Angiographic characteristics of patients with STEMI and COVID-19: Insights from NACMI registry.

BACKGROUND: To date, there has been no independent core lab angiographic analysis of patients with COVID-19 and STEMI. The study characterized the angiographic parameters of patients with COVID-19 and STEMI. METHODS: Angiograms of patients with COVID-19 and STEMI from the North American COVID-19 Myocardial Infarction (NACMI) Registry were sent to a Core Laboratory in Vancouver, Canada. Culprit lesion(s), Thrombolysis In Myocardial Infarction (TIMI) flow, Thrombus Grade Burden (TGB), and percutaneous coronary intervention (PCI) outcome were assessed. RESULTS: From 234 patients, 74% had one culprit lesion, 14% had multiple culprits and 12% had no culprit identified. Multivessel thrombotic disease and multivessel CAD were found in 27% and 53% of patients, respectively. Stent thrombosis accounted for 12% of the presentations and occurred in 55% of patients with previous coronary stents. Of the 182 who underwent PCI, 60 (33%) had unsuccessful PCI due to post-PCI TIMI flow <3 (43/60), residual high thrombus burden (41/60) and/or thrombus related complications (27/60). In-hospital mortality for successful, partially successful, and unsuccessful PCI was 14%, 13%, and 27%, respectively. Unsuccessful PCI was associated with increased risk of in-hospital mortality (risk ratio [RR] 1.96; 95% CI: 1.05-3.66, P = .03); in the adjusted model this estimate was attenuated (RR: 1.24; 95% CI: 0.65-2.34, P = .51). CONCLUSION: In patients with COVID-19 and STEMI, thrombus burden was pervasive with notable rates of multivessel thrombotic disease and stent thrombosis. Post-PCI, persistent thrombus and sub-optimal TIMI 3 flow rates led to one-third of the PCI's being unsuccessful, which decreased over time but remained an important predictor of in-hospital mortality.

Woven coronary artery with acquired etiology: the natural history documented by serial angiography and optical coherence tomography.

Woven coronary artery (WCA) is a rare anomaly and its etiology remains speculative. Both congenital and acquired factors are considered to be concerned with the pathogenesis. In a 35-year-old man, the tissue characteristics of WCA were evaluated by optical coherence tomography. Serial coronary angiography indicated that acquired factor is the cause, and thrombus recanalization is the most likely pathological mechanism.

Optical coherence tomography (OCT) - versus angiography-guided strategy for percutaneous coronary intervention: a meta-analysis of randomized trials.

BACKGROUND: Optical coherence tomography (OCT) guidance in percutaneous coronary intervention (PCI) has been shown to improve procedural outcomes. However, evidence supporting its superiority over angiography-guided PCI in terms of clinical outcomes is still emerging and limited. This study aimed to compare the efficacy and safety of OCT-guided PCI versus angiography-guided PCI in patients with coronary artery disease (CAD). METHODS: A systematic search of electronic databases was conducted to identify randomized control trials (RCTs) comparing the clinical outcomes of OCT-guided and angiography-guided PCI in patients with CAD. Clinical endpoints including all-cause mortality, myocardial infarction (MI), target lesion revascularization (TLR), stent thrombosis and major adverse cardiac events (MACE) were assessed. RESULTS: Eleven RCTs, comprising 2,699 patients in the OCT-guided group and 2,968 patients in the angiography-guided group met inclusion criteria. OCT-guided PCI was associated with significantly lower rates of cardiovascular death(RR 0.56; 95%CI: 0.32-0.98; p = 0.04; I2 = 0%), stent thrombosis(RR 0.56; 95%CI: 0.33-0.95; p = 0.03; I2 = 0%), and MACE (RR 0.79; 95%CI: 0.66-0.95; p = 0.01; I2 = 5%). The incidence of all-cause death (RR 0.71; 95%CI: 0.49-1.02; p = 0.06; I2 = 0%), myocardial infarction (RR 0.86; 95%CI: 0.67-1.10; p = 0.22; I2 = 0%) and TLR (RR 0.98; 95%CI: 0.73-1.33; p = 0.91; I2 = 0%) was non-significantly lower in the OCT-guided group. CONCLUSIONS: Among patients undergoing PCI, OCT-guided PCI was associated with lower incidences of cardiovascular death, stent thrombosis and MACE compared to angiography-guided PCI. TRIAL REGISTRATION: PROSPERO registration number: CRD42023484342.

