C65 POST–DISCHARGE ARRHYTHMIC RISK STRATIFICATION OF PATIENTS WITH ACUTE MYOCARDITIS AND LIFE–THREATENING VENTRICULAR TACHYARRHYTHMIAS

Aims

The outcomes of patients presenting with acute myocarditis and life–threatening ventricular arrhythmias (LT–VA) are unclear. The aim of this study was to assess the incidence and predictors of recurrent major arrhythmic events (MAEs) after hospital discharge in this patient population.

Methods and Results

We retrospectively analysed 156 patients (median age 44 years; 77% male) discharged with a diagnosis of acute myocarditis and LT–VA from 16 hospitals worldwide. Diagnosis of myocarditis was based on histology or the combination of increased markers of cardiac injury and cardiac magnetic resonance (CMR) Lake Louise criteria. MAEs were defined as the relapse, after discharge, of sudden cardiac death or successfully defibrillated ventricular fibrillation, or sustained ventricular tachycardia (sVT) requiring implantable cardioverter–defibrillator therapy or synchronized external cardioversion. Median follow–up was 23months [first to third quartile (Q1–Q3) 7–60]. Fifty–eight (37.2%) patients experienced MAEs after discharge, at a median of 8 months (Q1–Q3 2.5–24.0 months; 60.3% of MAEs within the first year). At multivariable Cox analysis, variables independently associated with MAEs were presentation with sVT [hazard ratio (HR) 2.90, 95% confidence interval (CI) 1.38–6.11]; late gadolinium enhancement involving ≥2 myocardial segments (HR 4.51, 95% CI 2.39–8.53), and absence of positive short–tau inversion recovery (STIR) (HR 2.59, 95% CI 1.40–4.79) at first CMR.

Conclusions

In this international multicentre study, patients discharged free from HTx or LVAD after an acute myocarditis complicated by LT–VA had a recurrence of MAEs during follow–up of 37.2%, after a median time of 8 months. Initial CMR pattern and sVT at presentation stratify the risk of arrhythmia recurrence.

C75 PHEOCHROMOCYTOMA–INDUCED CARDIOGENIC SHOCK: A MULTICENTER ANALYSIS OF CLINICAL PROFILES, MANAGEMENT AND OUTCOMES

Background

Pheochromocytoma is a rare neuroendocrine tumor that arises from the adrenal gland and overproduces catecholamines; it is an infrequent cause of cardiogenic shock (CS). Several case reports have investigated pheochromocytoma–induced CS, but larger studies have not yet been carried out.

Objectives

Our work aims to describe a multicenter experience in the diagnosis and management of patients with pheochromocytoma–induced CS, and to raise awareness around this rare condition. Methods: We enrolled all patients with a diagnosis of pheochromocytoma–induced CS admitted to the intensive care units of 8 European referral Hospitals.

Results

Among the 17 patients (47% males, mean age 49,5 years), we found that pulmonary congestion was the mostly represented clinical feature (82%). The most represented echocardiographic left ventricle (LV) pattern was the reverse Takotsubo (TTS) pattern with apical hyperkinesis associated with basal– to mid–ventricular hypokinesis (47%). Elevated systemic vascular resistances (SVR) were observed. Endomyocardial biopsy of the LV was performed in one patient showing contraction band necrosis, oedema and inflammatory reaction. 76% of patients were treated with dobutamine, 70% needed noradrenaline, 29% adrenaline, 23.5% were treated with levosimendan and 17% with milrinone. Mechanical circulatory support devices (MCS) were necessary for 65% of patients. All patients benefited from pheochromocytoma’s surgical excision, with 4 patients operated on while under ECLS. All patients recovered, excepted one (presenting a severe left ventricular dilatation at admission) who required cardiac transplantation.

Conclusion

Pheochromocytoma is an infrequent cause of CS, with most often a TTS–like presentation. It should be suspected in case of a CS with high initial SVR and rapid deterioration. MCS must be considered in the most severe cases. The main challenge is to stabilize the patient, mostly with MCS, since it remains a reversible cause of CS with a low mortality rate. Adrenalectomy can safely be performed even when the patient is under MCS.

The prevalence and clinical significance of a reduced ventricular ejection fraction in asymptomatic young elite endurance athletes

Funding Acknowledgements

Type of funding sources: Public grant(s) – National budget only. Main funding source(s): National Health and Medical Research Council of Australia

Background

Ventricular ejection fraction (EF) is the most widely used parameter to evaluate ventricular systolic function. Endurance athletes presenting with a reduced ventricular EF often raise the question of an underlying dilated or arrhythmogenic cardiomyopathy. The clinical significance of a reduced EF in athletes remains to be elucidated.

