Left Bundle Branch Block ECG Characteristics in the Evaluation of Acute Coronary Syndrome

NCT02283619 | Terminated

• 1 other identifier: Pro00051429
• Study Type: observational
• Target: 8
• Locations: 0 countries
• Sites: N/A

Brief Summary

Purpose of the study: The goal of this study is to evaluate the relationship of electrocardiogram (ECG) findings with clinical outcomes in a cohort of patients with left bundle branch block (LBBB) who are being evaluated for acute coronary syndrome (ACS) in the Emergency Department (ED). Background and significance: The significance of specific ECG findings in patients with LBBB being evaluated for ACS has been inadequately studied, and this gap in knowledge is a barrier to optimal management of this population. Due to the speed, availability, low cost, and non-invasive nature of the ECG, it would be ideal to identify ECG characteristics that help to risk stratify these patients in order to inform clinical decision-making, reduce unnecessary invasive testing, and conserve resources. Methods: In this prospective observational study the investigators will identify a consecutive series of adult patients with LBBB presenting to the ED with suspicion of ACS. The investigators will collect data including demographics, cardiac risk factors, initial ECG measurements, lab and radiographic results, procedure results, and clinical outcomes such as 30-day death or myocardial infarction (MI). The investigators will analyze the data using a cohort study design to calculate odds ratios between ECG characteristics and the outcomes of interest.

Conditions

Left Bundle Branch Block

Outcome Measures

Primary Outcomes (4)

• Sensitivity of non-discordant T waves for prediction of positive cardiac biomarkers on index visit

  Diagnostic properties (sensitivity, specificity, likelihood ratios) of item 1 for item 2 below: 1. Presence of at least two ECG leads with non-discordant T waves (meaning either entirely concordant or biphasic, relative to the PR interval) 2. Positive (above the assay's normal reference range) cardiac biomarkers (cardiac troponin I, T, or CK-MB) within 48 hours of presentation to the ED.

  The ECG will be the ECG on presentation to the ED. The maximum cardiac troponin within 48 hours of index visit will be used as the outcome.

• Specificity of non-discordant T waves for prediction of positive cardiac biomarkers on index visit

  Diagnostic properties (sensitivity, specificity, likelihood ratios) of item 1 for item 2 below: 1. Presence of at least two ECG leads with non-discordant T waves (meaning either entirely concordant or biphasic, relative to the PR interval) 2. Positive (above the assay's normal reference range) cardiac biomarkers (cardiac troponin I, T, or CK-MB) within 48 hours of presentation to the ED.

  The ECG will be the ECG on presentation to the ED. The maximum cardiac troponin within 48 hours of index visit will be used as the outcome.

• Positive likelihood ratio of non-discordant T waves for prediction of positive cardiac biomarkers on index visit

  Diagnostic properties (sensitivity, specificity, likelihood ratios) of item 1 for item 2 below: 1. Presence of at least two ECG leads with non-discordant T waves (meaning either entirely concordant or biphasic, relative to the PR interval) 2. Positive (above the assay's normal reference range) cardiac biomarkers (cardiac troponin I, T, or CK-MB) within 48 hours of presentation to the ED.

  The ECG will be the ECG on presentation to the ED. The maximum cardiac troponin within 48 hours of index visit will be used as the outcome.

• Negative likelihood ratio of non-discordant T waves for prediction of positive cardiac biomarkers on index visit

  Diagnostic properties (sensitivity, specificity, likelihood ratios) of item 1 for item 2 below: 1. Presence of at least two ECG leads with non-discordant T waves (meaning either entirely concordant or biphasic, relative to the PR interval) 2. Positive (above the assay's normal reference range) cardiac biomarkers (cardiac troponin I, T, or CK-MB) within 48 hours of presentation to the ED.

  The ECG will be the ECG on presentation to the ED. The maximum cardiac troponin within 48 hours of index visit will be used as the outcome.

Secondary Outcomes (4)

• Sensitivity of various exploratory ECG findings for positive cardiac biomarkers

  The ECG measurements at presentation to the ED will be used, to predict maximum cardiac troponin within 48 hours of presentation to the ED.

• Specificity of various exploratory ECG findings for positive cardiac biomarkers

  The ECG measurements at presentation to the ED will be used, to predict maximum cardiac troponin within 48 hours of presentation to the ED.

• Positive likelihood ratio of various exploratory ECG findings for positive cardiac biomarkers

  The ECG measurements at presentation to the ED will be used, to predict maximum cardiac troponin within 48 hours of presentation to the ED.

• Negative likelihood ratio of various exploratory ECG findings for positive cardiac biomarkers

  The ECG measurements at presentation to the ED will be used, to predict maximum cardiac troponin within 48 hours of presentation to the ED.

Study Arms (1)

Patients with LBBB being evaluated for ACS

Patients who present to the emergency department with left bundle branch block on the electrocardiogram, who are being evaluated for acute coronary syndrome, and who qualify based on the inclusion/exclusion criteria listed in the detailed description.

Other: None - no intervention, observational study

Interventions

None - no intervention, observational study OTHER

No intervention, observational study

Patients with LBBB being evaluated for ACS

Eligibility Criteria

• Age: 18 Years+
• Sex: all
• Healthy Volunteers: No
• Age Groups: Adult (18-64), Older Adult (65+)
• Sampling Method: Probability Sample

Study Population

Selection of Subjects: The population will be patients age 18 or older who present to the ED with LBBB and suspected ACS. The investigators expect the mean age of the population to be approximately 60 years old, with most patients between 40 and 90. They anticipate that these patients will on average have multiple medical comorbidities given that those with LBBB and ACS are reported to be a sicker, older population with more cardiac risk factors than the usual ACS patient without LBBB. Patients under age 18 will be excluded because they extremely rarely have ACS and/or LBBB.

You may qualify if:

• Age 18 and older
• LBBB on ECG
• Presenting to the ED and being evaluated for ACS

You may not qualify if:

• Prisoners
• Institutionalized individuals
• Patients who are incapable of giving legally effective consent
• Patients who cannot understand spoken English

Sponsors & Collaborators

• Duke University: lead

MeSH Terms

Conditions

Bundle-Branch Block

Interventions

Observation

Condition Hierarchy (Ancestors)

Heart Block; Arrhythmias, Cardiac; Heart Diseases; Cardiovascular Diseases; Cardiac Conduction System Disease; Pathologic Processes; Pathological Conditions, Signs and Symptoms

Intervention Hierarchy (Ancestors)

Methods; Investigative Techniques

Study Officials

• Alexander T Limkakeng, MD

  Duke University Hospital

  PRINCIPAL INVESTIGATOR

Study Design

• Study Type: observational
• Observational Model: COHORT
• Time Perspective: PROSPECTIVE
• Sponsor Type: OTHER
• Responsible Party: SPONSOR

Study Record Dates

• First Submitted: October 31, 2014
• First Posted: November 5, 2014
• Study Start: November 1, 2014
• Primary Completion: August 1, 2015
• Study Completion: August 1, 2015
• Last Updated: September 28, 2015

Record last verified: 2015-08