensitivity for correct diagnosis of different degrees of stenosis ranged between 67% and 80% (PPVs 67-82%); specificity ranged between 96% and 99% (NPVs 96-99%).

CONCLUSION

Multiplanar PMCMR coronary artery stenosis and thrombosis assessment based on an unenhanced T2 weighted 3D sequence provide moderate sensitivity and high specificity for the diagnosis of coronary artery stenosis and/or thrombosis. Hence, 3D T2w PMCMR cannot reliably detect existing coronary artery stenosis and thrombosis but may be particularly useful for the exclusion of stenosis or thrombosis of the main coronary arteries.

Fully automated pixel-wise quantitative CMR-myocardial perfusion with CMR-coronary angiography to detect hemodynamically significant coronary artery disease

OBJECTIVES

We applied a fully automated pixel-wise post-processing framework to evaluate fully quantitative cardiovascular magnetic resonance myocardial perfusion imaging (CMR-MPI). In addition, we aimed to evaluate the additive value of coronary magnetic resonance angiography (CMRA) to the diagnostic performance of fully automated pixel-wise quantitative CMR-MPI for detecting hemodynamically significant coronary artery disease (CAD).

METHODS

A total of 109 patients with suspected CAD were prospectively enrolled and underwent stress and rest CMR-MPI, CMRA, invasive coronary angiography (ICA), and fractional flow reserve (FFR). CMRA was acquired between stress and rest CMR-MPI acquisition, without any additional contrast agent. Finally, CMR-MPI quantification was analyzed by a fully automated pixel-wise post-processing framework.

RESULTS

Of the 109 patients, 42 patients had hemodynamically significant CAD (FFR ≤ 0.80 or luminal stenosis ≥ 90% on ICA) and 67 patients had hemodynamically non-significant CAD (FFR ˃ 0.80 or luminal stenosis < 30% on ICA) were enrolled. On the per-territory analysis, patients with hemodynamically significant CAD had higher myocardial blood flow (MBF) at rest, lower MBF under stress, and lower myocardial perfusion reserve (MPR) than patients with hemodynamically non-significant CAD (p < 0.001). The area under the receiver operating characteristic curve of MPR (0.93) was significantly larger than those of stress and rest MBF, visual assessment of CMR-MPI, and CMRA (p < 0.05), but similar to that of the integration of CMR-MPI with CMRA (0.90).

CONCLUSIONS

Fully automated pixel-wise quantitative CMR-MPI can accurately detect hemodynamically significant CAD, but the integration of CMRA obtained between stress and rest CMR-MPI acquisition did not provide significantly additive value.

KEY POINTS

• Full quantification of stress and rest cardiovascular magnetic resonance myocardial perfusion imaging can be postprocessed fully automatically, generating pixel-wise myocardial blood flow (MBF) and myocardial perfusion reserve (MPR) maps. • Fully quantitative MPR provided higher diagnostic performance for detecting hemodynamically significant coronary artery disease, compared with stress and rest MBF, qualitative assessment, and coronary magnetic resonance angiography (CMRA). • The integration of CMRA and MPR did not significantly improve the diagnostic performance of MPR alone.

Coronary computed tomography angiography imaging features combined with computed tomography-fractional flow reserve, pericoronary fat attenuation index, and radiomics for the prediction of myocardial ischemia

BACKGROUND

This study aimed to predict myocardial ischemia (MIS) by constructing models with imaging features, CT-fractional flow reserve (CT-FFR), pericoronary fat attenuation index (pFAI), and radiomics based on coronary computed tomography angiography (CCTA).

METHODS AND RESULTS

This study included 96 patients who underwent CCTA and single photon emission computed tomography-myocardial perfusion imaging (SPECT-MPI). According to SPECT-MPI results, there were 72 vessels with MIS in corresponding supply area and 105 vessels with no-MIS. The conventional model [lesion length (LL), MDS (maximum stenosis diameter × 100% / reference vessel diameter), MAS (maximum stenosis area × 100% / reference vessel area) and CT value], radiomics model (radiomics features), and multi-faceted model (all features) were constructed using support vector machine. Conventional and radiomics models showed similar predictive efficacy [AUC: 0.76, CI 0.62-0.90 vs. 0.74, CI 0.61-0.88; p > 0.05]. Adding pFAI to the conventional model showed better predictive efficacy than adding CT-FFR (AUC: 0.88, CI 0.79-0.97 vs. 0.80, CI 0.68-0.92; p < 0.05). Compared with conventional and radiomics model, the multi-faceted model showed the highest predictive efficacy (AUC: 0.92, CI 0.82-0.98, p < 0.05).

