Long-term prognosis in patients with non-type 1 Brugada ECG: results from a large Japanese cohort of Brugada syndrome

Background

Most recent consensus conference report recommends Brugada syndrome (BrS) is diagnosed in patients with ST segment elevation with spontaneous, drug-induced or fever-induced type 1 morphology. Prognosis in patients with type 2 or 3 ECG without drug-induced or fever-induced type 1 ECG is still unknown.

Purpose

To evaluate a long-term prognosis in patients with non-type 1 Brugada ECG in a large Japanese cohort of BrS (The Japan Idiopathic Ventricular Fibrillation Study [J-IVFS]).

Methods

From 528 patients in J-IVFS, a total of 28 consecutive non-type 1 patients (54±14 years, all male, previous sustained ventricular tachyarrhythmias (VTs) 1, syncope 11, asymptomatic 16) were enrolled. Cardiac events (CI: sudden cardiac death or VTs) during the follow-up period were evaluated, and risk factors for the cardiac events were assessed.

Results

During a mean follow-up period of 111±91 months (median 134 months), 4 patients experienced cardiac events (1.5%/yr), who all had received implantable cardioverter defibrillator implantation. There was no statistically significant clinical risk factor for cardiac events. However, the incidences of cardiac events tended to be higher in symptomatic patients (CI: 25.0, non-CI: 6.3%, p=0.17), those with wide QRS duration >90 msec in lead V2 (CI: 30.0, non-CI: 6.3%, p=0.11), and those with inducible VTs (CI: 21.1, non-CI: 0%, p=0.20), as determined by the Kaplan-Meier method. The annual incidences of cardiac events in patients with symptom, wide QRS duration >90msec in lead V2, or inducible VTs were 2.8, 3.5, and 2.0%/yr, respectively. The incidences of cardiac events were significantly higher in patients with all these 3 factors (9.9%/yr) than those without (p=0.01).

Conclusions

Our large-scaled multicentre study revealed long-term prognosis in patients with non-type 1 Brugada ECG. The combination of symptom, wide QRS duration in lead V2, and inducible VTs may be useful to evaluate risk for cardiac events. The patients with all these parameters showed high risk for cardiac events and need to be carefully followed.

Funding Acknowledgement

Type of funding source: None

Efficacy of cardiac rehabilitation with motion assistance from wearable cyborg hybrid assistive limb in patients with chronic heart failure: a randomized controlled trial

Background

Recent Cochrane Systematic Review suggested that the participation in cardiac rehabilitation is associated with approximately 20% lower cardiovascular mortality and morbidity. Exercise therapy is the key component of cardiac rehabilitation programs. In recent years, innovative technologies have been introduced into the field of rehabilitation, and a typical example is the wearable cyborg Hybrid Assistive Limb (HAL). The wearable cyborg HAL provides motion assistance based on detection of bioelectrical signals on the skin surface when muscle forces are generated. The lumbar-type HAL is expected to expand the therapeutic options for severe cardiac patients who have difficulty in performing usual cardiac rehabilitation programs, such as bicycle pedaling or walking.

Purpose

We aim to compare the efficacy of exercise therapy performed with motion assistance from a lumbar-type HAL versus conventional training (sit-to-stand exercise without HAL) in patients with chronic heart failure.

Methods

This clinical trial is a randomized, non-blinded, and controlled study. Twenty-eight heart failure patients (73.1±13.8 years) who have difficulty in walking at the usual walking speed of healthy subjects were randomly assigned to 2 groups (HAL group or control group) with a 1:1 allocation ratio and performed sit-to stand exercise either with HAL or without HAL for 5 to 30 minutes once a day, and 6 to 10 days during the study period. The brain natriuretic peptide (BNP), isometric knee extensor strength, standing ability (30-seconds chair-stand test: CS-30), short physical performance battery (SPPB) and 6-minute walking distance (6MWD) were measured before and after the completion of cardiac rehabilitation. Cardiac events such as death, re-hospitalization, myocardial infarction and worsening of angina pectoris and heart failure during 1 year after discharge were evaluated.

