Impact of heart rate on diagnostic accuracy of second generation 320-detector computed tomography coronary angiography

Subtraction coronary CT angiography in patients with high heart rate

All the previous subtraction coronary CT angiography (CCTA) had strict heart rate (HR) inclusion criteria. In this study, a new subtraction method was applied to patients with various HR. The post-contrast scan time was respectively 3.5 s after ascending aorta peak enhancement while HR >80 bpm, 4 s while 65≤ HR ≤80 bpm and 4.5 s while HR <65 bpm. Forty-six patients who underwent the new subtraction protocol were enrolled and patients were stratified into the high HR group (≥70 bpm) and low HR group (<70 bpm). Eighteen patients with 15 severe calcification segments and 25 stent segments further received invasive coronary angiography (ICA). In all included patients, the coronary artery enhancement was compared between the high and low HR groups. In patients with ICA performed, the image quality improvement and diagnostic effectiveness for detection of significant coronary segments stenosis (>50%) were compared between the conventional CCTA and subtraction CCTA and between the high HR group and low HR group, respectively. All enrolled patients got sufficient coronary artery enhancement. In patients with ICA performed, receiver operating characteristic (ROC) curve analysis showed that the area under the curve (AUC) for the diagnosis of significant stenosis was 0.93 in subtraction CCTA and 0.73 in conventional CCTA (p < 0.05). Furthermore, there were no significant differences in image quality improvement, specificity, positive predictive value and accuracy between the high HR group and low HR group. The new subtraction CCTA method broadened the clinical availability for patients with high HR.

Breast arterial calcification and epicardial adipose tissue volume, but not density are independently associated with cardiovascular risk

BACKGROUND

Mammographically detected breast arterial calcification (BAC) has been proposed as surrogate marker for coronary artery disease (CAD) in women. Epicardial adipose tissue (EAT) and peri-coronary adipose tissue (PCAT) are inflammatory fat depots linked to atherogenesis. BAC has demonstrated association with inflammation, therefore we aimed to determine the association between BAC, EAT and PCAT.

METHODS

Single-centre, retrospective, cross-sectional study of women with digital mammography and coronary computed tomography angiography (CCTA). EAT and PCAT were quantitively assessed using semi-automated software. Patient demographics and cardiovascular risk factors were obtained from medical records and mammograms reviewed for BAC. Pre-test cardiovascular risk was determined with CAD Consortium Score. Chi-square, t-test and Mann-Whitney U tests were used to assess between group differences. Multivariable linear and logistic regression modelling was conducted to adjust for confounders.

RESULTS

Among 153 patients (age 61, SD 11) included in this study, BAC was present in 37 (24%) patients. BAC-positive patients had higher EAT volume (EATv) (110.2 mL, SD 41 mL vs 94.4 mL, SD 41 mL, p = 0.02) but this association was not significant after adjusting for cardiovascular risk factors (p = 0.26). BAC did not associate with EAT density or PCAT. BAC and EATv were strongly associated with cardiovascular risk and CAD independent of each other: CV risk (BAC OR 7.55 (3.26-18.49), p < 0.001, EATv OR 1.02 (1.01-1.03), p < 0.001), CAD presence (BAC OR 4.26 (1.39-13), p = 0.01; EATv OR 1.01 (1.0-1.03), p = 0.04).

CONCLUSION

BAC and EATv are independent predictors of CV risk and CAD, but don't independently associate with each other, the relationship confounded by shared cardiovascular risk factors. BAC doesn't appear to associate with adipose tissue density and its presence may be cumulative result of long-term exposure to CV risk factors.

