Invasive assessment of myocardial bridging in patients with angina and no obstructive coronary artery disease

AIMS

Angina and no obstructive coronary artery disease (ANOCA) is common. A potential cause of angina in this patient population is a myocardial bridge (MB). We aimed to study the anatomical and haemodynamic characteristics of an MB in patients with ANOCA.

METHODS AND RESULTS

Using intravascular ultrasound (IVUS), we identified 184 MBs in 154 patients. We evaluated MB length, arterial compression, and halo thickness. MB muscle index (MMI) was defined as MB length×halo thickness. Haemodynamic testing of the MB was performed using an intracoronary pressure/Doppler flow wire at rest and during dobutamine stress. We defined an abnormal diastolic fractional flow reserve (dFFR) as ≤0.76 during stress. The median MB length was 22.9 mm, arterial compression 30.9%, and halo thickness 0.5 mm. The median MMI was 12.1. Endothelial and microvascular dysfunction were present in 85.4% and 22.1%, respectively. At peak dobutamine stress, 94.2% of patients had a dFFR ≤0.76 within and/or distal to the MB. MMI was associated with an abnormal dFFR.

CONCLUSIONS

In select patients with ANOCA who have an MB by IVUS, the majority have evidence of a haemodynamically significant dFFR during dobutamine stress, suggesting the MB as being a cause of their angina. A comprehensive invasive assessment of such patients during coronary angiography provides important diagnostic information that can guide management.

Filamentous fungi with high paraquat-degrading activity isolated from contaminated agricultural soils in northern Thailand

The contamination of paraquat (1,1'-dimethyl-4,4'-bipyridylium dichloride) herbicide from the farming area has become a public concern in many countries. This herbicide harms to human health and negatively effects the soil fertility. Several methods have been introduced for the remediation of paraquat. In this study, 20 isolates of the paraquat-tolerant fungi were isolated from the contaminated soil samples in northern Thailand. We found that isolate PRPY-2 and PFCM-1 exhibited the highest degradation activity of paraquat on synthetic liquid medium. About 80 and 68% of paraquat were removed by PRPY-2 and PFCM-1 respectively after 15 days of cultivation. Based on the morphological characteristic and molecular analysis, the fungal isolate PRPY-2 and PFCM-1 were identified as Aspergillus tamarii and Cunninghamella sp. respectively. The biosorption of paraquat on these fungal mycelia was also investigated. It was found that only 8-10% of paraquat could be detected on their mycelia, while 24-46% of paraquat was degraded by fungal mycelia. This is the first report on paraquat degrading ability by A. tamarii and Cunninghamella sp. It is demonstrated that these filamentous fungi are promising microorganisms available for remediation of paraquat contaminated environment.

Bioresorbable vascular scaffolds versus everolimus-eluting stents: a biomechanical analysis of the ABSORB III Imaging substudy

AIMS

The Absorb bioresorbable vascular scaffold (BVS) has high rates of target lesion failure (TLF) at three years. Low wall shear stress (WSS) promotes several mechanisms related to device TLF. We investigated the impact of BVS compared to XIENCE V (XV) on coronary WSS after device deployment.

METHODS AND RESULTS

In the prospective, randomised, controlled ABSORB III Imaging study (BVS [n=77] or XV [n=36]), computational fluid dynamics were performed on fused angiographic and intravascular ultrasound (IVUS) images of post-implanted vessels. Low WSS was defined as <1 Pa. There were no differences in demographics, clinical risks, angiographic reference vessel diameter or IVUS minimal lumen diameter between BVS and XV patients. A greater proportion of vessels treated with BVS compared to XV demonstrated low WSS across the whole device (BVS: 17/77 [22%] vs XV: 2/36 [6%], p<0.029). Compared to XV, BVS demonstrated lower median circumferential WSS (1.73 vs 2.21 Pa; p=0.036), outer curvature WSS (p=0.026), and inner curvature WSS (p=0.038). Similarly, BVS had lower proximal third WSS (p=0.024), middle third WSS (p=0.047) and distal third WSS (p=0.028) when compared to XV. In a univariable logistic regression analysis, patients who received BVS were 4.8 times more likely to demonstrate low WSS across the scaffold/stent when compared to XV patients. Importantly, in a multivariable linear regression model, hypertension (beta: 0.186, p=0.023), lower contrast frame count velocity (beta: -0.411, p<0.001), lower post-stent residual plaque burden (beta: -0.338, p<0.001), lower % underexpanded frames (beta: -0.170, p=0.033) and BVS deployment (beta: 0.251, p=0.002) remained independently associated with a greater percentage of stented coronary vessel areas exposed to low WSS.

