Clopidogrel discontinuation and platelet reactivity following coronary stenting.

Aims: Antiplatelet therapy with aspirin and clopidogrel are recommended for 1 year after drug-eluting stent (DES) implantation or myocardial infarction. However, the discontinuation of antiplatelet therapy has become an important issue as recent studies have suggested a clustering of ischaemic events within 90 days of clopidogrel withdrawal. The objective of this investigation was to explore the hypothesis that there is a transient \u22rebound\u22 increase in platelet reactivity within three months of clopidogrel discontinuation. Methods and Results: In this prospective study, platelet function was assessed in patients taking aspirin and clopidogrel for at least 1 year following DES implantation. Platelet aggregation was measured using a modification of light transmission aggregometry in response to multiple concentrations of adenosine diphosphate (ADP), epinephrine, arachidonic acid, thrombin receptor activating peptide and, collagen. Clopidogrel was stopped and platelet function was reassessed 1 week, 1 month and 3 months later. Thirty-two patients on dual antiplatelet therapy were recruited. Discontinuation of clopidogrel increased platelet aggregation to all agonists, except arachidonic acid. Platelet aggregation in response to ADP (2.5, 5, 10, 20 μM) and epinephrine (5, 20 μM) was significantly increased at 1 month compared to 3 months following clopidogrel withdrawal. Thus, a transient period of increased platelet reactivity to both ADP and epinephrine was observed 1 month after clopidogrel discontinuation. Conclusions: This study demonstrates a transient increase in platelet reactivity 1 month after clopidogrel withdrawal. This phenomenon may, in part, explain the known clustering of thrombotic events observed after clopidogrel discontinuation. This observation requires confirmation in larger populations

Primary Percutaneous Coronary Intervention in Patients With Acute Myocardial Infarction, Resuscitated Cardiac Arrest, and Cardiogenic Shock The Role of Primary Multivessel Revascularization

ObjectivesThis study sought to assess the impact of multivessel (MV) primary percutaneous coronary intervention (PCI) on clinical outcomes in patients with ST-segment elevation myocardial infarction (STEMI) presenting with cardiogenic shock (CS) and resuscitated cardiac arrest (CA).BackgroundThe safety and efficacy of MV primary PCI in patients with STEMI and refractory CS is unknown.MethodsWe conducted a multicenter prospective observational study of consecutive STEMI patients presenting to 5 French centers. Patients were classified as having single-vessel (SVD) or multivessel (MVD) coronary disease, and underwent culprit-only or MV primary PCI. Baseline characteristics and 6-month survival were compared.ResultsAmong 11,530 STEMI patients, 266 had resuscitated CA and CS. Patients with SVD (36.5%) had increased 6-month survival compared to those with MVD (29.6% vs. 42.3%, p = 0.032). Baseline characteristics were similar in those with MVD undergoing culprit-only (60.9%) or MV (39.1%) primary PCI. However, 6-month survival was significantly greater in patients who underwent MV PCI (43.9% vs. 20.4%, p = 0.0017). This survival advantage was mediated by a reduction in the composite of recurrent CA and death due to shock (p = 0.024) in MV PCI patients. In those with MVD, culprit artery PCI success (hazard ratio [HR]: 0.63; 95% confidence interval [CI]: 0.41 to 0.96, p = 0.030) and MV primary PCI (HR: 0.57; 95% CI: 0.38 to 0.84, p = 0.005) were associated with increased 6-month survival.ConclusionsThe results of this study suggest that in STEMI patients with MVD presenting with CS and CA, MV primary PCI may improve clinical outcome. Randomized trials are required to verify these results

Chimney Stenting During Transcatheter Aortic Valve Implantation

Acute coronary artery obstruction is a rare but life-threatening complication of transcatheter aortic valve implantation. In patients at risk of coronary artery obstruction, pre-emptive coronary artery protection with a coronary wire, balloon or stent provides a bailout treatment option. The authors describe the steps involved in performing chimney stenting and summarise the short- and long-term outcome data associated with this technique

Transcatheter Aortic Valve Implantation in a Nonagenarian with Aortic Aneurysm: Futility or Utility?

Transcatheter aortic valve implantation (TAVI) has emerged as the standard of care for older patients with symptomatic severe aortic stenosis (AS) at high or excessive operative risk. There remain patients that are of such considerable risk that even TAVI can be futile. Such patients present ethical conundrums for institutional heart teams. Herein we present a case of a 90-year-old female patient with symptomatic severe AS and significant comorbidities including diffuse peripheral vascular disease and a large ascending aortic aneurysm. Would TAVI be utile or futile in this patient

Validation of Prosthetic Mitral Regurgitation Quantification Using Novel Angiographic Platform by Mock Circulation.

This study aimed to validate a dedicated software for quantitative videodensitometric angiographic assessment of mitral regurgitation (QMR).Quantitative videodensitometric aortography of aortic regurgitation using the time-density principle is a well-documented technique, but the angiographic assessment of mitral regurgitation (MR) remains at best semi-quantitative and operator dependent.Fourteen sheep underwent surgical mitral valve replacement using 2 different prostheses. Pre-sacrifice left ventriculograms were used to assess MR fraction (MRF) using QMR and MR volume (MRV). In an independent core lab, the CAAS QMR 0.1 was used for QMR analysis. In vitro MRF and MRV were assessed in a mock circulation at a comparable cardiac output to the in vivo one by thermodilution. The correlations and agreements of in vitro and in vivo MRF, MRV, and interobserver reproducibility for QMR analysis were assessed using the averaged cardiac cycles (CCs).In vivo derived MRF by QMR strongly correlated with in vitro derived MRF, regardless of the number of the CCs analyzed (best correlation: 3 CCs y = 0.446 + 0.994x; R = 0.784; p =0.002). The mean absolute difference between in vitro derived MRF and in vivo derived MRF from 3 CCs was 0.01 ± 4.2% on Bland-Altman analysis. In vitro MRV and in vivo MRV from 3 CCs were very strongly correlated (y = 0.196 + 1.255x; R = 0.839; p 0.001). The mean absolute difference between in vitro MRV and in vivo MRV from 3 CCs was -1.4 ± 1.9 ml. There were very strong correlations of in vivo MRF between 2 independent analysts, regardless of the number of the CCs.In vivo MRF using the novel software is feasible, accurate, and highly reproducible. These promising results have led us to initiate the first human feasibility study comprising patients undergoing percutaneous mitral valve edge-to-edge repair