Abstract 5674: Low Mortality Rate Among Asymptomatic Brugada Syndrome Patients: a Multi-Center Control-Randomized Study Comparing ICD VS. No-ICD Treatment
How to treat asymptomatic patients (PTs) with the Brugada ECG pattern (AsymB) is unclear because prognosis of such PTs remains indeterminate. Furthermore, no risk-stratifying approach is proven to identify high-risk PTs for ICD treatment. Thus, we carried out the following randomized study to determine the mortality rate in AsymB and to compare outcomes between PTs treated with ICD versus those without ICD. Our study design includes only asymptomatic PTs with a type I Brugada ECG pattern, either occurred spontaneously or after ajamaline (AJ) infusion. PTs who had no family history of sudden unexplained death syndrome (SUDS) underwent elelectrophysiologic study(EPS), if VT/VF was inducible, then the PTs was randomized to ICD or no ICD; those who had no inducible VT/VF received no treatment. PTs who had a family history of SUDS were randomized to receive ICD implantation or no ICD regardless of EPS outcomes. We enrolled 105 Asym-Brug patients (mean age = 38 + 16; 75 males and 30 females); Brugada ECG pattern occurred spontaneously in 30 PTs and after AJ in the remaining 75 PTs. Of the 105 patients, 82 (78%) had family history of SUDS and 23 (22%) without family history of SUDS. Only 24 of the 82 PTs with family history of SUDS agreed to be randomized (13 received ICD and 11 no ICD); however the remaining 58 PTs, who declined to be randomized, continued to be followed in our registry. Of the 23 PTs without family history of SUDS, 5 received ICD and the remaining 18 received no treatment. Fifty-two patients had EPS, 36 had inducible VT/VF (69%). After the mean follow-up of 5.6 years, 2 (no-ICD) of the 105 PTs died suddenly at night time. None of the 18 PTs with ICD had appropriate ICD discharges due to VT/VF, but 5 PTs had inappropriate ICD discharges. For PTs without ICD, Kaplan-Meir 5-year mortality rate and the annual mortality rate was only 2.3% and 0.3% respectively compared to 0% in the ICD group (p=0.5).
Conclusions: Unlike symptomatic Brugada syndrome patients, AsymB PTs have a very low mortality rate and prophylactic ICD offers no benefit. Since, both spontaneous VT/VF event and mortality rates are so low that any risk stratification strategy would not be helpful even in PTs with family history of SUDS.