Why do we keep missing left circumflex artery myocardial infarctions?

BACKGROUND: Diagnosis of left circumflex artery (LCx) myocardial infarctions via 12­lead electrocardiogram (ECG) has posed a challenge to healthcare professionals for many years. METHODS AND RESULTS: A retrospective observational study was performed to analyze patients admitted with myocardial infarction. The study used electronic medical records and specific ICD-10 codes to identify eligible patients, resulting in 2032 encounters. After independent adjudication of cardiac biomarkers, coronary angiography, and electrocardiographic changes, a final patient population of 58 encounters with acute occlusion myocardial infarction (OMI) with a culprit LCx lesion was established. OMI was defined as a lesion with either thrombolysis in myocardial infarction flow (TIMI) 0-2 or TIMI 3 with Troponin I > 1 ng/mL (Reference range 0.00-0.03 ng/mL). ECGs of these patients were then independently evaluated and grouped into 8 different classifications based on the presence or absence of ST elevation and/or depression in corresponding leads. ECG patterns and anatomical characteristics (proximal or distal to the first obtuse marginal artery) of the LCx lesions were then correlated. The appropriateness of triage and delay in reperfusion therapy were also assessed. Those with a left dominant or codominant circulation, and with LCx lesions proximal to the first obtuse marginal artery, were more likely to present with no or subtle ST-segment changes that led to delays in reperfusion therapy. CONCLUSIONS: Patients with left or codominant coronary artery circulation, with OMI proximal to the first obtuse marginal artery, may be less likely to have "classic" findings of ST-segment elevation on ECG due to cancellation forces in the limb leads.

Unusual Initial Presentation of Hepatocellular Carcinoma as a Clavicular Head Mass.

BACKGROUND: Hepatocellular carcinoma (HCC) is a common cancer worldwide. Extrahepatic spread is not unusual during HCC disease, but bone metastases at initial presentation are rare. CASE DESCRIPTION: We describe a case of HCC presenting with a clavicular head mass and spinal metastases with normal α-fetoprotein (AFP) level and hepatitis C virus infection without cirrhosis. After undergoing bone and liver biopsies, the patient started a 12-week course of sofosbuvir/velpatasvir and bevacizumab/atezolizumab for lifelong therapy with palliative intent. Since 2021, the patient has been receiving a combination of bevacizumab and atezolizumab every 21 days. On this regimen as of March 2023, his osseous metastases were stable and his liver lesions had not enlarged. CONCLUSIONS: This case demonstrates a very unusual HCC presentation, the importance of a thorough workup of bone metastasis, and the limited value of AFP for HCC screening, even in disseminated disease.

Circular RNA as Therapeutic Targets in Atherosclerosis: Are We Running in Circles?

Much attention has been paid lately to harnessing the diagnostic and therapeutic potential of non-coding circular ribonucleic acids (circRNAs) and micro-RNAs (miRNAs) for the prevention and treatment of cardiovascular diseases. The genetic environment that contributes to atherosclerosis pathophysiology is immensely complex. Any potential therapeutic application of circRNAs must be assessed for risks, benefits, and off-target effects in both the short and long term. A search of the online PubMed database for publications related to circRNA and atherosclerosis from 2016 to 2022 was conducted. These studies were reviewed for their design, including methods for developing atherosclerosis and the effects of the corresponding atherosclerotic environment on circRNA expression. Investigated mechanisms were recorded, including associated miRNA, genes, and ultimate effects on cell mechanics, and inflammatory markers. The most investigated circRNAs were then further analyzed for redundant, disparate, and/or contradictory findings. Many disparate, opposing, and contradictory effects were observed across experiments. These include levels of the expression of a particular circRNA in atherosclerotic environments, attempted ascertainment of the in toto effects of circRNA or miRNA silencing on atherosclerosis progression, and off-target, cell-specific, and disease-specific effects. The high potential for detrimental and unpredictable off-target effects downstream of circRNA manipulation will likely render the practice of therapeutic targeting of circRNA or miRNA molecules not only complicated but perilous.

Interpreting the ECG in patients with chest pain and right bundle branch block: A case report.

A patient with right bundle branch block (RBBB) presented with chest pain. An ECG showed ST-elevation in leads V1, V2, and aVR, with widespread ST-depression in leads II, aVF, I, aVL, and V4-6. The initial ECG interpretation missed ST-elevation myocardial infarction (STEMI), as ST-elevation thresholds were not reached. Non-urgent angiography showed severe left anterior descending artery stenosis requiring percutaneous coronary intervention. The course was complicated by cardiac arrest necessitating resuscitation and dual chamber pacemaker placement with left bundle branch pacing. This case report outlines the deficiencies of the current voltage criteria for identification of anterior STEMI in patients with RBBB.

An Updated Review on the Role of Non-dihydropyridine Calcium Channel Blockers and Beta-blockers in Atrial Fibrillation and Acute Decompensated Heart Failure: Evidence and Gaps.