Diagnostic accuracy of prospectively gated, 128-slice or greater CTCA at high heart rates: a systematic review and meta-analysis

INTRODUCTION

Prospectively gated 64-slice CT coronary angiography (CTCA) may be contraindicated for heart rates (HRs) over 65 beats per minute (bpm) due to reduced diagnostic sensitivity. Newer CT scanners typically provide 128 or more slices and superior temporal resolution compared with older models; consequently, diagnostic accuracy for current technology prospectively gated CTCA may be adequate at HRs above 65 bpm. The aim of this systematic review was to investigate the diagnostic accuracy of CTCA using 128-slice or greater CT technology when compared with conventional coronary angiography for patients with HRs >65 bpm.

METHODS

A systematic search of PubMed, CINAHL, EMBASE and Scopus was performed as well as unpublished databases, sources and reference lists. Titles and abstracts were screened by two independent reviewers. Full-text screening was then performed. Studies that determined diagnostic accuracy of coronary artery stenosis in adult patients with high heart rates utilising prospectively gated 128 detector or greater scanners were included. Studies that were included in the review underwent critical appraisal using the QUADAS-2 tool.

RESULTS

Ten studies were included in the systematic review, with nine of these included in a diagnostic test accuracy meta-analysis, including six of which reported data at the patient level. Meta-analysis indicated very high pooled sensitivity 100% (95% CI 0.99, 1.00); however, pooled specificity was less at 79% (95% CI 0.69, 0.88).

CONCLUSIONS

Prospectively gated CT coronary angiography may be justifiable at heart rates above 65 bpm if performed on a 128-slice or greater CT unit. Caution regarding the implication of a positive result is recommended due to reduced specificity. Further evidence is required before consideration of a new higher heart threshold.

Computed tomography imaging using split-bolus contrast injection with volume scan of aortic root and heart for preoperative evaluation of transcatheter aortic valve implantation

The purpose of this study was to investigate using split-bolus contrast injection (SPBI) with volume scanning of the heart and aortic root with helical scanning of the access route, compared to single bolus contrast injection (SI) with variable helical pitch scanning (VHP) of the heart and aortic root and access route in a preoperative evaluation before transcatheter aortic valve implantation (TAVI). Thirty-five patients who underwent preoperative CT before TAVI using SPBI (contrast media: 24.5 mgI /kg/s, injected for 12 s for heart scan and then injected for 8 s for access route) were examined. Electrocardiogram (ECG) gated scans of the heart were performed by volume scan, after a period of time, non-gated helical scans of the aorto-iliac were performed (SPBI method). For comparison, 40 patients who had a single bolus injection (26.5 mg I/kg/s, injected for period of the scan time plus 3 s) and a VHP scan (SI method) before the SPBI method was performed were included in the study. The image qualities of the coronary arteries, aortic root, and access route (aorta-iliac), as well as radiation and iodine doses, were assessed. In visual assessment, image quality of coronary artery was significantly better with the SPBI method (grade; excellent: 57.1% in SPBI vs. 24.3% in SI, p = 0.03). There was no significant difference in image quality of the aortic root by visual assessment. The signal-to-noise (SNR) and contrast-to-noise ratio (CNR) of coronary and aortic root were not significantly different between the two methods. The access route showed significantly higher SNR (45.7 ± 11.5 vs. 34.3 ± 9.8, p < 0.001) and CNR (36.0 ± 9.7 vs. 28.0 ± 8.8, p < 0.001) for the SPBI method. The SPBI method compared to SI method reduced iodine dose by 10% and radiation dose by 45%. Preoperative CT imaging before TAVI using SPBI with volume scan is useful and can reduce iodine and radiation doses.

