Biological and Clinical Implications of the Vascular Endothelial Growth Factor Coreceptor Neuropilin-1 in Human Immunodeficiency Virus.

Plasma vascular endothelial growth factor (VEGF) coreceptor neuropilin-1 (NRP-1) had the largest association with coronary plaque in the Randomized Trial to Prevent Vascular Events in HIV (REPRIEVE) proteomics analysis. With little known about NRP-1 in people with human immunodeficiency virus (PWH), we explored its relation to other proteins in REPRIEVE and validated our findings through a Centers for AIDS Research Network of Integrated Clinical Systems (CNICS) case-cohort study by assessing its relation to host factors and incident cardiovascular disease and cancer. Within REPRIEVE, NRP-1 was associated with proteins involved in angiogenesis, signal transduction, immunoregulation, and cell migration/adhesion. Within CNICS, NRP-1 was associated with key host factors, including older age and male sex. NRP-1 was associated with an increased hazard of multiple cancers but a decreased prostate cancer risk. Finally, NRP-1 was most strongly associated with mortality and type 2 myocardial infarction. These data suggest that NRP-1 is part of a clinically relevant immunoregulatory pathway related to multiple comorbidities in PWH. Clinical Trials Registration. NCT02344290.

Identification of noncalcified coronary plaque characteristics using machine learning radiomic analysis of non-contrast high-resolution computed tomography.

BACKGROUND: Novel imaging and analysis techniques may offer the ability to detect noncalcified or high-risk coronary plaques on a non-contrast computer tomography (CT) scan, advancing cardiovascular diagnostics. AIMS: We aimed to explore whether machine learning (ML) radiomic analysis of low-dose high-resolution non-contrast electrocardiographically (ECG) gated cardiac CT scan allows for the identification of noncalcified coronary plaque characteristics. METHODS: We prospectively enrolled 125 patients with noncalcified plaques and adverse plaque characteristics (APC) and 25 controls without visible atherosclerosis on coronary CT angiography (CCTA). All patients underwent non-contrast CT exam before CCTA. Four hundred and nineteen radiomic features were calculated to identify the presence of any coronary artery disease (CAD), obstructive CAD (stenosis >50%), plaque with ≥2 APC, degree of calcification, and specific APCs. ML models were trained on a training set (917 segmentations) and tested (validation) on a separate set (292 segmentations). RESULTS: Among the radiomic features, 88.3% were associated with a plaque, 0.9% with obstructive CAD, and 76.4% with the presence of at least two APCs. Overall, 80.2%, 88.5%, and 36.5%, of features were associated with calcified, partially calcified, and noncalcified plaques, respectively. Regarding APCs, 61.1%, 61.8%, 84.2%, and 61.3% of features were associated with low attenuation (LAP), napkin-ring sign (NRS), spotty calcification (SC), and positive remodeling (PR), respectively. ML models outperformed conventional methods for the presence of plaque obstructive stenosis, and the presence of 2 APCs, as well as for noncalcified plaques and partially calcified plaques, but not for calcified plaques. ML models also significantly outperformed identification of LAP and PR, but neither NRS nor SC. CONCLUSION: Radiomic analysis of non-contrast cardiac CT exams may allow for the identification of specific noncalcified coronary plaque characteristics displaying the potential for future clinical applications.

Latent Coronary Plaque Morphology From Computed Tomography Angiography, Molecular Disease Activity on Positron Emission Tomography, and Clinical Outcomes.