Lipoprotein(a) Is Associated with Thrombus Burden in Culprit Arteries of Younger Patients with ST-Segment Elevation Myocardial Infarction.

BACKGROUND: Lipoprotein(a) (Lp[a]) is a risk factor for cardiovascular disease. The burden of thrombus in ST-segment elevation myocardial infarction (STEMI) has implications on treatment and outcomes. However, the association between Lp(a) and atherothrombosis in STEMI remains unclear. OBJECTIVES: The aim of the study was to determine the association between Lp(a) and culprit artery thrombus burden in younger patients with STEMI. METHODS: This was a single-center study of 83 patients aged <65 years with STEMI between 2016-2018 who underwent percutaneous coronary intervention and measurement of Lp(a); those receiving thrombolytic therapy were excluded. Thrombus burden in the culprit artery was determined angiographically using the Thrombolysis In Myocardial Infarction score and classified as absent-to-small, moderate, or large. Elevated Lp(a) was defined as plasma mass concentration >30 mg/dL. Multivariate analysis was performed adjusting for cardiovascular risk factors. RESULTS: The mean age was 48.0 ± 8.4 years, and 78.3% were male. Thirteen (16%), 9 (11%), and 61 (73%) patients had small, moderate, or large thrombus burden, respectively, and 34 (41%) had elevated Lp(a). Elevated Lp(a) was associated with greater thrombus burden compared to normal Lp(a) (large burden 85% vs. 65%; p = 0.024). Elevated Lp(a) was associated with moderate or large thrombus in univariate (OR 10.70 [95% CI 1.32-86.82]; p = 0.026) and multivariate analysis (OR 10.33 [95% CI 1.19-89.52]; p = 0.034). Lp(a) was not associated with culprit artery or stenosis location according to culprit artery. CONCLUSIONS: Elevated Lp(a) is associated with greater thrombus burden in younger patients with STEMI. The finding of this observational study accords with the thrombotic and anti-fibrinolytic properties of Lp(a). A causal relationship requires verification.

Acute myocardial infarction due to coronary embolism caused by a metastatic mass from lung cancer.

BACKGROUND: Acute arterial embolism due to tumor embolus is a rare complication in cancer patients, even rarer is lung tumor embolization leading to acute myocardial infarction. We report a patient who had a diagnosis of acute myocardial infarction(AMI)which was brought on by a coronary artery embolism by a metastatic lung cancer tumor. Clinicians need to be aware that tumor embolism can result in AMI. CASE PRESENTATION: An 80-yeal-old male patient presented with persistent chest pain for 2 h and his electrocardiogram(ECG)showed anterior ST-segment elevation myocardial infarction. Instead of implanting a stent, thrombus aspiration was performed. Pathological examination of coronary artery thrombosis showed that a few sporadic atypical epithelial cells were scattered in the thrombus-like tissue. Combined with immune phenotype and clinical history, metastatic squamous cell carcinoma is more likely. CONCLUSIONS: We report a rare case of a patient who was diagnosed of AMI due to a coronary artery embolism by a metastatic mass from lung cancer. Since there is no evidence-based protocol available for the treatment of isolated coronary thrombosis, we used thrombus aspiration to treat thrombosis rather than implanting a stent.

Mitigating the risk of flow deterioration by deferring stent optimization in STEMI patients with large thrombus burden: Insights from a prospective cohort study.

