P263 Characterisation of patients with acute myocardial infarction complicated by left ventricular thrombus

Funding Acknowledgements

None

Background/Introduction

Left ventricular (LV) thrombus is a widely recognized complication of acute myocardial infarction (AMI).  Limited data are available from South East Asian patients with this post-infarction complication nor on whether patients with non-ST segment elevation myocardial infarction (NSTEMI) or STEMI with associated LV thrombosis exhibit differing clinical characteristics and/or outcomes. Left Ventricular Ejection Fraction (LVEF) ≤ 40% is a recognized predictor of LV thrombus formation, but there is limited data on LV thrombus patients with EF > 40% or in NSTEMI patients.

Purpose

This study aims to investigate and compare the clinical characteristics, treatment and outcomes of post-AMI patients with LV thrombus formation, with a particular emphasis on those with EF ≤ 40% and in NSTEMI patients. 

Methods

Among 5829 consecutive echocardiogram results containing the keyword "thrombus" from August 2006 to September 2017, we identified 289 post-AMI patients with acute LV thrombus formation. Demographics, treatment and outcome measures were analysed.

Results

Cardiovascular risk factors such as dyslipidaemia (54.0%) and hypertension (50.5%) were commonly present in post-AMI patients with LV thrombus. Mean LVEF was 33.0 ± 10.4%. The majority (68.0%) of patients received triple therapy and 59.5% achieved thrombus resolution. NSTEMI patients had greater number of co-morbidities including heart failure (p < 0.01), documented history of  ischaemic heart disease preceding the AMI leading to thrombus formation (p < 0.01) and lower LVEF (28.3 ± 9.3% vs. 34.8 ± 10.3% , p < 0.01) compared with STEMI cases. On multivariate analysis, having a lower EF was a significant independent predictor of stroke (HR 0.96, 95% CI 0.93-1.00, p = 0.03) and all-cause mortality (HR 0.95, 95% CI 0.92-0.99, p < 0.01). The categories of STEMI and NSTEMI did not predict thrombus resolution, stroke events or all-cause mortality after adjustment.

Conclusion(s)

  Post-AMI LV thrombus patients with NSTEMI and STEMI differed in terms of their co-morbidities in their demographics and co-morbidities but it was a lower EF that was associated with an increased risk of stroke and all-cause mortality. Further studies on this topic are required.

P910An Asian perspective on left ventricular outflow tract cut-offs and the resulting discrepancy in severity grading of aortic stenosis

Objectives

Inconsistencies in grading of aortic stenosis (AS) severity have been reported based on measurement of left ventricular outflow tract diameter (LVOTd), but this remains to be studied in an Asian population. We investigated consistency of grading AS severity at various LVOTd, and subsequently postulated alternative cut-offs for more consistent grading of AS severity.

Methods

350 consecutive patients with index echocardiographic diagnosis of severe AS were divided them into three groups based on LVOTd: “small” (<20mm), “average” (20–22mm), “large” (>22mm). In each group, the consistency of flow-dependent (transaortic mean pressure gradient (MG)) and flow-independent parameters (AVA) were used for classification of AS severity.

Results

Of 350 patients, 51.7% had small LVOTd, while 30.8% and 17.5% had average and large LVOTd respectively. Consistent grading by LVOTd based on AVA and MG, was seen in 33.7% of patients with small, 47.6% with average, 57.7% with large LVOTd. When the hypothetical AVA cut-off of 0.9cm2 was used, consistent grading improved to 38.0% in small, 56.5% in average and 70% in large LVOTd. At an AVA cut-off of 0.8cm2, there was further incremental improvement in the small LVOTd group to 54.1% (p<0.05).

Table 1. Consistent grading by LVOTd based on current guidelines Small LVOTd (<20mm, n=181) Average LVOTd (20–22mm, n=108) Large LVOTd (>22mm, n=61) Consistent grading AVA < cut-off MG >40 Consistency (%) Consistent grading AVA < cut-off MG >40 Consistency (%) Consistent grading AVA < cut-off MG >40 Consistency (%) n=61 33.7 n=51 47.6 n=35 57.7 n=69 38 n=61 56.5 n=43 70* n=98 54.1*+ n=70 65.1* n=43 70.8* *p-value <0.05 when compared with AVA cut-off 0.8cm2 for each LVOTd category; +p-value <0.05 when compared with AVA cut-off 0.9cm2 for each LVOTd category.

Figure 1

Conclusion

Current severe AS guidelines are most consistent with those in the large LVOTd group. However, the majority of the study's Asian population is in the small LVOTd group, which is the group most susceptible to discrepancy in AS grading. Improved consistency in echocardiographic grading may be attained with a lower AVA cut-off in this Asian cohort.

Constrictive Pericarditis Following Correction of Partial Anomalous Pulmonary Venous Drainage

We report the case of a 23-year-old man who developed constrictive pericarditis within four months after pulmonary valve replacement and repair of partial anomalous pulmonary venous connection. He had previously undergone repair of tetralogy of Fallot in infancy. After an unsuccessful trial of medical management for persistent right heart failure, magnetic resonance imaging was done, which showed a thickened pericardium. He underwent a radical pericardiectomy with a good outcome. The case is presented to illustrate a less well-recognized cause of cardiac failure following congenital cardiac surgery, which may otherwise be attributed to the failure of surgery or residual complications.