BACKGROUND: Assessments of coronary disease activity with 18F-sodium fluoride positron emission tomography and radiomics-based precision coronary plaque phenotyping derived from coronary computed tomography angiography may enhance risk stratification in patients with coronary artery disease. We sought to investigate whether the prognostic information provided by these 2 approaches is complementary in the prediction of myocardial infarction. METHODS: Patients with known coronary artery disease underwent coronary 18F-sodium fluoride positron emission tomography and coronary computed tomography angiography on a hybrid positron emission tomography/computed tomography scanner. Coronary 18F-NaF uptake was determined by the coronary microcalcification activity. We performed quantitative plaque analysis of coronary computed tomography angiography datasets and extracted 1103 radiomic features for each plaque. Using weighted correlation network analysis, we derived latent morphological features of coronary lesions which were aggregated to patient-level radiomics nomograms to predict myocardial infarction. RESULTS: Among 260 patients with established coronary artery disease (age, 65±9 years; 83% men), 179 (69%) participants showed increased coronary 18F-NaF activity (coronary microcalcification activity>0). Over 53 (40-59) months of follow-up, 18 patients had a myocardial infarction. Using weighted correlation network analysis, we derived 15 distinct eigen radiomic features representing latent morphological coronary plaque patterns in an unsupervised fashion. Following adjustments for calcified, noncalcified, and low-density noncalcified plaque volumes and 18F-NaF coronary microcalcification activity, 4 radiomic features remained independent predictors of myocardial infarction (hazard ratio, 1.46 [95% CI, 1.03-2.08]; P=0.03; hazard ratio, 1.62 [95% CI, 1.04-2.54]; P=0.02; hazard ratio, 1.49 [95% CI, 1.07-2.06]; P=0.01; and hazard ratio, 1.50 (95% CI, 1.05-2.13); P=0.02). CONCLUSIONS: In patients with established coronary artery disease, latent coronary plaque morphological features, quantitative plaque volumes, and disease activity on 18F-sodium fluoride positron emission tomography are additive predictors of myocardial infarction.

High incidence of newly diagnosed obstructive coronary artery disease regardless of chest pain detected on pre-procedural cardiac computed tomography angiography in patients undergoing atrial fibrillation ablation.

BACKGROUND: Cardiac computed tomography (CT) is often performed before catheter ablation of atrial fibrillation to map atrial and pulmonary anatomy. Incident coronary artery disease (CAD) may also be diagnosed during cardiac CT angiography (CTA). Our aim was to assess whether coronary CTA might be able to identify a significant proportion of patients with obstructive CAD prior to their catheter ablation procedure event, even in asymptomatic patients. METHODS: Consecutive patients undergoing pre-ablation coronary CTA for atrial fibrillation between 2013 and 2020 were retrospectively selected. Patients with previously diagnosed CAD were excluded. Obstructive CAD was defined as ≥50% luminal stenosis. We analyzed the relationship between obstructive CAD, any chest pain, and traditional risk factors. RESULTS: Overall, 2321 patients [median age 63.0 (54.4-69.2), 1052/2321 (45.3%) female] underwent coronary CTA and 488/2321 (21.0%) were diagnosed with obstructive CAD. There was no difference regarding the rate of obstructive CAD in patients with any chest pain compared to patients without any chest pain [91/404 (22.5%) vs. 397/1917 (20.7%), P = 0.416, respectively). The following parameters were associated with obstructive CAD: age > 65 years [odds ratio (OR) = 2.51; 95% confidence interval (CI), 2.02-3.13; P < 0.001), male sex (OR = 1.59; 95% CI, 1.28-1.98; P < 0.001), hypertension (OR = 1.40; 95% CI, 1.08-1.81; P = 0.012), diabetes (OR = 1.50; 95% CI, 1.13-1.99; P = 0.006), dyslipidaemia (OR = 1.33; 95% CI, 1.07-1.66; P = 0.011) and history of smoking (OR = 1.34; 95% CI, 1.07-1.68; P = 0.011). CONCLUSIONS: The high prevalence of obstructive CAD even in patients without chest pain highlights the importance of additional coronary artery diagnostics in patients undergoing left atrial CTA awaiting catheter ablation for atrial fibrillation. These patients regardless of chest pain thus may require further risk modification to decrease their potential ischemic and thromboembolic risk.

High-risk Coronary Plaque Regression in Cash-based Contingency Management Intervention Among Cocaine Users With HIV-associated Subclinical Coronary Atherosclerosis.

