Subacute Stent Thrombosis Research Articles

FREQUENCY OF EARLY STENT THROMBOSIS (ACUTE AND SUBACUTE) IN PATIENTS PRESENTING WITH ACUTE ST ELEVATION MYOCARDIAL INFARCTION (STEMI) UNDERGOING PRIMARY PERCUTANEOUS CORONARY INTERVENTION (PCI)

Sudden cardiac stent thrombosis (ST) is a severe clinical risk that can lead to high fatality rates. However, data are scarce on the prevalence of early ST events following ‘primary percutaneous coronary intervention’ (pPCI) and the characteristics that predict it, particularly among Pakistani patients. Objective: The objective is to determine possible indicators and evaluate ‘the frequency of acute and sub-acute stent thrombosis’ (ST) after ‘primary percutaneous coronary intervention’ (PCI). Methods: Five hundred individuals who had undergone primary PCI were enrolled from July 2022 to December 2023. Telephone follow-up assessments were used to gather information on 30-day results, including death rates, recurrence of symptoms, and episodes of ST. ‘ST was classified as acute’ (occurring ‘during the procedure’) or ‘sub-acute’ (‘occurring within 30 days post-procedure) using standardised criteria established by the ‘Academic Research Consortium. Results: In this study, 500 patients were enrolled, primarily male (80.4%, 362 patients). ‘Stent thrombosis’ (either acute or sub-acute) was observed in 6.8% of patients, with 10.1% (4) classified as definite ST and the remaining 91.9% (34) as probable ST. Male patients were more prevalent among those who developed ST, along with a higher incidence of hypertension, diabetes, reduced left ventricular ejection fraction (LVEF) pre-PCI, and higher Killip Class. Patients with ST experienced a higher in-hospital mortality rate compared to those without ST, with a p-value of 0.02. Notably, ‘Killip Class’ (‘III-IV’) emerged as ‘an independent ST predictor in this patient cohort. These findings underscore the importance of risk assessment and vigilant management, particularly in patients presenting with higher Killip Class and other associated risk factors, to mitigate ST occurrence and adverse outcomes following primary PCI. Conclusion: Early stent thrombosis (ST) appears relatively common in patients undergoing primary PCI. Those with diabetes and hypertension face an elevated risk of ST, while patients presenting in ‘Killip Class III-IV’ demonstrate an ‘independent predictive’ factor for early ST.

Longitudinal Stent Deformation at the Proximal Segment of the Left Main Coronary Artery Caused by a Stuck OCT Catheter: Case Report and Review of Literature.

It has been rarely reported that a stuck optical coherence tomography (OCT) catheter can lead to longitudinal stent deformation (LSD). This complication can result in incomplete stent apposition and dissection after stent implantation. In this study, we present a case where a bailout stent was implanted in the distal segment of the left anterior descending artery (LAD) after longitudinal stent deformation caused by a stuck OCT catheter. This approach was taken to prevent acute stent thrombosis, subacute stent thrombosis, in-stent restenosis (ISR), and death. The patients were followed up for one year, and no adverse events were observed.

Coatings for Cardiovascular Stents-An Up-to-Date Review.

Cardiovascular diseases (CVDs) increasingly burden health systems and patients worldwide, necessitating the improved awareness of current treatment possibilities and the development of more efficient therapeutic strategies. When plaque deposits narrow the arteries, the standard of care implies the insertion of a stent at the lesion site. The most promising development in cardiovascular stents has been the release of medications from these stents. However, the use of drug-eluting stents (DESs) is still challenged by in-stent restenosis occurrence. DESs' long-term clinical success depends on several parameters, including the degradability of the polymers, drug release profiles, stent platforms, coating polymers, and the metals and their alloys that are employed as metal frames in the stents. Thus, it is critical to investigate new approaches to optimize the most suitable DESs to solve problems with the inflammatory response, delayed endothelialization, and sub-acute stent thrombosis. As certain advancements have been reported in the literature, this review aims to present the latest updates in the coatings field for cardiovascular stents. Specifically, there are described various organic (e.g., synthetic and natural polymer-based coatings, stents coated directly with drugs, and coatings containing endothelial cells) and inorganic (e.g., metallic and nonmetallic materials) stent coating options, aiming to create an updated framework that would serve as an inception point for future research.