OBJECTIVES: It is uncertain, if omitting post-dilatation and stent oversizing (stent optimization) is safe and may decrease the risk for distal thrombus embolization (DTE) in STEMI patients with large thrombus burden (LTB). BACKGROUND: In patients with ST-segment elevation myocardial infarction (STEMI) undergoing primary percutaneous coronary intervention (pPCI) with stenting, (DTE) and flow deterioration are common and increase infarct size leading to worse outcomes. METHODS: From a prospective registry, 74 consecutive STEMI patients with LTB undergoing pPCI with stenting and intentionally deferred stent optimization were analyzed. Imaging data and outcomes up to 2 years follow-up were analyzed. RESULTS: Overall, 74 patients (18% females) underwent deferred stent optimization. Direct stenting was performed in 13 (18%) patients. No major complications occurred during pPCI. Staged stent optimization was performed after a median of 4 (interquartile range (IQR) 3; 7) days. On optical coherence tomography, under-expansion and residual thrombus were present in 59 (80%) and 27 (36%) cases, respectively. During deferred stent optimization, we encountered no case of flow deterioration (slow or no-reflow) or side branch occlusion. Minimal lumen area (mm2) and stent expansion (%) were corrected from 4.87±1.86mm to 6.82±2.36mm (p<0.05) and from 69±18% to 91±12% (p<0.001), respectively. During follow-up, 1 patient (1.4%) required target lesion revascularization and 1 (1.4%) patient succumbed from cardiovascular death. CONCLUSIONS: Among STEMI patients with LTB, deferring stent optimization in the setting of pPCI appears safe and potentially mitigates the risk of DTE. The impact of this approach on infarct size and clinical outcomes warrants further investigation in a dedicated trial.

Heavy lone coronary artery thrombosis treated by stent retriever, in the setting of COVID-19 infection.

We present a case of heavy lone coronary thrombosis in the setting of COVID-19 infection. We highlight the special angiographic, ultrasonographic, and histological features of this thrombus, and we describe the application of carotid stent retriever for its removal.

Initial experience with a continuous mechanical aspiration system for thrombus removal before percutaneous coronary intervention.

OBJECTIVES: Here we investigate the safety and efficacy of a continuous mechanical aspiration system when used before percutaneous coronary intervention (PCI) in patients with acute coronary syndrome (ACS). BACKGROUND: Historically, trials of routine manual aspiration thrombectomy in ACS patients have reported mixed results. This may be due to the technical limitations of manual aspiration, which suffers from decreasing vacuum power as aspiration is performed. METHODS: This is a retrospective case series of all patients treated with continuous mechanical aspiration (Indigo CAT RX Aspiration System; Penumbra Inc.) before PCI between August 2017 and July 2020 at five centers in the United States. Data regarding angiographic assessments, procedure, and safety were examined. RESULTS: Seventy-two patients (mean age 60 ± 12.5 years, 34.7% female) with ST Elevation Myocardial Infarction (STEMI) (80.6%) or Non-ST Elevation Myocardial Infarction (NSTEMI) (19.4%) were included. Target vessels were the right coronary (43.1%), left anterior descending (33.3%), and left circumflex (23.6%). Preprocedure, 94.4% had a high thrombus burden (thrombolysis in myocardial infarction [TIMI] thrombus grade ≥ 3). Median aspiration time was 35 s and median access-to-reperfusion time was 10 min. After CAT RX alone, 86.1% had complete perfusion (TIMI flow grade 3). After the procedure, 94.4% had TIMI thrombus grade <3% and 97.2% had TIMI flow grade 3. There were no cases of ischemic stroke. Cardiovascular mortality at 30 days was 1.4%. CONCLUSIONS: In our initial experience, aspirating thrombus from ACS patients using the Indigo CAT RX Aspiration System before PCI was safe and effective for reducing thrombus burden and restoring flow.

Acute myocardial infarction with simultaneous total occlusion of the left anterior descending artery and right coronary artery successfully treated with percutaneous coronary intervention.

BACKGROUND: Simultaneous thrombosis in more than one coronary artery is an uncommon angiographic finding in patients with acute ST-segment elevation myocardial infarction. It is difficult to identify using 12-lead electrocardiography and usually leads to cardiogenic shock and fatal outcomes, including sudden cardiac death. Therefore, immediate revascularization and adequate mechanical circulatory support are required. CASE PRESENTATION: We report the case of a 58-year-old man who presented with vomiting and chest pain complicated by cardiogenic shock and complete atrioventricular block. Electrocardiography revealed ST-segment elevation in leads II, III, aVF, and V1-V6. Emergency coronary angiography revealed total occlusion of the proximal left anterior descending artery and right coronary artery. The patient successfully underwent primary percutaneous coronary intervention with ballooning and stenting for both arteries. An Impella CP was inserted during the procedure. Fifty-seven days after admission, he had New York Heart Association class II heart failure and was transferred to a rehabilitation hospital. CONCLUSIONS: Acute double-vessel coronary thrombosis, a serious event with a high mortality rate, requires prompt diagnosis and management to prevent complications such as cardiogenic shock and ventricular arrhythmias. A combination of judicious medical treatment, efficient primary percutaneous coronary intervention, and early mechanical support device insertion is crucial to improve the survival rate of patients with this disease.