BACKGROUND: Cocaine use exacerbates human immunodeficiency virus (HIV)-associated subclinical coronary atherosclerosis. We investigated whether cocaine abstinence or reduced use achieved with contingency management (CM) intervention would retard high-risk coronary plaque progression among cocaine users with HIV and subclinical coronary atherosclerosis. METHODS: Between March 2014 and August 2017, 76 cocaine users with HIV and coronary plaques were enrolled in a study designed to decrease cocaine use and determine whether doing so impacted progression of subclinical coronary atherosclerosis as measured by coronary artery computed tomography examinations. Of the 76, 7 did not complete the study, resulting in 69 participants. A 12-month cash-based CM intervention was implemented to promote cocaine abstinence or reduced cocaine use. Generalized estimating equation approach was used to perform longitudinal data analyses. FINDINGS: During the 12-month CM, all 69 participants reduced cocaine use, and of these, 25 (36%; 95% confidence interval, 25%-49%) achieved cocaine abstinence. After adjusting for potential confounding factors, generalized estimating equation analyses showed that (1) endothelin-1 (ET-1) levels, a proinflammatory biomarker for endothelial dysfunction, at the 6-month and 12-month visits were significantly lower compared with baseline ET-1 ( P = 0.001 and P < 0.001, respectively), and (2) low-attenuation noncalcified coronary plaque volume, a predictor for myocardial infarction, at 12-month visit was significantly lower compared with baseline low-attenuation noncalcified coronary plaque volume ( P < 0.05). CONCLUSIONS: The findings of this study have not only demonstrated that CM is effective in achieving a sustained reduction in cocaine use, but also provided compelling evidence that reduction in cocaine use leads to quantifiable cardiovascular health benefits, including concurrent decrease in high-risk plaque burden and ET-1, among cocaine users with HIV-associated coronary atherosclerosis.

CAD-RADS may underestimate coronary plaque progression as detected by serial CT angiography.

AIMS: We wished to assess whether different clinical definitions of coronary artery disease (CAD) [segment stenosis and involvement score (SSS, SIS), Coronary Artery Disease-Reporting and Data System (CAD-RADS)] affect which patients are considered to progress and which risk factors affect progression. METHODS AND RESULTS: We enrolled 115 subsequent patients (60.1 ± 9.6 years, 27% female) who underwent serial coronary computed tomography angiography (CTA) imaging with >1year between the two examinations. CAD was described using SSS, SIS, and CAD-RADS. Linear mixed models were used to investigate the effects of risk factors on the overall amount of CAD and the effect on annual progression rate of different definitions. Coronary plaque burdens were SSS 4.63 ± 4.06 vs. 5.67 ± 5.10, P < 0.001; SIS 3.43 ± 2.53 vs. 3.89 ± 2.65, P < 0.001; CAD-RADS 0:8.7% vs. 0.0% 1:44.3% vs. 40.9%, 2:34.8% vs. 40.9%, 3:7.0% vs. 9.6% 4:3.5% vs. 6.1% 5:1.7% vs. 2.6%, P < 0.001, at baseline and follow-up, respectively. Overall, 53.0%, 29.6%, and 28.7% of patients progressed over time based on SSS, SIS, and CAD-RADS, respectively. Of the patients who progressed based on SSS, only 54% showed changes in CAD-RADS. Smoking and diabetes increased the annual progression rate of SSS by 0.37/year and 0.38/year, respectively (both P < 0.05). Furthermore, each year increase in age raised SSS by 0.12 [confidence interval (CI) 0.05-0.20, P = 0.001] and SIS 0.10 (CI 0.06-0.15, P < 0.001), while female sex was associated with 2.86 lower SSS (CI -4.52 to -1.20, P < 0.001) and 1.68 SIS values (CI -2.65 to -0.77, P = 0.001). CONCLUSION: CAD-RADS could not capture the progression of CAD in almost half of patients with serial CTA. Differences in CAD definitions may lead to significant differences in patients who are considered to progress, and which risk factors are considered to influence progression.

Standardised computed tomographic assessment of left atrial morphology and tissue thickness in humans.