A nightmare of clopidogrel resistance in a resource-limited setting: case report of subacute stent thrombosis

BackgroundStent thrombosis, a life-threatening complication of percutaneous coronary intervention (PCI) continues to occur despite effective antiplatelet regimens and improved stenting methods. Noncompliance with dual antiplatelet therapy is the most common etiology; however, in spite of timely and their optimum administration the rates of recurrent myocardial infarction (MI) and stent thrombosis remain high. Clopidogrel resistance is increasingly evoked with elevated risk of anterothrombotic events particularly in the setting of stent implantation. In this case report, we present a case of subacute stent thrombosis associated with clopidogrel resistance in a resource-constrained setting.Case presentationA 60 year old man with a long standing history of hypertension presented with a 6-month history of progressive shortness of breath. Initial electrocardiogram (ECG) revealed T-wave inversion on lateral leads and echocardiogram revealed akinetic basal lateral wall and hypokinetic mid lateral wall with reduced systolic functions. An elective coronary angiography (CAG) revealed a 90% stenosis of mid left anterior descending (LAD) artery and an 80% stenosis on the proximal left circumflex artery. He underwent a successful PCI with a drug-eluting stent implantation to mid LAD. He was discharged in a stable state 48 h post revascularization with dual antiplatelet (clopidogrel and acetylsalicylic acid). Seven days later, he presented with a crushing substernal chest pain. Cardiac enzymes were elevated and ECG revealed anterior ST-elevation MI. An emergency CAG revealed a high thrombus burden with 100% occlusion of mid LAD. Following unsuccessful ballooning, intravenous and intracoronary thrombolysis with tenecteplase was given. A TIMI II flow was achieved and the patient was sent to the coronary care unit. However, 14 h later there was yet a new onset of severe chest pain. A 12-lead ECG previewed anterior ST-elevation MI and the cardiac enzymes were high. Urgent CAG revealed in-stent thrombotic total occlusion of mid LAD. A stent in stent was then implanted and TIMI III flow was restored. Clopidogrel resistance was suspected and the patient was transitioned to ticagrelol. There were no further ischemic events during the remainder of hospitalization and the patient was discharged in a hemodynamically stable state three days later. During follow-up after one and three months, he was fairly stable without any further cardiac events.ConclusionsOwing to clopidogrel resistance, stent thrombosis in the setting of dual antiplatelet therapy compliance may occur. While in a situation of clopidogrel resistance newer and more potent antiplatelet drugs should be used, their availability and cost remains a significant barrier particularly in the developing world. Nonetheless, a high index of suspicion and timely revascularization is fundamental to restore patency of the thrombosed vessel and confer better risk-adjusted survival rates.

Safety and efficacy of a novel calcified plaque modification technique - Shockwave Intravascular Lithotripsy - in patients with coronary artery disease: Mid-term outcomes.

Coronary interventions in calcified lesions are associated with a higher rate of adverse clinical events. Initial aggressive plaque modification along with post-implantation optimization is pivotal for achieving a favorable outcome of percutaneous coronary intervention (PCI). Recently, the Shockwave C2 Intravascular Lithotripsy (S-IVL) System, a novel acoustic wave-based device designed to modify calcified plaque, has been introduced into clinical practice. We evaluated the mid-term safety and efficiency of S-IVL in a cohort of 131 consecutive patients with severely calcified coronary lesions. We retrospectively analyzed a total of 131 consecutive S-IVL PCI procedures. The study had two main inclusion criteria - the presence of a calcified resistant lesion (defined by inadequate non-compliant balloon catheter inflation) or a significantly underexpanded stent (more than 20% of reference diameter). The study had two primary endpoints - successful clinical outcome and safety concerns. Clinical success was defined as effective stent deployment or optimization of a previously underexpanded stent (with less than <20% in-stent residual stenosis). Safety outcomes were defined as periprocedural complications, such as device failure and major adverse cardiac and cerebrovascular events (MACCE). Clinical follow-up was performed at the end of hospitalization and 6 months after the index procedure. In-hospital MACCE was 4.6% with 1.5% target lesion revascularization (TLR) and one case of subacute fatal stent thrombosis. At 6-month follow-up, the MACCE rate was 7.9% with a concomitant TLR rate of 3.8%. Our mid-term data confirm acceptable safety and efficacy of intravascular lithotripsy as a valuable strategy for lesion preparation and stent optimization in a cohort of 131 consecutive patients with severely calcified coronary lesions.

Comparison of myocardial reperfusion between intracoronary versus intravenous cangrelor administration in patients undergoing primary percutaneous coronary intervention.

