Impact of antiplatelet therapy on microvascular thrombosis during ST-elevation myocardial infarction.

During an acute coronary syndrome, atherosclerotic plaque rupture triggers platelet activation and thrombus formation, which may completely occlude a coronary artery leading to ST-elevation myocardial infarction (STEMI). Although emergency percutaneous coronary intervention (PCI) is effective in re-opening the main coronary arteries, the downstream microvasculature can become obstructed by embolised plaque material and thrombus. Dual antiplatelet therapy is recommended by guidelines and used routinely for the management of STEMI to reduce the risk of recurrent atherothrombotic events. However it is unclear to what extent antiplatelet therapy reduces microvascular thrombosis, largely because most tools to assess microvascular thrombosis only became available after antiplatelet therapy was already used in the majority of patients. Platelets play a central role in key aspects of microvascular thrombosis, such as atherosclerotic plaque-induced thrombus development, inflammation and microvascular dysfunction, making them a potential target for novel therapeutic interventions. Currently, more potent antiplatelet agents like GPIIb/IIIa inhibitors may be administered during PCI directly into coronary arteries with high thrombus burden but it is not well-established whether this reduces microvascular thrombosis and they significantly increase the risk of bleeding. In this review article we discuss the role of platelets in microvascular thrombosis, describe how microvascular thrombosis and obstruction can be assessed clinically and explore potential new antiplatelet treatments for this. In particular, we highlight novel antiplatelet drugs targeting the platelet receptor GPVI, as well as PAR4, GPIb-IX-V and 5HT2A receptors. We also discuss the potential benefit of P-selectin inhibitors as they have proven to be effective in reducing microvascular thrombosis in sickle-cell disease which could translate into potential benefits in acute coronary syndrome.

GPVI as an effective antithrombotic target.

Glycoprotein (GP) VI plays a major role in thrombosis but not haemostasis, making it a promising antithrombotic target. The primary role of GPVI on the surface of platelets is a signalling receptor for collagen, which is one of the most potent thrombotic sub-endothelial components that is exposed by atherosclerotic plaque rupture. Inhibition of GPVI has therefore been investigated as a strategy for treatment and prevention of atherothrombosis, such as during stroke and acute coronary syndromes. A range of specific GPVI inhibitors have been characterised and 2 of these inhibitors, glenzocimab and revacept, have completed phase II clinical trials in ischemic stroke. In this review, we summarise mechanisms of GPVI activation and the latest progress of clinically tested GPVI inhibitors, including their mechanisms of action. By focussing on what is known about GPVI activation, we also discuss whether alternate strategies could also be used to target GPVI.

Epidemiological findings on interventional cardiology procedures during the COVID-19 pandemic: A multi-center study.

BACKGROUND: The rates of in-hospital mortality following percutaneous interventional procedures (PIP) during the COVID-19 pandemic period compared to the non-pandemic period has not been reported so far. METHODS: We retrospectively enrolled all consecutive patients admitted for PIP across five centers from February 2020 to May 2020. RESULTS: A total of 4092 PIP were performed during the reference periods. The total number of procedures dropped from 2380 to 1712 (28.0% reduction). Overall in-hospital mortality increased from 1.1% in 2019, to 2.6% in 2020 (63% relative increase). CONCLUSION: During the COVID-19 pandemic, in-hospital all-cause mortality significantly increased in patients admitted for cardiological PIP.

Trends in cardiovascular mortality of cancer patients in the US over two decades 1999-2019.

BACKGROUND: Cancer is the second most common cause of death globally after cardiovascular disease, and cancer patients are at an increased risk of CV death. This recognition has led to publication of cardio-oncological guidelines and to the widespread adoption of dedicated cardio-oncology services in many institutes. However, it is unclear whether there has been a change in the incidence of CV death in cancer patients. METHODS AND RESULTS: Using Centers for Disease Control and Prevention Wide-Ranging, Online Data for Epidemiologic Research (CDC WONDER) Multiple Cause of Death dataset, we determined national trends in age-standardised mortality rates attributed to cardiovascular diseases in patients with and without cancer, from 1999 to 2019, stratified by cancer type, age, gender, race, and place of residence (state and urbanisation status). Among more than 17.8 million cardiovascular deaths in the United States, 13.6% were patients with a concomitant cancer diagnosis. During the study period, among patients with cancer, the age-adjusted mortality rate dropped by 52% (vs 38% in patients with no cancer). In cancer patients, age-adjusted mortality rate dropped more significantly among patients with gastrointestinal, breast, and prostate malignancy than among patients with haematological malignancy (59%-63% vs. 41%). Similar reduction was observed in both genders (53%-54%), but more prominent reduction was observed in older patients and in those living in metro areas. CONCLUSIONS: Our findings emphasise the role of multidisciplinary management of cancer patients. Widespread adoption of cardio oncology services have the potential to impact the inherent risk of increased CV mortality in both cancer patients and survivors.

Establishing the need for clinical follow-up after emergency appendicectomy in the modern era: Retrospective case series of 145 patients.

INTRODUCTION: Emergency appendicectomy (EA) is a commonly performed operation, with an increasing number of EAs being performed as day-case. The aim of this study is to establish if there is a need for post-operative follow-up and if this could prevent adverse outcomes. METHODS: A retrospective analysis of patients who underwent EA at multiple centres over a six-month period was undertaken. They were contacted by telephone and a standardised questionnaire was used to ascertain post-operative outcomes, including duration of analgesia use, duration before return to normal daily activity (ADLs), surgical site infection rates (SSI) and rates of re-presentation to medical services. Patients were stratified into those who underwent laparoscopic versus open appendicectomy, smokers versus non-smokers, and body mass index (BMI). RESULTS: A total of 145 patients were included in the study. Patients undergoing open surgery (vs. laparoscopic surgery) required analgesia for significantly longer periods, with a significantly longer return to ADLs. Smokers, when compared to non-smokers experienced a significantly longer return to work/school; and significantly higher risk of SSI and re-presenting to accident & emergency; as did patients with a BMI >30 when compared to those with a BMI <30. CONCLUSION: Most patients do not need formal outpatient assessment after EA. However, there is clearly a subset of higher risk patients who may benefit from this - patients who are smokers or obese. They have prolonged recovery times, and are at greater risk of SSI. Earlier surgical outpatient follow-up of these patients could prevent adverse outcomes.

Phaeochromocytoma found on cardiovascular magnetic resonance in a patient presenting with acute myocarditis: an unusual association.

Myocarditis is inflammation of the cardiac muscle. The symptoms, signs and basic investigation findings can mimic that of myocardial infarction. The most common cause is infection (most commonly viral). Cardiovascular magnetic resonance (CMR) is the gold standard non-invasive diagnostic test for potential acute myocarditis as it allows assessment of myocardial oedema and scar. A man aged 25 years was admitted with chest pain, dizziness, headache, palpitations and sweating. His troponin was mildly positive. A CMR was performed which showed mild myocarditis and a right suprarenal mass which was confirmed to be a phaeochromocytoma based on biochemistry and a dedicated imaging workup. Phaeochromocytoma can lead to cardiac involvement in the form of left ventricular dysfunction, or catecholamine-induced myocarditis.