Assessment of cardiac implantable electric device lead perforation using a metal artifact reduction algorithm in cardiac computed tomography.

PURPOSE: CT is considered the non-invasive gold standard for evaluating cardiac implantable electronic devices (CIEDs) lead perforation, but metal artifacts caused by the lead tip affect the image quality and make a definitive diagnosis challenging. We compared the performances of the metal artifact reduction (MAR) algorithm and the conventional algorithm for identification of the right ventricular (RV) lead tip position in cardiac CT studies of patients with CIEDs. METHOD: Forty-seven consecutive patients (26 men; age 70.3 ±â€¯15.4 years) with CIEDs underwent cardiac CT. Using the conventional and MAR algorithm, two image reconstructions were performed for each scan. We calculated the artifact index (AI) to assess the quantitative capability of the MAR algorithm for artifact reduction and visually assessed the RV lead tip position on both images as follows: non-perforation, perforation, and equivocal. RESULTS: The mean AIs were significantly lower with the MAR algorithm than with the conventional algorithm (96.7 ±â€¯40.1 HU vs. 284.6 ±â€¯134.1 HU, P < 0.001). Thirteen (27.7 %) patients were diagnosed as equivocal using the conventional algorithm but were diagnosed with perforation (2 patients) and non-perforation (11 patients) using the MAR algorithm (equivocal rate: 27.7 % vs. 0%, P < 0.001). Using the MAR algorithm, all cases were diagnosed with perforation (6 patients, 12.8 %) or non-perforation (41 patients, 87.2 %). CONCLUSIONS: The MAR algorithm effectively reduced metal artifacts and allowed us to diagnose the presence or absence of perforation in all cases, whereas definitive diagnosis was difficult with the use of conventional algorithm in 27.7 % of cases.

Role of acetylcholine spasm provocation test as a pathophysiological assessment in nonobstructive coronary artery disease.

Coronary angiography (CAG) sometimes shows nonobstructive coronary arteries in patients with suspected angina or acute coronary syndrome (ACS). The high prevalence of nonobstructive coronary artery disease (CAD) in those patients has recently been reported not only in Japan but also in Western countries, and is clinically attracting attention. Coronary spasm is considered to be one of the leading causes of both suspected stable angina and ACS with nonobstructive coronary arteries. Coronary spasm could also be associated with left ventricular dysfunction leading to heart failure, which could be improved following the administration of calcium channel blockers. Because we rarely capture spontaneous attacks of coronary spasm with electrocardiograms or Holter recordings, an invasive diagnostic modality, acetylcholine (ACh) provocation test, can be useful in detecting coronary spasm during CAG. Furthermore, we can use the ACh-provocation test to identify high-risk patients with coronary spasm complicated with organic coronary stenosis, and then treat with intensive care. Nonobstructive CAD includes not only epicardial coronary spasm but also microvascular spasm or dysfunction that can be associated with recurrent anginal attacks and poor quality of life. ACh-provocation test could also be helpful for the assessment of microvascular spasm or dysfunction. We hope that cardiologists will increasingly perform ACh-provocation test to assess the pathophysiology of nonobstructive CAD.

Development and assessment of total thrombus-formation analysis system-based bleeding risk model in patients undergoing percutaneous coronary intervention.

BACKGROUND: Antithrombotic therapy is established for the treatment of various cardiovascular events. However, it has been shown to increase the bleeding risk. Total Thrombus-formation Analysis System (T-TAS) is reported to be useful for evaluating thrombogenicity. Here, we estimated whether T-TAS is useful for predicting bleeding events risk in patients undergoing percutaneous coronary intervention (PCI). METHODS: This was a retrospective, observational study at Kumamoto University Hospital between April 2017 and March 2019. Blood samples obtained on the day of PCI were used in T-TAS to compute the thrombus formation area under the curve (AUC) (AR10-AUC30, AUC for AR chip). We divided the study population into 2 groups according to the Academic Research Consortium for High Bleeding Risk (ARC-HBR) (182 patients in ARC-HBR positive, 118 in ARC-HBR negative). The primary endpoint was 1-year bleeding events that were defined by Bleeding Academic Research Consortium type2, 3, or 5. RESULTS: The AR10-AUC30levels were significantly lower in the ARC-HBR positive group than in the ARC-HBR negative group (median [interquartile range] 1571.4 [1277.0-1745.3] vs. 1726.2 [1567.7-1799.6], p < 0.001). The combination of ARC-HBR and AR10-AUC30 could discriminate the bleeding risk, and improved predictive capacity compared with ARC-HBR by c-statistics. Decision-curve analysis also revealed that combining AR10-AUC30 with ARC-HBR ameliorated bleeding risk-prediction. In multivariate Cox hazards analyses, combining ARC-HBR with lower AR10-AUC30 levels was significantly associated with 1-year bleeding events. CONCLUSIONS: The results highlight that AR10-AUC30 evaluated by T-TAS could be a potentially useful marker for predicting high bleeding risk in patients undergoing PCI.