AIMS: Left atrial (LA) remodelling is a common feature of many cardiovascular pathologies and is a sensitive marker of adverse cardiovascular outcomes. The aim of this study was to establish normal ranges for LA parameters derived from coronary computed tomographic angiography (CCTA) imaging using a standardised image processing pipeline to establish normal ranges in a previously described cohort. METHODS: CCTA imaging from 193 subjects recruited to the Budapest GLOBAL twin study was analysed. Indexed LA cavity volume (LACVi), LA surface area (LASAi), wall thickness and LA tissue volume (LATVi) were calculated. Wall thickness maps were combined into an atlas. Indexed LA parameters were compared with clinical variables to identify early markers of pathological remodelling. RESULTS: LACVi is similar between sexes (31 ml/m2 v 30 ml/m2) and increased in hypertension (33 ml/m2 v 29 ml/m2, p = 0.009). LASAi is greater in females than males (47.8 ml/m2 v 45.8 ml/m2 male, p = 0.031). Median LAWT was 1.45 mm. LAWT was lowest at the inferior portion of the posterior LA wall (1.14 mm) and greatest in the septum (median = 2.0 mm) (p < 0.001). Conditions known to predispose to the development of AF were not associated with differences in tissue thickness. CONCLUSIONS: The reported LACVi, LASAi, LATVi and tissue thickness derived from CCTA may serve as reference values for this age group and clinical characteristics for future studies. Increased LASAi in females in the absence of differences in LACVi or LATVi may indicate differential LA shape changes between the sexes. AF predisposing conditions, other than sex, were not associated with detectable changes in LAWT.Clinical trial registration:http://www.ClinicalTrials.gov/NCT01738828.

Sex-specific associations between alcohol consumption, cardiac morphology, and function as assessed by magnetic resonance imaging: insights form the UK Biobank Population Study.

AIMS: Data regarding the effects of regular alcohol consumption on cardiac anatomy and function are scarce. Therefore, we sought to determine the relationship between regular alcohol intake and cardiac structure and function as evaluated with cardiac magnetic resonance imaging. METHODS AND RESULTS: Participants of the UK Biobank who underwent cardiac magnetic resonance were enrolled in our analysis. Data regarding regular alcohol consumption were obtained from questionnaires filled in by the study participants. Exclusion criteria were poor image quality, missing, or incongruent data regarding alcohol drinking habits, prior drinking, presence of heart failure or angina, and prior myocardial infarction or stroke. Overall, 4335 participants (61.5 ± 7.5 years, 47.6% male) were analysed. We used multivariate linear regression models adjusted for age, ethnicity, body mass index, smoking, hypertension, diabetes mellitus, physical activity, cholesterol level, and Townsend deprivation index to examine the relationship between regular alcohol intake and cardiac structure and function. In men, alcohol intake was independently associated with marginally increased left ventricular end-diastolic volume [ß = 0.14; 95% confidence interval (CI) = 0.05-0.24; P = 0.004], left ventricular stroke volume (ß = 0.08; 95% CI = 0.03-0.14; P = 0.005), and right ventricular stroke volume (ß = 0.08; 95% CI = 0.02-0.13; P = 0.006). In women, alcohol consumption was associated with increased left atrium volume (ß = 0.14; 95% CI = 0.04-0.23; P = 0.006). CONCLUSION: Alcohol consumption is independently associated with a marginal increase in left and right ventricular volumes in men, but not in women, whereas alcohol intake showed an association with increased left atrium volume in women. Our results suggest that there is only minimal relationship between regular alcohol consumption and cardiac morphology and function in an asymptomatic middle-aged population.

Long-term cocaine use is associated with increased coronary plaque burden - a pilot study.