CONCLUSIONS

In this randomised controlled study, the Absorb BVS was 4.8 times more likely than the XV metallic stent to demonstrate low WSS. BVS implantation, lower blood velocity and lower residual post-stent plaque burden were independently associated with greater area of low WSS.

Off-Pump Minithoracotomy Versus Sternotomy for Left Anterior Descending Myocardial Bridge Unroofing

BACKGROUND

Myocardial bridge (MB) of the left anterior descending (LAD) coronary artery occurs in approximately 25% of the population. When medical therapy fails in patients with a symptomatic, hemodynamically significant MB, MB unroofing represents the optimal surgical management. Here, we evaluated minimally invasive MB unroofing in selected patients compared with sternotomy.

METHODS

MB unroofing was performed in 141 adult patients by sternotomy on-pump (ST-on, n = 40), sternotomy off-pump (ST-off, n = 62), or minithoracotomy off-pump (MT, n = 39). Angina symptoms were assessed preoperatively and 6 months postoperatively using the Seattle Angina Questionnaire. Matching included all MT patients and 31 ST-off patients with similar MB characteristics, no previous cardiac operations or coronary interventions, and no concomitant procedures.

RESULTS

MT patients tended to have a shorter MB length than ST-on and ST-off patients (2.57 vs 2.93 vs 3.09 cm, P = .166). ST-on patients had a longer hospital stay than ST-off and MT patients (5.0 vs 4.0 vs 3.0 days, P < .001), and more blood transfusions (15.2% vs 0.0% vs 2.6%, P = .002). After matching, MT patients had a shorter hospital stay than ST-off patients (3.0 vs 4.0 days, P = .005). No deaths or major complications occurred in any group. In all groups, MB unroofing yielded significant symptomatic improvement regarding physical limitation, angina stability, angina frequency, treatment satisfaction, and quality of life.

CONCLUSIONS

We report our single-center experience of off-pump minimally invasive MB unroofing, which may be safely performed in carefully selected patients, yielding dramatic improvements in angina symptoms at 6 months after the operation.

Current status of hybrid intravascular ultrasound and optical coherence tomography catheter for coronary imaging and percutaneous coronary intervention

Both intravascular ultrasound (IVUS) and optical coherence tomography (OCT) play a crucial role in elucidating the pathophysiology of coronary artery disease (CAD) with the goal to improve patient outcomes of medical and/or interventional CAD management. However, no single intravascular imaging technique has been proven to provide complete and detailed evaluation of all CAD lesions due to some limitations. Although sequential use of multiple modalities may sometimes be performed, there may be issues related to risk, time, and cost. To overcome these problems, several hybrids involving dual-probe combined IVUS-OCT catheters have been developed. The aim of this review article is to demonstrate some limitations of stand-alone imaging devices for evaluation of CAD, summarize the advances in hybrid IVUS-OCT imaging devices, discuss the technical challenges, and present the potential value in the clinical setting, especially in patients receiving medical or interventional CAD management.

Occurrence and clinical course of peri-stent contrast staining: comparison between second-generation drug-eluting stents and third generation drug-eluting stents

Background

Peri-stent contrast staining (PSS) has been reported to be associated with very late stent thrombosis.