Myocardial reperfusion is the main target of treatment in patients with ST-segment elevation myocardial infarction (STEMI). The intracoronary administration of cangrelor bolus could favor a higher local drug concentration, favoring an earlier thrombotic resolution and a reduced distal micro-embolization. Seventy-one patients undergoing primary percutaneous coronary intervention (PCI) for STEMI: 37 treated with intracoronary and 34 with intravenous bolus administration of cangrelor. The primary endpoint was ST-segment elevation resolution (STR) ≥ 50% after 30 min from the end of the PCI. Other explorative reperfusion indices investigated were: STR ≥ 50% at 24 hours, STR ≥ 70% at 30 min, Thrombolysis In Myocardial Infarction frame count and the QT dispersion. Moreover, acute and subacute stent thrombosis, bleeding events and 30-day mortality have been evaluated. More frequent STR ≥ 50% was observed in the intravenous cangrelor bolus group as compared to the intracoronary administration at 30 min (71.9% vs. 45.5%; p = 0.033), the difference was maintained 24 hours after PCI (87.1% vs. 63.6%; p = 0.030). STR ≥ 70% at 30 min was statistically more frequent in the intravenous bolus administration cohort (66.7% vs. 28.6% p = 0.02). At multivariable analysis, intravenous cangrelor administration was significantly related to STR ≥ 50% (odds ratio: 3.586; 95% confidence interval: 1.134-11.335; p = 0.030). The incidence of Bleeding Academic Research Consortium 3-5 bleedings was 15.5% and mortality was 4.2% without any significant difference between the two groups. In conclusion the results of the study do not show any advantages in the administration of intracoronary bolus of cangrelor in patients affected by STEMI and treated with primary PCI.

Measuring Adverse Cardiovascular Outcomes (MACE) in diabetic vs nondiabetic Primary PCI (PPCI) patients suffering from STEMI in PIC, Lahore

Abstract&#x0D; Introduction:&#x0D; All over the world, particularly in developing countries, Coronary Artery Diseases (CADs) are a major cause of significant morbidity and mortality. Primary PCI (PPCI) is the standard of emergency care in patients suffering from STEMI. The major cardiovascular outcomes (MACE) may be different in diabetic and nondiabetic patients.&#x0D; Objective:&#x0D; This article aims at comparing major adverse cardiovascular outcomes in diabetic and nondiabetic STEMI patients going through pPCI.&#x0D; Study design:&#x0D; Descriptive case series&#x0D; Study setting:&#x0D; Emergency Department, Punjab Institute of Cardiology (PIC), Lahore.&#x0D; Methodology:&#x0D; A total of 245 patients were included out of which 85 were diabetic and 160 were nondiabetic. Post-PPCI in-hospital outcomes were recorded: mortality, cerebrovascular accident, acute and subacute stent thrombosis, heart failure, acute kidney injury and arrhythmias.&#x0D; Results: &#x0D; With mean age of 50.3 ± 9.7 years; mean BMI of 28.0 ± 2.0 kg/m2, risk factors included hypertension (73), family history of IHD (23) and smoking (81). Post-PPCI in hospital outcomes in 85 diabetics were as follows: mortality 0, heart failure in 1 (1.18%), acute stent thrombosis 0; acute kidney injury in 8 patients (9.41%). Among 160 nondiabetic patients, post PPCI outcomes were as follows: mortality 2 (1.25%), heart failure 4 (2.5%), acute stent thrombosis 1 (0.6%) and acute kidney injury 6 (3.75%). The only significant association among PPCI following STEMI and in-hospital outcomes was with acute kidney injury (P = 0.069).&#x0D; Conclusion:&#x0D; For acute STEMI, following the primary percutaneous intervention (PPCI), results among diabetic and nondiabetic patients seem to be favorable in terms of major undesirable outcomes and possible to achieve in PIC, Lahore. PPCI is associated with larger success rate, low mortality rate and complication rates. The hospital's experiences and results can be very valuable in establishing PPCI networks in our nation.&#x0D; Keywords: &#x0D; Primary PCI, Acute STEMI, MACE.

