Publication Type : Journal Article
Thematic Areas : Medical Sciences
Publisher : Journal of Cardiovascular Electrophysiology
Source : Journal of Cardiovascular Electrophysiology, Volume 28, Issue 6, p.677-683 (2017)
Url : https://www.ncbi.nlm.nih.gov/pubmed/28316113
Keywords : adult, Area Under Curve, Asymptomatic Diseases, brugada syndrome, Case-Control Studies, Death, Sudden, Cardiac, Disease-Free Survival, Electrocardiography, exercise test, female, Humans, Kaplan-Meier Estimate, Logistic Models, male, middle aged, Predictive Value of Tests, risk assessment, Risk Factors, ROC Curve, Time Factors, Ventricular Fibrillation
Campus : Kochi
School : School of Medicine
Department : Cardiology
Year : 2017
Abstract : Introduction: Risk stratification of asymptomatic patients with a Brugada type 1 ECG pattern remains an unresolved clinical conundrum. In contrast to provocative pharmacological testing in Brugada syndrome, there is limited data on the role of exercise stress testing as a risk stratification modality. The objective of this study was to evaluate the utility of exercise testing in asymptomatic patients with type 1 Brugada pattern to prognosticate major arrhythmic events (MAE) during follow-up.
Methods and results: Treadmill exercise testing was conducted for 75 asymptomatic patients with type 1 Brugada pattern and for 88 healthy control subjects. The clinical end point of MAE was defined as the occurrence of sudden cardiac death (SCD) or resuscitated ventricular fibrillation (VF). During a follow-up of 77.9 ± 28.9 months, eight MAE occurred (five VF and three SCD). Multivariate Cox regression analysis showed that the following were independent predictors of MAE in asymptomatic patients with a type 1 Brugada pattern: increase in S wave upslope duration ratio >30% at peak exercise (HR 1.35, 95% CI 1.08-10.97, P = 0.023), augmentation of J point elevation in lead aVR >2 mm in late recovery (HR 1.88, 95% 1.21-15.67, P = 0.011), and delayed HR recovery (HR 1.14, 95% CI 1.06-18.22, P = 0.042). A high-risk cohort was identified by the final step-wise regression model with good accuracy (specificity = 98.4%, sensitivity = 62.5%) and discriminative power (AUC = 0.93, 95% CI 0.89-0.96, P = 0.002). Kaplan-Meier analysis revealed increasing MAE in subjects with one, two, or three predictors, respectively (log rank P < 0.001).
Conclusions: Exercise testing in asymptomatic patients with type 1 Brugada pattern aids in identification of high-risk patients and provides a unique window of opportunity for early intervention.
Cite this Research Publication : Subramanian M., Prabhu M. A., Harikrishnan M. S., Pai P. G., Natarajan K. U., "The utility of exercise testing in risk stratification of asymptomatic patients with type 1 Brugada pattern," Journal of Cardiac Electrophysiology, June 2017; 28(6): 667-683.