CONCLUSION

pFAI is more effective for predicting MIS than CT-FFR. A multi-faceted model combining imaging features, CT-FFR, pFAI, and radiomics is a potential diagnostic tool for MIS.

Non-dominant right coronary artery (RCA) is associated with suspected inferior ischemia on SPECT in patients without significant coronary artery disease (CAD)

OBJECTIVE

There is a huge uncertainty in the medical community regarding the significance of non-dominant right coronary artery (RCA) in patients with inferior wall ischemia on myocardial perfusion single-photon emission computed tomography (SPECT). The purpose of this study is to determine the effect of non-dominant RCA on myocardial perfusion SPECT (MPS) with respect to the misleading detection of ischemia in the inferior wall of the myocardium.

METHODS

This is a retrospective study of 155 patients, who had undergone elective coronary angiography owing to an indication of inferior wall ischemia by MPS between 2012 and 2017. Patients were divided into two groups based on the coronary dominance: group 1 (n = 107), if RCA is the dominant artery, and group 2 (n = 48), if there are dominance of left artery and codominance of both arteries. Obstructive CAD was diagnosed in the case of stenosis that had severity greater than 50%. The positive predictive value (PPV), which was calculated as per the correlation between the inferior wall ischemia in MPS and obstruction level in RCA, was compared in both groups.

RESULTS

Majority of patients were male (109, 70%) and the mean age was 59.5 ± 10.2. There were 45 patients with obstructive RCA disease (PPV: 42%) among 107 patients in group 1, whereas there were only 8 patients with obstructive coronary artery disease (CAD) in RCA among 48 patients in group 2, (PPV: 16% and p = 0.004).

CONCLUSIONS

The results demonstrated that non-dominant RCA is associated with false-positive detection of inferior wall ischemia via MPS.

Characteristics and key differences between patient populations receiving imaging modalities for coronary artery disease diagnosis in the US

BACKGROUND

There are limited data on the impact of imaging modality selection for the assessment of coronary artery disease (CAD) risk on downstream resource utilisation. This study sought to identify differences between patient populations in the US undergoing stress echocardiography, single-photon emission computed tomography (SPECT) myocardial perfusion imaging (MPI), positron emission tomography (PET) MPI, and coronary computed tomography angiography (cCTA) for the assessment of CAD risk, and associated physician referral patterns.

METHODS

Claims and electronic health records data for 2.5 million US patients who received stress echocardiography, cCTA, SPECT MPI or PET MPI between January 2016 and March 2018, from the Decision Resources Group Real-World Evidence US Data Repository, were analysed. Patients were stratified into suspected and existing CAD cohorts, and further stratified by pre-test risk and presence and recency of interventions or acute cardiac events (within 1-2 years pre-index test). Linear and logistic regression were used to compare numeric and categorical variables.

RESULTS

Physicians were more likely to refer patients to standalone SPECT MPI (77%) and stress echocardiography (18%) than PET MPI (3%) and cCTA (2%). Overall, 43% of physicians referred more than 90% of their patients to standalone SPECT MPI. Just 3%, 1% and 1% of physicians referred more than 90% of their patients to stress echocardiography, PET MPI or cCTA. At the aggregated imaging level, patients who underwent stress echocardiography or cCTA had similar comorbidity profiles. Comorbidity profiles were also similar for patients who underwent SPECT MPI and PET MPI.

CONCLUSION

Most patients underwent SPECT MPI at the index date, with very few undergoing PET MPI or cCTA. Patients who underwent cCTA at the index date were more likely to undergo additional imaging tests compared with those who underwent other imaging modalities. Further evidence is needed to understand factors influencing imaging test selection across patient populations.

