title: Among Unstable Angina and Non-ST-Elevation Myocardial Infarction Patients, Transient Myocardial Ischemia and Early Invasive Treatment Are Predictors of Major In-hospital Complications.
abstract: Treatment for unstable angina (UA) or non-ST-elevation myocardial infarction (NSTEMI) is aimed at plaque stabilization to prevent infarction. Two treatment strategies are (1) invasive (ie, cardiac catheterization laboratory <24 hours after admission) or (2) selectively invasive (ie, medications with cardiac catheterization laboratory >24 hours for recurrent symptoms). However, it is not known if the frequency of transient myocardial ischemia (TMI) or complications during hospitalization varies by treatment.
  
  
  
  We aimed to (1) examine occurrence of TMI in UA/NSTEMI, (2) compare frequency of TMI by treatment pathway, and (3) determine predictors of in-hospital complications (ie, death, myocardial infarction [MI], pulmonary edema, shock, dysrhythmia with intervention).
  
  
  
  Hospitalized patients with coronary artery disease (ie, history of MI, percutaneous coronary intervention/stent, coronary artery bypass graft, >50% lesion via angiogram, or positive troponin) were recruited, and 12-lead electrocardiogram Holter initiated. Clinicians, blinded to Holter data, decided treatment strategy; offline analysis was done after discharge. Transient myocardial ischemia was defined as more than 1-mm ST segment ↑ or ↓, in more than 1 electrocardiographic lead, more than 1 minute.
  
  
  
  Of 291 patients, 91% were white, 66% were male, 44% had prior MI, and 59% had prior percutaneous coronary intervention/stent or coronary artery bypass graft. Treatment pathway was early in 123 (42%) and selective in 168 (58%). Forty-nine (17%) had TMI: 19 (15%) early invasive, 30 (18%) selective (P = .637). Acute MI after admission was higher in patients with TMI regardless of treatment strategy (early: no TMI 4% vs yes TMI 21%; P = .020; selective: no TMI 1% vs yes TMI 13%; P = .0004). Predictors of major in-hospital complication were TMI (odds ratio, 9.9; 95% confidence interval, 3.84-25.78) and early invasive treatment (odds ratio 3.5; 95% confidence interval, 1.23-10.20).
  
  
  
  In UA/NSTEMI patients treated with contemporary therapies, TMI is not uncommon. The presence of TMI and early invasive treatment are predictors of major in-hospital complications.
authors.affiliation: Michele M. Pelter, PhD, RN Director, ECG Monitoring Research Lab, School of Nursing, and Assistant Professor, Department of Physiological Nursing, University of California San Francisco. Denise L. Loranger, RN Research Nurse, Saint Mary's Hospital, Reno, Nevada. Teri M. Kozik, PhD, RN Supervisor of Clinical Research, Dignity Health, St Joseph's Medical Center, Stockton, California. Anita Kedia, MD Cardiologist, Saint Mary's Medical Group, Reno, Nevada. Richard P. Ganchan, MD Cardiologist, Renown Institute for Heart & Vascular Health, Reno, Nevada. Deborah Ganchan, BSN, RNResearch Nurse, University of Nevada, Reno. Xiao Hu, PhD Associate Professor, Department of Physiological Nursing, University of California San Francisco. Mary G. Carey, PhD, RN Associate Director of Nursing Research Strong Memorial Hospital, University of Rochester Medical Center, New York.
authors.forename: Michele M
authors.initials: MM
authors.lastname: Pelter
authors.forename: Denise L
authors.initials: DL
authors.lastname: Loranger
authors.forename: Teri M
authors.initials: TM
authors.lastname: Kozik
authors.forename: Anita
authors.initials: A
authors.lastname: Kedia
authors.forename: Richard P
authors.initials: RP
authors.lastname: Ganchan
authors.forename: Deborah
authors.initials: D
authors.lastname: Ganchan
authors.forename: Xiao
authors.initials: X
authors.lastname: Hu
authors.forename: Mary G
authors.initials: MG
authors.lastname: Carey
mesh_terms: D000368:Aged; D000789:Angina, Unstable; D001026:Coronary Artery Bypass; D003324:Coronary Artery Disease; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009203:Myocardial Infarction; D000072658:Non-ST Elevated Myocardial Infarction; D015607:Stents