Bioresorbable Scaffold for Treatment of Coronary Artery Lesions: Intravascular Ultrasound Results From the ABSORB Japan Trial

OBJECTIVES

The aim of this study was to characterize post-procedural intravascular ultrasound (IVUS) findings in the ABSORB Japan trial, specifically stratified by the size of target coronary arteries.

BACKGROUND

Despite overall noninferiority confirmed in recent randomized trials comparing bioresorbable vascular scaffolds (BVS) (Absorb BVS) and cobalt-chromium everolimus-eluting metallic stents (CoCr-EES), higher event rates of Absorb BVS have been reported with suboptimal deployment, especially in small coronary arteries.

METHODS

In the ABSORB Japan trial, 150 patients (2:1 randomization) were scheduled in the IVUS cohort. Small vessel was defined as mean reference lumen diameter <2.75 mm. Tapered-vessel lesions were defined as tapering index (proximal/distal reference lumen diameter) ≥1.2.

RESULTS

Overall, IVUS revealed that the Absorb BVS arm had smaller device expansion than the CoCr-EES arm did, which was particularly prominent in small- and tapered-vessel lesions. Higher tapering index was also associated with higher rates of incomplete strut apposition in Absorb BVS, but not in CoCr-EES. With respect to procedural techniques, small-vessel lesions were treated more frequently with noncompliant balloons at post-dilatation but using significantly lower pressure in the Absorb BVS arm. In contrast, tapered-vessel lesions were post-dilated at equivalent pressure but with significantly smaller balloon catheters in the Absorb BVS arm, compared with the CoCr-EES arm.

CONCLUSIONS

The significantly smaller device expansion especially in small vessels may account for the poorer outcomes of Absorb BVS in this lesion type. Appropriate optimization strategy, possibly different between polymeric and metallic devices, needs to be established for bioresorbable scaffold technology. (AVJ-301 Clinical Trial: A Clinical Evaluation of AVJ-301 Absorb™ BVS) in Japanese Population [ABSORB JAPAN]; NCT01844284).

Impact of Total Antithrombotic Effect on Bleeding Complications in Patients Receiving Multiple Antithrombotic Agents

BACKGROUND

Few reports have evaluated the total antithrombotic effect of multiple antithrombotic agents. Methods and Results: Thrombus formation was evaluated with the Total Thrombus-formation Analysis System (T-TAS^®) using 2 types of microchips in 145 patients with stable coronary artery disease receiving oral anticoagulants plus single- or dual-antiplatelet therapy. The PL-chip coated with collagen is designed for analysis of the platelet thrombus formation process under shear stress condition (18 µL/min). The AR-chip coated with collagen and tissue thromboplastin is designed for analysis of the fibrin-rich platelet thrombus formation process under shear stress condition (4 µL/min). The results were expressed as an area under the flow pressure curve (PL₁₈-AUC₁₀and AR₄-AUC₃₀, respectively). Bleeding events occurred in 43 patients during a 22-month follow-up. AR₄-AUC₃₀was significantly lower in patients with bleeding events than in those without (584 [96-993] vs. 1,028 [756-1,252], P=0.0003). Multivariate logistic regression analysis identified AR₄-AUC₃₀(odds ratio 3.18) as a significant predictor of bleeding events, in addition to baseline anemia and usage of the standard dose of direct oral anticoagulants. However, PL₁₈-AUC₁₀was not significantly related to bleeding events.

CONCLUSIONS

A lower AR₄-AUC₃₀level was associated with increasing risk of subsequent bleeding complications in patients with stable coronary artery disease who received multiple antithrombotic agents.

First Measurement of a Long-Lived π^{+}π^{-} Atom Lifetime

The adapted DIRAC experiment at the CERN PS accelerator observed for the first time long-lived hydrogenlike π^{+}π^{-} atoms, produced by protons hitting a beryllium target. A part of these atoms crossed the gap of 96 mm between the target and a 2.1  μm thick platinum foil, in which most of them dissociated. Analyzing the observed number of atomic pairs, n_{A}^{L}=436_{-61}^{+157}|_{tot}, the lifetime of the 2p state is found to be τ_{2p}=(0.45_{-0.30}^{+1.08}|_{tot})×10^{-11}  s, not contradicting the corresponding QED 2p state lifetime τ_{2p}^{QED}=1.17×10^{-11}  s. This lifetime value is three orders of magnitude larger than our previously measured value of the π^{+}π^{-} atom ground state lifetime τ=(3.15_{-0.26}^{+0.28}|_{tot})×10^{-15}  s. Further studies of long-lived π^{+}π^{-} atoms will allow us to measure energy differences between p and s atomic states and so to discriminate between the isoscalar and isotensor ππ scattering lengths with the aim to check QCD predictions.