Predisposing factors leading to subacute stent thrombosis (SAT) in patients who have undergone percutaneous coronary intervention (PCI) in patients presenting with acute coronary syndrome

Background: Stent thrombosis is less common but life-threatening that in most cases leads to death or a big non-fatal ST-elevation myocardial infarction (STEMI). Past research data suggests multiple predisposing factors play role in sub-acute thrombosis (usually with ST elevation). However, very few studies have been conducted regarding the predisposing factors of subacute stent thrombosis (SST) in Pakistan, and hence, there is very limited knowledge regarding the trend of risk factors associated with SST.&#x0D; Objective: This study will determine the predisposing factors that lead to subacute stent thrombosis in patients with the acute coronary syndrome who have undergone PCI.&#x0D; Methodology: Retrospective demographical and angiographical data of the patients who have undergone PCI and also were presented with ACS was gathered from the hospital registry. All the data were analyzed using SPSS and were presented as mean ± SD and percentages for continuous and categorical variables, respectively. Univariate and multivariate analysis was carried out to analyze the subacute stent thrombosis predictors.&#x0D; Results: The occurrence of subacute stent thrombosis was found to be 4..9 %. A significant higher number of patients who have developed subacute stent thrombosis were male (81.4 %, p = 0.037), suffered from diabetes mellitus (48.1 %, p = 0.034), had hypertension (59.2 %. P = 0.016), with pre-procedural decreased left ventricular ejection fraction (LVEF) (36.11?±?6.86, p &lt; 0.001) and Killip Class (p &lt; 0.001). Significantly higher odds were observed among patients with diabetes (2.13 [1.01–4.34]), hypertension (2.33 [1.17–4.86]), and the Killip Class III or IV patients (6.4 [2.35–17.41]). The single independent predictor of the subacute stent thrombosis was found to be Killip Class III-IV with an adjusted ratio of 5.1 [1.81–15.32].&#x0D; Conclusion: Subacute stent thrombosis in patients who have undergone PCI for acute myocardial infarction is not as infrequent as demonstrated by the previous studies accruing with a frequency of 4.9 % with a death rate of 7 % in the patients with SST. Diabetes and hypertension were observed to be associated and served as risk factors for the development of SST. Killip class III-IV was demonstrated to be the single independent predictor of subacute stent thrombosis.

Measuring Major Adverse Cardiovascular Events (MACE) in male vs female suffering from acute ST-Elevation Myocardial Infarction undergoing Primary Percutaneous Coronary Intervention (PPCI) at PIC, Lahore

Introduction:&#x0D; Worldwide, Coronary Artery Diseases (CADs) cause significant disability and death. Primary PCI (PPCI) is the gold-standard of emergency care in management of patients suffering from STEMI. Gender-based differences may be present in the major cardiovascular outcomes (MACE) of PPCI.&#x0D; Objective:&#x0D; This article aims at comparing major adverse cardiovascular outcomes male vs female STEMI patients going through PPCI.&#x0D; Study design:&#x0D; Descriptive case series&#x0D; Study setting:&#x0D; Emergency Department, Punjab Institute of Cardiology (PIC), Lahore.&#x0D; Methodology:&#x0D; With mean age just over 50.3 ± 9.7 years, 193 (78.8%) males and 52 (21.2%) female, a total of 245 patients were enrolled in the study. Risk factors included diabetes, hypertension, familial IHD and active smoking. We recorded in-hospital outcomes post-pPCI: mortality, cerebrovascular accident, acute and subacute stent thrombosis, heart failure, acute kidney injury and arrhythmias.&#x0D; Results: &#x0D; Post PPCI in-hospital outcomes in 193 males: mortality 0, heart failure 3 (1.6%), acute stent thrombosis 0 and acute kidney injury in 11 patients (5.7%). Among 52 females: mortality 2 (3.8%), heart failure 2 (3.8%), acute stent thrombosis 1 (1.9%) and acute kidney injury 3 (5.8%). The only significant association was found between female gender &amp; post PPCI mortality after STEMI (P = 0.006).&#x0D; Conclusion:&#x0D; Results of in-hospital complications among male &amp; female patients following PPCI for acute STEMI seem to show association of female gender with post-PPCI mortality which is significantly greater than the male population under study.

