3326Infective endocarditis after transcatheter aortic valve implantation: findings from a UK nationwide linkage study

Introduction

Infective endocarditis (IE) is a potentially fatal complication of prosthetic valve replacement and increasing use of transcatheter aortic valve implantation (TAVI) has resulted in a new elderly and frail population at increased risk of IE. The incidence of IE after TAVI and factors that influence the risk and subsequent outcome are relatively unknown.

Purpose

To describe the incidence, predictors, echocardiographic findings, microbiology and clinical outcomes of IE following TAVI in the United Kingdom (UK).

Methods

Patients who underwent TAVI between Jan 1 2007 and Dec 31 2016 were identified from the UK TAVI database held by the National Institute for Cardiovascular Outcomes Research. For this cohort, all hospital admissions with a primary diagnosis of IE were identified by linkage with the NHS Hospital Episode Statistics Admitted Patient Care database, or by contact with regional TAVI centres. Additional information concerning clinical presentation, imaging findings, microbiology, management and patient outcome were obtained where possible from the treating physician.

Results

A total of 16,014 patients underwent TAVI, of whom 157 developed IE over a median follow-up of 23.8 (IQR 7.8–52.4) months - an overall incidence of 0.98% (0.53% at one year post-TAVI). The mean age of patients with IE was 79.2±7.8 years, and 69% were male. The median time to IE following TAVI was 10.0 (IQR 4.0–22.3) months.

On multivariate analysis, IE was significantly more common in men (HR 2.05, 95% CI 1.35–3.11, p=0.001) and in patients receiving mechanically-expandable (HR 2.15, 95% CI 1.16–4.01, p=0.015) or balloon-expandable valves (HR 1.60, 95% CI 1.01–2.52, p=0.045) compared to self-expanding valves. IE was also more common in those with an aortic valve peak gradient following TAVI deployment greater than median (HR 1.81, 95% CI 1.23–2.67, p=0.003).

The most common presenting symptom was fever (present in 67.1%). The most frequent causal organisms were enterococci (25.9%), followed by oral streptococci (16.4%) and Staphylococcus aureus (11.8%). Transoesophageal echocardiography demonstrated vegetations in 72.5% of patients, most commonly on the TAVI valve leaflets (58.8%). Only 8.24% of patients underwent surgical valve intervention.

Survival rates at hospital discharge and one year follow up were 61.4% and 54.4%, respectively. Specific factors associated with one-year mortality were cardiogenic shock (HR 4.6, 95% CI 2.1–10.3, p=0.0002), septic shock (HR 3.4, 95% CI 1.4–8.3, p=0.006) and stroke (HR 4.9, 95% CI 1.46–16.7, p=0.01).

Conclusions

The incidence of IE one year after TAVI was 0.53% and greater risk was associated with male sex, mechanically-expandable and balloon-expandable valves, and elevated post-deployment valve gradient. Enterococci were the most common causative organism. Overall survival at one year was 54.4%, with adverse outcome predicted by cardiogenic shock, septic shock or stroke.

P4436Impaired myocardial healing in patients with diabetes after ST-Elevation Myocardial Infarction

Background

Diabetes mellitus (DM) significantly increases mortality following myocardial infarction (MI). The underlying mechanism explaining this adverse prognosis is not completely understood.

Purpose

This study sought to investigate the characteristics of myocardial healing after MI in DM patients.

Methods

62 recruited ST-elevation myocardial infarction (STEMI) patients (21 with DM and 41 controls) underwent acute (1–3 days post-STEMI) and 6 months (6M) follow-up cardiac magnetic resonance scans (CMR). Control cases were matched for the peak troponin levels and area at risk on the acute CMR scans. Blood samples were obtained 6, 24, 48 hours and 6 months after STEMI.

