Optical Coherence Tomographic Insights of Very Late Stent Thrombosis of a Second-Generation Drug-Eluting Stent: A case report

Background Very-very late stent thrombosis (VVLST) occurring more than five years after implantation of drug-eluting stent (DES) is extremely rare, being restricted to few case reports. Mainly described with 1st generation stents, this life-threatening complication has not been described with later-generation stents. We describe the first case of VVLST occurring 3309 days (> 9 years) after implantation of 2nd generation DES Case summary A 62-year-old male presented with the acute coronary syndrome. He has a history of percutaneous coronary intervention (PCI) to the right coronary artery (RCA) using the three second-generation DES more than nine years ago. Coronary angiogram revealed in-stent restenosis (ISR) with doubtful angiographic thrombus. Optical Coherence Tomography (OCT) confirmed the diagnosis of stent thrombosis (STh) localized to the stent overlap zone with underlying ISR. Patient underwent OCT guided PCI with DES implantation and was discharged on dual antiplatelet therapy including ticagrelor. He is doing well on follow-up at six months. Discussion STh can occur in second-generation stents nearly a decade after implant. Stent overlap segment is more prone to neo-atheroma formation and vulnerable plaque leading to STh. In addition to confirming the diagnosis, OCT provides exciting insights into the underlying mechanism. This has implications for long-term antiplatelet therapy in patients implanted with multiple stents.

Extremely Late Stent Thrombosis in a First Generation Drug- Eluting Stent 10 Years After Stent Deployment: A Case Report

Stent thrombosis is one of the gravest complications of percutaneous coronary intervention which usually manifest as ST-segment elevation myocardial infarction or sudden death. There are a very few case reports in the literature regarding extremely late stent thrombosis in a drug-eluting stent. Here we report a case of extremely late stent thrombosis in a first generation drug-eluting stent in a 54 year old gentleman. To the best of our knowledge, this is the first case report with the longest duration (10 years) after sirolimus eluting first-generation DES in Bangladesh. Bangladesh Heart Journal 2021; 36(2): 164-168

Very late stent thrombosis associated with COVID-19 infection: a case report and review of the literature

Coronavirus disease 2019 (COVID-19), caused by SARS-CoV-2 has varied manifestation with multisystem involvement. Acute coronary syndrome in COVID-19 as a result of stent thrombosis is an uncommon entity and is often due to hypercoagulable state. A 40-year-old male was referred to us with acute onset chest pain. He also reported fever, sore throat and dry cough for six days which mandated testing for COVID-19 which turned out to be positive. He had a prior history of coronary artery disease with a drug eluting stent implanted two years back. An electrocardiogram was suggestive of acute anterior wall myocardial infarction while echocardiogram revealed hypokinesia of left anterior descending (LAD) artery territory. Coronary angiogram revealed non-occlusive thrombus in proximal LAD stent. A Thrombolysis in Myocardial Infarction (TIMI) III flow was restored following balloon angioplasty with a non-compliant balloon and use of glycoprotein (GP) IIb-IIIa receptor antagonist. A diagnosis of very late stent thrombosis subsequent to COVID-19 was made.

Factors Influencing 1st and 2nd Generation Drug-Eluting Stent Performance: Understanding the Basic Pharmaceutical Drug-in-Polymer Formulation Factors Contributing to Stent Thrombosis Do We Really Need to Eliminate the Polymer?

Drug-eluting stents (DES) have a major role in treating cardiovascular disease. The evolution of bare metal stents into 1st generation durable-polymer DES (DP-DES) reduced the rate of in-stent restenosis (ISR) and the need for repeat-revascularization. However, clinical outcomes showed similar rates of late stent thrombosis (ST<1 year) and higher rates of very late stent thrombosis (ST>1 year) necessitating the advent of 2nd generation more biocompatible polymer DES and biodegradable-polymer DES (BP-DES) that reduced ST rates with shorter dual anti-platelet therapy (DAPT). Despite the improvements in drugs and polymer biocompatibility for both durable and biodegradable polymers, stent thrombosis remains an issue. Doubts remain about the safety and efficacy of the more biocompatible 2nd generation durable polymers in respect to vessel inflammatory and thrombogenic response as compared to biodegradable polymers despite clinical trial and meta-analyses evidence indicating that 2nd generation DP-DES are non-inferior to BP-DES for stent thrombosis. A long-term presence of the polymer can cause inflammation and thrombogenesis. However, the cause of stent thrombosis is multi-factorial from a drug-in-polymer formulation perspective; e.g., drug release kinetics, drug physiochemical and pharmacological properties, degradation kinetics; polymer biocompatibility and hemocompatibility and coating properties. It appears that the focus should be on controlling burst release and developing more biocompatible, durable polymers, especially considering the cost of PCI utilizing biodegradable, polymer-free and bioresorbable scaffolds. This may give an insight into certain DP-DES effectiveness as compared to BP-DES for the existing clinical data and improve future stent development.

Primary Percutaneous Coronary Intervention in Patients With Type 2 Diabetes With Late/Very Late Stent Thrombosis and de novo Lesions: A Single-Center Observational Cohort Study of Clinical Outcomes and Influencing Factors

Background: This study compared differences in the risk factors and clinical outcomes of primary percutaneous coronary intervention (PCI) in type 2 diabetes mellitus (DM) and non-DM patients with de novo lesions (DNLs) and late or very late stent thrombosis (LST/VLST).Methods: We used angiography to screen 4,151 patients with acute coronary syndrome for DNL and LST/VLST lesions. Overall, 3,941 patients were included in the analysis and were allocated to the DM (n = 1,286) or non-DM (n = 2,665) group at admission. The primary endpoint was a composite of major adverse cardiovascular events (MACEs), defined as death, myocardial infarction, revascularization, and ischemic stroke, within a median follow-up period of 698 days.Results: In the group with a total white blood cell count &gt;10 × 109/L (P = 0.004), a neutral granular cell count &gt;7 × 109/L (P = 0.030), and neutrophil–lymphocyte ratio &gt;1.5 (P = 0.041), revascularization was better for DNL than for LST/VLST lesions. Among DM patients with DNLs, each unit increase in age was associated with a 53.6% increase in the risk of MACEs [hazard ratio (HR): 1.536, 95% confidence interval (CI), 1.300–1.815, P &lt; 0.0001]. Older age (≥65 years) was associated with a significantly greater risk of MACEs (P &lt; 0.0001). Furthermore, each standard deviation (SD) increase in the level of peak white blood cell counts was associated with a 50.1% increase in the risk of MACEs (HR, 1.501; 95% CI, 1.208–1.864; P = 0.0002). When stratifying the DM population with DNLs according to the D-dimer baseline and peak levels &lt;0.5 vs. ≥0.5 mg/L, the high D-dimer group at baseline had a 2.066-fold higher risk of MACEs (P &lt; 0.0001), and the high peak level D-dimer group had a 1.877-fold higher risk of MACEs (P = 0.001) compared to the low-level groups. Among DM patients with LST/VLST, each unit increase in age was associated with a 75.9% increase in the risk of MACEs (HR: 1.759, 95% CI, 1.052–2.940, P = 0.032). Furthermore, for each SD increase in the peak D-dimer level, the risk of MACEs increased by 59.7% (HR, 1.597; 95% CI, 1.110–2.295; P = 0.041).Conclusion: Following successful primary PCI, the measurement of baseline and peak D-dimer values may help identify individuals at high cardiovascular risk. This suggests a potential benefit of lowering D-dimer levels among T2DM patients with DNL. Furthermore, age and the peak D-dimer values may facilitate the risk stratification of T2DM patients with LST/VLST.