Subacute stent thromboses in marijuana user associated with isolated protein S deficiency: Thirteenth month of the famine

Subacute stent thromboses in marijuana user associated with isolated protein S deficiency: Thirteenth month of the famine

Early stent thrombosis in Kounis syndrome - a case report

Introduction. Kounis syndrome is a simultaneous manifestation of acute coronary syndrome and conditions associated with mast cell activation, such as allergies or anaphylactic reactions. We present early stent thrombosis in a female with an atopic constitution without previous atherosclerosis of coronary arteries. Case report. A 50-year-old woman with typical anginal pain was admitted to the Clinic for Cardiology, University Clinical Center Nis. A few hours earlier, she had passed by a linden tree in bloom. She immediately felt chest pain, paresthesia and numbness in her left arm throat tightness, heaviness of the tongue, and swelling of the lips. The symptoms disappeared for 60 min after taking 10mg of loratadine, but then they recurred. On the electrocardiographic (ECG) findings, 30 minutes after admission, ST elevation was seen in leads D2, D3, aVF, and V6. She underwent an emergency percutaneous coronary intervention procedure. Occlusive thrombosis was seen in the ostium of the left anterior descending (LAD) coronary artery. A sirolimus-coated stent was placed and thrombolysis in myocardial infarction (TIMI) 3 flow was obtained. A few hours after the intervention, the patient reported a new onset of chest pain followed by ventricular fibrillation (VF), DC shock, and the occurrence of new ST-segment elevation in aVR and V1?V3 on the ECG. Repeated angiography showed acute instent thrombotic occlusion. Balloon angioplasty was performed, which restored TIMI 3 flow in LAD coronary artery. Anticoagulant and corticosteroid therapy was administered. Three days after the intervention, optical coherence tomography imaging was performed, which showed good stent expansion and apposition, without atherosclerosis and thrombosis. Conclusion. Coronary angiography proved type I Kounis syndrome after exposure to an allergen, and type III Kounis syndrome developed shortly after stent placement when acute instent thrombosis occurred. Newly described causes of acute and sub-acute stent thrombosis in type III Kounis syndrome are stent-associated hypersensitivity reactions.

Frequency of Subacute Stent Thrombosis (SAT) in Patients Presenting with Acute Coronary Syndrome Undergoing Percutaneous Coronary Intervention (PCI)

Objective: To assess the rate of occurrence of sub-acute Stent Thrombosis (SAT) after primary PCI in the patients presented with the acute coronary syndrome.&#x0D; Study Design: Retrospective cross-sectional study.&#x0D; Place and Duration of Study: At Tertiary Cardiac Care Center of Lahore Pakistan, from Jul 2019 to Jun 2021.&#x0D; Methodology: The retrospective demographical and angiographic data of the admitted patients who underwent PCI for ACS,was gathered from the Hospital Registry of a tertiary cardiac care center of Lahore. The sampling technique was nonprobability consecutive sampling, and all the data was analyzed using SPSS 20.0 and continuous data was presented as Mean±SD and frequencies &amp; percentages for categorical variables. Chi square test (CI=95%, α=5%) was used to find the association of SAT with predisposing factors. p-value &lt; 0.05 was taken as statistically significant.&#x0D; Results: Out of (n=551) patient underwent PPCI, the stent thrombosis was observed to occur in 29(5.2 %), among which 4.9 % were subacute stent thrombosis. The predisposing factors of sub-acute stent thrombosis were Diabetes Mellitus, ACS, smaller vessel size, presence of bifurcation lesion, under sizing of the stent and edge dissection and were in significant association with SAT (p &lt; 0.05).&#x0D; Conclusion: Our study reveals that subacute stent thrombosis is an event with a comparatively higher frequency in patients who go through primary PCI for acute coronary syndrome, demonstrating a frequency of 4.9% and a mortality rate of 74% within 30 days of the procedure.

Rota-Lithotripsy as a Novel Bail-Out Strategy for Highly Calcified Coronary Lesions in Acute Coronary Syndrome.

Heavily calcified lesions in acute coronary syndrome (ACS) still represent a challenging subset for percutaneous coronary intervention (PCI). Rota-lithotripsy-a marriage of rotational atherectomy and intravascular lithotripsy-has recently been introduced to clinical practice as a novel therapeutic option. This study is among the to present the 6-month clinical outcomes of rota-lithotripsy when performed in the ACS setting. The study cohort consisted of 15 consecutive ACS patients who underwent a rota-lithotripsy-PCI due to the presence of a highly calcified, undilatable lesion. The procedural success ratio reached 100%. During the 6-month follow-up, in two of the patients, instances of MACE (major adverse cardiac events) occurred, including one fatal event. Additionally, during the observation period, one target lesion failure, due to subacute stent thrombosis, was identified. Rotational atherectomy with the subsequent use of shockwave intravascular lithotripsy appears to be a safe and effective therapeutic bail-out option for the management of highly calcified coronary artery lesions. Despite, these initial favorable outcomes, carrying out a large number of studies with long-term observations is still necessary in order to establish the potential benefits and shortcomings of rota-lithotripsy.

