Heterogeneous plaque geometry is associated with major adverse cardiovascular events

Objectives

To determine whether coronary artery plaque-lumen geometry predicts major adverse cardiovascular events (MACE), and incorporating geometric measures enhances risk stratification from intravascular imaging.

Background

Prospective studies show that only a minority of plaques with higher-risk features result in future MACE, indicating the need for more predictive markers of plaque vulnerability. Plaques show heterogeneous structures and plaque-lumen geometry, both of which can promote high plaque structural stress (PSS); however, the relationships between geometric heterogeneity and MACE or PSS are unknown.

Methods

We examined plaque-lumen curvature, irregularity, lumen aspect ratio (LAR), roughness, PSS and their longitudinal heterogeneity (Figure 1A) in 35 non-culprit lesions (NCL) associated with MACE and 66 propensity-matched no-MACE NCL from the PROSPECT (Providing Regional Observations to Study Predictors of Events in the Coronary Tree) study. Causes of heterogeneous geometry and PSS were examined using a separate group of co-registered virtual histology-intravascular ultrasound (VH-IVUS) and optical coherence tomography (OCT) images (n=53 plaques).

Results

Plaque geometry heterogeneity indices (HI) were increased in NCL MACE vs. no-MACE lesions across the whole plaque and peri-minimal luminal area (MLA) segments (HI curvature: p=0.002; HI irregularity: p<0.001; HI LAR: p=0.001; HI roughness: p=0.002). Peri-MLA HI roughness was an independent predictor of future MACE (hazard ratio: 3.69, p<0.001) (Figure 1B). Inclusion of HI roughness improved identification of NCLs leading to MACE in VH-defined thin-cap fibroatheromas (VH-TCFA, p=0.005), MLA ≤4mm2 (p=0.001), and plaque burden (PB) ≥70% (p<0.001) (Figure 1C–E), and further improved the ability of PSS to identify MACE NCLs in VH-TCFA (p=0.041), MLA ≤4mm2 (p=0.033), and PB ≥70% (p<0.001). HI roughness generally corresponded with HI PSS, but was also increased at sites of local calcification and multilayering.

Conclusions

Plaque-lumen geometric heterogeneity is increased across whole plaque and peri-MLA segments of NCLs causing MACE. Inclusion of geometric heterogeneity may improve the ability of intravascular imaging to predict MACE.

Funding Acknowledgement

Type of funding sources: Other. Main funding source(s): British Heart Foundation

1069 ESSENTIAL FRAILTY TOOLSET AS A PREDICTOR OF PROLONGED LENGTH OF STAY AND DISCHARGE DESTINATION AFTER TRANSCATHETER AORTIC VALVE IMPLANTATION

Introduction

Frailty is associated with poor outcomes following transcatheter aortic valve implantation (TAVI). Rockwood is the widely used score for this population. In a recent trial, a more objective score, the Essential Frailty Toolset (EFT) outperformed Rockwood’s in predicting mortality and disability 1-year post-TAVI. Whether it predicts in-hospital length of stay (LOS) and discharge destination post-TAVI remains unclear.

Method

A cohort of patients undergoing TAVI for aortic stenosis was recruited, demographic characteristics collected, and frailty assessed with EFT and Rockwood scores. Primary outcomes were LOS post-TAVI, categorised as ‘not prolonged’ (≤2 days) or ‘prolonged’ (>2 days) and discharge destination, characterised as ‘home’ or ‘non-home’.

Results

86 patients were recruited, with median age 82 years (IQR 78–86). 54% were male. EFT identified 35% and Rockwood 11% as frail. 19% were cognitively impaired. 5 chair rises were completed by 70%, with 30% managing under 15 seconds. Median haemoglobin was 121 g/L (IQR 109.5–136). Median albumin was 36 g/L (IQR 33–39). 84% of procedures were transfemoral. 20% had moderate–severe left ventricular systolic dysfunction. Median LOS post-TAVI was 2 days (IQR 2–5). 94% were discharged home, 6% to referring local hospital or rehabilitation centre. 46% were NYHA class III-IV. A model for prolonged LOS including comorbidities, showed frailty determined by EFT (OR 4.80, CI 95% 1.52–15.2, p = 0.008) but not Rockwood (OR 5.00, CI 95% 0.865–29.0, p = 0.072) was the only significant independent predictor for prolonged LOS. A model adjusting for comorbidities also showed EFT to be an independent predictor for non-home discharge destination of borderline significance (OR 2.57 CI 95% 0.994–6.66, p = 0.051) but Rockwood was not (OR 1.38 CI95% 0.485–3.91, p = 0.548).

Conclusion

In a real-world elderly population, EFT score was a stronger, more independent predictor of prolonged LOS and non-home discharge post-TAVI, than Rockwood’s. EFT would be an effective pre-operative assessment tool for LOS and discharge destination for TAVI.