PET-MRI of Coronary Artery Disease

Simultaneous positron emission tomography and magnetic resonance imaging (PET-MRI) combines the anatomical detail and tissue characterization of MRI with the functional information from PET. Within the coronary arteries, this hybrid technique can be used to identify biological activity combined with anatomically high-risk plaque features to better understand the processes underlying coronary atherosclerosis. Furthermore, the downstream effects of coronary artery disease on the myocardium can be characterized by providing information on myocardial perfusion, viability, and function. This review will describe the current capabilities of PET-MRI in coronary artery disease and discuss the limitations and future directions of this emerging technique. LEVEL OF EVIDENCE: 5 TECHNICAL EFFICACY: Stage 3.

Diagnostic accuracy of myocardial perfusion imaging in patients evaluated for kidney transplantation: A systematic review and meta-analysis

BACKGROUND

Cardiovascular disease is the most common cause of death after kidney transplantation. Coronary artery disease (CAD) assessment is therefore mandatory in patients evaluated for transplantation. We aimed to assess the diagnostic accuracy for CAD of single-photon emission computed tomography (SPECT) compared to the standards invasive coronary angiography (ICA) and coronary computed tomography angiography (CCTA) in patients evaluated for kidney transplantation.

METHODS

We performed a systematic literature search in PubMed, EMBASE, Web of Science, OvidSP (Medline), The Cochrane Library and Google Scholar. Studies investigating the diagnostic accuracy of myocardial perfusion imaging (MPI) SPECT in patients evaluated for kidney transplantation were retrieved. After a risk of bias assessment using QUADAS-2, a meta-analysis was conducted.

RESULTS

Out of 1459 records, 13 MPI SPECT studies were included in the meta-analysis with a total of 1245 MPI SPECT scans. There were no studies available with CCTA as reference. Pooled sensitivity of MPI SPECT for CAD was 0.66 (95% CI 0.53 to 0.77), pooled specificity was 0.75 (95% CI 0.63 to 0.84) and the area under the curve (AUC) was 0.76. Positive likelihood ratio was 2.50 (95% CI 1.78 to 3.51) and negative likelihood ratio was 0.41 (95% CI 0.28 to 0.61). Pooled positive predictive value was 64.9% and pooled negative predictive value was 74.1%. Significant heterogeneity existed across the included studies.

CONCLUSIONS

MPI SPECT had a moderate diagnostic accuracy in patients evaluated for kidney transplantation, with a high rate of false-negative findings. The use of an anatomical gold standard against a functional imaging test in the included studies is however suboptimal.

Four-dimensional quantification on left atrial volume-strain in coronary heart disease patients without regional wall motion abnormalities: Correlation with the severity of coronary stenosis

OBJECTIVE

Echocardiography is a time and cost-effective imaging modality, providing evidence of myocardial ischemia by detecting the regional wall motion abnormalities (RWMA). However, quite a few coronary heart disease (CHD) patients do not present RWMA. The left atrium (LA) plays an irreplaceable role in determining the prognosis and risk stratification of cardiovascular disease including CHD. In this present study, we intend to explore the myocardial mechanics changes of LA mainly using four-dimensional (4D) LA quantitative volume-strain in CHD patients without RWMA at rest but were confirmed by coronary angiography (CAG) and to figure out several variables of the LA that could contribute to the identification of those patients.

METHODS

We prospectively enrolled 76 patients who underwent two-dimensional echocardiography (2DE), four-dimensional echocardiography (4DE), and CAG for suspected CHD but without echocardiographic visible RWMA at rest. Patients diagnosed with CHD by CAG were furtherly divided into three groups according to the extent of coronary stenosis accessed by Gensini score (GS) as the mild, moderate, and severe CHD group. Twenty-four subjects with negative CAG results served as the control group. LA end-systolic anteroposterior diameter (LAAPD) and biplane LV ejection fraction (Biplane LVEF) were measured by 2DE; LA maximum volume (LAVmax), LA minimum volume (LAVmin), LA volume at the onset of atrial contraction (LAVpreA), LAVmax index (LAVmaxI), LA ejection volume (LAEV), LA ejection fraction (LAEF) accompanied by LA longitudinal strain during reservoir phase (LASr), conduit phase (LAScd), contraction phase (LASct) and LA circumferential strain during reservoir phase (LASr_c), conduit phase (LAScd_c), contraction phase (LASct_c) were measured by 4DE automatically. We compared these parameters between groups, explored how they change and whether they are related to the CHD severity.