Background: There is a lack of research regarding whether prolonged use of cocaine would lead to increase of coronary plaque burden. Objectives: To study the effects of cocaine use on the coronary artery plaque volume. We hypothesize the longer the cocaine use, the greater the plaque burden. Methods: We used coronary computed tomography angiography to evaluate plaque volumes. The study included chronic (N = 33 with 27 HIV+) and non-cocaine users (N = 15 with 12 HIV+). Chronic cocaine use was defined as use by any route for at least 6 months, administered at least 4 times/month. The Student's t-test was used to compare the plaque volumes between chronic and non-cocaine users. Multivariable regression analysis adjusted for age, sex, body mass index, HIV status, cigarette smoking, diabetes, and total cholesterol was performed to determine the relationship between years of cocaine use and plaque volumes. Results: The total plaque volumes between groups showed no difference (p = .065). However, the total left anterior descending artery (LAD) plaque volume in the chronic cocaine group was significantly higher than that in the non-cocaine group (p = .047). For each year increase in cocaine use, total plaque volume and total LAD plaque volume increased by 7.23 mm3 (p = .013) and 4.56 mm3 (p = .001), respectively. In the multivariable analyses, both total plaque volume and total LAD plaque volume were significantly associated with years of cocaine use (p = .039 and 0.013, respectively). Conclusion: Prolonged cocaine use accelerates the development of sub-clinical atherosclerosis.

Increased visceral arterial tortuosity in Marfan syndrome.

BACKGROUND: Clinical evidence suggests that the currently recommended approach to estimate the risk of aortic dissection in Marfan syndrome (MFS) is not reliable enough. Therefore, we investigated the possible role of visceral arterial tortuosity in the risk stratification. METHODS AND RESULTS: Splenic and renal arteries of 37 MFS patients and 74 age and gender matched control subjects were segmented using CT angiography imaging. To measure tortuosity, distance metric (DM), sum of angles metric (SOAM), inflection count metric (ICM), and the ratio of ICM and SOAM (ICM/SOAM) were calculated. DM of the splenic, right and left renal artery was significantly higher in MFS patients than in controls (2.44 [1.92-2.80] vs. 1.75 [1.57-2.18] p < 0.001; 1.16 [1.10-1.28] vs. 1.11 [1.07-1.15] p = 0.011; 1.40 [1.29-1.70] vs. 1.13 [1.09-1.23] p < 0.001, respectively). A similar tendency for ICM and an opposite tendency for SOAM were observed. ICM/SOAM was significantly higher in the MFS group compared to controls in case of all three arteries (73.35 [62.26-93.63] vs. 50.91 [43.19-65.62] p < 0.001; 26.52 [20.69-30.24] vs. 19.95 [16.47-22.95] p < 0.001; 22.81 [18.64-30.96] vs. 18.38 [15.29-21.46] p < 0.001, respectively). MFS patients who underwent aortic root replacement had increased right and left renal DM and ICM/SOAM compared to MFS patients without surgery. CONCLUSION: To our knowledge this is the first demonstration of increased arterial tortuosity in MFS on visceral arteries. Visceral arterial tortuosity, dominated by curves of lower frequency but higher amplitude according to the observed opposite tendency between the DM and SOAM metrics, could be a possible new predictor of serious manifestations of MFS.

Association between Cyclothymic Affective Temperament and Age of Onset of Hypertension.

Affective temperaments represent a biologically stable core of emotional reactivity and have previously been associated with hypertension and arterial stiffening. The age, when hypertension is initiated, is influenced by different factors, but the role of personality traits in this regard is not clarified yet. Our aim was to study the association between affective temperaments and the age at onset of hypertension. In this cross-sectional study, 353 patients were included. After the evaluation of history, patients completed the Temperament Evaluation of Memphis, Pisa, Paris and San Diego Autoquestionnaire. We used linear regression analysis to identify predictors of the age of onset of hypertension in the whole cohort and in male and female subpopulations. The independent predictors of the age at onset of hypertension were male sex (B = -4.57 (95% CI = -1.40 to -7.74)), smoking (B = -4.31 (-7.41 to -1.22)), and positive family history (B = -6.84 (-10.22 to -3.45)). In women, cyclothymic temperament score was an independent predictor of the initiation of hypertension (B = -0.83 (-1.54 to -0.12)), while this association was absent in men. Besides traditional factors, cyclothymic affective temperament might contribute to the earlier initiation of hypertension in women.

Incomplete circle of Willis is associated with a higher incidence of neurologic events during carotid eversion endarterectomy without shunting.

