title: Clinical characteristics, myocardial perfusion deficits, and clinical outcomes of patients with non-specific chest pain hospitalized for suspected acute coronary syndrome: a 4-year prospective cohort study.
abstract: BACKGROUND
  Although the prognostic role of stress SPECT MPI is generally well established, its value in predicting non-fatal cardiac events in patients with acute, non-specific chest pain (NSCP) remains unclear. The aims of this study are 1) to describe the baseline clinical characteristics and prevalence of myocardial perfusion (MP) deficits, by use of an adenosine stress SPECT MPI, in NSCP patients without known CAD discharged after hospitalization for suspected ACS; and 2) to prospectively describe the 4-year clinical outcome in terms of all-cause and cardiac mortality; hospitalization and coronary revascularization procedures; and cardio-vascular events in patients with and without MP deficits.
  
  
  RESULTS
  We evaluated a series of 272 consecutive patients with acute NSCP and aged 18-75years. ICD10-based registries were used to determine the primary outcome (a composite measure of incident CAD death, ACS, or revascularization) and two secondary outcomes (1. all-cause death; 2. a composite measure of cardiovascular death, ACS, revascularization, or stroke). Forty two (15%) participants had a MP deficit. During follow-up (median 1361days), 7 participants had a primary event, 4 died, and 20 had a secondary composite event. Annual event rates were 0.70, 0.39 and 2.07, respectively. MP deficits predicted both subsequent primary and composite secondary events (HR: 7.54; 95% CI=[1.69; 33.69] and 2.93 (95% CI=[1.10; 7.81], respectively). Usual clinical cardiac risk classification could not meaningfully differentiate between patients with and without MP deficits.
  
  
  CONCLUSIONS
  SPECT MPI substantially improved prediction of incident CAD beyond usual clinical procedures and risk classification systems among NSCP patients.
authors.affiliation: Nordic Institute of Chiropractic and Clinical Biomechanics, Odense, Denmark. Electronic address: m.jensen@nikkb.dk.
authors.forename: Mette Jensen
authors.initials: MJ
authors.lastname: Stochkendahl
authors.affiliation: Department of Cardiology, Odense University Hospital, Odense, Denmark.
authors.forename: Hans
authors.initials: H
authors.lastname: Mickley
authors.affiliation: Clinical Epidemiology, Institute of Medical Biometry and Medical Informatics, University Medical Center Freiburg, Freiburg, Germany.
authors.forename: Werner
authors.initials: W
authors.lastname: Vach
authors.affiliation: Department of Cardiology, Odense University Hospital, Odense, Denmark.
authors.forename: Ahmed
authors.initials: A
authors.lastname: Aziz
authors.affiliation: Nordic Institute of Chiropractic and Clinical Biomechanics, Odense, Denmark.
authors.forename: Henrik Wulff
authors.initials: HW
authors.lastname: Christensen
authors.affiliation: Nordic Institute of Chiropractic and Clinical Biomechanics, Odense, Denmark; Institute of Sports Science and Clinical Biomechanics, University of Southern Denmark, Odense, Denmark.
authors.forename: Jan
authors.initials: J
authors.lastname: Hartvigsen
authors.affiliation: Department of Nuclear Medicine, Odense University Hospital, Odense, Denmark.
authors.forename: Poul Flemming
authors.initials: PF
authors.lastname: Høilund-Carlsen
mesh_terms: D054058:Acute Coronary Syndrome / Q000000981:diagnostic imaging* / Q000453:epidemiology / Q000601:surgery; D000293:Adolescent; D000328:Adult; D000368:Aged; D002637:Chest Pain / Q000150:complications / Q000000981:diagnostic imaging*; D003326:Coronary Circulation / Q000502:physiology*; D003718:Denmark / Q000453:epidemiology; D003937:Diagnosis, Differential; D005080:Exercise Test; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D007297:Inpatients; D008297:Male; D008875:Middle Aged; D009204:Myocardial Revascularization / Q000379:methods*; D015995:Prevalence; D011379:Prognosis; D011446:Prospective Studies; D018570:Risk Assessment; D012307:Risk Factors; D015996:Survival Rate / Q000639:trends; D013997:Time Factors; D015899:Tomography, Emission-Computed, Single-Photon; D055815:Young Adult
keywords: Clinical characteristics; Coronary artery disease; Myocardial perfusion imaging; Non-specific chest pain; Prognosis; Risk stratification