It's a long way to the top! Congenital venous anomalies and left isomerism limiting atrial fibrillation transcatheter ablation

BACKGROUND

Atrial fibrillation is the most common sustained cardiac arrhythmia in adults and it is associated with a high burden of mortality and morbidity worldwide. Catheter ablation is increasingly used to improve symptoms and prognosis in selected patients. Lower limb venous access with subsequent transseptal approach to the left atrium is the standard procedure for atrial fibrillation catheter ablation.

CASE PRESENTATION

We report an unusual case of complex venous anomaly with a left-sided inferior vena cava with hemiazygos continuation to a persistent left superior vena cava draining in an enlarged coronary sinus in a patient with persistent atrial fibrillation scheduled for transcatheter ablation.

DISCUSSION

Lower limb venous anomalies may limit a standard transseptal approach to the left atrium thus precluding an effective catheter ablation procedure for atrial fibrillation. Alternative interventions, such as unconventional percutaneous access, thoracoscopic approach and "ablate and pace" procedures, may be necessary in patients with symptomatic atrial fibrillation and complex venous anomalies.

Mechanical Cardiopulmonary Resuscitation Devices: Evidence Synthesis with an Umbrella Review

AIM

Sudden cardiac arrest is a significant cause of death worldwide. Good quality cardiopulmonary resuscitation increases patients' survival. Manual cardiopulmonary resuscitation is often ineffective as rescuers may experience physical and mental fatigue. Mechanical cardiopulmonary resuscitation devices are designed to address this issue, providing an automated approach for high-quality resuscitation. In the present comprehensive umbrella review we summarize current evidence on mechanical devices.

METHODS

We searched systematic reviews on mechanical devices in MEDLINE/PubMed. Effect estimates were obtained from original reports, including 95% confidence intervals and p values, when applicable and available, focusing on return of spontaneous circulation, survival to discharge or 30 days, survival with good neurological outcome, and resuscitation-related injuries.

RESULTS

From 21 potentially pertinent publications, we shortlisted 10 reviews, each including between 5 and 22 studies. AutoPulse, LUCAS, and LUCAS-2 were among the investigated devices. Most reviews concluded toward mechanical devices being similar or better than manual resuscitation for return of spontaneous circulation and 30-days survival. Regarding survival with good neurological function, some reviews lacked data, while the remaining ones reported similar results or worse outcomes in patients undergoing mechanical resuscitation. Focusing on resuscitation-related injuries, data were limited or conflicting with one review reporting higher rates of injuries with mechanical devices, and two others suggesting similar outcomes.

CONCLUSIONS

Manual and mechanical cardiopulmonary resuscitation appear to be similar in terms of return of spontaneous circulation and short-term survival. Mechanical devices appear to be associated with higher resuscitation-related injuries, while there are conflicting data in terms of survival with good neurological outcomes. A comprehensive and large dedicated randomized trial is urgently needed.

Kissing shockwave balloon in a case of extensive calcified abdominal aorta during transfemoral TAVI

An 84-year-old man with extensive calcified atherosclerosis of the infrarenal abdominal aorta was diagnosed with severe aortic valve stenosis, presenting with dyspnea. To facilitate transfemoral approach during the TAVI procedure, IVUS-guided intravascular lithotripsy was successfully performed using Kissing Shockwave Balloon Technique.

Impact of thrombus aspiration on left ventricular remodeling and function in patients with ST-segment elevation myocardial infarction: A meta-analysis of randomized controlled trials

BACKGROUND

Routine thrombus aspiration (TA) does not improve clinical outcomes in patients with ST-segment-elevation myocardial infarction (STEMI), although data from meta-analyses suggest that patients with high thrombus burden may benefit from it. The impact of TA on left ventricular (LV) functional recovery and remodeling after STEMI remains controversial. We aimed to pool data from randomized controlled trials (RCTs) on the impact of TA on LV function and remodeling after primary percutaneous coronary intervention (pPCI).

METHODS

PubMed and CENTRAL databases were scanned for eligible studies. Primary outcome measures were: LV ejection fraction (LVEF), LV end diastolic volume (LVEDV), LV end systolic volume (LVESV) and wall motion score index (WMSI). A primary pre-specified subgroup analysis was performed comparing manual TA with mechanical TA.