Cardiac function response to stenting in atherosclerotic renal artery disease with and without heart failure: results from the Carmel study

Aims

Consensus‐derived guidelines recommend renal stenting for patients with atherosclerotic renal artery disease (ARAD) and heart failure (HF). The aim of this prospective multi‐centre observational study was to verify our hypothesis that changes in E/e′, an echocardiographic correlate of left ventricular (LV) filling pressure, following renal stenting may differ between ARAD patients with and without HF.

Methods and results

This study enrolled de novo ARAD patients undergoing renal stenting at 14 institutions. The primary endpoint was the difference in E/e′ change between ARAD patients with and without HF. Clinical and echocardiographic data were prospectively collected at baseline, the day following renal stenting, and 1 month and 6 months afterwards. ARAD patients with HF were defined as patients with New York Heart Association (NYHA) Class 2 and more, or a history of HF hospitalization. A total of 76 patients were included, and 39% were ARAD patients with HF. ARAD patients with HF had significantly lower estimated glomerular filtration rate (P = 0.028) and higher NYHA functional class (P < 0.001) and Minnesota Living with Heart Failure Questionnaire (MLHFQ) score (P = 0.001) than ARAD patients without HF. Also, ARAD patients with HF had significantly lower LV ejection fraction (P = 0.003) and e′‐velocity (P = 0.003) and higher E/e′ ratio (P = 0.001), left atrial volume index (LAVI) (P = 0.046), LV end‐diastolic volume (LVEDV) (P = 0.001), LV end‐systolic volume (LVESV) (P = 0.001), and LV mass index (P = 0.009) than ARAD patients without HF. All procedures were successful. In contrast to blood pressure and renal function, there was a significant interaction in E/e′ (P_interaction < 0.001) between time and HF, and ARAD patients with HF showed a significant (P < 0.001) decrease in E/e′ albeit those without HF. By the same token, there was a significant interaction in NYHA class (P_interaction < 0.001), MLHFQ score (P_interaction = 0.018), E‐velocity (P_interaction = 0.002), LAVI (P_interaction = 0.001), LVEDV (P_interaction = 0.003), and LVESV (P_interaction = 0.001) between time and HF with a significant improvement in all these variables in ARAD patients with HF (NYHA class, P = 0.001; MLHFQ score, P = 0.002; E‐velocity, P = 0.005; LAVI, P = 0.001; LVEDV, P = 0.017; and LVESV, P = 0.011).

Conclusions

Change in LV filling pressure after renal stenting differed between ARAD patients with and without HF, with a significant improvement in LV filling pressure in patients with HF‐ARAD. These unique findings might support clinical cardiac benefits of renal stenting in ARAD patients with HF.

Association of Endothelin-1 With Accelerated Cardiac Allograft Vasculopathy and Late Mortality Following Heart Transplantation

BACKGROUND

Endothelin-1 (ET-1) has been implicated in the development of post-heart transplantation (HT) cardiac allograft vasculopathy (CAV), but has not been well studied in humans.

METHODS AND RESULTS

In 90 HT patients, plasma ET-1 was measured within 8 weeks after HT (baseline) via a competitive enzyme-linked immunosorbent assay. Three-dimensional volumetric intravascular ultrasound of the left anterior descending artery was performed at baseline and at 1 year. Accelerated CAV (lumen volume loss) was defined with the 75th percentile as a cutoff. Patients were followed beyond the first year after HT for late death or retransplantation. A receiver operating characteristic (ROC) curve demonstrated that a baseline ET-1 concentration of 1.75 pg/mL provided the best accuracy for diagnosis of accelerated CAV at 1 year (area under the ROC curve 0.69, 95% confidence interval [CI] 0.57-0.82; P = .007). In multivariate logistic regression, a higher baseline ET-1 concentration was independently associated with accelerated CAV (odds ratio [OR] 2.13, 95% CI 1.15-3.94; P = .01); this relationship persisted when ET-1 was dichotomized at 1.75 pg/mL (OR 4.88, 95% CI 1.69-14.10; P = .003). Eighteen deaths occurred during a median follow-up period of 3.99 (interquartile range 2.51-9.95) years. Treated as a continuous variable, baseline ET-1 was not associated with late mortality in multivariate Cox regression (hazard ratio [HR] 1.22, 95% CI 0.72-2.05; P = .44). However, ET-1 >1.75 pg/mL conferred a significantly lower cumulative event-free survival on Kaplan-Meier analysis (P = .047) and was independently associated with late mortality (HR 2.94, 95% CI 1.12-7.72; P = .02).