The aims of this study was to compare the occurrence rate of PSS between second generation drug-eluting stents (2nd DES) and third generation drug-eluting stents (3rd DES), and to identify clinical characteristics associated with PSS.

Methods and results

This study comprised 1899 patients with 2493 de novo lesions treated with 2nd or 3rd DES from October 2015 to September 2018. Follow-up angiography was available for 1883 lesions (75.5%). There were 725 patients with 968 lesions treated with 2nd DES, and 716 patients with 915 lesions treated with 3rd DES. The occurrence of PSS, types of PSS, and VLST related to PSS were compared between 2nd and 3rd DES implantation. Mean follow-up period was 30±12 months. The occurrence rate of PSS and segmental type of PSS were similar between two groups (2nd DES vs. 3rd DES, 1.5% vs. 1.7%, p=0.73, 47% vs. 50%, p=0.85, and respectively). The VLST related to PSS occurred in only one case in 3rd DES group. (0% vs. 6.3%, p=0.33).

Conclusion

The occurrence rate of PSS and clinical course were similar between 2nd and 3rd DES.

Funding Acknowledgement

Type of funding source: None

Scaffold underexpansion and late lumen loss after bioresorbable scaffold implantation: Insights from ABSORB JAPAN trial

Background

Device underexpansion is associated with late adverse outcomes after bioresorbable vascular scaffold (BVS) implantation. This study, representing official IVUS results of the ABSORB Japan trial, aimed to characterize IVUS findings, focusing specifically on acute device expansion, and to investigate its impact on late lumen loss (LLL) with Absorb-BVS compared with cobalt-chromium everolimus-eluting stents (CoCr-EES).

Methods

ABSORB Japan enrolled 148 patients (2:1 randomization) in the IVUS cohort. Serial IVUS was prescheduled at post-procedure and 3 years. Acute device expansion was evaluated with respect to the degree and uniformity of the implanted device.

Results

Overall, Absorb-BVS showed smaller and more nonuniform device expansion at post-procedure, compared with CoCr-EES, which was particularly prominent in small-vessel lesions. In serial analysis, Absorb-BVS showed unique associations of smaller device expansion (r = 0.40, p = 0.001) and more nonuniformity (r = 0.29, p = 0.007) at post-procedure with greater LLL at 3 years, primarily attributable to greater negative remodeling (r = 0.39, p = 0.006). In contrast, acute device expansion showed no relation with subsequent lumen change in CoCr-EES. In Absorb-BVS, ischemic-driven target lesion or vessel revascularization (ID-TLR or ID-TVR) at 3 years occurred more frequently in small- versus large-vessel lesions (12.5% vs. 0%, p = 0.04 for ID-TLR and 15.6% vs. 2.3%, p = 0.08 for ID-TVR). Conversely, Absorb BVS had no target lesion nor vessel failure, even in small-vessel lesions, when adequate device expansion was achieved at post-procedure.

Conclusions

Unlike CoCr-EES, underexpansion was associated with greater negative remodeling and LLL in Absorb-BVS. This may in part account for the poorer outcomes of Absorb-BVS than CoCr-EES when under-expanded.

Association between abdominal fat distribution and coronary plaque instability in patients with acute coronary syndrome

BACKGROUND AND AIMS

This study aimed to assess possible association of detailed abdominal fat profiles with coronary plaque characteristics in patients with acute coronary syndrome (ACS).