Results

Despite similar severity of the initial ischaemic injury, DM patients had lower myocardial salvage index (MSI) and as a result larger final infarct size at 6 months. Further segment-based analysis of the acute CMR scans showed significantly prolonged T1-mapping values in all segments including non-ischaemic myocardium in DM patients and poorer recovery of the late gadolinium enhancement (LGE) of the infarcted segments in that group. Additionally, DM patients had higher monocyte counts 24 hours post-MI (1.2±0.4x109/μl DM vs 0.88±0.3 x109/μl control, p=0.001). We found that HbA1C correlated with monocyte count measured 24 hours after STEMI (r=0.577, p=0.006, n=21). HbA1C also predicted myocardial salvage index (MSI) at 6M post STEMI in the DM patients (r=0.891, p=0.017, n=13).

Conclusions

DM patients presenting with STEMI have increased peripheral blood monocytosis and larger final infarct size compared with STEMI patients without DM. Poorly controlled DM predisposes to adverse cardiac remodelling after STEMI.

Acknowledgement/Funding

OHSRC Research Grant, National Institute for Health Research (NIHR), British Heart Foundation Centre of Excellence Oxford

Transradial arterial access catheter knots: how to stay out of trouble

Transradial access has nowadays become a standard of care for percutaneous coronary angiography and intervention. This approach has demonstrated significant reduction in bleeding rate, length of hospital stay, and improvement in clinical outcomes when compared to the traditional transfemoral approach. Due to its advantages this new access is also increasingly being used in non-coronary visceral or peripheral interventions. However, this novel approach may lead to severe catheter kinking and twisting and further manipulation may be required to unravel the catheter and avoid complication. Purpose of this technical review is to present the current techniques and trends in preventing and resolving issues related to radial access catheter kinks.

Spontaneous coronary artery dissection

We present a case of a 43-year-old lady who presented with an acute coronary syndrome, but without any cardiac risk factors or previous cardiac symptoms, and who had a spontaneous coronary artery dissection. This was successfully treated with percutaneous coronary intervention. A brief discussion of this clinical entity and literature review is presented.

What is the risk of intensifying platelet inhibition beyond clopidogrel? A systematic review and a critical appraisal of the role of prasugrel

Thienopyridines are a class of drug targeting the platelet adenosine diphosphate 2 receptor. They have been shown to significantly reduce platelet activity exerting an important role in those clinical settings in which such an effect is beneficial. Ticlopidine was first to be introduced several years ago but it was quickly replaced by clopidogrel as it had a better risk/benefit profile. Recently, prasugrel has been developed and tested in several ex vivo studies and clinical trials showing able to provide a more powerful antiplatelet effect at the expense of a higher risk of bleeding complications. Great debate rose around its recent approval in the US as well as in Europe. This review aims at exploring the development and available clinical data of this third-generation thienopyridine while discussing its practical implementation in routine practice.

Myocardial infarction after percutaneous coronary intervention: a meta-analysis of troponin elevation applying the new universal definition

AIM

Elevation of Troponin after scheduled percutaneous coronary intervention (PCI) is a recognized consequence. We sought to evaluate the prognostic significance and impact of the newly published definition of PCI-related myocardial infarction (MI) according to which any troponin elevation >3 times the upper reference limit identify a peri-procedural MI.

METHODS

Search of BioMedCentral, CENTRAL, mRCT and PubMed (updated May 2008). Outcomes of interest were: MACE [the composite of all cause death, MI, repeat target vessel PCI (re-PCI) and coronary artery bypass grafting (CABG)]; single end points were also assessed.

