<Emphasis Type="Bold">Discrepancies between coronary CT angiography and invasive coronary angiography with focus on culprit lesions which cause future cardiac events</Emphasis>

Objectives

To evaluate the clinical significance of discrepant lesions between coronary computed tomography angiography (CCTA) and invasive coronary angiography (ICA) in a longitudinal study.

Methods

In 220 patients with suspected coronary artery disease (CAD) who underwent both 256-row CCTA and ICA, the obstructive CAD (≥ 50% stenosis) on CCTA was compared with that on ICA as the reference standard. We analysed the causes of the discrepancy between CCTA and ICA. During a 40-month follow-up period, major adverse cardiac events (MACE) were assessed.

Results

Discordance between CCTA and ICA was observed in 121 of the 3166 coronary artery segments (3.8%). Common causes were calcification (45.9%) and positive remodelling (PR) (29.6%) in 83 false positive lesions, and noise (40.0%) and motion artefact (37.8%) in 38 false negative lesions. MACE occurred in seven lesions among the discrepant lesions; six among the 29 PR lesions (20.7%) and one among the 53 calcified lesions (1.9%). With respect to the prediction power of MACE in an intermediate stenosis, the CCTA-related value including PR was higher than the ICA-related value.

Conclusions

PR was a frequent cause of MACE among the false positive lesions on CCTA. Therefore, the presence of PR on CCTA may suggest clinical significance, although it can be missed by ICA.

Key Points

? Compared to ICA, PR in CCTA may be cause of false positive lesion. ? CCTA-related value including PR shows higher prediction power of MACE than ICA-related value. ? PR reflects atherosclerotic burden that can be related to cardiac events. ? PR in CCTA should be observed carefully, even if it is false positive.

     

Myocardial segmentation based on coronary anatomy using coronary computed tomography angiography: Development and validation in a pig model

Objectives

To validate a method for performing myocardial segmentation based on coronary anatomy using coronary CT angiography (CCTA).

Methods

Coronary artery-based myocardial segmentation (CAMS) was developed for use with CCTA. To validate and compare this method with the conventional American Heart Association (AHA) classification, a single coronary occlusion model was prepared and validated using six pigs. The unstained occluded coronary territories of the specimens and corresponding arterial territories from CAMS and AHA segmentations were compared using slice-by-slice matching and 100 virtual myocardial columns.

Results

CAMS more precisely predicted ischaemic area than the AHA method, as indicated by 95% versus 76% (p?<?0.001) of the percentage of matched columns (defined as percentage of matched columns of segmentation method divided by number of unstained columns in the specimen). According to the subgroup analyses, CAMS demonstrated a higher percentage of matched columns than the AHA method in the left anterior descending artery (100% vs. 77%; p?<?0.001) and mid- (99% vs. 83%; p?=?0.046) and apical-level territories of the left ventricle (90% vs. 52%; p?=?0.011).

Conclusions

CAMS is a feasible method for identifying the corresponding myocardial territories of the coronary arteries using CCTA.

Key Points

? CAMS is a feasible method for identifying corresponding coronary territory using CTA ? CAMS is more accurate in predicting coronary territory than the AHA method ? The AHA method may underestimate the ischaemic territory of LAD stenosis

     

Using coronary CT angiography for guiding invasive coronary angiography: potential role to reduce intraprocedural radiation exposure

Objectives

We investigated the potential reduction of patient exposure during invasive coronary angiography (ICA) if the procedure had only been directed to the vessel with at least one ≥ 50% stenosis as described in the CT report.

Methods

Dose reports of 61 patients referred to ICA because of at least one ≥ 50% stenosis on coronary CT angiography (CCTA) were included. Dose–area product (DAP) was documented separately for left (LCA) and right coronary arteries (RCA) by summing up the single DAP for each angiographic projection. The study population was subdivided as follows: coronary intervention of LCA (group 1) or RCA (group 2) only, or of both vessels (group 3), or further bypass grafting (group 4), or no further intervention (group 5).

Results

57.4% of the study population could have benefitted from reduced exposure if catheterization had been directly guided to the vessel of interest as described on CCTA. Mean relative DAP reductions were as follows: group 1 (n = 18), 11.2%; group 2 (n = 2), 40.3%; group 3 (n = 10), 0%; group 4 (n = 3), 0%; group 5 (n = 28), 28.8%.