Results

There was no significant difference in the number of days of exercise therapy between the two groups. BNP, SPPB and 6MWD were improved in both groups. In the HAL group, the isometric knee extensor strength (0.29±0.11 vs 0.35±0.11 kgf/kg, p=0.003) significantly improved and CS-30 (5.5±5.1 vs 8.2±5.3, p=0.054) tended to improve. However, in the control group, either the isometric knee extensor strength (0.35±0.11 vs 0.36±0.14 kgf/kg, p=0.424) or CS-30 (6.0±4.3 vs 9.2±6.2, p=0.075) did not significantly change. HAL group showed significantly more improvement in the isometric knee extensor strength than control group (p=0.045). Cardiac events occurred in 20% in the HAL group and 43% in the control group.

Conclusion

The improvement in isometric knee extensor strength with the assistance from lumbar-type HAL suggests that exercise therapy using this device may be useful in chronic heart failure patients with flail or sarcopenia, a strong poor prognostic factor in these patients.

Funding Acknowledgement

Type of funding source: Public grant(s) – National budget only. Main funding source(s): This work was supported in part by a grant-in-aid for Scientific Research from the Ministry of Education, Science, and Culture of Japan (JSPS KAKENHI grant number JP17K09485) and funded by the ImPACT Program of the Council for Science, Technology and Innovation (Cabinet Office, Government of Japan) (grant number 2017-PM05-03-01).

P5029Inducibility of ventricular tachyarrhythmias by up to two extrastimuli does not predict future cardiac events in asymptomatic Brugada patients: results from long-term follow-up

Background

Most recent consensus conference report recommends Implantable Cardioverter Defibrillator (ICD) implantation for asymptomatic Brugada patients with spontaneous or fever-induced type-1 ECG (A-BrS) and inducible ventricular tachyarrhythmias (VTs) by up to two extrastimuli as class IIb indication. However, the validity of the inducible VTs by up to two extrastimuli in A-BrS is still unknown.

Purpose

To evaluate the validity of the inducibility by up to two extrastimuli in A-BrS in a large Japanese cohort of BrS (The Japan Idiopathic Ventricular Fibrillation Study [J-IVFS]).

Methods

A total of 193 consecutive A-BrS patients performed programmed electrical stimulation (PES) with non-aggressive uniform protocol (mean age 50±13 years, 180 males) were enrolled. PES protocol was using 2 basic pacing cycles and the order of introduction of up to 2 ventricular extra-stimuli from right ventricular apex [RVA] first, then right ventricular outflow tract [RVOT], 3 ventricular extra-stimuli from RVA then RVOT down to the minimum of 200ms. Clinical outcomes during the follow-up period were compared between A-BrS patients with and without inducible VTs by up to two extrastimuli.

Results

Thirty-five A-BrS (18%) had inducible VTs by up to two extrastimuli. During a mean follow-up period of 101±48 months, 7 A-BrS experienced cardiac events (sudden cardiac death [SCD] or VTs, 0.4%/yr). None of the 7 A-BrS had inducible VTs by up to two extrastimuli. The incidences of cardiac events tended to be higher in A-BrS without inducible VTs by up to two extrastimuli than in those with inducible VTs (p=0.10), as determined by the Kaplan-Meier method. In the A-BrS, the annual incidences of cardiac events in A-BrS with family history of SCD, inferolateral J wave, wide QRS duration >90msec in lead V2, or inducible VT/VF by 3 extrastimuli were 0.7, 0.7, 0.6, and 0.3%/yr, respectively.

Conclusions

Our large-scaled multicentre study with long-term follow-up revealed the inducibility of ventricular tachyarrhythmias by up to two extrastimuli does not predict future cardiac events in A-BrS, even using non-aggressive uniform protocol. Rather, other parameters such as family history of SCD or inferolateral J wave might be helpful for risk assessment in A-BrS.