RESULTS

A total of 28 studies enrolling 4990 patients were included. WMSI was lower in TA group than in control (mean difference [MD] -0.11, 95% confidence interval [CI] -0.19 to -0.03). A greater LVEF (MD 1.91, 95% CI 0.76 to 3) and a smaller LVESV (MD -6.19, 95% CI -8.7 to -3.6) were observed in manual TA group compared to control. Meta regressions including patients with left anterior descending artery (LAD) involvement showed an association between TA use and the reduction of both LVEDV and LVESV (z = -2.13, p = 0.03; z = -3.7, p < 0.01) and the improvement in myocardial salvage index (z = 2.04, p = 0.04).

CONCLUSION

TA is associated with improved LV function. TA technique, total ischemic time and LAD involvement appears to influence TA benefit on post-infarction LV remodeling.

Pre-stenting residual thrombotic volume assessed by dual quantitative coronary angiography predicts microvascular obstruction in patients with ST-segment elevation myocardial infarction undergoing primary percutaneous coronary intervention

BACKGROUND

Microvascular obstruction (MVO) is a frequent occurrence after primary percutaneous coronary intervention (pPCI), and is associated with adverse left ventricular remodeling and worse clinical outcome. Distal embolization of thrombotic material is one of the most important underlying mechanisms. The aim of this study was to investigate the relation between the thrombotic volume evaluated by dual quantitative coronary angiography (QCA) prior to stenting and the occurrence of MVO as assessed by cardiac magnetic resonance (CMR).

METHODS

Forty-eight patients with ST-segment elevation myocardial infarction (STEMI) undergoing pPCI and receiving CMR within 7 days from admission were included. Pre-stenting residual thrombus volume at the site of the culprit lesion was measured by applying automated edge detection and video-assisted densitometry techniques (i.e., dual-QCA), and patients were categorized into tertiles of thrombus volume. The presence of delayed-enhancement MVO, as well as its extent (MVO mass), were assessed by CMR.

RESULTS

Pre-stenting dual-QCA thrombus volume was significantly greater in patients with MVO than in those without (5.85 mm³ [2.05-16.71] vs. 1.88 mm³ [1.03-6.92], P=0.009). Patients in the highest tertile showed greater MVO mass compared to those in the mid and lowest tertiles (113.3 gr [0.0-203.8] vs. 58.5 g [0.00-144.4] vs. 0.0 g [0.0-60.225], respectively; P=0.031). The best cut-off value of dual-QCA thrombus volume for prediction of MVO was 2.07 mm³ (AUC: 0.720). The addition of dual-QCA thrombus volume to the traditional angiographic indices of no-reflow enhanced the prediction of MVO by CMR (R=0.752).

CONCLUSIONS

Pre-stenting dual-QCA thrombus volume is associated with the presence and extent of MVO detected by CMR in patients with STEMI. This methodology may aid the identification of patients at higher risk of MVO and guide adoption of preventive strategies.

Case report: An unusual case of phrenic nerve stimulation in a patient with single chamber implantable cardioverter defibrillator

Background

Phrenic nerve stimulation is a well-recognized complication related to cardiac implantable electronic devices, in particular with left ventricular coronary sinus pacing leads for cardiac resynchronization therapy.

Case presentation

We report an unusual case of symptomatic phrenic nerve stimulation due to inadvertent placement of a right ventricular defibrillation lead in coronary sinus posterior branch in a patient with heart failure with reduced ejection fraction with a recently implanted single-chamber cardioverter defibrillator.

Discussion

Phrenic nerve stimulation is a relatively common complication of left ventricular pacing. Inadvertent placement of a right ventricular lead in a coronary sinus branch is a rare but possible cause of phrenic nerve stimulation. Careful evaluation of intraprocedural fluoroscopic and electrocardiographic appearance of pacing and defibrillation leads during implantation may prevent inadvertent placement of a right ventricular lead in the coronary sinus.

541 A CASE REPORT OF ACUTE CORONARY SYNDROME: VERY LATE STENT THROMBOSIS DUE TO MAJOR STENT MALAPPOSITION

Rational

The occurrence of stent thrombosis (ST) is a rare event, but it remains one of the most catastrophic complications following percutaneous coronary intervention (PCI). Coronary angiography has limited value in differentiating the causative factors responsible for ST.

