title: Non-sustained ventricular tachycardia as a predictor of sudden cardiac death in patients with left ventricular dysfunction: a meta-analysis.
abstract: BACKGROUND
  Identifying patients at risk of sudden cardiac death (SCD) remains a challenge.
  
  
  OBJECTIVE
  To evaluate the performance of non-sustained ventricular tachycardia (NSVT) from 24 hour ambulatory electrocardiography as a predictor of SCD in patients with heart failure or non-ischaemic dilated cardiomyopathy with left ventricular systolic dysfunction (LVSD).
  
  
  RESULTS
  Study search and selection were performed by independent reviewers using a validated strategy. Eleven prognostic studies with >100 patients with good quality data and multivariate analysis of predictors of SCD were included. Publication bias was evaluated by funnel plot with Kendall's tau b test. A summary ROC (sROC) curve was built to evaluate predictive performance of NSVT. There was threshold effect (Spearman's correlation between sensitivity and specificity=-0.818, p<0.01) which indicates that combining sensitivity and specificity was not appropriate. The area of 0.68+/-0.02 under the sROC curve indicates a statistically significant contribution of NSVT in the prediction of SCD. The true negative rate varied from 89 to 97%. Multivariate analysis and meta-regression suggested that the contribution of NSVT to risk stratification is independent of ejection fraction.
  
  
  CONCLUSIONS
  Absence of NSVT indicated a low probability of SCD in patients with LVSD. A risk score including NSVT should be evaluated in prospective studies.
authors.affiliation: Post-Graduate Program in Internal Medicine, Universidade Federal de Minas Gerais, Brazil. sousa.mr@uol.com.br
authors.forename: Marcos R
authors.initials: MR
authors.lastname: de Sousa
authors.forename: Carlos A
authors.initials: CA
authors.lastname: Morillo
authors.forename: Fábio T
authors.initials: FT
authors.lastname: Rabelo
authors.forename: Antônio M
authors.initials: AM
authors.lastname: Nogueira Filho
authors.forename: Antonio L P
authors.initials: AL
authors.lastname: Ribeiro
mesh_terms: D002311:Cardiomyopathy, Dilated / Q000503:physiopathology; D016757:Death, Sudden, Cardiac / Q000209:etiology* / Q000473:pathology; D006333:Heart Failure / Q000503:physiopathology; D006801:Humans; D015999:Multivariate Analysis; D011237:Predictive Value of Tests; D011379:Prognosis; D012372:ROC Curve; D012307:Risk Factors; D012680:Sensitivity and Specificity; D017180:Tachycardia, Ventricular / Q000150:complications* / Q000503:physiopathology; D013997:Time Factors; D018487:Ventricular Dysfunction, Left / Q000150:complications* / Q000503:physiopathology