Purpose

To investigate the prevalence and clinical significance of a reduced EF in asymptomatic endurance athletes.

Methods

Two hundred eighteen asymptomatic young elite endurance athletes were evaluated at baseline. Cardiac magnetic resonance imaging (CMR) was performed to assess cardiac volumes, left ventricular and right ventricular EF (LVEF and RVEF), mass and fibrosis. Athletes with reduced EF (ATrEF) were defined as those having LVEF<50% and/or RVEF<45%. Ventricular systolic and diastolic function were assessed by trans-thoracic echocardiography. A 12-lead ECG and 24-hour holtermonitoring assessed electrical alterations and arrhythmias. In 145 athletes, LV and RV contractile reserve was evaluated by exercise CMR. Cardiopulmonary testing was performed in all athletes to measure maximal oxygen uptake (VO2max).

Results

Thirty-one ATrEF (14.2%) were compared to 187 athletes with a preserved EF (ATpEF). ATrEF were more frequently males (93 vs 77% male, p=0.033) but did not differ from ATpEF with regard to age (18.8±2.1 vs 18.3±2.1 years, p=0.25). Ten athletes had an isolated reduced LVEF, 10 had an isolated reduced RVEF and 11 had both a reduced LVEF and RVEF. ATrEF had similar end-diastolic volumes and cardiac mass but differed by higher end-systolic volumes.

Peak exercise LVEF and RVEF determined by exercise CMR remained lower in ATrEF (68±3 vs 73±4% and 62±6 vs 69±5%, p<0.001) but contractile reserve was greater (ΔLVEF 18±5 vs 14±4% and ΔRVEF 19±5 vs 15±5%, p<0.01).

A reduced EF was not associated with lower exercise capacity, in fact VO2max was higher in ATrEF than in ATpEF (65±6 vs 62±9mL/kg/min, p=0.020) and the percentage of predicted VO2max by the Wasserman equation were similar (151±14 vs 149±21%, p=0.533).

Fibrosis was present in 3 ATrEF and 18 ATpEF (9.7 vs 9.6%, p=0.993) and was isolated to the RV hinge-points in all but 3 ATpEF who had midmyocardial LV lateral wall fibrosis. LV systolic strain (-17.5±2.0 vs -19±2.1%, p<0.001) was lower in ATrEF whereas RV free wall systolic strain (-24.9±3.7 vs -25.1±3.5%, p=0.776) was similar. Diastolic function was normal in all ATrEF and ATpEF. Pathologic T-wave inversions were present in 2 ATrEF and 13 ATpEF (6.5 vs 7%, p=0.999). Ventricular premature beats (VPB) were infrequent but more prevalent in ATrEF than in ATpEF (2[0-18] vs 1[0-2]/24h, p=0.025; 16.1 vs 2.7% >100/24h, p=0.006).

Conclusion

A reduced ventricular EF is common in asymptomatic young elite endurance athletes, is more frequent in males but is not associated with structural, functional or electrical abnormalities apart from a minor excess in VPB.

Clinical and haemodynamic effects of percutaneous edge-to-edge mitral valve repair in atrial versus ventricular functional mitral regurgitation

Background

Atrial functional mitral regurgitation (A-FMR) is a novel entity characterized by a MR due to atrial remodeling but with preserved left ventricular (LV) systolic function.

Purpose

To assess the clinical and haemodynamic impact of percutaneous edge-to-edge mitral valve repair with MitraClip in patients with A-FMR as compared to ventricular (V)-FMR.

Methods

MR grade, functional status (NYHA class), and major adverse cardiac events (MACE= all-cause mortality or hospitalization for heart failure (HF)) were evaluated in 52 A-FMR patients (pts.) and in 307 V-FMR pts. who underwent MitraClip implantation in 7 Belgian centers. In a subgroup of 56 pts (10 A-FMR and 46 V-FMR) haemodynamic assessment during a symptom-limited exercise echocardiography was performed before and 6-month after intervention.

Results

MitraClip implantation resulted in similar MR reductions in A-FMR and V-FMR (MR grade ≤2 at 6-month in 94% versus 82%, respectively (p=0.08)) and was associated with improvement of functional status in both groups (NYHA class ≤2 at 6 months in 90% versus 80%, respectively (p=0.2)). Serial haemodynamic assessment revealed that the cardiac output at 6-month was significantly higher in A-FMR pts. both at rest (5.1±1.5 L/min versus 3.8±1.5 L/min, p=0.002) and during peak exercise (7.9±2.4 L/min versus 6.1±2.1 L/min, p=0.02). Also the reduction in systolic pulmonary artery pressure (sPAP) was more pronounced in A-FMR: Δ sPAP at rest – 13.1±15.1 mmHg versus – 2.2±13.3 mmHg (p=0.03). During a follow-up period of 1.3±1.2 years MACE rate was significantly lower in A-FMR versus V-FMR with an adjusted OR of 0.46 (95% CI 0.24–0.88, see figure), which was mainly driven by a reduction in HF hospitalization.

