title: Prognostic usefulness of contemporary stress echocardiography in patients with left bundle branch block and impact of contrast use in improving prediction of outcome.
abstract: OBJECTIVE
  Patients with symptomatic left bundle branch block (LBBB) may have myocardial ischaemia due to both coronary artery disease and/or cardiomyopathy (microcirculatory abnormalities) and may have concomitant left ventricular (LV) dysfunction. We aimed to assess the feasibility and prognostic value of contemporary stress echocardiography (SE), which can uncover both pathophysiologies in LBBB patients in routine clinical practice, and also aimed to assess the additive value of contrast SE.
  
  
  RESULTS
  Accordingly, 190 consecutive patients (age 70.5 ± 11.3 years, LV ejection fraction = 50.1 ± 10%) with symptomatic LBBB who underwent SE over 6 years were assessed, of which 142 (75%) underwent contrast SE and 176 (92.6%) had diagnostic SE. Inducible ischaemia was present in 25 (14.2%) patients. During follow-up (35.4 ± 20.2 months) there were 32 deaths (18%) and 18 (10.2%) first cardiovascular (CV) events (acute myocardial infarction/mortality) in the 176 patients with diagnostic studies. Wall thickening score index at peak stress (WTSIpeak), which measures combined LV function and inducible ischaemia, was an independent predictor of mortality (HR = 3.78, 95% CI = 1.39-10.31, P = 0.01) and CV events (HR = 3.96, 95% CI = 1.1-14.3, P = 0.036). An abnormal SE (myocardial ischaemia and/or abnormal LV function) predicted an almost three-fold increase in all-cause mortality and CV events compared with normal SE. Amongst the confounders affecting assessment of wall thickening in LBBB and conventional prognostic variables, use of contrast was an independent predictor (P = 0.034) of WTSI1.16 (optimal predictor of mortality/CV outcome).
  
  
  CONCLUSIONS
  SE in patients with LBBB demonstrated high feasibility and the combination of LV systolic function and myocardial ischaemia provided important prognostic information. Contrast-enhanced SE improved the prediction of outcome.
authors.affiliation: Department of Cardiovascular Medicine, Northwick Park Hospital, Watford Road, Harrow, HA1 3UJ, UK.|Department of Cardiology, Royal Brompton Hospital, London, UK.|Cardiovascular Biomedical Research Unit, National Heart and Lung Institute, Imperial College, London, UK.
authors.forename: Anastasia
authors.initials: A
authors.lastname: Vamvakidou
authors.affiliation: Department of Cardiovascular Medicine, Northwick Park Hospital, Watford Road, Harrow, HA1 3UJ, UK.
authors.forename: Nikos
authors.initials: N
authors.lastname: Karogiannis
authors.affiliation: Department of Cardiovascular Medicine, Northwick Park Hospital, Watford Road, Harrow, HA1 3UJ, UK.
authors.forename: Vasilis
authors.initials: V
authors.lastname: Tzalamouras
authors.affiliation: Department of Cardiovascular Medicine, Northwick Park Hospital, Watford Road, Harrow, HA1 3UJ, UK.
authors.forename: Guy
authors.initials: G
authors.lastname: Parsons
authors.affiliation: Department of Cardiovascular Medicine, Northwick Park Hospital, Watford Road, Harrow, HA1 3UJ, UK.
authors.forename: Grace
authors.initials: G
authors.lastname: Young
authors.affiliation: Department of Cardiovascular Medicine, Northwick Park Hospital, Watford Road, Harrow, HA1 3UJ, UK.|Department of Cardiology, Royal Brompton Hospital, London, UK.|Cardiovascular Biomedical Research Unit, National Heart and Lung Institute, Imperial College, London, UK.
authors.forename: Sothinathan
authors.initials: S
authors.lastname: Gurunathan
authors.affiliation: Department of Cardiovascular Medicine, Northwick Park Hospital, Watford Road, Harrow, HA1 3UJ, UK.|Department of Cardiology, Royal Brompton Hospital, London, UK.|Cardiovascular Biomedical Research Unit, National Heart and Lung Institute, Imperial College, London, UK.
authors.forename: Roxy
authors.initials: R
authors.lastname: Senior
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D000704:Analysis of Variance; D002037:Bundle-Branch Block / Q000000981:diagnostic imaging* / Q000401:mortality / Q000503:physiopathology; D015331:Cohort Studies; D003287:Contrast Media; D017023:Coronary Angiography / Q000379:methods; D025401:Echocardiography, Stress / Q000379:methods*; D004562:Electrocardiography / Q000379:methods*; D005260:Female; D006801:Humans; D053208:Kaplan-Meier Estimate; D016015:Logistic Models; D008297:Male; D008875:Middle Aged; D015999:Multivariate Analysis; D009203:Myocardial Infarction / Q000000981:diagnostic imaging* / Q000401:mortality / Q000503:physiopathology; D011237:Predictive Value of Tests; D011379:Prognosis; D012189:Retrospective Studies; D018570:Risk Assessment; D012720:Severity of Illness Index; D013318:Stroke Volume / Q000502:physiology*; D015996:Survival Rate; D006113:United Kingdom
chemical_list: D003287:Contrast Media
keywords: contrast enhancement; left bundle branch block; stress echocardiography; wall thickening assessment