This document summarizes the results of a journal club presentation on using stellate ganglion block (SGB) to treat electrical storm. The following key points were discussed: 1. SGB significantly reduced the number of ventricular arrhythmia episodes and defibrillator shocks per day compared to before SGB. 2. The efficacy of SGB in reducing arrhythmias was independent of left ventricular function, presence or type of cardiomyopathy, and subtype of ventricular arrhythmia. 3. While SGB shows promise as an effective treatment for electrical storm, larger prospective randomized studies are still needed due to limitations of current retrospective studies.

1. Journal club
09.10.2017
Presenter
Praveen Gupta
Moderator
Dr Raja Selvaraj
JIPMER
Pondicherry
INDIA
1

2. 2

3. Introduction
 Electrical storm (ES) occurrence of 3 or more episodes of sustained ventricular arrhythmia
(VA) over 24 h
 Antiarrhythmic medications and catheter ablation standard of care
 Autonomic nervous system role in ventricular arrhythmia
 Cardiac sympathetic denervation, surgical resection effective in ES
 SGB is performed by injecting local anesthetic agents percutaneously to stellate ganglion,
less invasive performed at bedside in emergent setting in patients with hemodynamic
instability
3

4. METHODS
 Using PubMed/Medline and Google Scholar, we performed searches using the following
terms: left stellate ganglion block, ganglion block(ade), sympathetic block(ade), arrhythmia,
ventricular arrhythmia, ventricular tachycardia, ventricular fibrillation, electrical storm
 Inclusion criteria patients with ES who underwent SGB either unilateral or Bilateral
 Exclusion criteria patients with any supraventricular tachycardia, VA without ES (e.g.,
premature ventricular contractions), or patients treated only with surgical sympathectomy
4

5. Method (Clinical variables)
 Number of patients
 Age
 Sex
 Type of VA
 Episodes of VA and shocks
before and immediately after SGB
 Underlying cardiomyopathy
 LVEF
 Trigger of ES
 Antiarrhythmic used
 Treatment received before or after SGB
 Anesthetic administration techniques type
 Volume of local anesthetic agent used
 Inpatient survival to discharge
5

6. Statistical analysis
 Continuous variables summarized as mean SD
 Comparison of VA episodes and number of external or implantable cardioverter-defibrillator
shocks before and after SGB was performed using Wilcoxon signed rank test
 Change in VA burden or defibrillator shocks as relative reduction (post-SGB or pre-SGB)
 Relationship between arrhythmia reduction and LVEF by linear regression
 Comparison of CMY subtypes using analysis of variance
 Arrhythmia subtypes compared using the Kruskal- Wallis test
 p value <0.05 significant
 Relative reduction of VA and defibrillator shocks are calculated as the difference in episodes
per day pre-SGB versus post-SGB, divided by the number of episodes per day pre-SGB
6

7. Result
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8. 8

9. 9

10. 10

11. Result
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SGB decreased VA burden from 12.40 8.80 episodes/day to 1.04 2.12 episodes/day (p < 0.001). The number of
external or implantable cardioverter-defibrillator shocks was decreased from 10.00 9.10/day to 0.05 0.22/day(p <
0.01).

12. Result
There was no correlation between the LVEF and arrhythmia reduction (r2 ¼ 0.05, p ¼ 0.384). Patients with normal LV function
and mild, moderate, or severe LV dysfunction equally benefitted from SGB. Similarly, the presence and etiology of
CMY did not influence the ability of SGB to exert antiarrhythmic benefits (Figure 2B). Relative reduction
in VA burden was 0.95 0.07, 0.85 0.19, and 0.83 0.29 for no CMY, ischemic CMY, and nonischemic CMY, respectively (p ¼
0.78).

13. Result
13

14. DISCUSSION
 SGB is effective in reducing the number of episodes and therapies for VA
 Efficacy independent of the subtype of VA, presence or absence of CMY, and the degree of
LV dysfunction
14

15. Study limitations
 Number of studies in the published data meeting inclusion or exclusion criteria.
 Predominantly case reports and case series,
 Retrospective data
 small sample size limits reliability of the analyses
15

16. CONCLUSIONS
 Study support SGB as an effective adjunct to contemporary therapies in ES
 SGB is efficacious for a variety of VA subtypes and patient demographics
 Prospective randomized studies are needed to understand SGB in ES and other VA
16

17. 17

18. Introduction
 Cardiac implantable electrical device (CIED) infections are 2.0% to 3.0%
 Use of perioperative antibiotics is the standard of care for CIED implantation
 No data supporting antibiotic after the closure of the incision for CIED
 Guidelines recommend single dose of pre-incision antibiotics
 Actual practice patterns are not clear
 Aimed of study to characterize antibiotic practice surrounding CIED procedures
18

19. Method
 Physician members of the Heart Rhythm Society were eligible recruited by e-mail
 Survey presented hypothetical cases of new pacemaker or implantable cardioverter-
defibrillator (ICD) implantation, subcutaneous ICD implantation, pacemaker or ICD
replacement, and implantable loop recorder implantation.
 Each scenario, physicians asked to indicate whether practice included any of the following:
 Pre-incision intravenous antibiotics
 Antibiotic-impregnated pouch
 Pocket irrigation with antibiotic solution
 Post-procedure intravenous, oral, or topical antibiotics
19