Nonatrial Fibrillation Patients With Complete P Wave Disappearance: An Overlooked Population With High Stroke Risk.

BACKGROUND AND PURPOSE: Complete P wave disappearance (CPWD) in patients without atrial fibrillation is an uncommon clinical phenomenon. We aimed to study the relationship between CPWD and thromboembolism. METHODS: Between July 2007 and December 2018, consecutive patients with CPWD on surface ECG and 24-hour Holter recording were recruited into the study from 4 centers in China. All recruited patients underwent transesophageal echocardiography or cardiac computed tomography to screen for atrial thrombus. Atrial electrical activity and scar were assessed by electrophysiological study (EPS) and 3-dimensional electroanatomic mapping. Cardiac structure and function were assessed by multimodality cardiac imaging. RESULTS: Twenty-three consecutive patients (8 male; mean age 48.5±14.7 years) with CPWD were included. Only 3 patients demonstrated complete atrial electrical silence with atrial noncapture. Thirteen patients who had invasive atrial endocardial mapping demonstrated extensive scar. Pulse-wave mitral inflow Doppler demonstrated absent and dampened A waves in 18 and 5 patients, respectively. Pulse-wave tricuspid inflow Doppler showed absent and dampened A waves in 19 and 4 patients, respectively. Upon recruitment, 8 patients had previous stroke and 3 patients had atrial thrombus. Warfarin was prescribed to all patients. During median follow-up of 42.0 months, 2 patients developed massive ischemic stroke due to warfarin discontinuation. CONCLUSIONS: Our study suggested that CPWD reflects extensive atrial electrical silence and significantly impaired atrial mechanical function. It was strongly associated with thromboembolism and the clinical triad of CPWD-atrial paralysis-stroke was proposed. Anticoagulation should be recommended in such patients.

Laser Vaporization of Intracoronary Thrombus and Identifying Plaque Morphology in ST-Segment Elevation Myocardial Infarction as Assessed by Optical Coherence Tomography.

OBJECTIVES: We evaluated the thrombus-vaporizing effect of excimer laser coronary angioplasty (ELCA) in patients with ST-segment elevation myocardial infarction (STEMI) by optical coherence tomography (OCT). BACKGROUND: Larger intracoronary thrombus elevates the risk of interventional treatment and mortality in patients with STEMI. METHODS: A total of 92 patients with STEMI who presented within 24 hours from the onset and underwent ELCA following manual aspiration thrombectomy (MT) were analyzed. RESULTS: The mean baseline thrombolysis in myocardial infarction flow grade was 0.4 ± 0.6, which subsequently improved to 2.3 ± 0.7 after MT (p < 0.0001) and 2.7 ± 0.5 after ELCA (p=0.0001). The median residual thrombus volume after MT was 65.7 mm3, which significantly reduced to 47.5 mm3 after ELCA (p < 0.0001). Plaque rupture was identified by OCT in only 22 cases (23.9%) after MT, but was distinguishable in 36 additional cases after ELCA (total: 58 cases; 63.0%). Ruptured lesions contained a higher proportion of red thrombus than nonruptured lesions (75.9% vs. 43.3%, p=0.001). Significantly larger thrombus burden after MT (69.6 mm3 vs. 56.3 mm3, p < 0.05) and greater thrombus reduction by ELCA (21.2 mm3 vs. 11.8 mm3, p < 0.01) were observed in ruptured lesions than nonruptured lesions. CONCLUSIONS: ELCA effectively vaporized intracoronary thrombus in patients with STEMI even after MT. Lesions with plaque rupture contained larger thrombus burden that was frequently characterized by red thrombus and more effectively reduced by ELCA.

