AICD usage for primary prevention at Mercy Hospital:

successes, challenges and next steps

Mohammad Tahir

PGY-3

Automatic Implantable Cardioverter Defibrillator

• AICD: shock therapy in the event of VT/VF

• Indicated for prevention of suddent cardiac death (SCD)

• Secondary prevention: resuscitation after VT/VF arrest

• Primary prevention: high risk for development of VT/VF

Background• MADIT-I Trial1: mortality benefit in post MI,

NSVT & LVEF <35%

• MADIT-II Trail2: mortality benefit in post MI & LVEF <30%

• ACC/AHA 20023: for LVEF <30% (class IIa)

• SCD-HeFT Trial4: mortality benefit in ischemic & non-ischemic CM, LVEF <35%

1Moss AJ et al. N Engl J Med 1996;335:1933-1940 2Moss AJ et al. N Engl J Med. 2002 Mar 21;346:877-83.3ACC/AHA/NASPE 2002 Guideline Update Circulation 2002;106;2145-2161.4Bardy GH et al. N Engl J Med 2005;352:225-237.

Adapted from: ACC/AHA/HRS 2008 Guidelines for Device-Based Therapy of Cardiac Rhythm Abnormalities J. Am. Coll. Cardiol. 2008;51;e1-e62; May 15, 2008.

Background (contd…)

• ACC/AHA 2008: LVEF <35%– Post MI (after 40 days), NYHA II/III (class I)– Non-Ischemic NYHA II/III (class I)

• Cost effective: QALY, Hospitalization

ACC/AHA/HRS 2008 Guidelines for Device-Based Therapy of Cardiac Rhythm Abnormalities J. Am. Coll. Cardiol. 2008;51;e1-e62; May 15, 2008.

Objectives

• To determine the proportion of eligible patients receiving or referred to AICD implantation

• To analyze the factors affecting the referral

Methodology• Retrospective Chart review• IRB Approval: consent waived• Duration: Jan-July 2008 • Data Abstracted on

– Demographics– Duration of CHF– Ischemic/ Non-ischemic Cardiomyopathy, – History of

• coronary artery disease, • diabetes, • hypertension, • chronic kidney disease, • pacemaker implantation, • CABG or PCI

Methodology (contd…)

– Baseline rhythm: sinus rhythm/ atrial fibrillation, – QRS complex duration – Use of medications including

• beta blocker, • ACE inhibitor, • digoxin, • anti-arrhythmic drugs (amiodarone), • anti-coagulation with Coumadin,

– New York Heart Association (NYHA) class for CHF– Pedal edema – Acute myocardial infarction (AMI) during current

hospital admission

Inclusion criteria

• All hospital discharges with a primary or secondary diagnosis of Heart Failure or Cardiomyopathy

• Evidence of LVEF <35%– Echocardiography– Nuclear stress test– MUGA Scan– Left Ventriculography

Exclusion Criteria

• In-hospital death

• AICD previously implanted (in-situ)

• Discharge to hospice services

• Comfort measures only

Data Analysis

• Variables abstracted in MS excel

• Analysis software: SPSS & Epi Info

• Chi-square test: Categorical Variables

• Independent sample t-test: Continuous variables

• Statistical significance: p <0.05.

Results

AICD previously implanted 35

Hospice/comfort care13

Total patients with LVEF ≤ 35% 208

In-Hospital Death 15

Study PopulationN=145

Referred Group77 (53%)

Unreferred Group68 (47%)

Patient refusal for AICD9 (12%)

Re-evaluation after optimization of therapy

8 (10%)

Referred Group(n=77)

Out-patient evaluation for AICD16 (21%)

AICD implanted during hospitalization41 (53%)

AICD deferred in view of risk vs. benefit

3 (4%)

Clinical Variables of ‘referred’ (n=77) and ‘unreferred’ (n=68) groups

Demographic and clinical Characteristics

ReferredGroup(N=77)

UnreferredGroup(N=68)

P-Value

Age in years, Mean ± SD 69.9 ± 14.6 76.0 ± 12.0 <0.01

Sex, females, n (%) 27 (35.1) 28 (41.2) 0.5

Non-White race n (%) 4 (5.2) 4 (1.5) 1.0

NYHA class IV, n(%) 8 (10.4) 3 (4.4) 0.29

NYHA class II / III, n (%) 69 (89.6) 65 (95.6) 0.29

Acute/ exacerbation CHF, n (%) 52 (67.5) 45 (66.1) 0.99

Clinical Variables of ‘referred’ (n=77) and ‘unreferred’ (n=68) groups

Demographic and clinical Characteristics

ReferredGroup(N=77)

UnreferredGroup(N=68)

P-Value

Pedal Edema present, n (%) 20 (26) 17 (25) 0.95

Diabetes, n (%) 33 (42.9) 28 (41.2) 0.97

Hypertension, n (%) 63 (81.8) 57 (83.8) 0.92

Acute Myocardial Infarction, n (%)