OBJECTIVE: A complete circle of Willis (CoW) is considered an important collateral network to maintain blood flow during cross-clamping in carotid endarterectomy (CEA). The aim of this study was to evaluate the impact of an incomplete CoW with isolated middle cerebral artery (iMCA) on immediate neurologic events (INEs) after CEA. METHODS: We prospectively collected the clinical data and outcomes of 902 patients who underwent CEA under general anesthesia between 2013 and 2015. All patients had preoperative computed tomography angiography of the extracranial and intracranial cerebral circulation. Indications were asymptomatic (52%) and symptomatic (48%) carotid artery disease. Patients who had CEA with shunt (n = 35) and those with inadequate intracranial imaging to assess CoW were excluded (n = 322) only. Computed tomography angiography images were reviewed retrospectively and independently by two vascular radiologists who were blinded for treatment outcomes. Imaging assessment included the vertebral and carotid circulation and each segment of the CoW, which was classified as normal, hypoplastic (diameter < 0.8 mm) or absent. The ipsilateral MCA was considered isolated if there was an absence of the anterior and posterior communicating branches from the contralateral carotid or posterior circulations. INE was defined as any transient ischemic attack (TIA) and stroke diagnosed immediately after the procedure. RESULTS: Of the 545 included patients (331 males; mean age, 69 ± 8 years), 12 (2.2%) had a stroke in the postoperative period. There were 20 INEs (8 strokes and 12 TIAs). A complete CoW was rare; it was only detected in 19 patients (3.5%) and an iMCA was found in 34 patients (6.3%). When at least one collateral circulation was complete (in 330 patients), we observed only four INEs (1.2%). Of the 34 patients with an iMCA, 8 (24%) had INE (6 TIAs and 2 strokes). Overall, iMCA was an independent predictor of INEs (odds ratio, 11.12; 95% confidence interval, 3.57-35.87; P < .001). With logistic regression, the model included hypertension, smoking, diabetes, hyperlipidemia, carotid clamping time (minutes), contralateral significant internal carotid artery stenosis of greater than 90%, ipsilateral significant internal carotid artery stenosis of greater than 90%, preoperative symptoms in 6 months, and iMCA; above iMCA only symptomatic patients had significant risk (odds ratio, 3.34; 95% confidence interval, 1.19-9.73; P = .02), whereas all other parameters were not significant. CONCLUSIONS: An iMCA carries more than a 10-fold higher the risk of INEs after CEA with cross-clamping without shunt protection. In these patients, routine shunting is recommended to prevent INEs.

[Thoracic aortic stentgraft implantations in Hungary from 2012 to 2016]. / Mellkasiaortastentgraft-beültetések Magyarországon 2012 és 2016 között.

Thoracic aortic endograft implantation has become a widespread procedure in recent years, yet no report is available about Hungarian outcomes. Examination of our results is crucial to define further treatment strategies. Analysis of perioperative data from Hungarian thoracic endograft implantations based on the experience of 5 years is presented. Our retrospective, multicentric study analysed voluntarily reported data from all Hungarian institutions where thoracic endograft implantations are performed. Information was collected from every procedure performed in 5 years. Between 2012 and 2016, 131 thoracic stent graft implantations were performed in Hungary (67.18% male, mean age 62.80 years). 25.19% of the procedures were acute. 13.74% of the patients were diabetic. Indications for the procedure were aneurysm (64.89%), dissection (17.56%), aortic trauma (6.87%) and other conditions (10.69%). 73.91% of the dissection cases were acute. 16.47% of repaired aneurysms were ruptured. Additional preoperative revascularization (debranching) was performed in 26.72% of the cases. Postoperative stroke occured in 4.58%, temporary hemodialysis was needed in 1.53%, bowel ischaemia was present in 2.29% and reoperation within 30 days was needed in 5.34% of all cases. Thirty-day mortality of the procedure was 9.92%, 5-year long-term mortality reached 16.03%. Endovascular repair of the thoracic aorta is an effective procedure and our national data comfirmed its advantages compared to open thoracic surgery. Further use of the procedure in Hungary depends on the centralised care in vascular surgery and financial matters. Multidisciplinary cooperation and proper logistics are needed to provide patients with optimal treatment. Orv Hetil. 2018; 159(2): 53-57.