CONCLUSIONS

Elevated ET-1 early after HT is an independent predictor of accelerated CAV and late mortality, suggesting that ET-1 has durable prognostic value in the HT arena.

Comparison between instantaneous wave-free ratio versus morphometric assessments by intracoronary imaging

Anatomical measurements obtained by intracoronary imaging devices are reported to correlate significantly with fractional flow reserve (FFR). Instantaneous wave-free ratio (iFR) is a nonhyperemic index of stenosis severity with discordant reports regarding its accuracy in relation to FFR. There is no information on the correlation of iFR with measurements derived from intracoronary imaging devices. The purpose of this study was to assess the relationship among iFR, intravascular ultrasound (IVUS), and optical frequency domain imaging (OFDI) parameters. Eighty lesions in 72 patients who underwent elective angiography and had intermediate lesions were enrolled. All lesions were assessed by iFR, FFR, IVUS, and OFDI. iFR was ≤ 0.89 in 21 (26%) lesions and FFR was ≤ 0.80 in 41 (51%) lesions. iFR correlated significantly with both IVUS-derived minimum lumen area (MLA) (r = 0.375, p = 0.003) and OFDI-derived MLA (r = 0.357, p = 0.005). FFR also correlated significantly with both IVUS-derived MLA (r = 0.472, p < 0.001) and OFDI-derived MLA (r = 0.445, p < 0.001). Among the lesions with FFR ≤ 0.80, iFR > 0.89 (mismatch) was observed in 20 lesions. There was no lesion with iFR ≤ 0.89 (reverse mismatch) among the lesions with FFR > 0.80. The lesion location among three major coronary vessels was related with the discrepancy between iFR and FFR (p = 0.007). In conclusion, iFR and FFR showed a significant correlation with IVUS and OFDI measurements. The discrepancy of iFR and FFR was associated with the lesion locations.

PCR-based clonality analysis of antigen receptor gene rearrangements in canine cutaneous plasmacytoma

Plasmacytomas are discrete, B cell-derived, round cell tumours that sometimes are difficult to distinguish from canine cutaneous histiocytomas or T cell lymphosarcomas (lymphomas). Diagnosis of plasmacytomas relies on morphological observations and immunohistochemistry for multiple myeloma oncogene-1 (MUM-1) and cluster of differentiation 3 (CD3). Clonality testing often is used as an adjunct diagnostic tool to examine lymphoproliferative diseases. In this study, the sensitivity of PCR-based clonality analysis of antigen receptor gene rearrangements in canine cutaneous plasmacytomas was determined. Formalin-fixed paraffin-embedded sections of 29 canine plasmacytomas, 23 diffuse large B cell lymphomas (DLBCLs) and 23 lymph nodes without lymphoma were used for clonality analysis. New oligonucleotide primers for the framework (FR)2 and FR3 regions of the immunoglobulin heavy chain (IGH) V gene subgroup 3 were designed and used with previously reported FR3 primers. Although plasma cells are of B cell lineage, the detected frequency of IGH clonality in plasmacytoma was 0-34.5% with the seven primers used, whereas in DLBCLs it was 8.7-78.3%. In 23 lymph nodes without lymphoma, IGH clonality was detected in only one case with two out of the seven primers used. Sequence analysis of PCR products from plasmacytomas revealed mismatches in the annealing region of the FR3 primers. The sensitivity of detecting IGH clonality in canine plasmacytomas was lower than in DLBCLs. The low detection rate of IGH clonality in canine plasmacytoma may be due to somatic hypermutation of the variable region.