RESULTS

Fifteen studies have been included totalling 7578 patients. Troponin elevation occurred in 28.7% of the procedures. The incidence of PCI-related MI according to the new definition was 14.5%. During the hospitalization, any level of raised troponin was associated with an increased risk of MACE [OR 11.29 (3.00-42.48), Number needed to harm (NNH) 5], death [OR 7.16 (1.95-26.27), NNH = 100], MI [OR 30.85 (6.05-157.38), NNH = 4] and re-PCI [OR 4.13 (1.23-13.88), NNH = 50]. Patients with PCI-related MI had an increased risk of death [OR 17.25 (2.71-109.96), NNH = 100] and re-PCI [OR 10.86 (3.2-36.94), NNH = 25]. At follow up of 18 months any troponin elevation was associated with an increased risk of MACE [OR 1.48 (1.12-1.96), NNH = 20], death [OR 2.19 (1.59-3.00), NNH = 50], MI [OR 3.29 (2.71-6.31), NNH = 33] and re-PCI [OR 1.47 (1.06-2.03), NNH = 25]. In patients with PCI-related MI the risk of MACE was further increased: OR 2.25 (1.26-4.00), NNH = 3. An increase of the troponin level below the cut-off was not associated with MACE.

CONCLUSION

A diagnosis of MI according to the new guidelines applies to 15% of patients undergoing PCI and these patients are at high risk of further adverse events both during the hospital stay and at 18 months.

General anaesthesia versus local anaesthesia for carotid surgery (GALA): a multicentre, randomised controlled trial

BACKGROUND

The effect of carotid endarterectomy in lowering the risk of stroke ipsilateral to severe atherosclerotic carotid-artery stenosis is offset by complications during or soon after surgery. We compared surgery under general anaesthesia with that under local anaesthesia because prediction and avoidance of perioperative strokes might be easier under local anaesthesia than under general anaesthesia.

METHODS

We undertook a parallel group, multicentre, randomised controlled trial of 3526 patients with symptomatic or asymptomatic carotid stenosis from 95 centres in 24 countries. Participants were randomly assigned to surgery under general (n=1753) or local (n=1773) anaesthesia between June, 1999 and October, 2007. The primary outcome was the proportion of patients with stroke (including retinal infarction), myocardial infarction, or death between randomisation and 30 days after surgery. Analysis was by intention to treat. The trial is registered with Current Control Trials number ISRCTN00525237.

FINDINGS

A primary outcome occurred in 84 (4.8%) patients assigned to surgery under general anaesthesia and 80 (4.5%) of those assigned to surgery under local anaesthesia; three events per 1000 treated were prevented with local anaesthesia (95% CI -11 to 17; risk ratio [RR] 0.94 [95% CI 0.70 to 1.27]). The two groups did not significantly differ for quality of life, length of hospital stay, or the primary outcome in the prespecified subgroups of age, contralateral carotid occlusion, and baseline surgical risk.

INTERPRETATION

We have not shown a definite difference in outcomes between general and local anaesthesia for carotid surgery. The anaesthetist and surgeon, in consultation with the patient, should decide which anaesthetic technique to use on an individual basis.

FUNDING

The Health Foundation (UK) and European Society of Vascular Surgery.

Interaction between statins and clopidogrel: is there anything clinically relevant?

Since their introduction several years ago, the 3-hydroxy-3-methylglutaryl coenzyme A (HMGCoA) reductase inhibitors-the statins-have been widely used for hyperlipidemia and for the primary/secondary prevention of cardiovascular diseases. They have been shown to be safe as well as efficacious in a number of different clinical trials; however, studies have suggested that they can interact with other co-administered therapies. More recently, the thienopyridines have been successfully integrated with the conventional medical treatment of coronary disease as they showed effectiveness in reducing platelet activity both in stable and unstable settings. They also improve the outcome of patients treated with percutaneous coronary intervention. The potential interaction of statins and thienopyridines is a matter of concern. Despite some preclinical data suggesting an interaction between statins metabolized by the liver cytochrome P3A4-such as atorvastatin, lovastatin and simvastatin-and clopidogrel, there is no compelling clinical evidence to stop their co-administration.

Repeat thrombolysis or conservative therapy vs. rescue percutaneous coronary intervention for failed thrombolysis: systematic review and meta-analysis

BACKGROUND

Despite proven advantages of primary percutaneous coronary intervention (PCI), thrombolysis remains the first line treatment for ST-elevation myocardial infarction (STEMI) worldwide. Management of patients with failed thrombolysis is still debated, and data from existing randomized controlled trials are conflicting.