METHODS AND RESULTS

In 60 patients with ACS, culprit arteries were evaluated at 1-mm intervals (length analyzed: 66 ± 28 mm) by grayscale and integrated backscatter intravascular ultrasound (IB-IVUS) before percutaneous coronary intervention. Standard IVUS indexes (as a volume index: volume/length), plaque components (as percent tissue volume) and fibrous cap thickness (FCT) were assessed by IB-IVUS. Plain abdominal computed tomography was performed to evaluate subcutaneous adipose tissue (SAT) area, visceral adipose tissue (VAT) area, and VAT/SAT ratio. While SAT area only correlated with vessel volume (r = 0.27, p = 0.04), VAT area correlated positively with vessel (r = 0.30, p = 0.02) and plaque (r = 0.33, p = 0.01) volumes and negatively with FCT (r = -0.26, p = 0.049), but not with percent plaque volume and plaque tissue components. In contrast, higher VAT/SAT ratio significantly correlated with higher percent lipid (r = 0.34, p = 0.008) and lower percent fibrous (r = -0.34, p = 0.007) volumes with a trend toward larger percent plaque volume (r = 0.19, p = 0.15), as well as thinner FCT (r = -0.53, p < 0.0001). In the multiple regression analysis, higher VAT/SAT ratio was independently associated with higher percent lipid with lower percent fibrous volumes (p = 0.03 for both) and thinner fibrous cap thickness (p = 0.0001).

CONCLUSION

Coronary plaque vulnerability, defined as increased lipid content with thinner fibrous cap thickness, appears to be more related to abnormal abdominal fat distribution, or so-called hidden obesity, compared with visceral or subcutaneous fat amount alone in patients with ACS.

Search for η^{'} Bound Nuclei in the ^{12}C(γ,p) Reaction with Simultaneous Detection of Decay Products

We measured missing mass spectrum of the ^{12}C(γ,p) reaction for the first time in coincidence with potential decay products from η^{'} bound nuclei. We tagged an (η+p) pair associated with the η^{'}N→ηN process in a nucleus. After applying kinematical selections to reduce backgrounds, no signal events were observed in the bound-state region. An upper limit of the signal cross section in the opening angle cosθ_{lab}^{ηp}<-0.9 was obtained to be 2.2  nb/sr at the 90% confidence level. It is compared with theoretical cross sections, whose normalization ambiguity is suppressed by measuring a quasifree η^{'} production rate. Our results indicate a small branching fraction of the η^{'}N→ηN process and/or a shallow η^{'}-nucleus potential.

Long-term clinical outcomes with use of an angiotensin-converting enzyme inhibitor early after heart transplantation

BACKGROUND

The safety and efficacy of angiotensin converting enzyme inhibition (ACEI) after heart transplantation (HT) is unknown. This study examined long-term clinical outcomes after ACEI in HT recipients.

METHODS

The ACEI after HT study was a prospective, randomized trial that tested the efficacy of ACEI with ramipril after HT. In this study, long-term clinical outcomes were assessed in 91 patients randomized to either ramipril or placebo (median, 5.8 years). The primary endpoint was a composite of death, retransplantation, hospitalization for rejection or heart failure, and coronary revascularization.

RESULTS

The primary endpoint occurred in 10 of 45 patients (22.2%) in the ramipril group and in 14 of 46 patients (30.4%) in the placebo group (Hazard ratio (HR), 0.68; 95% CI, 0.29-1.51; P = .34). When the analysis was restricted to comparing patients who remained on a renin-angiotensin system inhibitor beyond 1 year with those who did not, there was a trend to improved outcomes (HR, 0.54; 95% CI, 0.22-1.28, P = .16). There was no significant difference in creatinine, blood urea nitrogen, and potassium at 3 years after randomization. The cumulative incidence of the primary endpoint was significantly higher in patients in whom the index of microcirculatory resistance increased from baseline to 1 year compared with those in whom it did not (39.1 vs 17.4%, HR: 3.36; 95% CI, 1.07-12.7; P = .037).

CONCLUSION

The use of ramipril after HT safely lowers blood pressure and is associated with favorable long-term clinical outcomes. Clinical Trial Registration-URL: https://www.clinicaltrials.gov. Unique identifier: NCT01078363.