Conclusions

Directing ICA to the vessel with stenosis as described on CCTA would reduce intraprocedural patient exposure substantially, especially for patients with single-vessel stenosis.

Key points

? Patients with CAD can benefit from decreased radiation exposure during coronary angiography. ? ICA should be directed solely to significant stenoses as described on CCTA. ? Severely calcified plaques remain a limitation of CCTA leading to unnecessary ICA referrals.

     

Iterative image reconstruction algorithms in coronary CT angiography improve the detection of lipid-core plaque – a comparison with histology

Objectives

To evaluate whether iterative reconstruction algorithms improve the diagnostic accuracy of coronary CT angiography (CCTA) for detection of lipid-core plaque (LCP) compared to histology.

Methods and materials

CCTA and histological data were acquired from three ex vivo hearts. CCTA images were reconstructed using filtered back projection (FBP), adaptive-statistical (ASIR) and model-based (MBIR) iterative algorithms. Vessel cross-sections were co-registered between FBP/ASIR/MBIR and histology. Plaque area <60 HU was semiautomatically quantified in CCTA. LCP was defined by histology as fibroatheroma with a large lipid/necrotic core. Area under the curve (AUC) was derived from logistic regression analysis as a measure of diagnostic accuracy.

Results

Overall, 173 CCTA triplets (FBP/ASIR/MBIR) were co-registered with histology. LCP was present in 26 cross-sections. Average measured plaque area <60 HU was significantly larger in LCP compared to non-LCP cross-sections (mm²: 5.78?±?2.29 vs. 3.39?±?1.68 FBP; 5.92?±?1.87 vs. 3.43?±?1.62 ASIR; 6.40?±?1.55 vs. 3.49?±?1.50 MBIR; all p?<?0.0001). AUC for detecting LCP was 0.803/0.850/0.903 for FBP/ASIR/MBIR and was significantly higher for MBIR compared to FBP (p?=?0.01). MBIR increased sensitivity for detection of LCP by CCTA.

Conclusion

Plaque area <60 HU in CCTA was associated with LCP in histology regardless of the reconstruction algorithm. However, MBIR demonstrated higher accuracy for detecting LCP, which may improve vulnerable plaque detection by CCTA.

Key Points

? A low attenuation plaque area is associated with the presence of lipid-core plaque ? MBIR leads to higher diagnostic accuracy for detecting lipid-core plaque ? The benefit of MBIR is mainly due to increased sensitivity at high specificities ? Semiautomated CCTA assessment can detect vulnerable plaques non-invasively

     

Influence of acquired obesity on coronary vessel wall late gadolinium enhancement in discordant monozygote twins

Objectives

The aim of this study was to investigate the impact of BMI on late gadolinium enhancement (LGE) of the coronary artery wall in identical monozygous twins discordant for BMI. Coronary LGE represents a useful parameter for the detection and quantification of atherosclerotic coronary vessel wall disease.

Methods

Thirteen monozygote female twin pairs (n?=?26) with significantly different BMIs (>1.6 kg/m2) were recruited out of >10,000 twin pairs (TwinsUK Registry). A coronary 3D-T2prep-TFE MR angiogram and 3D-IR-TFE vessel wall scan were performed prior to and following the administration of 0.2 mmol/kg of Gd-DTPA on a 1.5 T MR scanner. The number of enhancing coronary segments and contrast to noise ratios (CNRs) of the coronary wall were quantified.

Results

An increase in BMI was associated with an increased number of enhancing coronary segments (5.3?±?1.5 vs. 3.5?±?1.6, p?<?0.0001) and increased coronary wall enhancement (6.1?±?1.1 vs. 4.8?±?0.9, p?=?0.0027) compared to matched twins with lower BMI.

Conclusions

This study in monozygous twins indicates that acquired factors predisposing to obesity, including lifestyle and environmental factors, result in increased LGE of the coronary arteries, potentially reflecting an increase in coronary atherosclerosis in this female study population.

Key points

? BMI-discordant twins allow the investigation of the influence of lifestyle factors independent from genetic confounders. ? Only thirteen obesity-discordant twins were identified underlining the strong genetic component of BMI. ? In female twins, a BMI increase is associated with increased coronary late gadolinium enhancement. ? Increased late gadolinium enhancement in the coronary vessel wall potentially reflects increased atherosclerosis.