The effect of four-phasic versus three-phasic contrast media injection protocols on extravasation rate in coronary CT angiography: a randomized controlled trial.

OBJECTIVES: Contrast media (CM) extravasation is a well-known complication of CT angiography (CTA). Our prospective randomized control study aimed to assess whether a four-phasic CM administration protocol reduces the risk of extravasation compared to the routinely used three-phasic protocol in coronary CTA. METHODS: Patients referred to coronary CTA due to suspected coronary artery disease were included in the study. All patients received 400 mg/ml iomeprol CM injected with dual-syringe automated injector. Patients were randomized into a three-phasic injection-protocol group, with a CM bolus of 85 ml followed by 40 ml of 75%:25% saline/CM mixture and 30 ml saline chaser bolus; and a four-phasic injection-protocol group, with a saline pacer bolus of 10 ml injected at a lower flow rate before the three-phasic protocol. RESULTS: 2,445 consecutive patients were enrolled (mean age 60.6 ± 12.1 years; females 43.6%). Overall rate of extravasation was 0.9% (23/2,445): 1.4% (17/1,229) in the three-phasic group and 0.5% (6/1,216) in the four-phasic group (p = 0.034). CONCLUSIONS: Four-phasic CM administration protocol is easy to implement in the clinical routine at no extra cost. The extravasation rate is reduced by 65% with the application of the four-phasic protocol compared to the three-phasic protocol in coronary CTA. KEY POINTS: • Four-phasic CM injection-protocol reduces extravasation rate by 65% compared to three-phasic. • The saline pacer bolus substantially reduces the risk of CM extravasation. • The implementation of four-phasic injection-protocol is at no cost.

Thoracic Aortic Strain is Irrelevant Regarding Endograft Sizing in Most Young Patients.

BACKGROUND: The introduction of electrocardiogram gating in computed tomography (CT) angiography imaging of aortic disease raised questions whether diameters measured on diastolic images can lead to the undersizing of aortic endografts. As previous studies suggested that young patients may have the highest risk of an unintended undersize, the aim of our study was to analyze the strain of the thoracic aorta in a young patient cohort. METHODS: We assessed the descending aorta of 52 patients (35 men, mean age 41.1 ± 7.3 years) who underwent coronary CT angiography (CCTA) with suspected coronary artery disease. To reduce radiation dose, native calcium score scans triggered on late systole were compared with diastolic phase CCTA images. Cross-section areas were measured, and effective diameters were derived at 3 levels of the visible segment of the descending aorta (P1, P2, and P3) in systole and diastole. Aortic pulsatility (mm, dsystolic-ddiastolic) and strain (%, [dsystolic-ddiastolic]/ddiastolic) were calculated at each level. All measurements were performed 3 times by 2 independent readers to evaluate interreader and intrareader reproducibility. RESULTS: A total of 936 measurements were performed. Significant differences were found between systolic and diastolic diameters at each location (all P < 0.001). Average aortic pulsatility was 1.5 ± 0.6 mm at P1, 1.6 ± 0.7 mm at P2, and 1.7 ± 0.7 mm at P3, with a corresponding aortic strain of 6.7 ± 3.1% at P1, 7.4 ± 3.5% at P2, and 8.1 ± 3.6% at P3. The differences between the strain of the measurement levels were not significant (P = 0.344). Aortic strain and pulsatility did not show significant correlation with pulse pressure (P = 0.693), patient age (P = 0.649), or other anamnestic data. Intraclass correlation coefficient was in the range of 0.95-0.96 for interobserver and in the range of 0.95-0.97 for intraobserver analysis. CONCLUSIONS: This study shows that descending aortic strain can be measured precisely and reliably on images of routine CCTA examinations with native scans acquired during systole. We demonstrated that young adults have an aortic strain of 6.7-8.1%. As the average thoracic aortic strain was still lower than the recommended prosthesis oversize of 10%, routine use of systolic phase imaging cannot be recommended: it has no clinical benefit for the vast majority of the patients but increases the risk of motion artefacts. We also demonstrated that large interindividual differences are present in the scale of thoracic aortic strain, a phenomenon that needs further investigations to be fully understood.