Nasogastric Tube Feeding Versus Total Parenteral Nutrition in Older Dysphagic Patients with Pneumonia: Retrospective Cohort Study

OBJECTIVES

Many older patients with pneumonia cannot intake orally after admission and may need nutritional care such as nasogastric tube feeding or total parenteral nutrition. This study sought to compare in-hospital outcomes between patients receiving nasogastric tube feeding and total parenteral nutrition.

DESIGN

This is a retrospective cohort study.

SETTING

A hospital-based database constructed by the Diagnosis Procedure Combination survey data comprising more than 100 acute-care hospitals.

PARTICIPANTS

The study included consecutive older inpatients aged >65 years admitted to participating hospitals with a diagnosis of pneumonia from 2014 through 2017.

MEASUREMENTS

We compared patients who received total parenteral nutrition and those who received nasogastric tube feeding in terms of characteristics and outcomes.

RESULTS

Among the included inpatients, a total of 336 (73.2%) patients received total parenteral nutrition and 123 (26.8%) patients received nasogastric tube feeding. Patients with nasogastric tube feeding had less in-hospital mortality (13.8% vs 27.1%, p = 0.003) and a smaller number of complications (mean; 0.71 vs 1.44, p <0.001), shorter length of hospital stay (mean; 27.6 vs 48.9, p <0.001), more discharges home (72.4% vs 35.1%, p <0.001), and more discharges without oral intake (65.9% vs 45.8%, p <0.001) than patients with total parenteral nutrition. The same results were obtained in propensity score analysis.

CONCLUSIONS

Older patients with pneumonia treated with total parenteral nutrition were significantly more likely to have higher in-hospital mortality than those receiving nasogastric tube feeding.

Functional analysis of a novel G87V TNFRSF1A mutation in patients with TNF receptor-associated periodic syndrome

Tumor necrosis factor (TNF) receptor-associated periodic syndrome (TRAPS) is an autoinflammatory disease that is caused by heterozygous mutations in the TNFRSF1A gene. Although more than 150 TNFRSF1A mutations have been reported to be associated with TRAPS phenotypes only a few, such as p.Thr79Met (T79M) and cysteine mutations, have been functionally analyzed. We identified two TRAPS patients in one family harboring a novel p.Gly87Val (G87V) mutation in addition to a p.Thr90Ile (T90I) mutation in TNFRSF1A. In this study, we examined the functional features of this novel G87V mutation. In-vitro analyses using mutant TNF receptor 1 (TNF-R1)-over-expressing cells demonstrated that this mutation alters the expression and function of TNF-R1 similar to that with the previously identified pathogenic T79M mutation. Specifically, cell surface expression of the mutant TNF-R1 in transfected cells was inhibited with both G87V and T79M mutations, whereas the T90I mutation did not affect this. Moreover, peripheral blood mononuclear cells (PBMCs) from TRAPS patients harboring the G87V and T90I mutations showed increased mitochondrial reactive oxygen species (ROS). Furthermore, the effect of various Toll-like receptor (TLR) ligands on inflammatory responses was explored, revealing that PBMCs from TRAPS patients are hyper-responsive to TLR-2 and TLR-4 ligands and that interleukin (IL)-8 and granulocyte-macrophage colony-stimulating factor (GM-CSF) are likely to be involved in the pathogenesis of TRAPS. These findings suggest that the newly identified G87V mutation is one of the causative mutations of TRAPS. Our findings based on unique TRAPS-associated mutations provide novel insight for clearer understanding of inflammatory responses, which would be basic findings of developing a new therapeutic and prophylactic approach to TRAPS.

Current clinical use of intravascular ultrasound imaging to guide percutaneous coronary interventions

During the past three decades, since the invention of intravascular ultrasound (IVUS), it has become increasingly important as daily clinical applications. However, it evolved with no Japanese standards for the measurement of images, the index of percutaneous coronary intervention (PCI) procedures, and the reporting of results. Accordingly, the purpose of this review article is to provide an optimal and consistent approach to IVUS usage during PCI for clinicians and investigators.