     

Clinical implementation of an emergency department coronary computed tomographic angiography protocol for triage of patients with suspected acute coronary syndrome

Objectives

To evaluate the efficiency and safety of emergency department (ED) coronary computed tomography angiography (CTA) during a 3-year clinical experience.

Methods

Single-center registry of coronary CTA in consecutive ED patients with suspicion of acute coronary syndrome (ACS). The primary outcome was efficiency of coronary CTA defined as the length of hospitalization. Secondary endpoints of safety were defined as the rate of downstream testing, normalcy rates of invasive coronary angiography (ICA), absence of missed ACS, and major adverse cardiac events (MACE) during follow-up, and index radiation exposure.

Results

One thousand twenty two consecutive patients were referred for clinical coronary CTA with suspicion of ACS. Overall, median time to discharge home was 10.5 (5.7-24.1) hours. Patient disposition was 42.7 % direct discharge from the ED, 43.2 % discharge from emergency unit, and 14.1 % hospital admission. ACS rate during index hospitalization was 9.1 %. One hundred ninety two patients underwent additional diagnostic imaging and 77 underwent ICA. The positive predictive value of CTA compared to ICA was 78.9 % (95 %-CI 68.1-87.5 %). Median CT radiation exposure was 4.0 (2.5-5.8) mSv. No ACS was missed; MACE at follow-up after negative CTA was 0.2 %.

Conclusions

Coronary CTA in an experienced tertiary care setting allows for efficient and safe management of patients with suspicion for ACS.

Key points

? ED Coronary CTA using advanced systems is associated with low radiation exposure. ? Negative coronary CTA is associated with low rates of MACE. ? CTA in ED patients enables short median time to discharge home. ? CTA strategy is characterized by few downstream tests including unnecessary ICA.

     

Image quality and radiation dose of coronary CT angiography performed with whole-heart coverage CT scanner with intra-cycle motion correction algorithm in patients with atrial fibrillation

Objectives

To evaluate image quality, coronary evaluability and radiation exposure of coronary CT angiography (CCTA) performed with whole-heart coverage cardiac-CT in patients with atrial fibrillation (AF).

Materials and methods

We prospectively enrolled 164 patients with AF who underwent a clinically indicated CCTA with a 16-cm z-axis coverage scanner. In all patients CCTA was performed using prospective ECG-triggering with targeted RR interval. We evaluated image quality, coronary evaluability and effective dose (ED). Patients were divided in two subgroups based on heart rate (HR) during imaging. Group 1: 64 patients with low HR (<75 bpm), group 2: 100 patients with high HR (≥75 bpm). Written informed consent was obtained from all patients and the institutional ethics committee approved the study protocol.

Results

In a segment-based analysis, coronary evaluability was 98.4 % (2,577/2,620 segments) in the whole population, without significant differences between groups (1,013/1,024 (98.9 %) and 1,565/1,596 (98.1 %), for groups 1 and 2, respectively, p=0.15). Mean ED was similar in both groups (3.8±1.9 mSv and 3.9±2.1 mSv in groups 1 and 2, respectively, p=0.75)

Conclusions

The whole-heart-coverage scanner could evaluate coronary arteries with high image quality and without increase in radiation exposure in AF patients, even in the high HR group.

Key points

? Last-generation CT scanner improves coronary artery assessment in AF patients. ? The new CT scanner enables low radiation exposure in AF patients. ? Diagnostic ICA maybe avoided in AF patients with suspected CAD. ? Whole-heart coverage CT scanner enables low radiation exposure in AF patients.

     

Diagnostic accuracy of coronary CT angiography using 3<Superscript>rd</Superscript>-generation dual-source CT and automated tube voltage selection: Clinical application in a non-obese and obese patient population

Purpose

To investigate diagnostic accuracy of 3^rd-generation dual-source CT (DSCT) coronary angiography in obese and non-obese patients.

Methods

We retrospectively analyzed 76 patients who underwent coronary CT angiography (CCTA) and invasive coronary angiography. Prospectively ECG-triggered acquisition was performed with automated tube voltage selection (ATVS). Patients were dichotomized based on body mass index in groups A (<30 kg/m², n?=?37) and B (≥30 kg/m², n?=?39) and based on tube voltage in groups C (<120 kV, n?=?46) and D (120 kV, n?=?30). Coronary arteries were assessed for significant stenoses (≥50 % luminal narrowing) and diagnostic accuracy was calculated.

