[Ablation of an idiopathic "ventricular rarity"--ventricular tachycardia originating from the crux cordis]

HISTORY AND ADMISSION FINDINGS

A 62-year-old woman presented with history of repeat syncope and palpitations. She experienced aggravation of symptoms within the last few months. At referring hospital a ventricular tachycardia was already inducible during electrophysiological study. The patient was transferred to our hospital for VT ablation vs. ICD implantation.

INVESTIGATION

No evidence for structural heart disease was revealed during TTE nor was a coronary heart disease detectable during coronary angiography, only hypertension was verifiable. No ICD implantation so far.

TREATMENT AND COURSE

The patient underwent repeat EP study at our facility with induction of VT. Pace-mapping and mapping for earliest ventricular activation was performed. The middle-cardiac vein was revealed as site of earliest ventricular activation (50 ms) and good pace-map. Therefore, radiofrequency ablation at this site terminated successfully VT into sinus rhythm.

CONCLUSION

Ablation of epicardial VT foci is successfully feasible via coronary sinus. With regard to typical ECG parameters an epicardial foci may be assumed precociously. The great cardiac vein is one of the most common sites of origin for epicardial foci, however, VT partially may originate from the crux cordis which is accessible for ablation via the middle cardiac vein with good ablation results.

Abstract 475: Circulating Immunoglobulins Are Not Associated With Intraplaque Mast Cell Number and Other Vulnerable Plaque Characteristics in Patients With Carotid Artery Stenosis

Background: Atherosclerosis is a chronic systemic inflammatory disease in which many immune cells participate. Recently we have shown that mast cell numbers are associated with atherosclerotic plaque vulnerability and interestingly with future cardiovascular events (S. Willems et.al. 2013). The endogenous trigger that activates mast cells within the lesion remains unidentified. We hypothesized that mast cells are activated via receptors for IgG and/or IgE.

In this study we aimed to establish whether specific immunoglobulin levels in plasma of atherosclerotic patients were related to intraplaque mast cell numbers. In addition, the levels were related to other vulnerable plaque characteristics and baseline clinical data.

Results: Serum levels of total IgG, total IgE and oxLDL specific IgG were determined in 135 patients that underwent carotid endarterectomy. The studied patient population with a mean age of 67 and a male prevalence (71%) reflects a relatively typical population of patients with vascular occlusive diseases. The majority of patients were symptomatic (74%) as illustrated by the incidence of amaurosis fugax, a TIA or a stroke.

No associations were observed between either the serum immunoglobulin levels or the total mast cell numbers in atherosclerotic plaques (total IgG vs. total mast cells r= -0,038, p=0.664) (tIgE vs total mast cells r=-0.038, p=0.664) (oxLDL-IgG vs total mast cells r=0.137 p=0.114). Furthermore, no associations were found between immunoglobulin levels and the following plaque characteristics: lipid core size, degree of calcification, number of macrophages or smooth muscle cells, amount of collagen and number of microvessels.

Interestingly, we observed a negative association between statin use and total IgE (97.5 [43.1-276.8] vs. 157.3 [75.2-545.4] ng/mL, p=0.012) and statin use and oxLDL-IgG (288 [224-406] vs. 399 [282-584] mU/mL, p=0.004).

Conclusions: In patients suffering from carotid artery disease, total IgG or IgE and oxLDL-IgG levels do not associate with plaque mast cell numbers or vulnerable plaque histopathological characteristics These data may indicate that other endogenous factors activate mast cells within the atherosclerotic plaque.

Circulating immunoglobulins are not associated with intraplaque mast cell number and other vulnerable plaque characteristics in patients with carotid artery stenosis

Background

Recently, we have shown that intraplaque mast cell numbers are associated with atherosclerotic plaque vulnerability and with future cardiovascular events, which renders inhibition of mast cell activation of interest for future therapeutic interventions. However, the endogenous triggers that activate mast cells during the progression and destabilization of atherosclerotic lesions remain unidentified. Mast cells can be activated by immunoglobulins and in the present study, we aimed to establish whether specific immunoglobulins in plasma of patients scheduled for carotid endarterectomy were related to (activated) intraplaque mast cell numbers and plasma tryptase levels. In addition, the levels were related to other vulnerable plaque characteristics and baseline clinical data.

