219 ISOLATED CORONARY OSTIAL STENOSIS DUE TO RECURRENT AORTIC WALL THROMBOSIS

Background

Coronary ostial lesions are a rare entity and isolated coronary ostial stenosis is even less frequent. Diffuse coronary artery atherosclerosis is the main cause for the non-isolated stenosis, based on old post-mortem series and histological analysis of tissue removed during atherectomies.

Case presentation

A 49-year-old woman suffering from mild non-familial hypercholesterolemia reported to her family physician repeated episodes of chest pain related to exercise. During a cardiological outpatient evaluation, 12 lead electrocardiogram (ECG) and echocardiography turned out normal. During a stress test she had recurrent chest pain coupled with ECG ischemic changes (diffuse ST segment elevation). She was immediately referred to the emergency department where the ECG was back to normal and the troponin dosage within normal range. Coronary angiography was performed: non-selective cannulation revealed some irregularities of the aortic wall profile at the level of the right coronary ostium, with inability to visualize the right coronary artery. The selective cannulation of the left main coronary artery (LMCA), left anterior descending (LAD) and left circumflex branches showed a critical ostial stenosis at the origin of the LMCA without any other relevant lumen restriction, in a left-dominant pattern of coronary circulation. A suspicion of LAD dissection was raised when a laminar flux was observed at its origin. At the end of the procedure, the patient suddenly collapsed. The recorded rhythm was initially bradycardia, evolving to episodes of ventricular tachycardia for which multiple shocks were applied. Despite the resuscitation efforts, the patient never recovered. Autopsy was performed at the local hospital. At gross analysis, a non-uniform pale-tan thickening at the level of the sino-tubular junction was evident with involvement of both the right and left coronary ostia. Histological examination allowed to ascribe the thickening to recurrent thrombosis, without any underlying inflammatory process at the level of the aortic wall and with only minimal atherosclerotic plaques. No coronary artery dissection nor significant stenosis was present in all the coronary tree. Regarding the ventricular myocardium, one focus of replacement-type fibrosis was identified at subendocardial level in the infero-septal wall coupled with a small spot of loose connective tissue rich in hemosiderin-laden macrophages in the same region, consistent with an area of subacute ischemic damage.

Conclusion

Several series reported a higher frequency of isolated coronary ostial stenosis in women versus men. In fact, female sex along with hypertriglyceridemia have been recognized as independent risk factors for ostial lesions. The case herein reported highlights the diagnostic relevance of the autopsy investigation together with clinicopathological correlation, particularly in cases where the definite diagnosis can't be achieved in vivo.

Towards life in hydrocarbons: aggregation behaviour of “reverse” surfactants in cyclohexane

Unconventional life forms based on membranes able to self-assemble in hydrocarbons instead of water might exist in the hydrocarbon-rich environment of Titan. We present evidence of the self-assembly of reverse surfactants to yield typical micelles in a hydrocarbon solvent.

Unravelling the (arte)fact of increased pacemaker rate with the Edwards SAPIEN 3 valve

AIMS

Early data on the Edwards SAPIEN 3 valve (S3-THV) have shown low rates of paravalvular leaks and vascular complications but relatively high 30-day permanent pacemaker implantation (PPMI) rates. No direct comparisons on clinical outcomes including PPMI rates are available for the S3-THV and the Edwards SAPIEN XT (XT-THV). We aimed to compare the 30-day PPMI rates in patients treated with the two prostheses and to assess the interplay among valve type, depth of implantation and PPMI rate.

METHODS AND RESULTS

Two hundred and nine patients treated by TAVI were considered. The S3-THV was associated with higher PPMI rates compared to the XT-THV, both overall and in subgroups matched for several predictors of PPMI. However, in the S3-THV group, 30-day PPMI was strictly associated with deep valve implantation, and PPMI risk of high-implanted S3-THVs was similar to that of the overall XT-THV matched group. No cases of significant paravalvular leak were observed in the S3-THV group.

CONCLUSIONS

The S3-THV was associated with a higher incidence of PPMI compared to the XT-THV. In the S3-THV group, pacemaker implantation was strictly associated with deep valve implantation. An implantation technique involving higher initial placement of the central marker (from 0 to 3 mm above the base of the aortic cusps) and, as a consequence, higher final valve depth might help in preventing post-TAVI PPMI with the S3-THV, without affecting the risk of paravalvular leak.