Results

Per-patient overall sensitivity, specificity, positive predictive value, negative predictive value (NPV) and accuracy were 96.9 %, 95.5 %, 93.9 %, 97.7 % and 96.1 %, respectively. Sensitivity and NPV were lower in groups B and D compared to groups A and C, but no statistically significant differences were observed (group A vs. B: sensitivity, 100.0 % vs. 93.3 %, p?=?0.9493; NPV, 100 % vs. 95.5 %, p?=?0.9812; group C vs. D: sensitivity, 100.0 % vs. 92.3 %, p?=?0.8462; NPV, 100.0 % vs. 94.1 %, p?=?0.8285).

Conclusion

CCTA using 3^rd-generation DSCT and (ATVS) provides high diagnostic accuracy in both non-obese and obese patients.

Key Points

? Coronary CTA provides high diagnostic accuracy in non-obese and obese patients. ? Diagnostic accuracy between obese and non-obese patients showed no significant difference.? <120 kV studies were performed in 44 % of obese patients. ? Current radiation dose-saving approaches can be applied independent of body habitus.

     

Short-term changes in arterial inflammation predict long-term changes in atherosclerosis progression

Purpose

It remains unclear whether changes in arterial wall inflammation are associated with subsequent changes in the rate of structural progression of atherosclerosis.

Methods

In this sub-study of the dal-PLAQUE clinical trial, multi-modal imaging was performed using 18-fludeoxyglucose (FDG) positron emission tomography (PET, at 0 and 6 months) and magnetic resonance imaging (MRI, at 0 and 24 months). The primary objective was to determine whether increasing FDG uptake at 6 months predicted atherosclerosis progression on MRI at 2 years. Arterial inflammation was measured by the carotid FDG target-to-background ratio (TBR), and atherosclerotic plaque progression was defined as the percentage change in carotid mean wall area (MWA) and mean wall thickness (MWT) on MRI between baseline and 24 months.

Results

A total of 42 participants were included in this sub-study. The mean age of the population was 62.5 years, and 12 (28.6 %) were women. In participants with (vs. without) any increase in arterial inflammation over 6 months, the long-term changes in both MWT (% change MWT: 17.49 % vs. 1.74 %, p?=?0.038) and MWA (% change MWA: 25.50 % vs. 3.59 %, p?=?0.027) were significantly greater. Results remained significant after adjusting for clinical and biochemical covariates. Individuals with no increase in arterial inflammation over 6 months had no significant structural progression of atherosclerosis over 24 months as measured by MWT (p?=?0.616) or MWA (p?=?0.373).

Conclusions

Short-term changes in arterial inflammation are associated with long-term structural atherosclerosis progression. These data support the concept that therapies that reduce arterial inflammation may attenuate or halt progression of atherosclerosis.

     

Correlation and predictive value of aortic root calcification markers with coronary artery calcification and obstructive coronary artery disease

Objective

To evaluate the correlation between aortic root calcification (ARC) markers and coronary artery calcification (CAC) derived from coronary artery calcium scoring (CACS) and their ability to predict obstructive coronary artery disease (CAD).

Methods

We retrospectively analyzed 189 patients (47% male, age 60.3 ± 11.1 years) with an intermediate probability of CAD who underwent clinically indicated CACS and coronary CT angiography (CCTA). ARC markers [aortic root calcium score (ARCS) and volume (ARCV)] were calculated and compared to CAC markers: coronary artery calcium score (CACS), volume (CACV), and mass (CACM). CCTA datasets were visually evaluated for significant CAD (stenosis ≥ 50%) and the ability of ARC markers to predict obstructive CAD was assessed.