Technical resolutions

We report a case of a 78-year-old male, hypertensive and dyslipidemic who underwent PCI with stenting of the mid left anterior descending artery (LAD) due to chronic coronary syndrome (CCD) two years before. He was admitted to our emergency department for syncopal episode occurred at rest followed by chest pain radiating to the left arm and to the neck. At the time of admission, his electrocardiogram showed diffuse ST-segment elevation in V2-V6 and DI-aVL, therefore patient was urgently sent to the cath lab. Coronary angiography showed LAD occlusion at the proximal edge of the previously implanted stent with TIMI flow grade 0 and TIMI thrombus grade 5. Multiple thrombus aspiration passes were performed with distal flow restoration, followed by intracoronary abciximab administration. After additional thrombus aspiration passes, ST-segment resolution was observed and chest pain improved significantly. OCT imaging of mid-to-proximal LAD was then performed to better characterize the cause of thrombosis. OCT revealed in stent-thrombosis with mixed thrombus (6 mm length, arc &gt;270°) associated with major stent malapposition (maximum malapposition distance: 1.3 mm) at the proximal edge of the previous implanted stent, without evidence of neoatherosclerosis and/or residual disease with unstable features at the stent edges. Additional thrombus aspiration was performed, further reducing the thrombotic burden. As te patient was hemodynamically stable and asymptomatic, with TIMI flow grade 3 at coronary angiography, we decided to start dual antiplatelet therapy (ASA+ticagrelor) plus continuous heparin i.v. infusion, and to defer PCI, planning a control coronary angiography after 72 hours. After 72 hours, OCT revealed almost complete thrombus resolution, and guided PCI with a 4.0/8 mm everolimus-eluting stent in overlap with the previously implanted stent, postdilated with a 4.5 semi-compliant balloon at 18 atm. Revascularization was completed with an OCT-guided PCI of the proximal left circumflex during the same procedure.

Clinical implications

Our case demonstrates the utility of OCT in determining thrombus burden and assessing the causes of late stent failure, guiding PCI. In this case, OCT was useful as diagnostic tool to identify the mechanism underlying the very-late ST, and as guidance for treatment. It enabled to exclude neoatherosclerosis and/or unstable plaques at stent edges, leaving us more confident to defer PCI after 72 h of antithrombotic therapy.

Perspectives

The occurrence of ST is rare, but it remains one of the most catastrophic complications following PCI. Coronary angiography has limited value in differentiating the causative factors responsible for ST, while OCT allows to detect and characterize the causes of stent thrombosis (i.e., evaluate thrombus burden, presence of neoatherosclerosis, stent malapposition/underxpansion, uncovred stent struts, significant disease and/or unstable plaques at the stent edges, etc.). A better understanding of the pathophysiological mechanism underlying ST is an important clinical need. The increasing availability of high-resolution intravascular imaging techniques such as OCT provides new opportunities for tailoring treatment strategy and guiding PCI.

1094 MULTIVESSEL CORONARY ARTERY SPASM TRIGGERED BY GANGLIONATED PLEXI STIMULATION DURING ATRIAL FIBRILLATION RADIOFREQUENCY CATHETER ABLATYION: A CASE REPORT

Background

Atrial fibrillation is the most common sustained cardiac arrhythmia in adults and it is associated with a high burden of mortality and morbidity worldwide. Atrial fibrillation could be managed with rate-control or rhythm-control strategies. The latter is increasingly used to improve symptoms and prognosis in selected patients, especially after the development of catheter ablation. Although this technique is generally considered safe, it is not free from rare but life-threatening procedure-related adverse events. Among these, coronary artery spasm is an uncommon but potentially fatal complication that requires immediate diagnosis and treatment.

Case summary

We report a case of severe multivessel coronary artery spasm triggered by ganglionated plexi stimulation during pulmonary vein isolation with radiofrequency catheter ablation in a patient with persistent atrial fibrillation, promptly resolved after intracoronary nitrate administration.