The Natural history of Epicardial Adipose Tissue Volume and Attenuation: A long-term prospective cohort follow-up study

Epicardial adipose tissue (EAT) is associated with cardiovascular risk. The longitudinal change in EAT volume (EATv) and density (EATd), and potential modulators of these parameters, has not been described. We prospectively recruited 90 patients with non-obstructive coronary atherosclerosis on baseline computed tomography coronary angiography (CTCA) performed for suspected coronary artery disease to undergo a repeat research CTCA. EATv in millilitres (mL) and EATd in Hounsfield units (HU) were analysed and multivariable regression analysis controlling for traditional cardiovascular risk factors (CVRF) performed to assess for any predictors of change. Secondary analysis was performed based on statin therapy. The median duration between CTCA was 4.3years. Mean EATv increased at follow-up (72 ± 33 mL to 89 ± 43 mL, p < 0.001) and mean EATd decreased (baseline −76 ± 6 HU vs. −86 ± 5 HU, p < 0.001). There were no associations between baseline variables of body mass index, age, sex, hypertension, hyperlipidaemia, diabetes or smoking on change in EATv or EATd. No difference in baseline, follow-up or delta EATv or EATd was seen in patients with (60%) or without baseline statin therapy. In this select group of patients, EATv consistently increased and EATd consistently decreased at long-term follow-up and these changes were independent of CVRF, age and statin use. Together with the knowledge of strong associations between EAT and cardiac disease, these findings may suggest that EAT is an independent parameter rather than a surrogate for cardiovascular risk.

Diagnostic Accuracy of a Novel On-site Virtual Fractional Flow Reserve Parallel Computing System

PURPOSE

To evaluate the diagnostic accuracy of a novel on-site virtual fractional flow reserve (vFFR) derived from coronary computed tomography angiography (CTA).

MATERIALS AND METHODS

We analyzed 100 vessels from 57 patients who had undergone CTA followed by invasive FFR during coronary angiography. Coronary lumen segmentation and three-dimensional reconstruction were conducted using a completely automated algorithm, and parallel computing based vFFR prediction was performed. Lesion-specific ischemia based on FFR was defined as significant at ≤0.8, as well as ≤0.75, and obstructive CTA stenosis was defined that ≥50%. The diagnostic performance of vFFR was compared to invasive FFR at both ≤0.8 and ≤0.75.

RESULTS

The average computation time was 12 minutes per patient. The correlation coefficient (r) between vFFR and invasive FFR was 0.75 [95% confidence interval (CI) 0.65 to 0.83], and Bland-Altman analysis showed a mean bias of 0.005 (95% CI -0.011 to 0.021) with 95% limits of agreement of -0.16 to 0.17 between vFFR and FFR. The accuracy, sensitivity, specificity, positive predictive value, and negative predictive value were 78.0%, 87.1%, 72.5%, 58.7%, and 92.6%, respectively, using the FFR cutoff of 0.80. They were 87.0%, 95.0%, 80.0%, 54.3%, and 98.5%, respectively, with the FFR cutoff of 0.75. The area under the receiver-operating characteristics curve of vFFR versus obstructive CTA stenosis was 0.88 versus 0.61 for the FFR cutoff of 0.80, respectively; it was 0.94 versus 0.62 for the FFR cutoff of 0.75.

CONCLUSION

Our novel, fully automated, on-site vFFR technology showed excellent diagnostic performance for the detection of lesion-specific ischemia.

Severe obstructive sleep apnea is associated with significant coronary artery plaque burden independent of traditional cardiovascular risk factors

Obstructive Sleep Apnea (OSA) is strongly associated with adverse cardiovascular events. In these patients, increased oxidative stress has been associated with accelerated coronary atherosclerosis. However, it is unclear if OSA is associated with significant coronary artery plaque burden. Our aim is to determine whether OSA and/or markers of hypoxemia are associated with coronary plaque burden (CPB). Patients who had coronary computed tomography angiography (CCTA) and a polysomnogram within 1 year of each other between 2011 and 2016 were analyzed. Apnea-Hypopnea Index (AHI) and hypoxemic burden (ODI3%, ODI4%, nadir SpO2, average spO₂ and time of spO₂ < 88%) were obtained from the polysomnogram. Total CPB was assessed using the prognostically validated CT-Leaman score (CT-LeSc). Significant CPB was defined as CT-LeSc ≥ 8.3. There were 119 patients with mean (± SD) age of 59 ± 12 years. Using logistical regression analysis; AHI, ODI4% and ODI3% were the only parameters associated with significant CPB. Severe OSA (AHI ≥ 30 events/h) was associated with significant CPB with adjusted OR of 3.21 (p = 0.010) independent of traditional cardiovascular risk factors. Mechanisms associated with apnea and hypopnea events (as measured by AHI, ODI3% and ODI4%), but not the severity of arterial desaturation (nadir SpO₂, burden of SpO₂ < 88%) were associated with significant CPB.