Results

ARCS (mean 67.7 ± 189.5) and ARCV (mean 67.3 ± 184.7) showed significant differences between patients with and without CAC (109.4 ± 238.6 vs 9.42 ± 31.4, p < 0.0001; 108.5 ± 232.4 vs 9.9 ± 30.5, p < 0.0001). A strong correlation was found for ARCS and ARCV with CACS, CACM, and CACV (all p < 0.0001). In a multivariate analysis, ARCS (OR 1.09, p = 0.033) and ARCV (OR 1.12, p = 0.046) were independent markers for CAC. Using a receiver-operating characteristics analysis, the AUC to detect severe CAC was 0.71 (p < 0.0001) and 0.71 (p < 0.0001) for ARCS and ARCV, respectively. ARCS (0.67, p < 0.0001) and ARCV (0.68, p < 0.0001) showed discriminatory power for predicting obstructive CAD, yielding sensitivities 61 and 78% and specificities of 62 and 80%, respectively.

Conclusion

ARC markers are associated with and independently predict the presence of CAC and obstructive CAD. Further testing is required in patients with severe ARC and significant CAD in order to reliably obtain these markers from thoracic-CT or X-ray for proper risk classification.

     

Coronary artery calcium score and CT angiography in asymptomatic elderly patients with high pretest probability for coronary artery disease

Purpose

To evaluate the role of coronary artery calcium scoring (CACS) and/or coronary CT angiography (CCTA) in asymptomatic elderly patients with high pretest probability for coronary artery disease (CAD).

Materials and methods

Forty-eight consecutive asymptomatic elderly (>65 years) subjects who had a high pretest probability and underwent CACS/CCTA were included. Each CCTA was evaluated for adequacy for assessment of coronary stenosis. Significant stenosis (>50 % diameter narrowing) was assessed on evaluable CT images and by invasive catheter angiography (ICA).

Results

All subjects were men with mean CACS of 880 ± 1779. Among those with low (0–99), intermediate (100–399), and high (400–999) CACS, ICA-verified significant stenosis was present in 8 % (1/13), 23 % (2/13), and 67 % (8/12), respectively. Among those with very high CACS (≥1000) (n = 10), 90 % of CCTAs were not evaluable for stenosis.

Conclusion

In asymptomatic elderly subjects with high pretest probability, CACS followed by CCTA may be considered for those with intermediate to high CACS.

     

Feasibility of 320-row area detector CT coronary angiography using 40 mL of contrast material: assessment of image quality and diagnostic accuracy

Objectives

To assess the image quality and diagnostic accuracy of 320-row area detector CT (320-ADCT) coronary angiography using 40 mL of contrast material in comparison with 60-mL protocol.

Methods

This retrospective study included 183 patients who underwent 320-ADCT coronary angiography using 40 mL of contrast and additional 183 sex- and body mass index-matched patients using 60 mL of contrast constituting the control group. Both groups used the same 5-mL/sec injection rate. Quantitative image quality measurements and diagnostic accuracies were calculated and compared.

Results

Mean attenuation and contrast-to-noise ratio (CNR) at the aorta and all coronary arteries were lower in the 40-mL group than in the 60-mL group (all, p?<?0.05), except for the CNR at proximal coronary arteries at 100 kVp (p?=?0.073). However, the proportion of coronary segments with vessel attenuation >250 HU was not different between groups (all, p?>?0.05), except for distal coronary arteries at 80 kVp (p?=?0.001). Furthermore, there were no differences in per-patient and per-segment diagnostic accuracies between the groups (all, p?>?0.05).

Conclusions

320-ADCT coronary angiography using 40 mL of contrast showed image quality and diagnostic accuracy comparable to the 60-mL protocol, demonstrating the clinical feasibility of lowering the risk of contrast-induced nephropathy through contrast volume reduction.

Key points

? 320-ADCT might enable reduction of contrast material volume.? A 40-mL contrast protocol for 320-ADCT provided acceptable image quality.? A 40-mL contrast protocol for 320-ADCT demonstrated sufficient diagnostic accuracy.

     

Intracranial arterial calcifications as a prognostic factor for subsequent major adverse cardiovascular events (MACE)

Background

Intracranial arterial calcifications (ICAC) are often detected on unenhanced CT of patients with an age > 60. However, association with the subsequent occurrence of major adverse cardiovascular events (MACE) has not yet been evaluated.

Purpose

This study aimed at evaluating the association of ICAC with subsequent MACE and overall mortality.

Methods

In this retrospective, IRB approved study, we included 175 consecutive patients (89 males, mean age 78.3 ± 8.5 years) of age > 60 years who underwent an unenhanced CT of the head due to minor trauma or neurological disorders. Presence of ICAC was determined in seven intracranial arteries using a semi-quantitative scale, which resulted in the calcified plaque score (CPS). Clinical follow-up information was obtained by questionnaires and telephone interviews. MACE was defined as myocardial infarction or revascularization, stroke or death due to cardiovascular event.