Discussion

Although rare, coronary artery spasm is a serious complication of atrial fibrillation catheter ablation. Immediate invasive coronary angiography is key for both diagnosis confirmation and treatment of such dangerous condition. As the number of invasive procedures increases, it is important that both interventional and general cardiologists are aware of possible procedure-related adverse events.

1101 AN UNUSUAL CASE OF PHRENIC NERVE STIMULATION IN A PATIENT WITH SINGLE CHAMBER IMPLANTABLE CARDIOVERTER DEFIBRILLATOR

Background

Phrenic nerve stimulation is a well-recognized complication related to cardiac implantable electronic devices, in particular with left ventricular coronary sinus pacing leads for cardiac resynchronization therapy.

Case presentation

We report an unusual case of symptomatic phrenic nerve stimulation due to inadvertent placement of a right ventricular defibrillation lead in coronary sinus posterior branch in a patient with heart failure with reduced ejection fraction with a recently implanted single-chamber cardioverter defibrillator.

Discussion

Phrenic nerve stimulation is a relatively common complication of left ventricular pacing. Inadvertent placement of a right ventricular lead in a coronary sinus branch is a rare but possible cause of phrenic nerve stimulation. Careful evaluation of intraprocedural fluoroscopic and electrocardiographic appearance of pacing and defibrillation leads during implantation may prevent inadvertent placement of a right ventricular lead in the coronary sinus.

1150 SEX-BASED DIFFERENCES IN CORONARY PLAQUE PHENOTYPE AND HEALING AT OPTICAL COHERENCE TOMOGRAPHY (OCT) ANALYSIS

Introduction

Atherosclerotic plaque healing is a dynamic process that promotes plaque repair after destabilization. Previous studies showed that healed plaques are more common in patients with chronic coronary syndrome than in those with acute coronary syndrome, suggesting that they might be a marker of clinical stability. The mechanisms underlying plaque healing are not completely understood. The aim of the present study was to evaluate sex-based differences in plaque phenotype and healing of non-culprit coronary lesions by optical coherence tomography.

Methods

In this observational, single-center cohort study, we enrolled patients from the OCT Registry of the Fondazione Policlinico A Gemelli IRCCS. A total of 205 patients with both acute coronary syndromes or chronic coronary syndromes undergoing coronary angiography and intravascular OCT imaging of non-culprit vessels were included in the analysis and divided into two groups according to gender.

Results

Of 205 patients, 153 were male (75%) and 52 (25%) female. Compared with male patients, female patients had lower prevalence of lipid-rich plaque (40.4% vs. 57.7%; p=0.030), plaque rupture (7.7% vs. 21.2%; p=0.028) and cholesterol crystal (13.5% vs. 29.5%; p=0.022). Mean lipid arc and calcium depht were significantly lower in female patients than in male ones (118.0° ± 79.9° vs. 135.5° ± 77.9°; p=0.011; and 52.7 µm ± 79.2 µm vs. 72.3 µm ± 93.5 µm; p=0.007) while fibrous cap tended to be thicker (108.2 µm ± 70.4 µm vs. 96.2 µm ± 72.9 µm; p=0.055). Healed plaques were significantly more frequent in female patients than in male patients (51.9% vs 34.6%; p = 0.027). The prevalence of fibrous plaque, thrombi, neovascularization, diffuse calcifications and spotty calcification was not different between the two groups.

Conclusion

Females have a distinct atherosclerotic phenotype and healing capacity compared with male patients, including lower prevalence of lipid-rich plaque, cholesterol crystals and plaque ruptures and higher prevalence of healed plaques in non-culprit coronary lesions.

499 What light through yonder window breaks? Benefits of optical coherence tomography (OCT) in a case of spontaneous coronary artery dissection

Aims

Spontaneous coronary artery dissection (SCAD) is a non-traumatic and non-iatrogenic separation of the coronary arterial walls, creating a false lumen. SCAD is an infrequent and often missed diagnosis especially in women presenting with acute coronary syndrome and in the majority of cases angiography alone could be insufficient for identification.