Potential Mechanisms of In-stent Neointimal Atherosclerotic Plaque Formation.

ABSTRACT: Percutaneous coronary intervention has become the main revascularization strategy for coronary artery disease. Compared with early percutaneous coronary angioplasty and the extensive clinical application of bare metal stents, drug-eluting stents can significantly reduce the stenosis caused by the elastic retraction of plaque and neoatherosclerosis (NA), but there is still a high incidence of in-stent restenosis (ISR), which restricts the clinical efficacy of stent implantation. In-stent neoatherosclerosis (ISNA), defined as atherosclerotic lesions in the neointima, is one of the main causes of late stent failure. ISNA plays an important role in stent thrombosis and ISR. The rate of target lesion revascularization and in-stent thrombosis is high when NA arises. Therefore, it is of great clinical significance to explore the occurrence of NA and its development mechanism after stent implantation to prevent ISR and improve stent implantation efficacy and associated clinical prognosis. In this article, we systematically reviewed the existing clinical research on ISNA and the role of optical coherence tomography in its evaluation.

Post-Stent Optical Coherence Tomography Findings at Index Percutaneous Coronary Intervention　- Characteristics Related to Subsequent Stent Thrombosis.

BACKGROUND: The association between unfavorable post-stent optical coherence tomography (OCT) findings and subsequent stent thrombosis (ST) remains unclear. This study investigated the ST-related characteristics of post-stent OCT findings at index percutaneous coronary intervention (PCI).Methods and Results:Fifteen patients with ST onset after OCT-guided PCI (ST group) were retrospectively enrolled. Post-stent OCT findings in the ST group were compared with those in 70 consecutive patients (reference group) without acute coronary syndrome onset for at least 5 years after OCT-guided PCI. The incidence of acute myocardial infarction (AMI) was higher in the ST than reference group (60.0% vs. 17.1%, respectively; P=0.0005). The incidence of incomplete stent apposition (93.3% vs. 55.7%; P=0.0064), irregular protrusion (IP; 93.3% vs. 62.8%; P=0.0214), and thrombus (93.3% vs. 51.4%; P=0.0028) was significantly higher in the ST than reference group. The maximum median (interquartile range) IP arc was significantly larger in the ST than reference group (265° [217°-360°] vs. 128° [81.4°-212°], respectively; P<0.0001). In AMI patients, the incidence of a maximum IP arc >180° was significantly higher in the ST than reference group (100% vs. 58.3%, respectively; P=0.0265). CONCLUSIONS: IP with a large arc was a significant feature on post-stent OCT in patients with ST.

Near fatal stent thrombosis in an aneurysmatic RCX as first manifestation of heparin induced thrombocytopenia (HIT) without thrombocytopenia.

BACKGROUND: Thrombosis resulting from heparin-induced thrombocytopenia (HIT) occurs in about 2% of patients without a significant decrease in platelet counts. We report on such a near fatal thrombotic event caused by coronary intervention. CASE PRESENTATION: A supposedly "completely healthy" 53-year-old patient was admitted to hospital with covered rupture of an aneurysm of the Aorta descendens. He was successfully operated on and underwent coronary angiography due to NSTEMI six days later. Immediately after intervention of a 90% RCX stenosis he developed ventricular flutter, was defibrillated, and re-angiography showed partial occlusion of the RCX stent. Lots of white thrombi could be retrieved by aspiration catheter and gave reason for a HIT without thrombocytopenia. The detection of platelet factor 4/heparin complex antibodies by immunoassay supported and the subsequent Heparin Induced Platelet Activation Assay proved this diagnosis. CONCLUSIONS: The clinical event of an acute stent thrombosis should alarm the interventional team to the diagnosis of HIT even with a normal platelet count.

Early stent thrombosis confirmed in a cancer patient receiving regorafenib, despite triple antithrombotic therapy: a case report.