Conclusion

Percutaneous edge-to-edge mitral valve repair with MitraClip is at least as effective in A-FMR as in V-FMR in reducing MR. But, the haemodynamic and clinical impact is stronger in A-FMR pts.

Funding Acknowledgement

Type of funding sources: None. MACE in A-FMR versus V-FMR pts

Pulmonary congestion during exercise stress echocardiography in hypertrophic cardiomyopathy

Background

B-lines detected by lung ultrasound (LUS) indicate pulmonary congestion during exercise stress echo (ESE).

Aim

To assess B-lines during ESE in hypertrophic cardiomyopathy (HCM).

Methods

We enrolled 110 HCM patients (age 52±16 years, 74 males) referred for ESE (treadmill in 39, semi-supine bicycle in 71 patients) in 10 quality-controlled centers from 8 countries (Belgium, Brazil, Bulgaria, Hungary, Italy, Portugal, Serbia, Spain). ESE assessment included: left ventricular outflow tract gradient (LVOTG); mitral regurgitation (MR, score from 0 to 3); E/e'; systolic pulmonary arterial pressure (SPAP, from tricuspid regurgitant jet velocity); end-diastolic volume (EDV); left atrial volume (LAV). B-lines were assessed by LUS with the 4-site simplified scan, each site scored from 0 (normal A-lines) to 10 (coalescing B-lines). The positivity criterion was a B-line score stress ≥2 points.

Results

LUS was feasible in all subjects, with additional scanning and analysis time <1 minute for each stage (rest and peak stress). B-lines were present in 13 patients at rest and in 33 during stress (12 vs 30%, p<0.001). When compared to patients without stress B-lines (Group 2, n=77), patients with B-lines (Group 1) showed higher values of change from rest to stress (Δ) in LVOTG (Group 1= 39±54 vs Group 2= 21±24 mm Hg, p=0.015) and ΔMR grade (Group 1= 0.7±0.8 vs Group 2= 0.1±0.5, p<0.001), more frequent peak stress E/e' ≥15 (Group 1=61% vs Group 2=27%, p=0.007), lower peak EDV (Group 1= 86±35 vs Group 2= 102±33 ml, p=0.039) and higher peak SPAP (Group 1= 60±21 vs Group 2= 39±12 mm Hg, p<0.001): see figure. At multivariable logistic regression analysis, presence of stress B-lines was predicted by ΔMR grade (odds ratio: 3.96, 95% CI 1.46–10.71) and stress E/e' ≥15 (odds ratio: 4.95, 95% CI 1.24–19.70).

Conclusion

B-lines are found in about 1 of 10 HCM patients at rest and in 1 of 3 during ESE. Acute backward heart failure during exercise can recognize multiple mechanisms in HCM, and ESE can help to capture this heterogeneity.

Funding Acknowledgement

Type of funding sources: None. Functional correlates of stress B-lines

Hinge point fibrosis in athletes is not associated with structural, functional or electrical consequences: a comparison between young and middle-aged elite endurance athletes

Background

The health benefits of extensive endurance training have been debated due to the report of myocardial fibrosis (MF), arrhythmias and temporary post-race cardiac impairment in middle-aged and veteran athletes. The extent of these changes is unknown in elite young athletes.

Purpose

To assess the prevalence of MF and its structural, functional and electrical impact in highly trained young endurance athletes (YA, 15–23 years) as compared to middle-aged athletes (MA, 30–50 years). We hypothesised that MF would be more frequent in MA and associated with more structural, functional and electrical abnormalities.

Methods

We prospectively assessed 197 YA and 34 MA. All had ECG, maximal oxygen consumption (VO2max) testing, cardiac magnetic resonance imaging (CMR), echocardiography and 24h-holter. Indexed left ventricular and right ventricular end diastolic volume (LVEDVi, RVEDVi), ejection fraction (LVEF, RVEF), left ventricular mass (LVMi), and MF defined as delayed gadolinium enhancement were assessed by CMR. LV and RV free wall strain (LVSL, RVfwSL) were assessed by 2D speckle tracking echocardiography. Ventricular premature beats (VPB) and non-sustained ventricular tachycardia (nsVT) were assessed by 24h-holter.