Methods and results

A 43-year-old woman presented to the Emergency Department of Fondazione Policlinico Universitario A. Gemelli IRCCS (Rome, Italy) for oppressive acute chest pain radiated to the right jaw, resolved spontaneously within a few minutes. Physical examination, including cardiovascular evaluation, was normal. High-sensitivity troponin was 152 ng/l and 250 ng/l in two serial determination (reference range, 0.0–37 ng/l). EKG showed sinus rhythm with no significant ST-segment alterations. Echocardiography revealed preserved biventricular systolic function with mild hypokinesia of the apical segments of the left ventricle. A diagnosis of NSTEMI was made based on clinical and laboratory parameters. Thus, urgent coronary angiography was performed, which demonstrated a single vessel disease with an eccentric, and angiographically complex stenosis of the proximal left anterior descending (LAD) artery with an image of plus compatible with a plaque ulceration. In order to define the extension of the disease and ostium involvement for a better procedural planning, OCT imaging was performed. Surprisingly, OCT showed a intramural haematoma extending from the ADA ostium to the proximal tract (approximately 22 mm) with ulceration in the body, minimal lumen area (MLA) 2.0 mm2 and evidence of normal trilaminar structure of the vessel both on downstream and upstream of the lesion. The angiographic features were compatible with type 2A SCAD. The therapeutic management was conservative with continuation of the double antiplatelet therapy and remote CT monitoring. Three days later, because of a new onset of chest pain and slight elevation of the ST segment on EKG, was performed a coronarographic control: the angiographic appearance of the lesion was substantially unchanged; OCT showed unmodified longitudinal extension of the lesion (about 22 mm) and relative increase in the endoluminal caliber compared to the previous examination (MLA 4.0 mm2).After 2 weeks, coronary CTA control was carried out, which documented the stability of the intramural hematoma in the proximal LAD, extended for 22 mm and with a maximum thickness of 2 mm, determining lumen narrowing of 40–45% The patient was discharged on medical therapy and no events occurred during the follow-up. Six month later, repeat CTA showed a complete resorption of the intramural haematoma.

Conclusions

In this case we highlight the utility of intravascular imaging, in particular OCT, in the evaluation of angiographic lesions of non-univocal interpretation and how its use can change the management and prognosis of ACS patients. Furthermore, the spontaneous resolution of the clinical and anatomical scenario through conservative treatment additionally confirms spontaneous healing as the natural history of SCAD and foreground the role of precise diagnosis (and intravascular imaging showed to improve it) for therapy shift and calibration.

734 Have I lost my large rupture cavity? The fingerprint of atherosclerotic plaque healing detected by serial optical coherence tomography imaging

A 64-year-old man, prior smoker, with a history of paroxysmal atrial fibrillation was referred to our hospital due to worsening dyspnoea, progressively worsening angina, and a positive stress EKG testing. Coronary angiography (CAG) showed an angiographically intermediate stenosis of the mid left anterior descending (LAD) artery and a focal, complex lesion of the distal right coronary artery (RCA) (Figure 1A and B, red arrow). Treatment of the LAD stenosis was deferred based on a negative fractional flow reserve value (i.e. 0.85). Optical coherence tomography (OCT) imaging (ILUMIEN OPTIS, Abbott Vascular, Santa Clara, CA) was performed to better characterize the RCA lesion, which disclosed a ruptured thin-cap fibroatheroma (TCFA) with a large ‘empty’ cavity (Figure 1C–G, red arrows) and overlying ‘layered’ tissue (Figure 1H, white arrowheads). Based on these OCT findings, suggestive of initial plaque healing, and on a large residual lumen dimension (i.e. minimum lumen area, MLA, at the rupture site: 7.7 mm2), this lesion was not treated with percutaneous coronary intervention. The patient was discharged on aspirin, edoxaban, metoprolol, rosuvastatin, and ezetimibe, and remained clinically stable for more than 1 year. Due to angina recurrence, a new CAG was performed 18 months after the first admission, revealing a progression of the mid LAD stenosis that was treated with a 2.5/28 mm drug-eluting stent, and an improvement of the RCA lesion angiographic appearance (smooth contour) (Figure 1A′–B′). RCA OCT imaging was repeated demonstrating a complete healing of the large rupture cavity with all the hallmarks of the reparative process (Figure 1C′–H′): (1) re-established fibrous cap integrity and smooth vessel lumen profile; (2) thickening of the fibrous cap and reduction of lipid burden (i.e., transformation of TCFA into thick-cap fibroatheroma, ThCFA); (3) replacement of the ‘empty’ cavity with new ‘granulation tissue’; (4) initial calcification of the plaque; (5) heterogeneous signal-rich layers with distinct optical-signal intensity (layered, ‘onion-like’ pattern); and (6) mild lumen narrowing (MLA at the rupture site: 6.9 mm2).