BACKGROUND: While developments in oncology have lengthened survival in patients with cancer, such patients often develop cardiovascular diseases. Thus, percutaneous coronary intervention (PCI) is frequently undertaken in them. Although stent thrombosis remains a fatal complication in stent-based PCI, worldwide consensus panels tend to recommend shorter duration of dual-antiplatelet therapy. This is based on its clinical efficacy that has resulted from technological innovation. However, there is insufficient discussion on the risk of stent thrombosis in cancer patients with coronary artery disease, especially in those undergoing chemotherapeutic regimens that have a risk for thrombosis, such as regimens with the anti-vascular endothelial growth factor. Presented here is a case of early stent thrombosis that occurred in a cancer patient on regorafenib, despite the administration of triple antithrombotic therapy. Case presentation A 66-year-old Japanese male patient received regorafenib for metastatic colorectal carcinoma and apixaban for deep vein thrombosis. Coronary angiography revealed severe stenosis in the proximal left anterior descending artery. A sirolimus-eluting stent was implanted, without malapposition and under-expansion, under intravascular ultrasound guidance while administering a triple antithrombotic therapy (aspirin: 100 mg/day, prasugrel: 3.75 mg/day, and apixaban: 5 mg/day). However, he was admitted to the hospital for exacerbation of heart failure 1 month after PCI. Coronary angiography revealed contrastive defects in the previous stent. Optical frequency domain imaging confirmed stent thrombosis. PCI was successfully performed with perfusion balloon long-inflation. Antithrombotic therapy was enhanced (aspirin: 100 mg/day, ticagrelor: 120 mg/day, and apixaban: 10 mg/day) and regorafenib was discontinued permanently. While ischemic events did not occur thereafter, the patient died due to metastatic carcinoma progression. CONCLUSIONS: This case suggests that anti-vascular endothelial growth factor might contribute to early stent thrombosis, despite triple antithrombotic therapy. Further discussion is needed on the surveillance and management of cancer patients with coronary artery disease receiving chemotherapy, which carries a risk of thrombosis.

High thrombus burden despite thrombolytic therapy in ST-elevation myocardial infarction in a patient with COVID-19.

Consideration of thrombolysis as first-line reperfusion therapy in patients with COVID-19 and STEMI is recommended by ACC/SCAI guidelines. We describe a patient with COVID-19, who presented with ST-elevation myocardial infarction and was treated with thrombolysis and anticoagulation. He was later found to have a significant persistent thrombus burden requiring thrombectomy and stent placement. Invasive hemodynamics on multiple high-dose pressers revealed a high cardiac output state with low systemic vascular resistance, consistent with distributive rather than cardiogenic shock. Our case illustrates that thrombolytic therapy alone may not be adequate in patients with STEMI and COVID-19, as well as the importance of early invasive hemodynamics in management of shock in patient with STEMI and COVID-19 infection.

Impact of strut thickness and number of crown and connectors on clinical outcomes on patients treated with second-generation drug eluting stent.

INTRODUCTION: In new generation drug eluting stents (DESs) era, the impact of stent geometry on freedom from recurrent events has been poorly explored. Impact of struts thickness and the number of crowns and connectors on clinical outcomes were evaluated in the present study. METHODS: Randomized controlled trials comparing last generation DESs were selected. The primary endpoint was the rate of target lesion revascularization (TLR), while secondary was definite stent thrombosis (ST). RESULTS: Fifty-three studies with 52,006 patients were included. A struts thickness ≤81 nm was associated with a lower incidence of TLR (2.9%: 2.4-3.4 vs. 3.6%: 3.0-4.3) and ST (0.8%: 0.6-1.1 vs. 1.3%: 0.9-1.8). A mean number of connectors >2.5 was also associated with a lower incidence of TLR (3.2%: 2.8-3.6 vs. 3.5%: 2.9-4.2) and ST (1.0%:0.8-1.3 vs. 1.3%: 0.9-1.7 vs. for ST). On the other hand, stents with average number of crowns <7.5 did not perform better than stents with higher average number of crowns. CONCLUSIONS: The findings of the study support that lower struts thickness and higher numbers of connectors have a positive clinical outcome reducing stent thrombosis and target lesion revascularizations, while the average number of stent crowns plays a secondary role.

Residual atherothrombotic burden after primary percutaneous coronary intervention and myocardial reperfusion-An optical frequency domain imaging study.