Which patients could benefit the most from bioresorbable vascular scaffold implant: from clinical trials to clinical practice

Bioresorbable scaffold technology has evol-ved over the last few years with a number of devices either available or under clinical and preclinical investigation. The absence of a permanent metallic segment in the treated vessel wall has the potential of addressing some of the issues still encountered with metallic drug-eluting stents (DES) despite improvements in stent platform, polymer and drug elution. To date however, the use of bioresorbable vascular scaffolds (BVS) has largely been restricted to patients recruited into clinical trials with a relatively small number of "real-world" patients treated with these devices. Here we explore the issue of BVS use in "real-world" patients and try to identify, on the basis of our experience, the subset of patients that could benefit the most.

Altered re-excitation thresholds and conduction of extrasystolic action potentials contribute to arrhythmogenicity in murine models of long QT syndrome

AIM

QT interval prolongation reflecting delayed action potential (AP) repolarization is associated with polymorphic ventricular tachycardia and early after depolarizations potentially initiating extrasystolic APs if of sufficient amplitude. The current experiments explored contributions of altered re-excitation thresholds for, and conduction of, such extrasystolic APs to arrhythmogenesis in Langendorff-perfused, normokalaemic, control wild-type hearts and two experimental groups modelling long QT (LQT). The two LQT groups consisted of genetically modified, Scn5a(+/ΔKPQ) and hypokalaemic wild-type murine hearts.

METHODS

Hearts were paced from their right ventricles and monophasic AP electrode recordings obtained from their left ventricular epicardia, with recording and pacing electrodes separated by 1 cm. An adaptive programmed electrical stimulation protocol applied pacing (S1) stimulus trains followed by premature (S2) extrastimuli whose amplitudes were progressively increased with progressive decrements in S1S2 interval to maintain stimulus capture. Such protocols culminated in either arrhythmic or refractory endpoints.

RESULTS

Arrhythmic outcomes were associated with (1) lower conduction velocities in their initiating extrasystolic APs than refractory outcomes and (2) higher conduction velocities in the LQT groups than in controls. Furthermore, (3) the endpoints were reached at longer S1S2 coupling intervals and with smaller stimulus amplitudes in the LQT groups compared with controls. This was despite (4) similar relationships between conduction velocity and S1S2 coupling interval and between re-excitation thresholds and S1S2 coupling interval in all three experimental groups.

CONCLUSIONS

Arrhythmias induced by extrasystolic APs in the LQT groups thus occur under conditions of higher conduction velocity and greater sensitivity to extrastimuli than in controls.

Acute coronary syndromes can be a headache

Ischaemic heart disease is a common cause of morbidity and mortality worldwide. Patients typically present with chest pain and breathlessness either on exertion or at rest. Cardiac ischaemia can also lead to headache, although this is very rarely its only manifestation. Headache is mostly associated with migraine, cluster and tension headache disorders. More sinister causes include subarachnoid haemorrhage, temporal arteritis, meningitis, venous sinus thrombosis as well as vertebral and carotid artery dissection. A case of headache is presented where the underlying cause was cardiac ischaemia, itself the result of triple vessel coronary artery disease. This, also referred to as cardiac cephalgia, should be suspected in the older patient with risk factors for atherosclerotic disease presenting with recent-onset headache. Diagnosis of this requires high clinical suspicion and is essential for correct patient management.

An inguinal hernia that was not meant to be: a female with seminoma

Complete androgen insensitivity is a rare X-linked disorder characterised by a female phenotype in a chromosomally male individual. It usually presents at puberty with primary amenorrhoea or as an inguinal mass in a female infant. Treatment includes bilateral orchidectomy and hormone replacement therapy. We present the case of a 31-year-old female with complete androgen insensitivity and a presumed inguinal hernia. We discuss the importance of early diagnosis, emphasise the consequences of misdiagnosis, and raise the question of whether such patients have been appropriately managed in the past.

Multicenter evaluation of the fully automated bactec MGIT 960 system and three molecular methods for the isolation and the identification of mycobacteria from clinical specimens

A combination of Bactec MGIT 960 system, a PCR-based assay and a PCR-Restriction Analysis procedure (PRA) was assessed for the detection and identification of mycobacteria from clinical samples. The MGIT recovered 243 from 266 mycobacterial isolates. The PCR-based assay correctly identified all (234) Mycobacterium tuberculosis isolates, while 35 nontuberculous mycobacterial isolates were identified by PRA.