RESULTS

LAEF, LASr_c, and LASct_c was lower in CHD group compared with the control group (p = .031, .002, .004, respectively). Pearson correlation analysis showed that LASr, LASct, LASr_c, and LASct_c negatively correlated with the GS. Additionally, LASr of patients in the severe CHD group decreased significantly compared with those in the mild CHD group, moderate CHD group, and control group, demonstrating the highest area under the receiver operating characteristic (ROC) curve (AUC) (AUC = .736 [p = .003, 95% CI .589-.884], sensitivity 67.8%, specificity 70.6%) with the cut-off value of 17.5% for predicting severe CHD patients.

CONCLUSION

Four-dimensional LA strain may provide new insight into identification and management for CHD patients and correlate with CHD severity. LASr showed good sensitivity (67.8%) and specificity (70.6%) for diagnosing severe CHD individuals.

Identifying Coronary Artery Lesions by Feature Analysis of Radial Pulse Wave: A Case-Control Study

Background

Cardiovascular diseases have been always the most common cause of morbidity and mortality worldwide. Health monitoring of high-risk and suspected patients is essential. Currently, invasive coronary angiography is still the most direct and accurate method of determining the severity of coronary artery lesions, but it may not be the optimal clinical choice for suspected patients who had clinical symptoms of coronary heart disease (CHD) such as chest pain but no coronary artery lesion. Modern medical research indicates that radial pulse waves contain substantial pathophysiologic information about the cardiovascular and circulation systems; therefore, analysis of these waves could be a noninvasive technique for assessing cardiovascular disease.

Objective

The objective of this study was to analyze the radial pulse wave to construct models for assessing the extent of coronary artery lesions based on pulse features and investigate the latent value of noninvasive detection technology based on pulse wave in the evaluation of cardiovascular disease, so as to promote the development of wearable devices and mobile medicine.

Method

This study included 529 patients suspected of CHD who had undergone coronary angiography. Patients were sorted into a control group with no lesions, a 1 or 2 lesion group, and a multiple (3 or more) lesion group as determined by coronary angiography. The linear time-domain features and the nonlinear multiscale entropy features of their radial pulse wave signals were compared, and these features were used to construct models for identifying the range of coronary artery lesions using the k-nearest neighbor (KNN), decision tree (DT), and random forest (RF) machine learning algorithms. The average precision of these algorithms was then compared.

Results

(1) Compared with the control group, the group with 1 or 2 lesions had increases in their radial pulse wave time-domain features H2/H1, H3/H1, and W2 (P < 0.05), whereas the group with multiple lesions had decreases in MSE1, MSE2, MSE3, MSE4, and MSE5 (P < 0.05). (2) Compared with the 1 or 2 lesion group, the multiple lesion group had increases in T1/T (P < 0.05) and decreases in T and W1 (P < 0.05). (3) The RF model for identifying numbers of coronary artery lesions had a higher average precision than the models built with KNN or DT. Furthermore, average precision of the model was highest (80.98%) if both time-domain features and multiscale entropy features of radial pulse signals were used to construct the model.

Conclusion

Pulse wave signal can identify the range of coronary artery lesions with acceptable accuracy; this result is promising valuable for assessing the severity of coronary artery lesions. The technique could be used to development of mobile medical treatments or remote home monitoring systems for patients suspected or those at high risk of coronary atherosclerotic heart disease.

