Radionuclide imaging techniques for assessing myocardial viability: Clinical applications, evidence, and future directions.

Ischemic cardiomyopathy (ICM) is a leading cause of heart failure globally. Myocardial viability testing aims to identify dysfunctional but potentially reversible myocardium in patients with ICM. This review examines the clinical application and diagnostic performance of radionuclide imaging techniques including thallium-201 (Tl) and technetium-99 m (Tc) single positron emission tomography (SPECT), and flourine-18-flourodeoxyglucose (F-FDG) positron emission tomography (PET) for assessing myocardial viability.

Lack of Change in the Incidence of Unstable Angina after Transition to High-Sensitivity Cardiac Troponin T.

Objective: This study evaluated the impact of high-sensitivity cardiac troponin T (hs-cTnT) implementation on the incidence and cardiac evaluations of patients with unstable angina.

Methods: This was a retrospective U.S.

Cardiac Biomarkers for the Prediction, Discrimination, and Risk-Stratification of Type 2 Myocardial Infarction: A Critical Appraisal.

Distinguishing between myocardial infarction caused by atherothrombotic (type 1) and non-atherothrombotic (type 2) etiologies is a frequently encountered and clinically important distinction. This review provides a critical appraisal of studies addressing the use of cardiac biomarkers in type 2 myocardial infarction for a) discrimination, b) prediction, and c) risk-stratification. No single biomarker thus far provides robust performance for these purposes.

Diagnosis of acute myocardial infarction in patients with renal failure using high-sensitivity cardiac troponin T.

Aims: Diagnosing myocardial infarction (MI) in patients with chronic kidney disease (CKD) is difficult as they often have increased high-sensitivity cardiac troponin T (hs-cTnT) concentrations.

Methods And Results: Observational US cohort study of emergency department patients undergoing hs-cTnT measurement. Cases with ≥1 hs-cTnT increase > 99th percentile were adjudicated following the Fourth Universal Definition of MI.

High Baseline High-Sensitivity Cardiac Troponin T Concentrations and Risk of Index Acute Myocardial Infarction.

Objective: To evaluate the diagnostic performance of the previously recommended baseline high-sensitivity cardiac troponin T (hs-cTnT) thresholds of 52 and 100 ng/L in identifying patients at high risk of acute myocardial infarction (AMI).

Patients And Methods: This study compared the positive predictive value (PPV) for index AMI of these high-risk hs-cTnT thresholds in adult patients in the emergency department undergoing hs-cTnT measurement.

Results: The adjudicated MAyo Southwest Wisconsin 5th Gen Troponin T ImplementatiON cohort included 2053 patients, with 157 (7.

Use of the HEAR Score for 30-Day Risk-Stratification in Emergency Department Patients.

Background: The 2021 American College of Cardiology/American Heart Association chest pain guidelines recommend risk scores such as HEAR (History, Electrocardiogram, Age, Risk factors) for short-term risk stratification, yet limited data exist integrating them with high-sensitivity cardiac troponin T (hs-cTnT).

Methods: Retrospective, multicenter (n = 2), observational, US cohort study of consecutive emergency department patients without ST-elevation myocardial infarction who had at least one hs-cTnT (limit of quantitation [LoQ] <6 ng/L, and sex-specific 99th percentiles of 10 ng/L for women and 15 ng/L for men) measurement on clinical indications in whom HEAR scores (0-8) were calculated. The composite major adverse cardiovascular event (MACE) outcome was 30-day prognosis.

Diagnosis and Prognosis of Type 2 Myocardial Infarction Using Objective Evidence of Acute Myocardial Ischemia: A Validation Study.

Background: Differentiating type 2 myocardial infarction from myocardial injury can be difficult. In addition, the presence of objective evidence of myocardial ischemia may facilitate identification of high-risk type 2 myocardial infarction patients.

Methods: This was an observational cohort study of adult emergency department patients undergoing high-sensitivity cardiac troponin T (hs-cTnT) measurement.

Prophylactic Intravenous Aminophylline for Preventing Bradyarrhythmias During Coronary Atherectomy: A 10-Year Single-Center Experience.

Background: Aminophylline, an adenosine antagonist, can be used to prevent adenosine-mediated bradyarrhythmias.

Methods: Retrospective, observational, descriptive analysis of patients undergoing rotational atherectomy with intravenous (IV) aminophylline pretreatment during a 10-year period (2010-2020). The primary composite outcome was the occurrence of a documented bradyarrhythmia requiring pharmacologic intervention and/or temporary pacemaker (TPM) implantation.

Artificial intelligence-augmented electrocardiography for left ventricular systolic dysfunction in patients undergoing high-sensitivity cardiac troponin T.

Aims: Our goal was to evaluate a previously validated artificial intelligence-augmented electrocardiography (AI-ECG) screening tool for left ventricular systolic dysfunction (LVSD) in patients undergoing high-sensitivity-cardiac troponin T (hs-cTnT).

Methods And Results: Retrospective application of AI-ECG for LVSD in emergency department (ED) patients undergoing hs-cTnT. AI-ECG scores (0-1) for probability of LVSD (left ventricular ejection fraction ≤ 35%) were obtained.

Major adverse cardiovascular events after diagnosis of myocardial injury and types 1 and 2 myocardial infarction.

Aims: Limited US outcome data exist among patients with myocardial injury and types 1 and 2 myocardial infarction (MI) evaluated with high-sensitivity cardiac troponin (hs-cTn).

Methods And Results: This is an observational US cohort study of emergency department (ED) patients undergoing hs-cTnT measurement. Cases with ≥1 hs-cTnT increase >99th percentile were adjudicated following the Fourth Universal Definition of MI.

Rapid Exclusion of Acute Myocardial Injury and Infarction With a Single High-Sensitivity Cardiac Troponin T in the Emergency Department: A Multicenter United States Evaluation.

Background: There are good data to support using a single high-sensitivity cardiac troponin T (hs-cTnT) below the limit of detection of 5 ng/L to exclude acute myocardial infarction. Per the US Food and Drug Administration, hs-cTnT can only report to the limit of quantitation of 6 ng/L, a threshold for which there are limited data. Our goal was to determine whether a single hs-cTnT below the limit of quantitation of 6 ng/L is a safe strategy to identify patients at low risk for acute myocardial injury and infarction.

Clinical Impact of High-Sensitivity Cardiac Troponin T Implementation in the Community.

Background: Limited U.S. data exist regarding high-sensitivity cardiac troponin (cTn) implementation.

High-Sensitivity Cardiac Troponin T for the Detection of Myocardial Injury and Risk Stratification in COVID-19.

Background: Limited data exist on high-sensitivity cardiac troponin (hs-cTn) for risk-stratification in COVID-19.

Methods: We conducted a multicenter, retrospective, observational, US-based study of COVID-19 patients undergoing hs-cTnT. Outcomes included short-term mortality (in-hospital and 30-days post-discharge) and a composite of major adverse events, including respiratory failure requiring mechanical ventilation, cardiac arrest, and shock within the index presentation and/or mortality during the index hospitalization or within 30-days post-discharge.