11 (14.3) 13 (19.1) 0.58

H/o Coronary artery Disease, n (%)

51 (66.2) 42 (61.8) 0.7

H/O CABG, n (%) 26 (33.8) 24 (35.3) 0.99

Clinical Variables of ‘referred’ (n=77) and ‘unreferred’ (n=68) groups

Demographic and clinical Characteristics

Referred group

(N=77)

Unreferred group (N=68)

P-Value

H/O PCI, n (%) 6 (7.8) 7 (10.3 ) 0.81

H/O Pacemaker Implantation, n (%)

6 (7.8) 9 (13.2) 0.42

CKD stage ≥3,n (%) 20 (26 ) 23 (33.8) 0.4

Beta Blocker at admission, n (%) 51 (66.2) 40 (58.8) 0.45

Beta Blocker at discharge, n (%) 66 (85.7) 56 (82.4) 0.75

Clinical Variables of ‘referred’ (n=77) and ‘unreferred’ (n=68) groups

Demographic and clinical Characteristics

ReferredGroup(N=77)

UnreferreGroup(N=68)

P-Value

Digoxin use at at admission, n (%) 16 (20.8) 11 (16.2) 0.62

Coumadin Use at admission, n (%) 16 (20.8) 19 (27.9) 0.42

Anti-arrythmics use at admission, n (%)

2 (2.6) 1 (1.5) 1.0

ACE inhibitor at discharge, n (%) 56 (72.7) 47 (69.1) 0.77

ACE inhibitor at admission, n (%) 43 (55.8) 37 (54.4) 1.0

Imaging/ EKG variables of ‘referred’ (N=77) and ‘unreferred’ (N=68) groups

CharacteristicReferred

group (N=77)

Unreferredgroup(N=68)

P-Value

LVEF (%), Mean ± SD 25.6 ± 6.3 28.9 ± 6 <0.01

Ischemic Cardiomyopathy, n (%)

50 (65) 42 (62) 0.82

Coronary Angiogram done, n (%)

28 (36.4 ) 12 (17.6 ) 0.02

LVEF on angiogram (%), Mean ± SD

24.6 ± 8.0 19.5 ± 13.6 0.14

Sinus Rhythm 45 (58.4) 36 (52.9) 0.62

Imaging/ EKG variables of ‘referred’ (N=77) and ‘unreferred’ (N=68) groups

CharacteristicReferred

Group(N=77)

UnreferredGroup(N=68)

P-Value

Atrial Fibrillation 23 (29.9) 26 (38.2) 0.38

QRS duration (ms), Mean ± SD

127.2 ± 41.5 120.0 ± 31.5 0.27

LVEDD (mm) Mean ± SD 60.9 ± 8.0 56.9 ± 7.0 <0.01

Severe Aortic Stenosis, n (%)

1 (1.3) 8 (11.8) 0.01

Severe Mitral regurgitation, n (%)

3 (3.9) 5 (7.4) 0.59

Severe Aortic regurgitation, n (%)

1 (1.3) 1 (1.5) 1.0

Limited F/U data

• Cross sectional

• One patient from each group was found to have AICD implanted in the interim period before second hospitalization.

Discussion

• Only 53% of eligible patients had documentation of such discussion

• AICD implantation: 53% of those referred

• Referred Patients: – Younger– Lower EF

Discussion (contd..)

• Most of the patients with severe Aortic Stenosis: in unreferred group– The need of aortic valve replacement

evaluation being of paramount importance.– Not considered immediate candidates– Such documentation was missing.

Discussion (contd..)

• Coronary Angiogram: 36.4 % in referred group vs. 12 % in unreferred group– Patients undergoing coronary angiogram

more likely to have a discussion about the AICD.

– Acute presentation– Consultative assistance

Discussion (contd..)

• Significant difference in the mean LVEDD:– likely an incidental finding– Sicker patients with lower EF.

• Also noted that, recommendations made after procedures such as coronary angiograms were more likely to be followed by the team.

Conclusions

• AICD referral in only 53 %– Need for improvement.

• Hospitalization provides an opportunity:– Greater amount of time spent by patients– Make an in-depth assessment– Involve cardiovascular specialist– Referral/ recommendations.– Likely to be followed as out-patient as in CHF1

1Reibis R, Dovifat C, Dissmann R, et al. Clin Res Cardiol. 2006 Mar;95(3):154-61.

Limitations

• Retrospective review type

• Cross sectional

• Dependence on documented medical information.

Recommendation

• Despite limitations: – A real life patient care outcome report– Insight for the need to improve.

• Creation of ‘centralized recommendation’ from points of diagnostic procedures– Echocardiogram– Radionuclide cardiac imaging– Left ventriculography.

• Importance of medical records documentation• Continued education of all the providers

Acknowledgement

• Dr. Aravind Herle

• Dr. Syed J Noor

• Dr. Khalid J Qazi

• CHS IRB Team

• HIM Staff