Outcomes in Patients With Transcatheter Aortic Valve Replacement and Left Main Stenting: The TAVR-LM Registry

BACKGROUND

A percutaneous approach with transcatheter aortic valve replacement (TAVR) and percutaneous coronary intervention (PCI) of the left main coronary artery (LM) is frequently used in high-risk patients with coexisting aortic stenosis and LM disease. Outcomes of TAVR plus LM PCI have not been previously reported.

OBJECTIVES

The primary objective of the TAVR-LM registry is to evaluate clinical outcomes in patients undergoing TAVR plus LM PCI.

METHODS

Clinical, echocardiographic, computed tomographic, and angiographic characteristics were retrospectively collected in 204 patients undergoing TAVR plus LM PCI. In total, 128 matched patient pairs were generated by performing 1:1 case-control matching between 167 patients with pre-existing LM stents undergoing TAVR and 1,188 control patients undergoing TAVR without LM revascularization.

RESULTS

One-year mortality (9.4% vs. 10.2%, p = 0.83) was similar between the TAVR plus LM PCI cohort and matched controls. One-year mortality after TAVR plus LM PCI was not different in patients with unprotected compared with protected LMs (7.8% vs. 8.1%, p = 0.88), those undergoing LM PCI within 3 months compared with those with LM PCI greater than 3 months before TAVR (7.4% vs. 8.6%, p = 0.61), and those with ostial versus nonostial LM stents (10.3% vs. 15.6%, p = 0.20). Unplanned LM PCI performed because of TAVR-related coronary complication, compared with planned LM PCI performed for pre-existing LM disease, resulted in increased 30-day (15.8% vs. 3.4%, p = 0.013) and 1-year (21.1% vs. 8.0%, p = 0.071) mortality.

CONCLUSIONS

Despite the anatomic proximity of the aortic annulus to the LM, TAVR plus LM PCI is safe and technically feasible, with short- and intermediate-term clinical outcomes comparable with those in patients undergoing TAVR alone. These results suggest that TAVR plus LM PCI is a reasonable option for patients who are at high risk for surgery.

Phosphonium-based tetrakis dibenzoylmethane Eu(iii) and Sm(iii) complexes: synthesis, crystal structure and photoluminescence properties in a weakly coordinating phosphonium ionic liquid

Luminescent anionic β-diketonate complexes of formula [P_8,8,8,1][Ln(dbm)₄], (Ln = Eu³⁺ and Sm³⁺, [P_8,8,8,1] = trioctylmethylphosphonium and dbm = 1,3-diphenylpropane-1,3-dione) were synthesized, characterized and their photoluminescence properties studied.

The SAPIEN 3 valve: lights and shadows

Transcatheter aortic valve implantation (TAVI) has become an accepted alternative treatment option for high-risk or inoperable patients with symptomatic severe aortic stenosis. The future challenge for TAVI devices is to ensure results in terms of safety and efficacy that may justify an eligibility extension for this procedure to patients at intermediate and low risk for surgery. The ideal aortic valve prosthesis should be durable, with optimal hemodynamic performance and able to reduce the current major complications of TAVI procedure, in particular vascular complications (not infrequent with the transfemoral access route), paravalvular leaks, stroke and atrioventricular block requiring a permanent pacemaker. The SAPIEN 3™ (S3) (Edwards Lifesciences, Irvine, CA, USA) is the last Edwards family's transcatheter heart valves and incorporates a number of new and enhanced features intended to reduce the risk of vascular injury and paravalvular regurgitation, and to facilitate rapid and accurate positioning and implantation. The first data on S3 (SAPIEN3 trial) were presented at the EuroPCR 2014 and confirmed the advantage of the S3 compared with the previous Edwards valves (SAPIEN and SAPIEN XT) in terms of prevention of vascular complications and of moderate-severe paravalvular leaks, but showed an increase in the need of a permanent pacemaker post-TAVR. The S3 is certainly a promising evolution of transcatheter valves which may effectively reduce the risk of vascular complications and paravalvular leak. However, the S3 seems to be related to an increased risk of atrioventricular block, even if this complication could be due to the need to implant the valve in a higher position compared to previous models.