Results

Mean follow-up time was 39.8 ± 7.8 months, resulting in 579.7 patient-years of follow-up. Overall, 36 MACE occurred during follow-up (annual event rate = 6.2%/year). Mean CPS was significantly higher in subjects with MACE during follow-up compared to subjects without MACE (p < 0.01). In 15 patients CPS was 0; in none of these patients MACE was registered. Kaplan–Meier-analysis revealed that patients with a low plaque burden (CPS < 5) had a significant longer MACE-free and overall survival than patients with a high plaque burden (CPS ≥ 5) (p < 0.01).

Conclusion

Patients with ICAC have an increased risk for future cardio- or cerebrovascular events. Therefore, ICAC might be a prognostic factor to determine the risk for these events in older patients.

     

Myocardial ischemia in the absence of obstructive coronary lesion: The role of post-stress diastolic dysfunction in detecting early coronary atherosclerosis

Background

The interactions between non-obstructive coronary atherosclerosis (<50% stenosis) and myocardial perfusion and functional parameters on myocardial perfusion imaging (MPI) have never been evaluated.

Methods and Results

One-hundred and ninety-five patients were submitted to stress-rest MPI and invasive coronary angiography. The presence of obstructive coronary lesions (>50% stenosis) was excluded. The summed stress score (SSS) was calculated in every patient. Moreover, the left ventricular (LV) ejection fraction (EF) and peak filling rate (PFR) were computed from gated MPI images as measures of systolic and diastolic functions. Sixty/195 patients (31%) showed the presence of non-obstructive atherosclerosis (>20% and <50% diameter reduction). Interestingly, they presented a higher SSS than those with normal coronary arteries (P < 0.001) despite a similar myocardial scar burden. If compared to patients with normal coronary arteries, those with non-obstructive atherosclerosis showed more abnormal post-stress PFR values (2.5 ± 0.9 vs 2.9 ± 0.8, P = 0.004), despite a similar EF. On multivariate analysis, the presence non-obstructive atherosclerosis was the only significant predictor (P = 0.026) of post-stress LV diastolic impairment, independently from perfusion parameters.

Conclusions

In patients without anatomically significant coronary lesions, the development of post-stress LV diastolic dysfunction on MPI associates with the presence of non-obstructive atherosclerosis on coronary angiography.

     

Sex differences in the long-term prognostic value of <Superscript>13</Superscript>N-ammonia myocardial perfusion positron emission tomography

Purpose

Evidence to date on the unique female determinants of cardiovascular risk is inadequate. Positron Emission Tomography (PET) is considered to have the highest accuracy for the assessment of myocardial perfusion in patients with suspected coronary artery disease (CAD), but its long-term prognostic accuracy in women has not been established.

Methods

A total of 619 consecutive patients (138 women, mean age 60.0?±?11.8 years) underwent clinically indicated ¹³N-ammonia PET at our institution and were followed up (median 5.7 years) for major adverse cardiovascular events (MACE) including cardiac death, nonfatal myocardial infarction, hospitalization for any cardiac reason and late revascularization.

Results

During follow-up, 271 patients had at least one cardiac event, including 64 cardiac deaths and 33 nonfatal myocardial infarctions. In both women and men, abnormal myocardial perfusion was associated with reduced event-free survival (log rank p <?0.001). In women, abnormal myocardial perfusion was associated with a higher risk of a worse outcome than in men (adjusted HR 4.1, 95% CI 1.8–9.0 in women; HR 2.4, 95% CI 1.5–3.8 in men; p_interaction <?0.001). In contrast, abnormal coronary flow reserve (CFR) was a significant predictor of 10-year MACE in men (p =?0.006) but not in women (p =?NS). Accordingly, an interaction term of sex and abnormal myocardial perfusion or CFR was significant (p <?0.001).

Conclusion

While perfusion findings in ¹³N-ammonia PET provide effective risk stratification in women and men, CFR adds incremental prognostic value for long-term cardiac outcomes only in men. Refined strategies in noninvasive imaging are needed in women to improve CAD risk prediction.