Collapse

736 Hazy spots: through the eye of optical coherence tomography

Aims

Acute stent thrombosis after coronary artery stent placement is a rare but serious complication in percutaneous coronary intervention (PCI). Stenting culprit lesions in acute coronary syndrome (ACS) has higher risk of acute stent thrombosis than stable coronary artery disease, and many local and systemic factors may contribute to increase this risk. Tissue protrusion (TP), and in particular, plaque prolapse after PCI can play a role in acute stent thrombosis, and intra-vessel imaging is the principal instrument to identify such underlying lumen alteration after stent implantation, and guide intervention.

Methods and results

We report the case of a 54-year-old man with a history of hypertension, dyslipidemia, type 2 diabetes mellitus, obesity and no other relevant comorbidities in remote history, who underwent a coronary angiography for an unstable angina. A long, calcific sub-occlusion of the left anterior descending artery (LAD), which involved LAD-first diagonal branch (D1) bifurcation (Medina 1.1.1) and LAD-D2 bifurcation (Medina 1.1.0) was found. After deployment of two overlapping drug-eluting stents (DES), (ULTIMASTER TANSEI 3.0 × 38 mm and 3.0 × 21 mm) and struts apposition optimization with sequence of proximal optimization technique (POT) on D1 and D2, and a kissing balloon technique (KS) on LAD-D2 bifurcation, a ‘hazy’ in-stent image was detected right after the LAD-D2 bifurcation, suggesting an acute in-stent thrombosis, in absence of flow alteration (TIMI 3), symptoms or ECG modifications. Multiple thrombus-aspiration were made and resulted in abundant thrombus removal and improvement in the angiographic image, with persistent valid flow on every three vessels (TIMI 3). After 5 days of triple anticoagulant therapy with ticagrelor, cardioaspirin and UFH infusion, he underwent a new coronary angiography control. A similar ‘hazy’ image was detected right after LAD-D2 bifurcation within the LAD. An optical coherence tomography (OCT) pullback was made to assess the nature of the angiographic finding. OCT showed good struts apposition in almost every cross-sectional images, but an evident TP was detected right on the angiographic hazy spot. OCT allowed to evaluate the lipid-richness of the stented plaque and the nature of the TP, which was mixed with evident both white and red thrombus apposition (minimum luminal area measured 4.5 mm2). OCT guided a new PCI, with a stent-in-stent implantation on LAD. TP was absent on the post-PCI OCT run.

Conclusions

In this report, we showed the usefulness of OCT in revealing a potential high risk thrombogenic source. OCT not only characterized something that angiography alone couldn’t, but suggested the etiology of the amount of thrombus removed by the vessel during the first PCI. Indeed, despite an optimized cycle of anticoagulant therapy, OCT still revealed several mixed thrombus apposition on the TP, and this suggested its role in the acute stent thrombosis. OCT guided the choice to appose a new stent-in-stent to solve a potential thrombogenic source.

698 Acute coronary syndrome in neoatherosclerosis with major stent malapposition and OCT-guided PCI

Aims

Due to its bidimensional nature, angiography is not always sufficient to accurately define coronary lesions, in particular when they are ambiguous or indeterminate. Intracoronary imaging, such as intravascular ultrasound or optical coherence tomography (OCT), is often useful in these cases to better characterize the ambiguous angiographic images, to identify the culprit lesion during acute coronary syndrome (ACS) and to guide percutaneous coronary intervention (PCI).