OBJECTIVES: We aimed to assess the relationship between residual in-stent atherothrombotic burden (ATB) after primary percutaneous coronary intervention (PCI) measured by optical frequency domain imaging (OFDI) using different measurement methods and myocardial blush grade (MBG). BACKGROUND: The impact of residual ATB after primary PCI on myocardial reperfusion remains unclear. METHODS: We prospectively included 60 ST-elevation myocardial infarction patients pretreated with aspirin and ticagrelor. OFDI volumetric quantification using planimetry (with intervals every frame or every millimeter) and semiquantitative score were used to determine ATB. Patients were divided into two groups according to final MBG 3 or <3. RESULTS: The mean ATB was 10.08 ± 5.21%. ATB was lower in patients with final MBG 3 compared to those with impaired MBG, regardless of the measurement method (8.15 ± 5.58 vs. 11.77 ± 4.28%; p = .007 for quantification per frame; 7.8 ± 5.19 vs. 11.07 ± 4.07%; p = .009 for quantification per mm and 11.21 ± 11.75 vs. 22.91 ± 17.35; p = .003 for the semiquantitative thrombus score, respectively). CONCLUSION: Residual post-stenting ATB remains substantial after primary PCI in STEMI patients, even when pretreated with ticagrelor and aspirin. ATB appears as a significant correlate of suboptimal myocardial reperfusion, a known surrogate of clinical outcome.

Assessment of residual thrombus burden in patients with ST-segment elevation myocardial infarction undergoing bivalirudin versus unfractionated heparin infusion: The MATRIX (minimizing adverse hemorrhagic events by transradial access site and angioX) OCT study.

BACKGROUND: Residual stent strut thrombosis after primary percutaneous coronary intervention (PCI), negatively affects myocardial perfusion, may increase stent thrombosis risk, and it is associated with neointima hyperplasia at follow-up. OBJECTIVES: To study the effectiveness of any bivalirudin infusion versus unfractionated heparin (UFH) infusion in reducing residual stent strut thrombosis in patients with ST-elevation myocardial infarction (STEMI). METHODS: Multi-vessel STEMI patients undergoing primary PCI and requiring staged intervention were selected among those randomly allocated to two different bivalirudin infusion regimens in the MATRIX (Minimizing Adverse Haemorrhagic Events by TRansradial Access Site and angioX) Treatment-Duration study. Those receiving heparin only were enrolled into a registry arm. Optical coherence tomography (OCT) of the infarct-related artery was performed at the end of primary PCI and 3-5 days thereafter during a staged intervention. The primary endpoint was the change in minimum flow area (ΔMinFA) defined as (stent area + incomplete stent apposition [ISA] area) - (intraluminal defect + tissue prolapsed area) between the index and staged PCI. RESULTS: 123 patients in bivalirudin arm and 28 patients in the UFH arm were included. Mean stent area, percentage of malapposed struts, and mean percent thrombotic area were comparable after index or staged PCI. The ΔMinFA in the bivalirudin group was 0.25 versus 0.05 mm2 in the UFH group, which resulted in a between-group significant difference of 0.36 [95% CI: (0.05, 0.71); p = .02]. This was mostly related to a decrease in tissue protrusion in the bivalirudin group (p = .03). There was a trend towards more patients in the bivalirudin group who achieved a 5% difference in the percentage of OCT frames with the area >5% (p = .057). CONCLUSIONS: The administration of bivalirudin after primary PCI significantly reduces residual stent strut thrombosis when compared to UFH. This observation should be considered hypothesis-generating since the heparin-treated patients were not randomly allocated.

Challenges associated with treatment of left internal mammary artery graft thrombosis.

Acute occlusion of the left internal mammary artery (LIMA) graft late after coronary artery bypass grafting surgery is a rare and potentially life-threatening complication. We describe a case of acute myocardial infarction 19 years after coronary artery bypass graft surgery due to acute occlusion of the distal anastomosis of a LIMA graft to the left anterior descending artery. Aspiration thrombectomy failed to remove the thrombus. Laser thrombectomy caused perforation. After drug-eluting and covered stent implantation, antegrade TIMI 3 flow was restored with an uneventful postprocedural course.