Vitamin D Deficiency as a Risk Factor for Myocardial Ischemia

Background and Objectives: Vitamin D (Vit D) deficiency has been implicated in various conditions, including cardiovascular disease. The purpose of this retrospective study was to investigate the incidence of patients with myocardial ischemia in relation to their serum levels of vitamin D. Materials and Methods: A 64-month search (January 2016 to April 2021) in our database of the Nuclear Medicine Laboratory revealed 113 patients who had both myocardial perfusion imaging with single photon emission computed tomography (MPI SPECT) and Vit D measurements. MPI SPECT obtained myocardial images during both stress (summed stress score, SSS) and rest (summed rest score, SRS). Abnormal MPI SPECT was when the SSS was ≥4. Vit D was determined by radioimmunoassay (RIA). Patients with Vit D values <10 ng/mL, 10-29 ng/mL and ≥30 ng/mL were defined as having a deficiency, insufficiency and sufficiency, respectively. Results: Among patients, 46/113 (40.7%) were male and 67/113 (59.3%) were female. Abnormal MPI was found in 58/113 (51.3%) patients. Vit D deficiency was noted in 20/113 (17.7%) patients, insufficiency in 86/113 (76.1%) patients, and normal Vit D was noted in only 7/113 (6.2%) patients. Sixteen of the 20 patients (80%) with Vit D deficiency, and 38/86 (44.2%) with insufficiency had an abnormal MPI SPECT. In contrast, only 1/7 (14.3%) patients with sufficient Vit D levels had an abnormal MPI SPECT. The Mann-Whitney U-test showed that ischemia reduced the values of Vit D. Correlation analysis showed a negative association of Vit D levels with SSS (rho = -0.232, p = 0.014) and SRS (rho = -0.250, p = 0.008). Further evaluation with a Vit D cut off 20 ng/mL retrieved no statistical significance. Finally, Vit D and gender were independently associated with myocardial ischemia. Conclusions: Low Vit D levels may represent a risk factor for myocardial ischemia.

Role of trans-radial band protocols in radial artery occlusion: Randomized trial

BACKGROUND

Radial artery occlusion is a common complication of coronary angiography via radial artery, attributed to the prolonged use of trans-radial band post procedure. Literature suggests there is no standard protocol for radial band deflation, and it varies across institutions. However, the protocol suggested by Cohen and Alfonso is widely used globally. This study aims to test whether our hospital's radial band deflation protocol is non-inferior to the protocol of Cohen and Alfonso, which affirms lesser complications.

METHODS

This is an outcome assessor blinded, non-inferiority trial conducted at a tertiary care hospital in Karachi. We enrolled 100 patients who underwent coronary angiography from radial access and gave written informed consent. The intervention group received protocol A, that is in practice at the institution, while the control group received protocol B, developed by Cohen and Alfonso. The primary outcome was occurrence of radial artery occlusion at 24 h. The secondary outcomes included hematoma and bleeding after radial band removal.

RESULTS

The mean age of the participants in the trial was 58.3 ± 11.5 years, while 63% of them were men. Participants in both the groups had similar baseline characteristics. Radial artery occlusion was not significantly different between protocol A and protocol B (10% vs. 14%, p = 0.49, respectively). Similarly, hematoma and bleeding after trans-radial band removal showed no statistical difference between the groups.

CONCLUSION

Trans-radial band deflation practice at our institution was non-inferior to Cohen and Alfonso's protocol in the incidence of radial artery occlusion after coronary angiography.

TRIAL REGISTRATION NUMBER

This trial is registered at clinicaltrials.gov (https://clinicaltrials.gov) with registration number NCT03298126.

Preoperative Cardiovascular Assessment of the Renal Transplant Recipient: A Narrative Review

Patients with end-stage kidney disease (ESKD) have a high prevalence of cardiovascular disease; it is the leading cause of death in these patients and the optimisation of their cardiovascular health may improve their post-transplant outcomes. Patients awaiting renal transplant often spend significant amounts of time on the waiting list allowing for the assessment and optimisation of their cardiovascular system. Coronary artery disease (CAD) is commonly seen in these patients and we explore the possible functional and anatomical investigations that can help assess and manage CAD in renal transplant candidates. We also discuss other aspects of cardiovascular assessment and management including arrhythmias, impaired ventricular function, valvular disease, lifestyle and pulmonary arterial hypertension. We hope that this review can form a basis for centres hoping to implement an enhanced recovery after surgery (ERAS) protocol for renal transplantation.

Diffuse breast uptake of technetium-99m tetrofosmin during myocardial perfusion imaging in a lactating mother

Myocardial perfusion imaging (MPI) is a useful modality to rule out myocardial ischaemia in patients presenting with chest pain. In nursing mothers imaging with radioisotope is usually avoided but under certain circumstances it is unavoidable. We present the case of a 45-year-old woman with chest pain, who underwent MPI for assessment of ischaemia. The scan showed anterior artefact due to diffuse breast uptake in both the breasts, as the patient was a lactating mother. The case highlights the importance of breast uptake of radioisotope in the lactating mother on MPI and the necessary steps which need to be taken if radiotracer is injected into a lactating woman.