Clinical Case 31—Active gastrointestinal bleeding during STEMI: a management dilemma

Abstract A man in his 40s presented to the emergency department with chest pain for 8 hours. ECG showed an anterior wall ST-segment elevation myocardial infarction (MI). He received a loading dose of both aspirin and ticagrelor. Coronary angiography demonstrated occlusion of the proximal left anterior descending artery, and primary percutaneous coronary intervention (PCI) with one drug-eluting stent was performed. The patient also presented melena for 5 days. At admission, his hemoglobin was 6.3 g/dL and he was stable. He received a blood transfusion and was started on IV pantoprazole. Endoscopic study was postponed due to concerns related to performing such exam in the setting of a recent MI. The day after PCI, the patient presented major bleeding and hypotension, leading to interruption of the P2Y12 inhibitor. On day 3 of hospitalization, while on single antiplatelet therapy with aspirin, the patient presented new onset of chest pain. He was diagnosed with subacute stent thrombosis (type 4b MI), and thrombus aspiration and balloon angioplasty were performed (Figure 1A, and B). Dual antiplatelet therapy was immediately restarted. Echocardiography revealed worsened left ventricular disfunction (LVEF of 20%). Endoscopy showed tears in the esophagogastric junction (Mallory-Weiss syndrome). This case challenged clinical decision-making, especially the antithrombotic strategy after primary PCI in a patient with major bleeding. Learning points Management of a bleeding patient with acute MI should be individualized. The decision to withhold antithrombotic treatment should weigh the risks related to ongoing bleeding and stent thrombosis. Early endoscopy for acute gastrointestinal bleed in recent MI appears to be a safe procedure for hemorrhage control, although evidence is lacking. Figure 1 Coronary angiography. A—Total occlusion with in-stent thrombus in the proximal left anterior descending artery. B—After thrombus aspiration and angioplasty with paclitaxel-coated balloon of stent thrombosis in the proximal left anterior descending artery, remaining a residual lesion of 50–70%, and distal flow TIMI grade 3.

Subacute stent thrombosis with spontaneously resolved secondary thrombi in paroxysmal nocturnal hemoglobinuria: a case report

BackgroundStent thrombosis (ST) is a serious complication; however, a method to prevent ST in patients with thrombophilic diseases has not been established.Case presentationWe report a case of subacute ST in a patient with paroxysmal nocturnal hemoglobinuria (PNH) who was receiving continuous heparin treatment in addition to the usual dual antiplatelet therapy for contrast defects at the proximal site of the occluded right coronary artery and the proximal site of the left circumflex artery. Despite the resolution of thrombi in secondary lesions, subacute ST occurred. After percutaneous coronary intervention for ST, triple therapy, including oral anticoagulation for PNH-related thrombosis, was initiated. The patient subsequently underwent craniotomy hematoma removal for hemorrhagic cerebral infarction.ConclusionsReported cases of ST in patients with PNH are very few, and this case adds evidence with respect to antithrombotic therapy in patients with thrombotic tendencies. Both thrombosis and bleeding should be considered when administering antithrombotic therapy to patients with thrombotic diseases. If there are specific treatments for thrombophilic diseases, they should be initiated early.

Frequency, Risk Factors, and Outcome of Definite Stent Thrombosis: A Single-Center Experience

IntroductionStent thrombosis (ST) is a serious and potentially life-threatening complication of primary or complex high-risk percutaneous coronary intervention (PCI). Multiple factors are said to precipitate ST, related to the patient's clinical comorbidities, lesion characteristics, operative technique, and post-procedural care. The older-generation stents were thought to be involved in early ST. Though the new generation of drug-eluting stents decreases the incidence of early and late ST, patients are still at risk of very late stent thrombosis (VLST).ObjectiveTo evaluate the frequency, risk factors, and outcomes of definite ST in developing and resource-constrained countries like Pakistan, where PCIs, including primary PCI, complex PCI, and PCI in high-risk populations, are performed routinely.MethodsThis observational cross-sectional study included all patients who underwent primary and complex high PCI between 2012 and 2017 at TABBA Heart Institute (THI), Karachi, Pakistan.ResultsWe included a total of 6587 patients in our study, and among the enrolled sample size, 22 (0.33%) had definite ST. Acute stent thrombosis (AST) was found in seven patients, sub-acute stent thrombosis (SAST) in 10, late stent thrombosis (LST) in two, and VLST were observed in three patients. The basic characteristics of our study ST population were as follows: mean age was 58 years, 95.5% were male, 4.5% were female, nine patients (40%) had diabetes mellitus, 15 patients (68%) had hypertension, 11 (50%) had dyslipidemia, and four patients were smokers (18%).ConclusionThe frequency, risk factors, and rate of mortality of definite ST in the Pakistani population who underwent primary and complex high-risk PCI reflect nearly equal statistics observed in other studies. As seen in other international studies, the incidence rate of VLST was higher in our population.