Methods and Results

OxLDL-IgG, total IgG and total IgE levels were measured in 135 patients who underwent carotid endarterectomy. No associations were observed between the tested plasma immunoglobulin levels and total mast cell numbers in atherosclerotic plaques. Furthermore, no associations were found between IgG levels and the following plaque characteristics: lipid core size, degree of calcification, number of macrophages or smooth muscle cells, amount of collagen and number of microvessels. Interestingly, statin use was negatively associated with plasma IgE and oxLDL-IgG levels.

Conclusions

In patients suffering from carotid artery disease, total IgE, total IgG and oxLDL-IgG levels do not associate with plaque mast cell numbers or other vulnerable plaque histopathological characteristics. This study thus does not provide evidence that the immunoglobulins tested in our cohort play a role in intraplaque mast cell activation or grade of atherosclerosis.

Soluble ST2 levels are not associated with secondary cardiovascular events and vulnerable plaque phenotype in patients with carotid artery stenosis

OBJECTIVE

Soluble ST2 (sST2), a novel biomarker predictive for heart disease, has recently been shown associated with the progression of atherosclerotic disease in a mouse model. The present study was designed to assess sST2 plasma levels in patients scheduled for carotid endarterectomy and relate it with the occurrence of adverse cardiovascular events during follow-up. In addition, sST2 levels were associated to patient clinical data and atherosclerotic plaque characteristics.

METHODS AND RESULTS

Plasma sST2 levels were measured in 391 patients who underwent carotid endarterectomy and were subsequently followed for 3 years. Primary composite endpoint was the occurrence of an adverse cardiovascular event. At baseline, no differences were observed in sST2 levels between asymptomatic (n = 75) and symptomatic (n = 316) patients (85 [49-122] versus 90 [58-137] pg/ml, p = 0.263). Soluble ST2 plasma levels did not differ between patients who experienced a secondary manifestation of cardiovascular disease and patients who remained free of symptoms (90 [60-129] versus 88 [46-140] pg/ml, p = 0.519). There was no association between sST2 levels and any of the following plaque characteristics: size of a lipid core, degree of calcification, number of macrophages or smooth muscle cells, amount of collagen and number of microvessels.

CONCLUSIONS

Soluble ST2 plasma levels have no predictive value for future cardiovascular events in patients with significant carotid artery stenosis. In addition, we did not observe an association between plasma sST2 levels and the histopathological features of a rupture prone plaque. This study does not provide supportive evidence that sST2 reflects a progressive state of advanced atherosclerotic disease.

Mast cells in human carotid atherosclerotic plaques are associated with intraplaque microvessel density and the occurrence of future cardiovascular events

AIMS

Human autopsy, animal, and cell culture studies together have merged in a concept suggesting participation of mast cells (MCs) in the generation of atherosclerotic plaques. More specifically, these studies have suggested MC-induced intraplaque neovascularization as one mechanism by which MCs may render the plaques vulnerable. The present study was designed to assess the association between MC numbers and neovascularization in human atherosclerotic plaques, and to relate the abundance of plaque MCs to the occurrence of adverse cardiovascular events during the follow-up.

METHODS AND RESULTS

Atherosclerotic plaques of 270 patients suffering from carotid artery stenosis were stained for the presence of MCs (MC tryptase). Furthermore, during a follow-up of 3 years, cardiovascular-related endpoints were assessed in 253 patients. On average a high number of MCs were observed per plaque cross-section [median 108 (55-233) cells per section]. Plaques with high MC numbers revealed an unstable lipid-rich inflammatory phenotype and were associated with symptomatic patients. In addition, MC numbers were positively associated with microvessel density (r = 0.416, P < 0.001). Patients with high intraplaque MC numbers showed significantly more cardiovascular events during the follow-up (58/142 vs. 31/111 events, P = 0.029). In a multivariate analysis with correction for the main risk factors of cardiovascular diseases, MCs remained independently associated with adverse cardiovascular events (P = 0.025).

CONCLUSION

Mast cells are highly prevalent in human carotid atherosclerotic lesions and associated with plaque microvessel density. Furthermore, intraplaque MC numbers associate with future cardiovascular events.