Long-term clinical course and prognostic factors of heart failure with reduced ejection fraction (HFrEF) patients underwent primary prophylactic implantable cardioverter defibrillator (ICD)

Background

For decades, ICD is a well-established therapy for improving prognosis of structural heart disease with severe cardiac dysfunction, and ICD for primary prophylaxis against sudden cardiac death were routinely provided. However, long-term prognosis and clinical course are different in each individual patient with an ICD, and it is moreover unclear what kind of factors might have influences on their clinical outcomes.

Purpose

The aim of this study is to clarify long-term prognosis and predictors of future major adverse cardiac events (MACEs) in HFrEF patients with an ICD as primary prophylaxis in Japanese population.

Methods

We retrospectively analyzed our ICD database. Patients underwent primary prophylactic ICD implantation from 2006 to 2020 at our institute and met the criteria of ICD recommendation of the latest Japanese guideline. Its requirements are receiving optimal medication therapy, symptomatic heart failure (New York Heart Association classification II or greater), and severe cardiac dysfunction (left ventricular ejection fraction (LVEF) is 35% or less). Additionally, prior NSVT is considered Class I ICD recommendation. In the case of ischemic cardiomyopathy (ICM), ICD implantation was done at least 40 days after myocardial infarction and at least 90 days after revascularization. MACEs were defined as composite outcome of cardiovascular death, heart failure hospitalization, and appropriate ICD therapies.

Results

A total of 148 consecutive patients were enrolled (male, 120 (81%); age, 62.1±11.8 years; LVEF, 23.0±5.86%; left ventricular end-diastolic diameter (LVDd), 67.6±9.26mm; paroxysmal or persistent atrial fibrillation (AF), 38 (26%); NSVT, 113 (76%); use of class III antiarrhythmic drugs, 48 (32%); ICM, 49 (33%); cardiac resynchronization therapy (CRT), 63 (43%)). One hundred twenty patients (81%) were programmed with a shock-only zone over 200 beats per minute. The median follow-up duration was 58.5 months. Among those 148 patients, MACEs were occurred to 60 patients (41%). As a result of dividing all patients into two groups by the occurrence of MACE, LVEF and LVDd were worse in MACE(+) group, whereas, MACE(−) had greater number of co morbidities. The results of cox-regression analysis showed LVDd (HR: 1.07, 95% CI: 1.03–1.12, p<0.001), AF (HR: 2.88, 95% CI: 1.56–5.31, p<0.001) and ICM (HR: 1.78, 95% CI: 1.00–3.16, p=0.049) were the independent predictors of MACEs (Table). However, initial ICD programming was not related to the occurrence of MACE.

Conclusions

The incidence of MACEs in patients with an ICD and severe HFrEF was substantially high in this Japanese population. Etiology of ICM, left ventricle size, and AF were the potential risk factors for future MACEs.

Funding Acknowledgement

Type of funding sources: None.

Negative prognostic implications of non-sustained ventricular tachycardias in patients after prophylactic defibrillator implantation

Funding Acknowledgements

Type of funding sources: None.

Background

Non-sustained ventricular tachycardia (NSVT) is frequent phenomenon in severe heart failure with reduced ejection fraction (HFrEF) patients, and causes any negative impacts on such patients. In the Japanese Circulation Society (JCS) and Japanese Heart Rhythm Society (JHRS) guidelines, NSVT is regarded as a major component of indication for implantable cardioverter defibrillator (ICD) implantation. However, the long-term prognostic significance of NSVT in severe HFrEF is incompletely resolved.

Purpose

The aim of this study is to investigate the relation between prior NSVT episodes and major adverse cardiac events (MACEs) in HFrEF patients with an ICD as primary prophylaxis.

Methods

We retrospectively analyzed our ICD database. Patients underwent primary prophylactic ICD implantation from 2007 to 2018 following ICD recommendation of JCS and JHRS guidelines. Patients met the criteria of receiving optimal medication therapy, symptomatic heart failure (New York Heart Association classification II or greater), and severe cardiac dysfunction (left ventricular ejection fraction (LVEF) is 35% or less). In the case of ischemic cardiomyopathy (ICM), implantation of ICD was done at least 40 days after myocardial infarction and at least 90 days after revascularization. Incidence of NSVT episodes were identified through daily electrocardiogram (ECG), Holter ECG or monitor ECG in the hospital. MACEs were defined as composite outcome of cardiovascular death, heart failure hospitalization, and appropriate ICD therapies.

Results

A total of 148 consecutive patients were enrolled (male, 120 (81%); age, 62.1±11.8 years; LVEF, 23.0±5.86%; left ventricular end-diastolic diameter (LVDd), 67.6±9.26mm; paroxysmal or persistent atrial fibrillation (AF), 38 (26%); NSVT, 113 (76%); use of class III antiarrhythmic drugs, 48 (32%); ICM, 49 (33%); cardiac resynchronization therapy (CRT), 63 (43%)). The median follow-up duration was 58.5 months. As a result of comparison of the Kaplan-Meier curve between NSVT group (n=113) and non-NSVT group (n=35), cardiovascular death, heart failure hospitalization, and appropriate ICD therapy were not statistically different (Figures). Of those, MACEs were occurred to 60 patients (41%). The results of cox-regression analysis showed LVDd (HR: 1.07, 95% CI: 1.03-1.12, p<0.001), AF (HR: 2.88, 95% CI: 1.56-5.31, p<0.001) and ICM (HR: 1.78, 95% CI: 1.00-3.16, p=0.049) were the independent predictors of MACEs, however NSVT was not (Table).

Conclusions

In this Japanese population, the long-term prognosis of severe HFrEF patients is considered to be comparable regardless of prior NSVT episodes. However, the incidence of MACEs in patients with severe HFrEF after ICD implantation was substantially high. ICM, left ventricle size, and atrial fibrillation were the potential risk factors for MACEs as the previous reports showed.

P6552Is it possible to recognize free-wall implantation of leadless pacemakers from an ECG?

Background

Leadless pacemaker (Micra, Medtronic, US) is a effective treatment for bradycardia and eliminates any malfunctions related to intravenous leads. However, some cases exhibit pericardial effusion, presumably associated to device implantation to right ventricular free-wall.

Objectives

The present study was carried out to find ECG features during ventricular pacing by Micra, which enabled to distinguish free-wall implantation from septal implantation without imaging modalities.

Methods

Consecutive 21 patients who received implantation of Micra in our facility were enrolled. Location of device in the right ventricle was evaluated using echocardiography or computed tomography in order to determine whether the device was implanted on the septum or the freewall. The difference of 12-lead ECG during ventricular pacing from Micra were analyzed between the septum group and the free wall group.

Results

According to the imaging investigation, body of Micra was clearly identifiable in 17 patients. The locations of device were classified into septum in 11 patients, free-wall in 4 patients, and indeterminate but apex in 2 patients. Further analysis regarding ECG was performed exclusively between the septum group and the free-wall group. In lead V1, peak deflection index (PDI) was significantly larger in free-wall group than septum group (0.64±0.06 vs. 0.45±0.10, P=0.005), whereas there was no difference of QRS duration, transitional zone and QRS pattern.

PDI of V1 and Location of LPM

Conclusion

PDI of V1 could be useful to predict implantation of Micra to free-wall and may potentially stratify the risk of postprocedural pericardial effusion.