P202 PRETREATMENT WITH ANTAGONISTS OF P2Y12 PLATELETS RECEPTORS IN ST–ELEVATION MYOCARDIAL INFARCTION: CLINICAL AND ANGIOGRAPHIC OUTCOMES

Abstract Background The use of antagonists of P2Y12 platelets receptors as antiplatelets drugs is a cornerstone in the treatment of ACS. Many efforts are made to understand the right timing of beginning this therapy with the purpose to reduce intra– and periprocedural complications (stent thrombosis, no reflow phenomenon). The rationale behind “pretreatment” (administration of antagonists of P2Y2 platelet receptor before the coronarography) is valuable but the evidences are lacking, also in the setting of ACS–STEMI. Method and Objectives We conduct an observational, monocentric (Ospedale dell’Angelo – Venezia Mestre), retrospective study including patients with STEMI (1st January 2016 – 9th august 2018). We compared two strategies of administration of clopidogrel, ticagrelor and prasugrel (pretreatment vs no pretreatment). Primary endpoints were bleeding BARC 3–5, acute or subacute stent thrombosis and TIMI flow grade &amp;gt; 0 in the culprit coronary. Secondary endpoints were cardiovascular and no cardiovascular in–hospital mortality and in–hospital neurological complications. Results We studied 501 patients (199 in the group pretreated and 302 in the group no pretreated). The median time from first medical contact to PCI was 70,5 minutes in the pretreated group and 60 minutes in the no pretreated group (p = 0.022). No significant differences between the two groups were observed in terms of acute or subacute stent thrombosis (OR 3.72 [0.82–14.20], p = 0.09) e TIMI flow grade &amp;gt; 0 in the culprit coronary (OR 1.11 [0.77–1.58], p = 0.58). In the multivariate analysis we observed that bleeding BARC 3–5 significantly were increased in the pretreated group (adjusted OR 2.78 [1.13–6.83, p = 0.025). In the subgroup analysis, the pretreated subjects with age &amp;gt; 75 were at augmented risk of bleeding BARC 3–5. Conclusions Pretreatment in the setting of ACS–STEMI is not associated with benefits in terms of acute or subacute stent thrombosis and perfusion of culprit coronary but may cause clinically relevant bleedings, in particular in the elderly (age &amp;gt; 75).

Incidence, Predictors, and Outcomes of Acute and Sub-acute Stent Thrombosis after Emergency Percutaneous Coronary Revascularization with Drug-Eluting Stents: A Prospective Observational Study.

Background:Stent thrombosis (ST) remains the most feared complication of percutaneous coronary intervention (PCI). Therefore, this study aimed to determine acute and sub-acute ST incidence, predictors, and outcomes after primary PCI.Methods:This prospective observational study included patients who had undergone primary PCI at a tertiary care cardiac center. All the patients were followed at 30-days of index hospitalization for the incidence of acute or sub-acute ST. ST was further categorized as definite, probable, or possible per the Academic Research Consortium definition. All the survivors of ST were followed after 6-months for the incidence of major adverse cardiovascular events.Results:An aggregate of 1756 patients were included with 79% (1388) male patients and mean age was 55.59 ± 11.23 years. The incidence of ST was 4.9% (86) with 1.3% (22) acute and 3.6% (64) sub-acute. ST was categorized as definite in 3.3% (58) and probable in 1.6% (28). Independent predictor of ST were observed to be male gender (odds ratio (OR); 2.51 [1.21–5.2]), left ventricular end-diastolic pressure ≥20 mmHg (OR; 2.55 [1.31–4.98]), and pre-procedure thrombolysis in myocardial infarction (TIMI) flow 0 (OR; 3.27 [1.61–6.65]). Cumulative all-cause mortality among patients with ST after 164.1 ± 76.2 days was 46.5% (40/86).Conclusion:We observed a substantial number of patients vulnerable to the acute or sub-acute ST after primary PCI. Male gender, LVEDP, pre-procedure TIMI flow grade can be used to identify and efficiently manage highly vulnerable patients.