Evidence for phospholipase B activity in Fusobacterium necrophorum cultures and its association with hemolysin/leucocidin activities

Phospholipase B (PLB) activity was present in Fusobacterium necrophorum cultures and it correlated closely with virulence and co-purified with the hemolysin/leucocidin activities. All three activities were associated with a large molecule or molecular complex (6 x 10(2)-2 x 10(3) kDa) exhibiting varying degrees of aggregation. These were present mainly in the culture medium and to a lesser extent in cell sonicates. The PLB and toxin activities were sensitive to heat, dissociating agents, proteolytic enzymes, prolonged purification regimes, freeze-drying and repeated freeze-thawing. The toxin(s) were stable over a broad range of pH, did not require divalent ions or reducing agents and could be kept for several months as an ammonium sulfate precipitate at 4 degrees C, or stored as a concentrated liquid in the presence of proteolytic inhibitors at - 20 degrees C.

Use of the insertion element IS6110 for DNA fingerprinting of Mycobacterium tuberculosis isolates presenting various profiles of drug susceptibility

IS6100 is an insertion sequence of the IS3 family and it is present in multiple copies in the chromosome of Mycobacterium tuberculosis. Four to 15 copies are present in various strains of M. tuberculosis. In this study, the value of IS6110 as an epidemiological marker of tuberculosis was examined. Unrelated clinical strains from Greek patients presented, in restriction fragment length polymorphism analysis, a high degree of polymorphism, whereas patterns of related clinical strains from familial outbreaks were identical. Since RFLP analysis with acetylaminofluorene labeled IS6110 as the probe gave satisfactory results, it is suggested that this non-radioactive probe can be used in hospitals and health centres for the epidemiological survey of M. tuberculosis infections.

Serological reactivity to Mycobacterium bovis protein antigens in cattle

The serological response to 12 purified Mycobacterium bovis antigens were examined in an ELISA assay. These antigens included the majority of M. bovis protein antigens described to date and in most cases they were very similar to the M. tuberculosis antigens of the same molecular mass. The purified antigens were tested against sera from M. bovis infected cattle, M. bovis culture-negative cattle from infected herds and animals infected with related microorganisms, mainly other mycobacterial species. All the antigens gave strong reactions with at least some sera from the M. bovis infected group and showed cross-reactivity with some of the sera from the other two groups. The antigen with the highest specificity reacted strongly with only 60% of the M. bovis infected sera. Antigens that reacted with most or all of the M. bovis infected sera also gave the highest cross-reactivity with sera from the other two groups. These results indicate that a serological test based on any one or a combination of these antigens, without removal of the cross-reacting epitopes, would be unsatisfactory.

Purification and characterization of major antigens from a Mycobacterium bovis culture filtrate

Ten major antigens from Mycobacterium bovis culture filtrate of 39, 32, 30, 25, 24, 22 (a and b forms), 19, 15, and 12 kDa have been purified and characterized by classical physicochemical methods. With monoclonal antibodies and/or N-terminal amino acid sequencing data, it was found that the antigens of 32, 30, 24, 22 (a), 19, and 12 kDa are related to M. bovis or M. tuberculosis antigens P32, MPB59, MPB64, MPB70, 19 kDa, and 12 kDa, respectively. The 39-, 25-, 22 (b)-, and 19-kDa antigens showed concanavalin A-binding properties and were positive in a glycan detection test, suggesting that they are glycoproteins. The 25- and 22 (b)-kDa proteins were found to be glycosylated forms of MPB70.

Comparison of in vitro activities of eight new beta-lactam compounds against cephalothin-resistant Enterobacteriaceae from hospital patients

The in vitro antibacterial activity of eight newer beta-lactam antibiotics (mecillinam, piperacillin, mezlocillin, cefoxitin, cefotaxime, moxalactam, ceftriaxone and ceftazidime) was determined against 87 cephalothin-resistant strains of Enterobacteriaceae isolated during 6 months in a general hospital. Ceftriaxone, cefotaxime, moxalactam and ceftazidime proved to be highly active; only a minority of strains required higher concentrations than 0.125 microgram/ml for inhibition of growth. Cefoxitin, mecillinam, mezlocillin and piperacillin were less active. Mecillinam displayed greater efficacy against Escherichia coli, Klebsiella and Enterobacter spp., while the same was the case for piperacillin against Proteus mirabilis and Serratia marcescens, and for cefoxitin against indole-positive Proteus spp. The production of beta-lactamase was correlated with a reduced activity of mecillinam, mezlocillin and piperacillin but not of cefoxitin or the other beta-lactamase-stable cephalosporins. However, some strains, mainly those of Proteus, Enterobacter and Serratia, though resistant to mecillinam, mezlocillin and piperacillin did not produce beta-lactamases. This observation might indicate that ceftriaxone, moxalactam, cefotaxime and ceftazidime, besides their indifference to beta-lactamases, are characterized also by a high degree of intrinsic activity.