Coronary Magnetic Resonance Angiography: Technical Innovations Leading Us to the Promised Land?

Coronary artery disease remains the leading cause of cardiovascular morbidity and mortality. Invasive X-ray angiography and coronary computed tomography angiography are established gold standards for coronary luminography. However, they expose patients to invasive complications, ionizing radiation, and iodinated contrast agents. Among a number of imaging modalities, coronary cardiovascular magnetic resonance (CMR) angiography may be used in some cases as an alternative for the detection and monitoring of coronary arterial stenosis, with advantages including its versatility, excellent soft tissue characterization, and avoidance of ionizing radiation and iodinated contrast agents. In this review, we explore the recent advances in motion correction, image acceleration, and reconstruction technologies that are bringing coronary CMR angiography closer to widespread clinical implementation.

The Role of Carotid and Femoral Plaque Burden in the Diagnosis of Coronary Artery Disease

PURPOSE OF REVIEW

With limitations of cardiovascular disease risk stratification by traditional risk factors, the role of noninvasive imaging techniques, such as vascular ultrasound, has emerged as a prominent utility for decision-making in coronary artery disease. A review of current guidelines and contemporary approaches for carotid and femoral plaque assessment is needed to better inform the diagnosis, management, and treatment of atherosclerosis in clinical practice.

RECENT FINDINGS

The recent consensus-based guidelines for carotid plaque assessment in coronary artery disease have been established, supported by some outcomes-based research. Currently, there is a gap of evidence on the use of femoral ultrasound to detect atherosclerosis, as well as predict adverse cardiovascular outcomes. The quantification and characterization of individualized plaque burden are important to stratify risk in asymptomatic or symptomatic atherosclerosis patients. Standardized quantification guidelines, supported by further outcomes-based research, are required to assess disease severity and progression.

Association between cardiovascular risk factors and coronary artery disease assessed using CAD-RADS classification: a cross-sectional study in Romanian population

OBJECTIVES

This study aimed to evaluate the association between cardiovascular risk factors and Coronary Artery Disease-Reporting and Data System (CAD-RADS) score in the Romanian population. CAD-RADS is a new, standardised method to assess coronary artery disease (CAD) using coronary CT angiography (CCTA).

DESIGN

A cross-sectional observational, patient-based study.

SETTING

Referred imaging centre for CAD in Transylvania, Romania.

PARTICIPANTS

We retrospectively reviewed 674 patients who underwent CCTA between January 2017 and August 2018. The exclusion criteria included: previously known CAD, defined as prior myocardial infarction, percutaneous coronary intervention or coronary artery bypass graft surgery (n=91), cardiac CT for other than evaluation of possible CAD (n=85), significant arrhythmias compromising imaging quality (n=23). Finally, 475 patients fulfilled the inclusion criteria.

METHODS

Demographical, clinical and CCTA characteristics of the patients were obtained. CAD was evaluated using CAD-RADS score. Obstructive CAD was defined as ≥50% stenosis of ≥1 coronary segment on CCTA.

RESULTS

We evaluated the association between risk factors and CAD-RADS score in univariate and multivariable analysis. We divided the patients into two groups according to the CAD-RADS system: group 1: CAD-RADS score between 0 and 2 (stenosis <50%) and group 2: CAD-RADS score ≥3 (stenosis ≥50%). On univariate analysis, male gender, age, hypertension, dyslipidaemia, smoking and diabetes mellitus were positively associated with a CAD-RADS score ≥3. The multivariate analysis showed that male sex, age, dyslipidaemia, hypertension and smoking were independently associated with obstructive CAD.

CONCLUSION

This study demonstrated a significant association between multiple cardiovascular risk factors and a higher coronary atherosclerotic burden assessed using CAD-RADS system in the Romanian population.

Cardiac Computed Tomography - More Than Coronary Arteries? A Clinical Update

BACKGROUND

 Rapid improvement of scanner and postprocessing technology as well as the introduction of minimally invasive procedures requiring preoperative imaging have led to the broad utilization of cardiac computed tomography (CT) beyond coronary CT angiography (CTA).