20. Method
 Next, we asked physicians to indicate clinical factors that influence decisions to extend
antibiotics use, as well as circumstances in which agents targeting methicillin-resistant
Staphylococcus aureus (MRSA) would be selected.
 Lastly, physicians were asked whether or not they believed post-procedure antibiotics to be
the standard of care for either new or replacement CIED procedures, and if fear of
medicolegal consequences influenced their practice.
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21. 21

22. Result
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23. 23

24. Result
 Use of antibiotics after wound closure was considered to be the standard of care for both new
pacemaker and ICD implants by 28% of respondents, and by 32% for replacement
procedures, with 14% “not sure” for both scenarios.
 10% of respondents identified medicolegal concerns as decision making
 66% indicated they not provide MRSA prophylaxis in nares screens positive for MRSA
 Pre-incision prophylaxis for new and replacement pacemakers and ICD was nearly universal,
but less common for subcutaneous ICD (92%) or implantable loop recorders (70%).
24

25. Result
 Pocket irrigation with antibiotic solution (most commonly gentamicin, vancomycin, or both)
was common (53% to 62%)
 Antibiotic-impregnated pouch was more frequent for replacement procedures (16% vs. 6% for
new implants)
 A substantial proportion of physicians indicated that they would use additional postprocedure
intravenous (25% to 50%) or oral (22% to 36%) antibiotics after closure of the wound
 Implantable loop recorder implants, 70% used pre-incision antibiotics, but 29% used no
antibiotics at all.
25

26. Result
 Despite the morbidity of CIED infections and the need for meticulous adherence to evidence-
based prevention, there is no high-quality evidence to support the practices of postprocedure
antibiotic administration and antibiotic irrigation identified in our survey
 Approaches to managing suspected MRSA-colonization—a risk factor for MRSA infection
similarly conflict with guidelines
26

27. Conclusion
 Findings resonate with CDC report arguing for immediate implementation of more rational
use of antibiotics
 Current cardiology practice vary widely and includes usage contrary to the recommended
single dose at the time of the procedure
 Overuse of antibiotics may contribute to bacterial resistance while needlessly exposing
patients to adverse drug effects
 Study suggests that current practice is diffuse and greatly in need of standardization
27

28. 28

29. Introduction
 Cardiac resynchronization therapy (CRT) established therapy for heart failure (HF)
 MIRACLE study, 34% of patients NO improvement
 Cause of nonresponse to CRT is multifactorial, complex,
 Stimulation of multiple left ventricular (LV) sites effective
 Use 2 LV leads, but increased technical difficulty and adverse events.
 Alternative approach, pace multiple LV sites using a single quadripolar lead, using
MultiPoint Pacing (MPP) programming
29

30. 30

31. METHODS
 Prospective, randomized, double-blind, multicenter, clinical trial
 Patients with indication for CRT-D enrolled
 Patients who had the CRT-D system successfully implanted had Bi-V
pacing with a quadripolar LV lead activated at that time
31

32. 32

33. Study blinding
 Electrophysiologist and electrophysiology nurses were unblinded to randomization.
 Personnel designated as blinded assessors and authorized to assess NYHA
functional class and PGA
 Patients were also blinded to randomization assignment and carried a card
identifying them as clinical trial patients to minimize the risk of unblinding by other
health care providers
33

34. Definition of response to crt
 Response evaluated at 3 months and 9 months
 Patient’s classified as worsened, improved, or unchanged
 Worsened: Patient died of cardiovascular reasons OR experienced a HF event OR
demonstrated worsening in NYHA functional class
 Improved: Patient survived without HF event AND demonstrated improvement in NYHA
class
 Unchanged: Patient neither improved nor worsened
34

35. 35

36. 36

37. Primary end points (safety andefficacy)
• Kaplan-Meier freedom from system-related complications through 9 months was
estimated as 93.2% and the 97.5% LCB was 90.4%, which was above the
performance goal of 75%
• A total of 1.7% of patients in the Bi-V arm experience a complication between 3
months and 9 months, as compared with 1.5% of patients in the MPP arm (p ¼
0.89). Poolability of the primary safety endpoint across sites was verified (p ¼
0.90).
37

38. Primary end points
• A total of 381 patients were randomized at 3 months, of whom 180 in the Bi-V arm
and 201 in the MPP arm were included in the ITT population.
• Likewise, a total of 378 patients randomized at 3 months were included in the as-
treated population, of whom 186 were in the Bi-V arm and 192 were in the MPP
arm.
• In both ITT and as-treated populations, there were no statistically significant
differences at the 5% significance level in any of the demographic or baseline
characteristics between the Bi-V and MPP arms and a significant proportion of
patients were in NYHA functional class I or II (w78%) at the 3-month visit.
38