PURPOSE: The 2021 European Society of Cardiology guidelines on acute and chronic heart failure (HF) recommend that non-dihydropyridine calcium channel blockers (NDCC) should be avoided in patients with HF with reduced ejection fraction. It also emphasizes that beta-blockers only be initiated in clinically stable, euvolemic patients. Despite these recommendations, NDCC and beta-blockers are often still employed in patients with AF with rapid ventricular response and acute decompensated HF. The relative safety and efficacy of these therapies in this setting is unclear. METHODS: To address the question of the safety and efficacy of NDCC and beta-blockers for acute rate control in decompensated HF, we provide a perspective on the literature of NDCC and beta-blockers in chronic HF with reduced and preserved ejection fraction and AF, including trials on the management of AF with rapid ventricular response with and without HF. RESULTS: Robust data demonstrates mortality benefits when beta-blockers are used in patients with chronic HF with reduced ejection fraction. The data that inform the contraindication of NDCC in HF with reduced ejection fraction are outdated and were not primarily designed to address the efficacy and safety of rate control of AF in patients with HF. Several studies indicate that for acute rate control, NDCC and beta-blockers are both efficacious therapies, especially in the setting of tachycardia-induced cardiomyopathy. CONCLUSION: Future studies are needed to assess the safety and efficacy of beta-blockers and NDCC in both acute and chronic AF with HF with reduced and preserved ejection fraction.

Right Bundle Branch and Bifascicular Blocks: Insensitive Prognostic Indicators for Acute Myocardial Infarction.

The clinical significance of right bundle branch block (RBBB) or bifascicular block (BFB) in the setting of acute myocardial infarction (AMI) is uncertain. RBBB was found in 211 of 7,626 patients (2.8%), presenting to the ED (emergency department) with chest pain, of which 18 (8.5%) also had acute coronary syndrome (ACS). Incidences of ACS were not significantly different between new or presumed new RBBB and prior known RBBB or new or presumed new BFB and prior known BFB. In 2 patients, baseline ST-segment depression in leads V1-3 masked anterior ST-elevation detected on electrocardiogram (ECG). In opposition to the guidelines, the presence of RBBB or BFB does not appear to offer any clinical utility when evaluating patients with suspected AMI. Patients with suspected AMI who present with RBBB and any ST-elevation in leads V1-3 should be considered for emergent coronary angiography rather than RBBB alone.

A Comprehensive Review of the Pleiotropic Effects of Ticagrelor.

AIMS: This review summarizes the findings of preclinical studies evaluating the pleiotropic effects of ticagrelor. These include attenuation of ischemia-reperfusion injury (IRI), inflammation, adverse cardiac remodeling, and atherosclerosis. In doing so, it aims to provide novel insights into ticagrelor's mechanisms and benefits over other P2Y12 inhibitors. It also generates viable hypotheses for the results of seminal clinical trials assessing ticagrelor use in acute and chronic coronary syndromes. METHODS AND RESULTS: A comprehensive review of the preclinical literature demonstrates that ticagrelor protects against IRI in the setting of both an acute myocardial infarction (MI), and when MI occurs while on chronic treatment. Maintenance therapy with ticagrelor also likely mitigates adverse inflammation, cardiac remodeling, and atherosclerosis, while improving stem cell recruitment. These effects are probably mediated by ticagrelor's ability to increase local interstitial adenosine levels which activate downstream cardio-protective molecules. Attenuation and augmentation of these pleiotropic effects by high-dose aspirin and caffeine, and statins respectively may help explain variable outcomes in PLATO and subsequent randomized controlled trials (RCTs). CONCLUSION: Most RCTs and meta-analyses have not evaluated the pleiotropic effects of ticagrelor. We need further studies comparing cardiovascular outcomes in patients treated with ticagrelor versus other P2Y12 inhibitors that are mindful of the unique pleiotropic advantages afforded by ticagrelor, as well as possible interactions with other therapies (e.g., aspirin, statins, caffeine).

The Cost of Breaking Even: a Perspective on the Net Clinical Impact of Adding Aspirin to Antithrombotic Therapies in Patients with Atrial Fibrillation Undergoing Percutaneous Coronary Intervention.

PURPOSE: Outcomes from randomized controlled trials (RCTs) inform the latest recommendations on percutaneous coronary intervention (PCI) management of a short period of oral anticoagulation (OAC), a P2Y12 receptor inhibitor, and aspirin for 1 week or until hospital discharge in patients with atrial fibrillation (AF) undergoing PCI, and up to 4 weeks in individuals considered to be at high-risk for ischemic events, followed by discontinuation of aspirin and continuation of OAC and a P2Y12 inhibitor for up to 12 months. METHODS: We examined and summarized the outcomes of bleeding and major adverse cardiac events (MACEs) from RCTs and meta-analyses, published between 2013 and 2022, comparing therapy with OAC and a P2Y12 inhibitor with and without aspirin in AF patients undergoing PCI with stenting. RESULTS: Data comparing dual therapy with OAC and a P2Y12 inhibitor alone to triple therapy with OAC, a P2Y12 inhibitor, and aspirin with respect to the risks of MACEs, including stent thrombosis within the first 30 days, are underpowered and inconclusive. The addition of aspirin does not appear to be associated with a decreased risk of ischemic events, even in patients with high-risk CHA2DS2-VASc scores, but does significantly increase bleeding hazards. The increased safety of newer generation drug-eluting stents may have further minimized any theoretical anti-ischemic benefits of aspirin. The possible attenuation of the pleiotropic effects of concomitant cardiovascular medications by aspirin may also have been a contributing factor. CONCLUSION: The addition of aspirin to OAC and a P2Y12 inhibitor is likely associated with a net clinical harm in patients with AF who undergo PCI with stenting, even within the first 1-4 weeks after PCI. Revisiting the guideline recommendations to administer aspirin in this timeframe may be warranted.