     

Increased arterial pulsatility and progression of single subcortical infarction

Objective

We investigated the association of clinical, laboratory, sonographic and imaging parameters, in the progression of single subcortical infarctions.

Methods

Consecutive 169 patients with lacunar (n?=?89) and striatocapsular infarctions (n?=?80) in the middle cerebral artery (MCA) territory with nonstenotic MCAs were recruited and examined for stroke progression. The pulsatility index (PI) was measured by transcranial Doppler from ipsilateral M1.

Results

The striatocapsular infarction group exhibited more stroke progression. The patients with progressive lacunar infarctions had more diabetes, higher HbA1c levels, and higher initial National Institutes of Health Stroke Scale (NIHSS) scores, and the patients with progressive striatocapsular infarctions had more hypertension, higher cholesterol levels, and higher NIHSS scores. The MCA PI was higher in the lacunar infarction patients with progression (0.99?±?0.19 vs. 0.90?±?0.14, p?=?0.048), while the striatocapsular infarction patients did not differ according to progression. From a multivariate analysis, higher MCA PI were independently associated with lacunar infarction progression (by 0.1 increase, OR 1.51; 95 % CI 1.06–2.15; p?=?0.024).

Conclusions

Higher pulsatility was associated with progression in lacunar infarction. PI measured by transcranial Doppler sonography might reflect downstream arterial resistance and vascular/paravascular perfusion status and be a possible indicator of stroke progression.

Key Points

? Higher pulsatility index was observed in progression group of lacunar infarction patients. ? Higher pulsatility index seemed to be associated with progression in lacunar infarction patients. ? Differences in the factors associated with stroke progression suggest different underlying pathophysiologies.

     

Long-term prognostic value of stress myocardial perfusion imaging and coronary computed tomography angiography: A meta-analysis

Background

We conducted a meta-analysis to compare the long-term prognostic value of stress single-photon emission computed tomography myocardial perfusion imaging (MPI) and coronary computed tomography angiography (CCTA) for adverse cardiovascular events in subjects with suspected or known coronary artery disease.

Methods and Results

We searched PubMed, Cochrane, Web of Science, and Scopus database between January 2000 and December 2014 for stress MPI and CCTA studies that followed up ≥ 100 subjects for ≥ 2.5 years and provided the unadjusted and/or adjusted hazard ratio (HR) at Cox regression analysis. Summary risk estimates for abnormal perfusion at MPI or ≥ 50% coronary stenosis at CCTA were derived in random effect regression analysis, and causes of heterogeneity were determined in meta-regression analysis. We identified 21 eligible articles (10 MPI and 11 CCTA) including 25,258 participants (13,484 in MPI and 11,774 in CCTA studies) with suspected or known coronary artery disease. Among the included publications, 8 MPI and 8 CCTA studies reported the HR for the occurrence of hard events (death and nonfatal myocardial infarction). The pooled HR was comparable for MPI and CCTA studies. The HR for the occurrence of a combined endpoint including revascularization as event was reported in 4 MPI and 6 CCTA studies. The pooled HR was higher for CCTA compared to MPI (P < .05) also when only MPI and CCTA studies with limited representation of prior CAD were considered.

Conclusions

The long-term prognostic value of MPI and CCTA for the occurrence of hard events is similar. However, the association between event-free survival and CCTA is higher than MPI when coronary revascularization is included in the endpoint.

     

Comprehensive morphologic and functional imaging of heart transplant patients: first experience with dynamic perfusion CT

Objectives

We aimed to assess the diagnostic performance of a combined protocol with coronary computed tomography angiography (CCTA) and stress CT perfusion imaging (CTP) in heart transplant patients for comprehensive morphological and functional imaging.

Methods

In this prospective study, 13 patients undergoing routine follow-up 8±6 years after heart transplantation underwent CCTA and dynamic adenosine stress CTP using a third-generation dual-source CT scanner, cardiac magnetic resonance (MR) adenosine stress perfusion imaging at 1.5 T, and catheter coronary angiography. In CCTA stenoses >50% luminal diameter narrowing were noted. Myocardial perfusion deficits were documented in CTP and MR. Quantitative myocardial blood flow (MBF) was calculated with CTP. Left ventricular ejection fraction was determined on cardiac MR cine images. Radiation doses of CT were determined.