How temporal evolution of intracranial collaterals in acute stroke affects clinical outcomes

OBJECTIVE

We compared intracranial collaterals on pretreatment and day 2 brain CT angiograms (CTA) to assess their evolution and relationship with functional outcomes in acute ischemic stroke (AIS) patients treated with IV tissue plasminogen activator (tPA).

METHODS

Consecutive AIS patients who underwent pretreatment and day 2 CTA and received IV tPA during 2010-2013 were included. Collaterals were evaluated by 2 independent neuroradiologists using 3 predefined criteria: the Miteff system, the Maas system, and 20-point collateral scale by the Alberta Stroke Program Early CT Score methodology. We stratified our cohort by baseline pre-tPA state of their collaterals and by recanalization status of the primary vessel for analysis. Good outcomes at 3 months were defined by a modified Rankin Scale score of 0-1.

RESULTS

This study included 209 patients. Delayed collateral recruitment by any grading system was not associated with good outcomes. All 3 scoring systems showed that collateral recruitment on the follow-up CTA from a baseline poor collateral state was significantly associated with poor outcome and increased bleeding risk. When the primary vessel remained persistently occluded, collateral recruitment was significantly associated with worse outcomes. Interestingly, collateral recruitment was significantly associated with increased mortality in 2 of the 3 grading systems.

CONCLUSIONS

Not all collateral recruitment is beneficial; delayed collateral recruitment may be different from early recruitment and can result in worse outcomes and higher mortality. Prethrombolysis collateral status and recanalization are determinants of how intracranial collateral evolution affects functional outcomes.

An unusual case of anomalous origin of the right coronary artery and hepatic focal nodular hyperplasia

Anomalous origin of the right coronary artery (ARCA) and focal nodular hyperplasia (FNH) are frequently reported in association with congenital heart abnormalities but not with each other. We propose that both conditions may share common origins in a maladative hyperplastic response to differential vascular flow due to developmental arterial malformations or aberrant Notch signalling during simultaneous gut and cardiac vasculorigenesis.

Demographics of severe valvular aortic stenosis in Singapore

INTRODUCTION

The treatment of aortic valve stenosis (AS) is seeing renewed interest mainly due to the availability of transcatheter therapies. However, the number of epidemiological studies of this disease in Singapore is limited. We aimed to describe the aetiology and clinical presentation of AS in Singapore, as well as patients' attitudes toward it. Our findings may facilitate the future planning and utilisation of resources to better manage these patients.

METHODS

249 consecutive patients who underwent transthoracic echocardiography (from April 1999 to April 2008) and diagnosed with severe AS were assessed. Demographic and clinical data were collected, and patients' decisions on surgery were determined.

RESULTS

The mean patient age was 71 (range 23-98) years. 50.2% of patients were male. The commonest presenting symptom was dyspnoea, and 40 (16.0%) patients had coexistent atrial fibrillation. The aetiology of AS was degenerative in 216 (86.7%), rheumatic in 11 (4.4%) and related to a bicuspid valve in 22 (8.9%) patients. The average peak velocity across the aortic valve was 4.2 ± 0.8 m/s and the mean aortic valve area was 0.76 ± 0.13 cm2. The overall mean logistic EuroSCORE was 10.7 ± 12.3. 105 (42.2%) patients who were offered surgery refused. 87 (35%) deaths were seen during the follow-up period (mean duration 14.5 months), which also saw 68 (27%) patients undergo surgery and 86 (34%) patients hospitalised for heart failure.

CONCLUSION

Degenerative AS was the commonest aetiology in this contemporary cohort of patients. Despite the known benefits of surgery, the refusal rate for surgery remained high.

A high-risk period for cerebrovascular events exists after transcatheter aortic valve implantation

OBJECTIVES

This study assesses if there exists a high-risk period for cerebrovascular events (CeV) after transcatheter aortic valve implantation (TAVI).

BACKGROUND

Even though acute strokes after TAVI have been described, it is uncertain if stroke rates continue to remain high in the early months after TAVI. Furthermore, the optimal dose and duration of thromboprophylaxis is unclear.

METHODS

Patients who underwent TAVI were evaluated at baseline, at discharge, at 1 and 6 months, and yearly. Risk factors for CeV events, procedural details, and antithrombotic therapy were recorded. Outcomes assessed were CeV events and death. The timing of such events, predictors, and impact on survival were analyzed.

RESULTS

A total of 253 patients were assessed. Median age was 85 years. The median Society of Thoracic Surgeons score was 8.1% (interquartile range [IQR]: 5.5% to 12.0%). Risk factors included smoking (47%), hypertension (70%), dyslipidemia (66%), and diabetes mellitus (25%). Twenty-three percent had known cerebrovascular disease and 39% had atrial fibrillation. Median follow-up was 455 days (IQR: 160 to 912 days) at which time 23 patients experienced a CeV event. The incidence was highest in the first 24 h but remained high for 2 months. In-hospital mortality rate after a CeV event was 21%. A prior history of CeV disease was an independent predictor of an event (hazard ratio: 4.23, 95% CI: 1.60 to 11.11, p = 0.004).

CONCLUSIONS

The incidence of CeV events is highest within 24 h of TAVI, but this risk may remain elevated for up to 2 months. A prior history of cerebrovascular disease is an independent predictor. This may have implications for patient selection and antithrombotic strategies.