Prevalence of Acute Stent Thrombosis after Primary PCI in STEMI Patients

Background: In-hospital mortality data of patients who have been experiencing ST (stent thrombosis) shows 7.9% statistics for acute stent thrombosis (AST) within 24 hours of PCI, Sub-Acute Stent Thrombosis (SAST) occurs during 30 days of Percutaneous Coronary Intervention (PCI), Late Stent Thrombosis (LST) found 3.8% within the first year after PCI, and Very Late Stent Thrombosis found 3.6% in 1 year after PCI. From our study, we found out the frequency of Acute Stent Thrombosis (AST) in ST-elevation myocardial infarction (STEMI) Patients after Primary Percutaneous Coronary Interventions (PPCI).&#x0D; Methods: This descriptive-analytic case series was conducted in 06 months data collection time in the NICVD Karachi Pakistan. All the study sample were computed and analyzed by using SPSS (20.0 Version). Mean ± standard deviation was calculated for age, duration of surgery, weight, height, and BMI. Chi-square test by using P ≤ 0.05 as significant on 95% Confidence Interval were used for other variables.&#x0D; Results: Out of 142 patients of 55.56 years of mean age was evaluated with standard deviation ±12.24 and BMI mean was 27.56±6.28. The mean ± SD duration of surgery was 33.48±9.26.&#x0D; Conclusion: It is to be concluded that the frequency of AST after primary PCI was found to be significant. Patients presenting with STEMI were at high risk of AST whether they were hemodynamically unstable or they had ACS stenting of multivessel coronary diseases.

The Frequency of Early Subacute Stent Thrombosis after Primary Percutaneous Coronary Intervention in Patients with St-Segment Elevation Myocardial Infarction

Introduction: Acute coronary syndrome(ACS) is associated with activation ofplateletsand thecoagulationsystem which could influence the incidence of early stentthrombosis(EST).Stent thrombosis is a relatively uncommon phenomenon, yet it is a serious complication which often presents as an ST-segment elevation myocardial infarction (STEMI) and/or sudden cardiac death1,2.Stent thrombosis (ST) is an uncommon but life-threatening complication after percutaneous coronary intervention (PCI), frequently manifesting as acute coronary syndrome (ACS) or even cardiac death.Platelet activation and the heightening of the coagulation system play a major role in the pathogenesis of acute coronary syndrome (ACS) and might impact the occurrence of stent thrombosis in those patients who undergo stenting during ACS. Unfortunately, stent thrombosis (ST) is more frequent after stenting for STEMI than after elective stenting with both drug-eluting stents (DES) and baremetal stents (BMS). Objective: To determine the frequency of early subacute stent thrombosis after primary percutaneous coronary intervention in patients with STsegment elevation myocardial infarction Methodology: Study Design: Descriptive Case Series Setting: This study was conducted in NICVD Hospital, Karachi Subjects and Methods: Study was approved by hospital ethical review committee. All patients who fulfilled the inclusion criteria were included in the study. Pre-operatively a written consent was taken from each patient by the primary investigator of this study. All these patients were undergone primary PCI and stent either drug-eluting stents (coated with medication) or bare-metal stent was placed. These patients were observed for 24 hours for early subacute stent thrombosis. All the collected data were entered into the proforma attached at the end. Results: Mean ± SD of age was 55.56±12.24 with C.I (53.52------57.59) years. Mean ± SD duration of surgery was 33.48±9.26 with C.I (31.90------35.05) minutes. Out of 142 patients 103 (72.53%) were male and 39 (27.4%) were female. Frequency of early subacute stent thrombosis was found to be 4(2.82%). Conclusion: It is to be concluded that frequency of early acute stent thrombosis after primary PCI was found to be 2.82%.Patients presenting with STEMI who are hemodynamically unstable and have multivessel coronary disease undergoing coronary stenting during ACS, are at increased risk of EST. Keywords: Acute myocardial Infarction, Primary PCI, Early Subacute Stent, Thrombosis, STEMI