Results

One of the 13 patients had to be excluded because of severe motion artifacts. CCTA identified three patients with stenosis >50%, which were confirmed with catheter coronary angiography. CTP showed four patients with stress-induced myocardial hypoperfusion, which were confirmed by MR stress perfusion imaging. Quantitative analysis of global MBF showed lower mean values as compared to known reference values (MBF under stress 125.5 ± 34.5 ml/100 ml/min). Average left ventricular ejection fraction was preserved (56 ± 5%).

Conclusions

In heart transplant patients, a comprehensive CT protocol for the assessment of morphology and function including CCTA and CTP showed good concordance to results from MR perfusion imaging and catheter coronary angiography.

Key Points

? Stress CT perfusion imaging enables the detection of myocardial ischemia ? CT myocardial perfusion imaging can be combined with coronary computed tomography angiography ? Combining perfusion and coronary CT imaging is accurate in heart transplant patients ? CT myocardial perfusion imaging can be performed at a reasonable radiation dose

     

Prognostic value of atherosclerotic burden and coronary vascular function in patients with suspected coronary artery disease

Purpose

To evaluate the prognostic value of coronary atherosclerotic burden, assessed by coronary artery calcium (CAC) score, and coronary vascular function, assessed by coronary flow reserve (CFR) in patients with suspected coronary artery disease (CAD).

Methods

We studied 436 patients undergoing hybrid ⁸²Rb positron emission tomography/computed tomography imaging. CAC score was measured according to the Agatston method, and patients were categorized into three groups (0, <400, and ≥400). CFR was calculated as the ratio of hyperemic to baseline myocardial blood flow, and it was considered reduced when <2.

Results

Follow-up was 94% complete during a mean period of 47±15 months. During follow-up, 17 events occurred (4% cumulative event rate). Event-free survival decreased with worsening of CAC score category (p < 0.001) and in patients with reduced CFR (p < 0.005). At multivariable analysis, CAC score ≥400 (p < 0.01) and CFR (p < 0.005) were independent predictors of events. Including CFR in the prognostic model, continuous net reclassification improvement was 0.51 (0.14 in patients with events and 0.37 in those without). At classification and regression tree analysis, the initial split was on CAC score. For patients with a CAC score < 400, no further split was performed, while patients with a CAC score ≥400 were further stratified by CFR values. Decision curve analyses indicate that the model including CFR resulted in a higher net benefit across a wide range of decision threshold probabilities.

Conclusions

In patients with suspected CAD, CFR provides significant incremental risk stratification over established cardiac risk factors and CAC score for prediction of adverse cardiac events.

     

Increased severity of liver fat content and liver fibrosis in non-alcoholic fatty liver disease correlate with epicardial fat volume in type 2 diabetes: A prospective study

Objectives

To determine whether severity of non-alcoholic fatty liver disease (NAFLD) and liver fibrosis quantitatively assessed in individuals with diabetes mellitus (DM)-2 correlate with increased coronary heart disease (CHD) risk using non-invasive markers.

Methods

We conducted a single-centre, prospective, cross-sectional study in 100 consecutive diabetic individuals without known CHD recruited between March 2013 and September 2014. History, physical examination, serum markers, cardiac computed tomography (CT), magnetic resonance (MR) imaging-estimated proton density fat fraction (PDFF) and MR elastography (MRE) were obtained for 95 participants. Written informed consent was provided. Institutional review board approved this study. Spearman rank correlation was performed to assess for correlations. Multiple linear regression model determined independent predictors of epicardial adipose tissue (EAT) volume.

Results

A p value < 0.05 determined statistical significance. The EAT volume was higher in the NAFLD group, defined as MR-imaging PDFF ≥ 5 %, compared to the non-NAFLD group (126.5 ml (IQR 80.9) versus 85.4 ml (IQR 44.7), p=0.002). MR imaging-PDFF correlated with EAT (r=0.42, p < 0.0001). MR imaging-PDFF and liver fibrosis were independently associated with EAT.

Conclusions

Higher liver fat content and liver fibrosis may portend worse cardiovascular risk in diabetics.

Key Points

? EAT volume is higher in diabetic individuals with NAFLD. ? Liver fat content is positively correlated with EAT. ? Liver fat content and liver fibrosis were independently associated with EAT. ? Higher liver fat content and fibrosis may adversely affect cardiovascular risk.