AIM

To compare the risk/benefit profile of repeat thrombolysis (RT) vs. rescue PCI in patients with failed thrombolysis.

METHODS

Search of BioMedCentral, CENTRAL, mRCT and PubMed for randomized controlled trials comparing rescue PCI vs. conservative therapy and/or RT vs. conservative therapy. Outcomes of interest assessed by adjusted indirect meta-analysis: major adverse events (MAE, defined as the composite of overall mortality and re-infarction), stroke, congestive heart failure (CHF), major bleeds (MB), and minor bleeds. Overall mortality and re-infarction have been also analysed individually.

RESULTS

Eight trials were included (1318 patients). Follow-up ranged from 'in-hospital' to 6 months. No significant difference was found for the risk of MAE [OR 0.93(0.26-3.35), P = 0.4], overall mortality [OR 1.01(0.52-1.95), P = 0.15], stroke [OR 5.03(0.64-39.1), P = 0.58] and CHF [OR 0.74(0.28-1.96), P = 0.6]. Compared with conservative therapy, rescue PCI was associated with a 70% reduction in the risk of re-infarction [OR 0.32(0.14-0.74), P = 0.008], number needed to treat 17. No difference in terms of MB was found [OR 0.5(0.1-2.5), P = 0.09], while a greater risk of minor bleeds was observed with rescue PCI [OR 2.48(1.08-5.7), P = 0.04], number needed to harm 50.

CONCLUSION

Although the observed benefit is modest, these data support the use of PCI after failed thrombolysis.

Filter no reflow during percutaneous coronary interventions using the Filterwire distal protection device

BACKGROUND

Distal protection devices are increasingly used to prevent embolization during percutaneous coronary interventions (PCI) in saphenous vein grafts (SVG) and native coronary arteries (NV). During interventions with the Filterwire device we have observed reduced flow that is reversible following removal of the filter (filter no reflow, FNR), which might be erroneously interpreted as true no reflow and might be associated with reduced capture efficiency of the basket.

METHODS

We analyzed the incidence of FNR in 58 patients (60 lesions) at high risk of embolization undergoing PCI of either a SVG or a NV using the Filterwire (Boston Scientific, Natick, MA). Qualitative and quantitative angiographic analysis was performed, and the volume of collected debris was estimated using a photographic technique.

RESULTS

In our population, about 1/3 of the cases showed FNR, which was associated with angiographically visible filling defects within the basket, indicating macroembolism. However some patients (especially those undergoing vein graft interventions) showed filling defects without FNR, and some others FNR without filling defects. Thus we tried to understand the predictors of FNR: FNR was associated with higher amount of collected debris (36.97 +/- 42.98 mm(3) vs. 11.31 +/- 18.47 mm(3), p = 0.005), was neither prevented by abciximab, nor predicted by high thrombotic burden, increasing stent volume or need for predilatation. When patient with and without angiographically evident macroembolisation were separately analyzed, a linear correlation of FNR with the quantity of debris was only apparent in the macroembolization group.

CONCLUSIONS

Interventionalists should be aware of the "Filter No Reflow", a common but reversible angiographic complication when the Filterwire device is used. Reduced flow seen during these procedures should be treated conservatively. Mechanical obstruction of the filter, but also other mechanisms (pharmacologically active debris? platelet aggregates?) play a role in this phenomenon.

Population-based study of event-rate, incidence, case fatality, and mortality for all acute vascular events in all arterial territories (Oxford Vascular Study)

BACKGROUND

Acute coronary, cerebrovascular, and peripheral vascular events have common underlying arterial pathology, risk factors, and preventive treatments, but they are rarely studied concurrently. In the Oxford Vascular Study, we determined the comparative epidemiology of different acute vascular syndromes, their current burdens, and the potential effect of the ageing population on future rates.