Myocardial Infarction Caused by Accelerated Plaque Formation Related to Myocardial Bridge in a Young Man

A 28-year-old man without coronary risk factors was admitted to the hospital with acute coronary syndromes (ACS). The angiogram and intravascular ultrasound revealed myocardial bridge (MB) in the mid-left anterior descending artery and flow-limiting plaque located 15.4 mm proximal to MB. The culprit lesion was treated only with drug-coated balloon, considering the patient's extremely young age. This case suggests that an accelerated formation of plaque caused by MB appeared to contribute to the development of ACS; thus, MB should be considered as an important cause of ACS in young patients with low cardiovascular risk.

Glycemic variability determined with a continuous glucose monitoring system can predict prognosis after acute coronary syndrome

Background

Impaired glucose metabolism is an established risk factor for coronary artery disease. Previous studies revealed that glycemic variability (GV) is also important for glucose metabolism in patients with acute coronary syndrome (ACS). We explored the association between GV and prognosis in patients with ACS.

Methods

A total of 417 patients with ACS who received reperfusion wore a continuous glucose monitoring system (CGMS) in a stable phase after admission and were monitored for at least 24 consecutive h. The mean amplitude of glycemic excursion (MAGE) was calculated as a marker of GV. We divided into two groups based on the highest tertile levels of MAGE (MAGE = 52 mg/dl). The groups were followed up for a median of 39 months [IQR 24–50 months]. The primary endpoint was the incidence of major adverse cardiovascular and cerebrovascular events (MACCE).

Result

During follow-up, 66 patients experienced MACCE (5 patients had cardiovascular death, 14 had recurrence of ACS, 27 had angina requiring revascularization, 8 had acute decompensated heart failure, and 16 had a stroke). MACCE was more frequently observed in the high MAGE group (23.5% vs. 11.6%, p = 0.002). In multivariate analysis, high MAGE was an independent predictive factor of poor prognosis for MACCE (odds ratio, 1.84; 95% confidence interval, 1.01–3.36; p = 0.045).

Conclusion

Glycemic variability determined with a CGMS is a predictor of prognosis in patients with ACS without severe DM.

Trial registration UMIN 000010620. Registered April 1st 2012

Comparative Fibrinolytic Properties of Staphylokinase and Streptokinase in Animal Models of Venous Thrombosis

The thrombolytic and pharmacokinetic properties of staphylokinase were compared with those of streptokinase in hamsters with a pulmonary embolus produced from human plasma or from hamster plasma, and in rabbits with a jugular vein blood clot produced from rabbit blood. In both models, a continuous intravenous infusion of staphylokinase and streptokinase over 60 min in hamsters or over 4 h in rabbits, induced dose-dependent progressive clot lysis in the absence of significant systemic activation of the fibrinolytic system. The results of thrombolytic potency (clot lysis at 30 min after the end of the infusion, in percent, versus dose administered, in mg/kg) were fitted with an exponentially transformed sigmoidal function and the maximal percent clot lysis (c), the maximal rate of lysis (z = ¼ac · e b ) and the dose at which the maximal rate of lysis is achieved (b) were determined. In hamsters with a pulmonary embolus produced from human plasma, streptokinase had a somewhat higher thrombolytic potency than staphylokinase, as revealed by a higher z value (2,100 ± 1,100% lysis per mg/kg streptokinase administered versus 1,100 ± 330% lysis per mg/kg for staphylokinase). In hamsters with a pulmonary embolus produced from hamster plasma, staphylokinase had a somewhat higher thrombolytic potency than streptokinase (z = 1,600 ± 440 versus 1,200 ± 370% lysis per mg/kg). Staphylokinase had a higher thrombolytic potency than streptokinase in rabbits, as revealed by a higher z-value (950 ± 350% lysis per mg/kg staphylokinase administered versus 330 ± 39% lysis per mg/kg for streptokinase) and a lower b-value (0.035 ± 0.010 mg/kg staphylokinase versus 0.091 ± 0.008 mg/kg for streptokinase). The plasma clearance following bolus injection of staphylokinase or streptokinase in hamsters or rabbits was comparably rapid (1.1 to 1.4 ml/min in hamsters and 14 to 15 ml/min in rabbits) as a result of a short initial half-life (1.8 to 1.9 min in hamsters and 1.7 to 2.0 min in rabbits). These results in two quantitative rodent models of thrombolysis suggest that staphylokinase is a potent thrombolytic agent with an in vivo thrombolytic potency that is comparable to that of streptokinase. Further investigation of the thrombolytic potential of staphylokinase seems to be warranted.