Basal septal perforator vein mimicking the "late iodine enhancement" in delayed phase cardiac CT for myocardial scar assessment.

Delayed-phase cardiac CT is a useful tool for scar detection, based on differences in the volume of distribution of iodine. Although it covers the entire heart, provides uniform, high isotropic spatial resolution, and therefore may be useful for detecting small late iodine enhancement (LIE), we need to correctly differentiate small LIE and pseudo-lesions mimicking LIE. In this case report, we demonstrate basal septal perforator vein mimicking LIE in delayed phase cardiac CT. Left ventricular myocardium includes not only septal vein and artery but also capillaries, arterio- and venoluminal vessels, and sinusoids, etc. which connect to septal veins. To avoid misinterpretations of myocardial LIE on the delayed phase images, we need to understand those anatomical features.

Comprehensive assessment of takotsubo cardiomyopathy by cardiac computed tomography.

Cardiac computed tomography (CT) now plays an important role in emergency settings because of its accessibility and fast acquisition time, which cardiac magnetic resonance imaging (CMR) cannot match. Although cardiac CT was originally conceived for the assessment of the coronary artery tree, it has evolved to embrace several non-coronary applications. These include myocardial assessment, resulting in myocardial characterization comparable with that of CMR and cardiac CT for late enhancement imaging. In this report, we describe a patient with takotsubo cardiomyopathy who underwent a comprehensive assessment using cardiac CT. This technique enabled to identify the condition of the coronary arteries and to evaluate the four-dimensional left ventricular function and myocardial late iodine enhancement immediately. The information obtained was similar to that provided by CMR; however, cardiac CT is more practical than CMR in emergency settings. Comprehensive assessment by cardiac CT can be beneficial for a noninvasive evaluation of patients with suspected takotsubo cardiomyopathy.

Novel assessment of retrospective on-demand analysis of venous thromboembolism by dual-layer spectral-detector CT.

Because the prognosis of pulmonary thromboembolism (PTE) will be often poor, early diagnosis and assessing severity at the first visit is important. A 76-year-old man with suspected venous thromboembolism and a contrast deficit in the pulmonary artery (PA) was revealed by contrast-enhanced computed tomography (CT) imaging by dual-layer spectral-detector CT (IQon Spectral CT®, Philips Healthcare, Best, The Netherlands). The lung perfusion image showed decreased perfusion in the culprit lesion. The dual-energy analysis of the virtual monoenergetic imaging showed clear visualization of deep vein thrombosis (DVT). In a 64-year-old man, an IQon Spectral CT® revealed a small contrast deficit in the PA. However, no perfusion abnormality was detected in the lung perfusion analysis. The IQon Spectral CT® enables the detection of lung perfusion abnormalities in addition to PTE. The IQon Spectral CT® imaging may be useful for the "one-stop shop" evaluation of PTE and DVT. .

Serial intravascular ultrasound assessment of very late stent thrombosis after sirolimus-eluting stent placement.

PURPOSE: In-stent restenosis has been decreasing through the introduction of drug-eluting stents (DES). On the other hand, adverse events such as very late stent thrombosis (VLST) and late catch-up phenomenon can occur especially with sirolimus-eluting stents (SES, first-generation DES) in long-term follow-up. However, the precise mechanisms underlying VLST have not been well investigated in vivo. METHODS AND RESULTS: From 2004 to 2010, 2034 SES were implanted in 1656 patients and caused eight VLST (0.48% per patient) at Fukuoka Tokushukai Medical Center. Of these, serial intravascular ultrasound (IVUS) images (post-stent implantation and at the time of VLST onset) were obtained from three patients with VLST. Comparing them with eight control patients with SES implanted, the vascular reactivity of VLST patients was analyzed. Eight VLST happened 50 ± 15 months after stent implantation and three of the eight patients with VLST had not taken aspirin daily. There were no differences in minimum stent area, maximum external elastic membrane (EEM) area, and stent edge (distal and proximal) EEM area in post-procedural IVUS images. Compared with the control group patients, ΔEEM area (10.6 ± 3.4mm(2) vs. 1.7 ± 1.9 mm(2), p=0.01) and vessel expansion ratio (185.6 ± 40.3% vs. 112.0 ± 12.1%, p=0.01) were significantly greater in the VLST group based on the greater peri-stent plaque expansion (262.1 ± 72.8% vs. 118.7 ± 21.2%, p=0.01). CONCLUSION: Our serial IVUS study showed that the vascular positive remodeling after SES implantation is one of the most probable morphological mechanisms for VLST development.