Results

YA and MA (18±2 vs 38±5 years [p<0.01]; 78% vs 80% male [p=0.99]) with an elite level of fitness (VO2max 61±8 vs 54±10 mL/min/kg [p<0.01]; % predicted VO2max 150±20 vs 158±30 [p=0.02]) had a large variance in LV and RV remodelling (Figure 1). MF was seen in 28 athletes (12.5%) and more prevalent in MA than in YA (23.5 vs 10.5%, p=0.048). MF was limited to the hinge points in all 8 MA with MF and 17 YA. 3 YA had LV lateral wall subepicardial MF. 27 of 187 (14.4%) male athletes had MF compared to 1 of 50 (2%) female athletes (p=0.01).

MF+ MA(A) and YA(B) as well as MF− MA(C) and YA(D) had similar structural remodelling (LVEDVi 110±14 vs 118±14 vs 113±19 vs 110±16 mL/m2; RVEDVi 120±14 vs 128±17 vs 117±19 vs 125±23mL/m2; LVMi 77±11 vs 83±14 vs 81±14 vs 77±15g/m2, p>0.05). LVEF, LVSL and RVSL were similar (59±3 vs 58±5 vs 61±6 vs 58±6%; −18.8±2 vs −18.8±2 vs −19.8±2 vs −19.3±2%; −26.3±2.4 vs −24.4±2.4; −26.3±3 vs −25.8±3.5% respectively, p>0.05). LVEF <50% was seen in 19 (8.2%) athletes (0 [0%] vs [5%] 1 vs 1 [3.8%] vs 17 [9.6%]; p=0.51). RVEF was higher in D compared to C without further differences between groups (54±4 vs 54±6 vs 53±6 vs 57±5, p=0.005). RVEF<45% was seen 21 (9.1%) athletes (0 [0%] vs 1 [5%] vs 0 [0%] vs 20 [11.3%]; p=0.14). Abnormal T-wave inversion was similar (12.5 vs 5 vs 7.4 vs 6.2%, p=0.93) as was the prevalence of >100VPB/24h (12.5 vs 5 vs 11.1 vs 5.1%, p=0.42). 2 athletes had nsVT, both in D. All had similar exercise capacity (% predicted VO2max 157±26 vs 152±15 vs 147±24 vs 158±32%; p=0.11).

Conclusion

Hinge-point fibrosis was more prevalent in MA, possibly due to repeated hemodynamic stress during exercise, but is not associated with structural, functional or electrical consequences.

Figure 1. Cardiac remodelling in elite athletes

Funding Acknowledgement

Type of funding source: Public grant(s) – National budget only. Main funding source(s): Fonds voor Wetenschappelijk Onderzoek (FWO)

P1878Long-term effect of atrial fibrillation on the evolution of mitral and tricuspid valve regurgitation

Background

While severe mitral regurgitation is a well-established risk factor for atrial fibrillation (AF), it is less known whether atrial fibrillation induces mitral/tricuspid valve regurgitation (MR/TR). The present study aims to identify the long-term effects of permanent or non-permanent AF on atrial remodelling and on the progression of MR/TR.

Methods

The severity of MR/TR was assessed at baseline and after a period of 65±10 months in 37 patients with permanent AF, in 80 patients with non-permanent AF (of whom 43 were treated with ablation) and in 53 control patients with persistent sinus rhythm. MR/TR was qualitatively assessed by the multi-integrative approach, and quantitatively by measurement of the colour jet area.

Results

At baseline, AF patients had larger MR jet areas than control patients. At follow up, progression of MR, expressed as delta MR jet area, was 0.05±1.3 cm2 in the control group, 0.73±2.1 cm2 in the non-permanent AF group and 1.95±3.6 cm2 in the permanent AF group (p=0.001). Severe MR at follow up was observed in 0%, 2.5%, 8%, respectively. After adjustment for baseline clinical and echocardiographic parameters, permanent AF remained independently associated with the progression of MR. There was a significant positive correlation between a progression of MR and an increase in left atrial volume index (r=0.31, p<0.001). Although rhythm control in non-permanent AF patients was better with AF ablation than with medical treatment only, the MR evolution was similar (delta MR jet area: 0.85±2.05 cm2 vs 0.61±2.12 cm2, p=0.6). Comparable findings, albeit less pronounced, were observed for the association between of AF and TR progression.

MR jet area

Conclusions

The presence of longstanding AF is associated with a significant progression of MR/TR mainly due to atrial remodelling. Our data showed a beneficial effect of sustained rhythm control, either medically or by ablation, on MR/TR progression.