METHOD

 This review article presents an overview of recent literature on cardiac CT. The goal is to summarize the current guidelines on performing cardiac CT and to list established as well as emerging techniques with a special focus on extracoronary applications.

RESULTS AND CONCLUSION

 Most recent guidelines for the appropriate use of cardiac CT include the evaluation of coronary artery disease, cardiac morphology, intra- and extracardiac structures, and functional and structural assessment of the myocardium under certain conditions. Besides coronary CTA, novel applications such as the calculation of a CT-derived fractional flow reserve (CT-FFR), assessment of myocardial function and perfusion imaging, as well as pre-interventional planning in valvular heart disease or prior pulmonary vein ablation in atrial fibrillation are becoming increasingly important. Especially these extracoronary applications are of growing interest in the field of cardiac CT and are expected to be gradually implemented in the daily clinical routine.

KEY POINTS

  · Coronary artery imaging remains the main indication for cardiac CT. · Novel computational fluid dynamics allow the calculation of a CT-derived fractional flow reserve in patients with known or suspected coronary artery disease. · Cardiac CT delivers information on left ventricular volume as well as myocardial function and perfusion. · CT is the cardinal element for pre-interventional planning in transcatheter valve implantation and pulmonary vein isolation.

CITATION FORMAT

· Taron J, Foldyna B, Eslami P et al. Cardiac Computed Tomography - More Than Coronary Arteries? A Clinical Update. Fortschr Röntgenstr 2019; 191: 817 - 826.

Myocardial Perfusion Imaging: A Brief Review of Nuclear and Nonnuclear Techniques and Comparative Evaluation of Recent Advances

Coronary artery disease (CAD) is the leading cause of morbidity and mortality worldwide. Invasive coronary angiography (ICA) is the gold standard for the evaluation of epicardial CAD. In the pathogenesis of the CAD, myocardial perfusion abnormalities are the first changes that appear followed by wall motion abnormalities, electrocardiogram changes, and angina. Myocardial perfusion imaging (MPI) demonstrates the cumulative effect of pathology at epicardial coronary arteries, small vessels, and endothelium. Thus, it evaluates the overall burden of ischemic heart disease (IHD). MPI is used noninvasively to diagnose early asymptomatic CAD or to know the functional significance of known CAD. There are evidence that early detection of myocardial perfusion abnormalities followed by aggressive intervention against cardiovascular risk factors may restore myocardial perfusion. This may lead to reduce morbidity and mortality. Various MPI modalities have been used to diagnose and define the severity of CAD. Cardiac myocardial perfusion single-photon emission computed tomography (myocardial perfusion scintigraphy [MPS]) has been in use since decades. Several newer modalities such as positron emission tomography, cardiac magnetic resonance imaging, computed tomography perfusion, and myocardial contrast echocardiography are developing utilizing the similar principle of MPS. We shall be reviewing briefly these modalities, their performance, comparison to each other, and with ICA.

Nanotechnology, an alternative with promising prospects and advantages for the treatment of cardiovascular diseases

Cardiovascular diseases (CVDs) are one of the most important causes of mortality and affecting the health status of patients. At the same time, CVDs cause a huge health and economic burden to the whole world. Although a variety of therapeutic drugs and measures have been produced to delay the progress of the disease and improve the quality of life of patients, most of the traditional therapeutic strategies can only cure the symptoms and cannot repair or regenerate the damaged ischemic myocardium. In addition, they may bring some unpleasant side effects. Therefore, it is vital to find and explore new technologies and drugs to solve the shortcomings of conventional treatments. Nanotechnology is a new way of using and manipulating the matter at the molecular scale, whose functional organization is measured in nanometers. Because nanoscale phenomena play an important role in cell signal transduction, enzyme action and cell cycle, nanotechnology is closely related to medical research. The application of nanotechnology in the field of medicine provides an alternative and novel direction for the treatment of CVDs, and shows excellent performance in the field of targeted drug therapy and the development of biomaterials. This review will briefly introduce the latest applications of nanotechnology in the diagnosis and treatment of common CVDs.