39. • The difference in 9-month nonresponder rates between the Bi-V and MPP arms was 4.9% (45 of 180 [25%]
and 60 of 201 [29.9%], nonresponder rate in Bi-V and MPP) for the ITT population and 3.9% (48 of 186
[25.8%] and 57 of 192 [29.7%] nonresponder rate in Bi-V and MPP) for the as-treated population.
• The 97.5% LCB for the difference in 9-month nonresponder rates between the Bi-V and MPP arms in the
ITT and as-treated populations were 13.8% and 12.9%, respectively, which were both greater than the
noninferiority margin of 15%.
• The primary efficacy endpoint was therefore met for both ITT and as-treated populations.
• Poolability of the primary efficacy endpoint across sites was verified (p value for the interaction effect was
> 0.95).
39

40. IMPORTANCE OF MPP PROGRAMMING: RESPONDER
RATE, CONVERSION RATE INCREMENTAL-RESPONDER
RATE
40
MPP therapy provided a significantly higher clinical responder rate at 9 months of 87% (45 of 52) (Figure 2A)
versus 65% (95 of 147) in MPP-Other (p ¼ 0.003) and converted 100% (8 of 8) of patients who were nonresponders
at 3 months to responders at the 9-month assessment (Figure 2B) versus 49% (18 of 37) in MPP–Other (p ¼ 0.014),
despite having a significantly higher number of patients with ischemic cardiomyopathy (Figure 2C), 65% (34 of 52)
versus 43% (62 of 145) (p ¼ 0.005).

41. IMPORTANCE OF MPP PROGRAMMING: RESPONDER
RATE, CONVERSION RATE INCREMENTAL-RESPONDER
RATE
41
The incidence of incremental response was significantly higher in patients with MPP-AS versus with MPP-Other (Figure 3), 54%
(28 of 52) versus 41% (61 of 147) (p ¼ 0.008).

42. IMPORTANCE OF MPP PROGRAMMING: RESPONDER
RATE, CONVERSION RATE INCREMENTAL-RESPONDER
RATE
42
In patients with de novo CRT-D implants, the MPP-AS subgroup had a significantly higher clinical responder rate (35 of
38; 92%) compared with MPP-Other (81 of 124; 65%) (Figure 4) (p ¼ 0.001).

43. Discussion
 First large-scale clinical trial examining the safety and efficacy of multisite LV
pacing with a single LV lead to treat patients with HF
 Trial indicate the use of MPP therapy in treating patients with HF is safe and
effective and not inferior to standard Bi-V pacing with a quadripolar LV lead.
 MPP, with certain programming settings, may be superior to standard single-site
LV CRT, particularly in those who fail to respond to standard CRT.
43

44. Discussion
 Trial results indicate a higher response rate in patients programmed with MPP-AS
 MPP-AS subgroup showed a significantly higher rate of response in patient with ischemic
cardiomyopathy.
 Pacing widely separated areas more closely resembles multibranch pacing, whereas pacing
adjacent poles is similar to conventional bipolar CRT.
 Optimal MPP programming capturing a larger volume of LV, resulting in more rapid LV
conduction and possibly further reduction in mechanical dyssynchrony.
 Wider separation also makes it more likely at least 1 of the pacing sites is not overlying
previous myocardial scar
44

45. Discussion
 Better response with MPP-AS in patients with indication for CRT implantation
 Caused by the de novo population being slightly healthier than patients previously implanted
with a pacemaker or defibrillator.
 It is also possible the response to MPP therapy is higher in patients with intrinsic left bundle
branch block compared with pacing-induced left bundle branch block, because the LV
activation sequence may be different in the 2 situations
45

46. Discussion
 Trial also first report of clinical outcomes using conventional CRT with the Quartet
quadripolar LV lead, as distinct from CRT with a conventional bipolar or unipolar lead
 Quartet quadripolar LV lead design allows pacing from a more basal pacing site in a higher
proportion of patients.
46

47. Study limitations
 Trial used a complex design to evaluate the safety and effectiveness of the MPP technology
 Study design was partially at the behest of regulatory bodies to ensure a new therapy (MPP)
should not impact patient safety
 All patients underwent an acute assessment of EA VTI before randomization with the MPP
feature turned on, to ensure MPP did not impair hemodynamics and could therefore be safely
programmed for the study duration
 Patients with improved or equal EA VTI were eligible for randomization, thus potentially
selecting long-term clinical responders
47

48. Study limitations
 Acute hemodynamic response to CRT may not predict long-term clinical response
 Improved CRT response identified based on MPP programming was result of post hoc
analyses
 Prospective studies designed and powered to evaluate potential superiority of MPP needed
 MPP was shown to be safe and effective for the 9-month duration of this trial, but long-term
follow-up data are warranted.
48

49. 49

50. Conclusions
 MPP using aquadripolar LV lead is safe and effective for HF
 MPP-AS had the highest response rate
 Patients in this specific MPP programming subgroup, and those with a de novo CRT implant
had an incremental improvement in CRT response over 9 months.
 MPP technology provides physicians with an additional tool for improving response to CRT
50

51. Take home message
 SGB is effective in ES
 Judicious use of antibiotic use after CIED implantation in the needed
 MPP-AS pacing in new modality in patient with HF and non response to conventional CRT
51

52. 52
Thank you