Methods and results

We report a case of a 61-year-old male with multiple cardiovascular risk factors and a previous ST-segment elevation myocardial infarction treated by PCI of the right coronary artery (RCA) about 7 years before, wo was admitted to our emergency department after acute onset chest pain. At the time of admission, his ECG was normal and cardiac troponin was below the upper reference limit of normality with positive molecular SARS-CoV-2 diagnostic test. Echocardiogram disclosed a mild left ventricular dysfunction with inferior wall hypokinesia. Coronary angiography showed a moderate in-stent restenosis at mid RCA and a hazy, undetermined image at the proximal edge of the previously implanted stent. Left coronary artery angiography showed only diffuse atherosclerotic disease without significant stenoses and a myocardial bridge at the mid tract of left anterior descending artery. OCT pullback of RCA to better characterize the undetermined lesions shown by angiography. OCT revealed significant neointima hyperplasia and a focal area of neoatherosclerosis with unstable features (fissure/microthrombi) at mid RCA. Severe stent strut malapposition embedded neointimal hyperplasia was observed at the proximal stent edge, resulting in ‘dual’ lumen appearance. The two lesions were treated with a single 3.5/48 mm everolimus-eluting stent (stent-in-stent), which was post-dilated with a 3.5/20 mm non-compliant balloon (18 atm) in the mid-to-distal segments, and 4.5/15 mm (16 atm) and 5.0/8 mm (14 atm) semi-compliant balloons in the proximal stent segment. Post-PCI OCT imaging confirmed good stent expansion and apposition. Our case demonstrates the utility of OCT in clarifying the aetiology of ambiguous angiographic lesions and as a guide for PCI. Indeed, the ‘hazy’ appearance on the angiograms corresponded to the major stent malapposition covered by neointima disclosed by OCT as a ‘dual-lumen’. Of note, OCT allowed to confirm the correct guidewire position in the ‘true’ lumen preventing a crush of the previously implanted stent. OCT was also useful as a diagnostic modality for the identification and characterization of the mechanism underlying the ACS (neoatherosclerosis instability).

Conclusions

Due to its unprecedented spatial resolution, OCT enables an ‘optical biopsy’ of the coronary artery wall and intrastent tissue. Therefore, OCT imaging should be considered when lesions are ambiguous or indetermined by coronary angiography to guide the diagnosis and treatments of ACS patients. OCT imaging is also useful to guide stenting and to optimize PCI result, and its impact on clinical outcome is under investigation in large randomized clinical trials.

713 Culprit plaque morphology and healing capacity in patients with and without preinfarction angina: an optical coherence tomography imaging study

Aims

The relationship between culprit plaque morphology, healed culprit plaques prevalence and clinical presentation of acute myocardial infarction (AMI) remains largely unexplored. We hypothesized that angina preceding the occurrence of AMI (pre-infarction angina, PIA) may reflect a distinct morphologic phenotype of culprit plaques and potentially different healing capacity.

Methods and results

We conducted a retrospective observational study in patients with AMI who underwent intracoronary optical coherence tomography (OCT) imaging of the culprit lesion before PCI at the Fondazione Policlinico A. Gemelli–Istituto di Ricovero e Cura a Carattere Scientifico (IRCCS), Rome. Based on the clinical history, patients were classified into two groups: (i) PIA group, defined as either intermittent chest pain within 6 h preceding the final episode of chest pain, or unstable angina (or both) in the week preceding AMI or (ii) no-PIA group, defined as a single episode of chest pain without prodromal symptoms in the preceding week. Culprit plaques were classified as plaque rupture (PR) or intact fibrous cap (IFC), and presence of layered appearance (healed plaque, HP) was assessed. Thrombus burden (TB) was estimated, and prevalence of diffuse calcification, neovascularization, and OCT-defined macrophage accumulation were evaluated. A total of 102 patients with AMI were included (50 PIA, 52 no-PIA). Patients with PIA showed a higher prevalence of IFC than PR (58% vs. 42%, P = 0.030). PR in patients with PIA were more frequently associated with macrophage accumulation (71.4% vs. 28.6% P = 0.001), and TB tended to be lower [22.0 (15.8–30.3) vs. 38.5 (12.8–67.5), P = 0.145]. Diffuse calcifications were significantly less frequent in patients with PIA (22.0% vs. 40.4%, P = 0.045), while neovascularization tended to be more frequent (58.0% vs. 42.3%, P = 0.113). HPs prevalence was significantly higher in the PIA than in the no-PIA group (66.0% vs. 25.0%, P &lt; 0.001).

Conclusions

Patients with PIA have a distinct culprit plaque phenotype, more frequently characterized by IFC and a relatively lower TB, with a significantly higher prevalence of plaque healing.