Digital assessment of endothelial function and ischemic heart disease in women.

OBJECTIVES: We investigated the utility of digital reactive hyperemia peripheral arterial tonometry (RH-PAT) in predicting ischemic heart disease (IHD), including obstructive coronary artery disease (CAD) and nonobstructive coronary artery disease (NOCAD), in women. BACKGROUND: IHD is the leading cause of mortality, and its pathogenesis is diverse in women. Fingertip RH-PAT is a new device that provides noninvasive, automatic, and quantitative evaluation of endothelial dysfunction. METHODS: RH-PAT was measured using Endo-PAT2000 (Itamar Medical, Caesarea, Israel) before cardiac catheterization in 140 stable women scheduled for hospitalization to examine chest pain. NOCAD was diagnosed by angiography with measurement of coronary blood flow and cardiac lactate production during intracoronary acetylcholine provocation test and cardiac scintigraphy with stress tests. RESULTS: Sixty-eight women (49%) had obstructive CAD and 42 women (30%) had NOCAD. RH-PAT indexes were significantly attenuated in both obstructive CAD and NOCAD as compared with non-IHD (n = 30) (obstructive CAD: median 1.57, interquartile range [IQR] 1.42 to 1.76; NOCAD: median 1.58, IQR 1.41 to 1.78; non-IHD: median 2.15, IQR 1.85 to 2.48, p < 0.001). By multivariate logistic regression analysis, only RH-PAT index was significantly associated with IHD, including obstructive CAD and NOCAD (odds ratio 0.51; 95% confidence interval: 0.38 to 0.68; p < 0.001). In receiver-operating characteristic analysis, RH-PAT index was a significant predictor of IHD (area under the curve 0.86; p < 0.001). Furthermore, only RH-PAT was useful for the prediction of NOCAD after excluding obstructive CAD (area under the curve 0.85; p < 0.001; RH-PAT index of <1.82 had 81% sensitivity and 80% specificity). CONCLUSIONS: RH-PAT indexes were significantly attenuated in women with IHD. Digital RH-PAT can predict patients with IHD, especially NOCAD before angiography. RH-PAT is potentially useful for identifying high-risk women for IHD. (Endothelial Dysfunction and Coronary Artery Spasm; NCT00619294).

Targeted deletion of class A macrophage scavenger receptor increases the risk of cardiac rupture after experimental myocardial infarction.

BACKGROUND: Class A macrophage scavenger receptor (SR-A) is a macrophage-restricted multifunctional molecule that optimizes the inflammatory response by modulation of the activity of inflammatory cytokines. This study was conducted with SR-A-deficient (SR-A(-/-)) mice to evaluate the relationship between SR-A and cardiac remodeling after myocardial infarction. METHODS AND RESULTS: Experimental myocardial infarction (MI) was produced by ligation of the left coronary artery in SR-A(-/-) and wild-type (WT) male mice. The number of mice that died within 4 weeks after MI was significantly greater in SR-A(-/-) mice than in WT mice (P=0.03). Importantly, death caused by cardiac rupture within 1 week after MI was 31% (17 of 54 mice) in SR-A(-/-) mice and 12% (6 of 51 mice) in WT mice (P=0.01). In situ zymography demonstrated augmented gelatinolytic activity in the infarcted myocardium in SR-A(-/-) mice compared with WT mice. Real-time reverse transcription-polymerase chain reaction at day 3 after MI showed that the expression of matrix metalloproteinase-9 mRNA increased significantly in the infarcted myocardium in SR-A(-/-) mice compared with WT mice. Furthermore, SR-A(-/-) mice showed augmented expression of tumor necrosis factor-alpha and reduction of interleukin-10 in the infarcted myocardium at day 3 after MI. In vitro experiments also demonstrated increased tumor necrosis factor-alpha and decreased interleukin-10 expression in activated SR-A(-/-) macrophages. CONCLUSIONS: The present findings suggest that SR-A deficiency might cause impairment of infarct remodeling that results in cardiac rupture via insufficient production of interleukin-10 and enhanced expression of tumor necrosis factor-alpha and of matrix metalloproteinase-9. SR-A might contribute to the prevention of cardiac rupture after MI.