METHODS

We prospectively assessed all individuals presenting with an acute vascular event of any type in any arterial territory irrespective of age in a population of 91 106 in Oxfordshire, UK, in 2002-05.

FINDINGS

2024 acute vascular events occurred in 1657 individuals: 918 (45%) cerebrovascular (618 stroke, 300 transient ischaemic attacks [TIA]); 856 (42%) coronary vascular (159 ST-elevation myocardial infarction, 316 non-ST-elevation myocardial infarction, 218 unstable angina, 163 sudden cardiac death); 188 (9%) peripheral vascular (43 aortic, 53 embolic visceral or limb ischaemia, 92 critical limb ischaemia); and 62 unclassifiable deaths. Relative incidence of cerebrovascular events compared with coronary events was 1.19 (95% CI 1.06-1.33) overall; 1.40 (1.23-1.59) for non-fatal events; and 1.21 (1.04-1.41) if TIA and unstable angina were further excluded. Event and incidence rates rose steeply with age in all arterial territories, with 735 (80%) cerebrovascular, 623 (73%) coronary, and 147 (78%) peripheral vascular events in 12 886 (14%) individuals aged 65 years or older; and 503 (54%), 402 (47%), and 105 (56%), respectively, in the 5919 (6%) aged 75 years or older. Although case-fatality rates increased with age, 736 (47%) of 1561 non-fatal events occurred at age 75 years or older.

INTERPRETATION

The high rates of acute vascular events outside the coronary arterial territory and the steep rise in event rates with age in all territories have implications for prevention strategies, clinical trial design, and the targeting of funds for service provision and research.

Transthoracic echocardiography using second harmonic imaging with Valsalva manoeuvre for the detection of right to left shunts

AIMS

To assess transthoracic echocardiography (TTE) using second harmonic imaging with Valsalva manoeuvre compared to transesophageal echocardiography (TEE) for the diagnosis of right to left cardiac and pulmonary shunts.

METHODS AND RESULTS

One hundred and ten patients referred for TEE underwent TTE with bubble contrast. Bubbles in the left atrium within three cardiac cycles were considered diagnostic for a patent foramen ovale (PFO) and later as a pulmonary shunt. Greater than 20 bubbles in the left atrium was considered a large shunt and less than 20 a small shunt. TEE was performed immediately afterwards and read blinded to the TTE results. Pick-up rates were similar with 19 TEE positive (13 PFO) and 18 TTE positive (14 PFO) patients. There were five TEE positive/TTE negative cases who had significantly poorer TTE image quality score (2.7 +/- 0.8 vs 1.9 +/- 0.6, p < 0.05). There were six TEE negative/TTE positive cases, two cases requiring Valsalva manoeuvre to become positive. The Valsalva manoeuvre significantly increased the number of bubbles shunting (10 +/- 11 vs 20 +/- 19, p < 0.005).

CONCLUSION

TTE with Valsalva manoeuvre is as good as TEE in diagnosing shunts. Valsalva manoeuvre increases the size of shunt. Both techniques produce false negative results.

Heparin dose during percutaneous coronary intervention: how low dare we go?

Despite dramatic advances in percutaneous coronary intervention, including coronary stents and potent antiplatelet agents, unfractionated heparin remains the standard procedural anticoagulant. Tradition and habit may have considerable influence over dose selection. A review of the role and dosage of heparin during PCI appears to be overdue

Multifocal cardiac leiomyosarcoma. Diagnosis and surveillance by transoesophageal echocardiography and contrast enhanced cardiovascular magnetic resonance

Primary cardiac sarcomas are rare and typically undergo aggressive local spread. There is no reliable definitive treatment, although radical surgical resection can provide palliation in the medium term. A case of a pleomorphic leiomyosarcoma with dramatic images is presented. The relative usefulness of transoesophageal echocardiography and cardiovascular magnetic resonance imaging to define the extent of tumour involvement, allowing planning of treatment, is demonstrated.