Impact of heart rate on coronary computed tomographic angiography interpretability with a third-generation dual-source scanner

BACKGROUND

Guidelines suggest coronary computed tomography angiography (CCTA) should be performed with a heart rate (HR) below 60. Third-generation dual-source CT (DSCT) scanners, with improved temporal resolution, and end-systolic acquisition may facilitate imaging at higher HRs. We determined the influence of HR and end-systolic acquisition on image interpretability and quality with a third-generation DSCT.

METHODS

Patients who underwent CCTA between July 2017 and December 2018 were retrospectively identified. All images were acquired using a SOMATOM Force scanner (Siemens Healthcare). The primary outcome was the presence of any uninterpretable coronary segment. The association between HR and CCTA with uninterpretable segments was assessed with multivariable logistic regression, correcting for demographics and imaging variables.

RESULTS

In total, 2620 patients were included, mean age 61.4 ± 12.9 years and 61.2% male, with uninterpretable segments present in 229 (8.7%) scans. In multivariable analysis, HR 80-89 was associated with an increased likelihood of having a scan with uninterpretable segments (adjusted odds ratio [OR] 4.53, p < 0.001). However, no significant association was present with end-systolic acquisition (HR 80-89, adjusted OR 2.32, p = 0.125). HR ≥ 90 was associated with a decreased likelihood of good or excellent image quality (adjusted OR 0.26, 95% CI 0.11-0.63, p = 0.003).

CONCLUSIONS

With third-generation dual-source CT scanners, patients with HR 60-80 can be imaged without impacting image interpretability. End-systolic image acquisition facilitates imaging at HRs > 80 without increasing non-diagnostic scans. Routine use of systolic gating could omit the need for strict HR control and pre-test beta blockade currently required for CCTA.

Diagnostic accuracy of computed tomography coronary angiography utilizing recent advances in technology in patients with high heart rates: a systematic review protocol

OBJECTIVE

The objective of this review is to determine the diagnostic accuracy of computed tomography coronary angiography (CTCA) using recent scan technologies for detecting coronary artery disease (CAD) in adults with high heart rates.

INTRODUCTION

Invasive coronary angiography is the gold standard for detecting significant CAD, but it is costly and carries risks of complications. Computed tomography coronary angiography has a high sensitivity for diagnosing CAD, although image quality may be affected by elevated heart rates. Recent technological advances in scanner design may increase the diagnostic accuracy of CTCA.

INCLUSION CRITERIA

This review will consider diagnostic test accuracy studies that include adults 18 years and older with a heart rate greater than 65 beats per minute who have undergone CTCA to diagnose CAD (greater than 50% stenosis). Eligible studies will compare invasive coronary angiography with computed tomography scanner technologies that use either single- or dual-source scanner configuration in prospective electrocardiogram scan acquisition mode, and with a total scanner coverage equal to or greater than 128 detector-rows. Studies published in English from 2007 will be considered.

METHODS

PubMed, Embase, CINAHL and Scopus will be searched, along with Google Scholar, the NIHR-HTA register, computed tomography vendors and conference abstracts. Screening of potential titles and abstracts, retrieval of full-text studies, assessment of methodological quality and data extraction will be performed independently by two reviewers. Meta-analyses will be performed, if possible, and a Grading of Recommendations, Assessment, Development and Evaluation (GRADE) Summary of Findings presented.