Comparison of impact of mortality risk on the survival benefit of primary percutaneous coronary intervention versus facilitated percutaneous coronary intervention

Available data suggest that thrombolytic therapy facilitated percutaneous coronary intervention (FPCI) is not beneficial, and recent analyses have shown a correlation between mortality risk and outcomes of patients with ST elevation myocardial infarctions treated with FPCI. The aim of this study was to analyze the impact of the mortality risk on the survival benefit of primary percutaneous coronary intervention (PPCI) compared to FPCI. A total of 13 trials enrolling 5,789 patients were pooled for analyses. PPCI survival benefit was calculated as the 30-day mortality after FPCI minus the 30-day mortality after PPCI, and the mortality rate of FPCI was interpreted as a proxy for mortality risk. A weighted metaregression was used to test the relation between mortality risk and explanatory variables. A fixed-effect linear regression analysis modeling the log odds ratio (PPCI/FPCI) as a linear function of the log odds of FPCI mortality was used to estimate the mortality risk that nullified the 30-day survival benefit of PPCI over FPCI. Across all studies, the absolute survival benefit ranged from -5.6 (favoring FPCI) to +7.2 (favoring PPCI). According to the slope of the regression line (-0.7, x-axis intercept -2.1) for the patients with baseline mortality risk > 4.2%, it is unlikely to obtain a survival benefit by FPCI compared to PPCI. In conclusion, the higher the mortality risk of patients with ST elevation myocardial infarctions, the higher the likelihood of a survival advantage of PPCI over FPCI.

Identification of a glucan-associated enolase as a main cell wall protein of Candida albicans and an indirect target of lipopeptide antimycotics

Growth-subinhibitory nonlytic doses of cilofungin (lipopeptide antibiotic affecting (1,3)-beta-D-glucan synthesis) inhibited the incorporation of 46- to 48-kDa glucan-associated (46K) protein into the growing cell wall of Candida albicans. The purified 46K protein constituent strongly reacted with a monoclonal antibody against enolase, a major cytoplasmic enzyme of the fungus. In addition, two internal fragments of 12- and 15-amino acid residues from a tryptic digest of 46K protein showed 100% identity with amino acids in positions 34-45 and 66-80 of enolase. By immunoelectron microscopy with polyclonal and monoclonal anti-enolase antibodies, the 46K protein was clearly detected in the inner layers of the fungal cell wall. Thus, consistent with the proposed immunogenic and diagnostic roles of enolase in candidiasis, biochemical, immunochemical, and ultrastructural evidence strongly suggest that the cilofungin-susceptible 46K protein is a cell wall-associated form of this enzyme.

The activity of cilofungin on the incorporation of glucan associated proteins into hyphal cells of Candida albicans

The effect of the cilofungin, a beta 1-3 glucan synthase inhibitor, on the incorporation of the glucan associated proteins (GAP) into the mycelial wall of Candida albicans was investigated. For this study sub-inhibitory (< 2 micrograms/ml) doses of cilofungin were employed during the yeast to mycelial transition in a defined chemical medium, at 37 degrees C for 24 hours. Under these conditions, and particularly at the dose of 0.50 micrograms/ml cilofungin exerted a marked effect on GAP incorporation into the mycelial cell wall. The changes were essentially the absence of the two prominent bands of 46 and 31 kDa of the untreated cell wall coupled with an apparent increase in the amount of 55-56 kDa constituent, as well as of a minor constituent of 27-28 kDa. Radiolabel incorporation experiments demonstrated increased synthesis of a 34 kDa GAP, in addition to confirming the absence of the 46 kDa constituent, in mycelial cells under cilofunging treatment. Thus, sub-inhibitory doses of cilofungin may greatly alter the pattern of essential cell wall constituents such as the glucan-associated proteins, suggesting that this drug also has important effects on cell wall structure and fine organization, independent of, or prior to, its principal lytic effect on the fungal organism.

A simplified technique for laparoscopic instrument ties

A technique is described which simplifies intracorporeal knot-tying during laparoscopic surgery. The technique is applicable to both novice and experienced laparoscopic surgeons, and has ergonomic, cost and safety advantages over previously reported methods.