103 Coronary plaque healing and diabetes: insights from optical coherence tomography imaging

Aims

Atherosclerotic plaque healing is a dynamic process developing after plaque rupture or erosion, which aims to prevent lasting occlusive thrombus formation and to promote plaque repair. We hypothesized that diabetes mellitus, one of the major conventional cardiovascular risk factors, may influence the healing capacity after plaque destabilization.

Methods and results

In this single-centre observational cohort study, patients with acute coronary syndrome (ACS) or chronic coronary syndrome (CCS) who underwent optical coherence tomography (OCT) imaging at Fondazione Policlinico A. Gemelli–IRCCS, Rome, were included. Patients were divided into two groups (i.e. diabetes vs. no diabetes), and stratified based on diabetes medications (i.e. insulin, vs. oral antidiabetic drugs). OCT analysis of non-culprit coronary segments was performed. 105 patients were included (44 diabetes, 61 no diabetes). Prevalence of HCPs was not significantly different between patients with and without diabetes (3.6% vs. 3.8%, P = 0.854). However, patients with diabetes on insulin showed a lower prevalence of HCPs both at patient-based (7.1% vs. 26.4%, P = 0.116) and at segment-based analysis (1.2% vs. 4.2%, P = 0.020). When comparing HbA1c levels based on the presence or absence of healed plaque at the non-culprit lesions, patients with healed plaque showed significantly lower levels of HbA1c compared to patients without healed plaques (43.5 ± 12.1% vs. 61.2 ± 10.4%, P &lt; 0.001). At segment-based analysis, normal vessel structure, pathological intimal thickening (PIT), and spotty calcifications were significantly less prevalent in diabetic patients (2.1% vs. 5.1%, P = 0.001; 7.2% vs. 9.5%, P = 0.05; 9.9% vs. 13.6%, P = 0.02, respectively), whereas neovascularization was significantly higher (19.2% vs. 15.6%, P = 0.035).

Conclusions

Patients with diabetes have a distinct coronary non-culprit plaque phenotype. Healing capacity may be impaired in patients with advanced diabetes on insulin therapy and in those with a suboptimal control of the disease. Further prospective, larger scale studies are warranted to confirm these findings.

100Culprit plaque morphology in patients with and without preinfarction angina: an optical coherence tomography imaging study

Background

The relation between culprit plaque morphology and the clinical presentation of an acute myocardial infarction (AMI) has not been examined in detail.

Purpose

To study the culprit plaque morphology in patients with AMI with or without preinfarction angina using optical coherence tomography (OCT) imaging.

Methods

A total of 102 patients with AMI (32 STEMI, 70 NSTEMI) who underwent OCT imaging before percutaneous coronary intervention were enrolled. Patients were classified as: i) having either intermittent chest pain in the six hours preceding the final episode of pain, or unstable angina (or both) in the week preceding AMI (preinfarction angina group); or ii) having a single episode of chest pain without unstable symptoms in the preceding week (no preinfarction angina group). Culprit plaque was classified as plaque rupture (PR) or intact fibrous cap (IFC), as previously described. Prati thrombus score was calculated, and the prevalence of calcification, neovascularization, and OCT-defined macrophage accumulation was assessed.

Results

Patients with preinfarction angina showed a significantly higher prevalence of IFC than PR, while those without preinfarction angina showed a significantly higher prevalence of PR than IFC (Figure). PR in patients with preinfarction angina were more frequently associated with macrophage accumulation, while those in patients without preinfarction angina were not (Figure). White thrombus tended to be more frequent in patients with preinfarction angina than in those without (85.7% vs. 63.6%, p=0.097), and Prati thrombus score tended to be lower [22.0 (15.8–30.3) vs. 38.5 (12.8–67.5), p=0.145]. Calcifications were significantly less frequent in patients with preinfarction angina than in those without (22.0% vs. 40.4%, p=0.045), while neovascularization tended to be more frequent (58.0% vs. 42.3%, p=0.113).

Conclusions

Patients with preinfarction angina have a distinct culprit plaque phenotype, frequently characterized by IFC and a relatively lower thrombotic burden, probably reflecting a prevalence of reparative mechanisms and spontaneous thrombolytic activity in these patients.