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Circulation. 2018;138:e272–e391. DOI: 10.1161/CIR.0000000000000549 September 25, 2018 e305 CLINICAL STATEMENTS AND GUIDELINES

contrast, when survival was not increased by ICD implantation, as in the CABG-Patch trial,S7.1.2-18 the ICD did not provide value, because the higher costs were unaccompanied by a gain in life expectancy. 4.	 MUSTT (Multicenter Unsustained Tachycardia Trial) demonstrated that patients with prior MI, NSVT, and reduced LVEF with inducible VT at electrophysiological study have a higher overall mortality rate than similar patients without inducible sustained VT.S7.1.2-21 Patients who received an ICD after failing to have inducible VT suppressed by an antiarrhythmic medication had lower mortality rate than those who did not receive an ICD. Although the entry criteria into MUSTT required an LVEF of ≤40%, the average LVEF in enrolled patients was 30%, and ICD placement was not randomized but rather was selected by the treating physician for patients with VT that could not be suppressed with antiarrhythmic medication therapy. MUSTT allowed enrollment of patients who were ≥4 days after an acute MI or revascularization. The ICD was of no benefit in 2 other RCTs that examined the efficacy of the ICD in the acute phase of an MI.S7.1.2-10,S7.1.2-11 In a single center observational study, an electrophysiological study was performed a median of 9  days after acute MI in 115 patients with LVEF  <40% and ICDs recommended for those with inducible VT. Median follow-up was 12 months. Sustained VT was induced in 27% of patients, and 22% of those who received ICDs had spontanous VT terminated by the ICD during follow-up. None of the patients without inducible VT had VT or SCD during follow-up.S7.1.2-22 5.	 In a retrospective analysis of the UNOS (United Network for Organ Sharing) registry that extended from 1999 to 2014, data on 32 599 patients showed that during a median follow-up of 154 days, 3638 patients (11%) died while on the waitlist for cardiac transplantation (9% in the ICD group versus 15% in the non-ICD group; P<0.0001). The presence of an ICD at listing was associated with an adjusted 13% relative risk reduction in mortality. In the subgroup of patients with an LVAD (n=9478), an ICD was associated with an adjusted 19% relative risk reduction in mortality.S7.1.2-9 In another study of 380 patients listed for heart transplantation between 2005 and 2009 at 1 tertiary heart transplant center, 122 patients received an ICD before or within 3 months after being listed for heart transplantation. Non-ICD patients were more likely to die while on the transplant list. In a multivariable model, the ICD was not associated with improved survival; however, that analysis was limited by the small sample size.S7.1.2-8 Another small study (n=79) conducted at 1 institution suggested that ICDs reduce the risk of SCD in patients with LVEF ≤30% who are awaiting heart transplantation; however, this study was limited by the small number of patients.S7.1.2-6 In a retrospective multicenter study of 1089 patients listed for heart transplantation, 550 patients (51%) had an ICD. In 216 patients, the ICD was for primary prevention of SCD and, in 334 patients, the ICD was for secondary prevention. The remaining 539 patients did not receive an ICD. During a median time on the waiting list of 8 months, the ICD was associated with a reduction in all-cause mortality in the primary and secondary prevention cohorts (estimated 1-year: 88±3% versus 77±3% versus 67±3%; P =0.0001). This relationship between the ICD and improved survival persisted even after adjusting for potential confounders.S7.1.2-7

6.	 There are insufficient data from RCTs regarding the value of the ICD in patients with NYHA class IV HF. Ambulatory class IV patients with HF were included in the COMPANION (Comparison of Medical Therapy, Pacing, and Defibrillation in Heart Failure) trial, which showed an overall improved functional status and survival with a CRT defibrillator.S7.1.2-23 Unless such a patient is a candidate for CRT or advanced HF therapies such as heart transplantation or an LVAD, an ICD is not expected to meaningfully prolong survival.S7.1.2-23

7.1.3 Treatment and Prevention of Recurrent VA in Patients With Ischemic Heart Disease

Recommendations for Treatment of Recurrent VA in Patients With Ischemic Heart Disease References that support the recommendations are summarized in Online Data Supplements 22 and 23.

COR LOE Recommendations

I B-R 1. In patients with ischemic heart disease and recurrent VA, with significant symptoms or ICD shocks despite optimal device programming and ongoing treatment with a beta blocker, amiodarone or sotalol is useful to suppress recurrent VA.S7.1.3-1–S7.1.3-3

I B-R

2. In patients with prior MI and recurrent episodes of symptomatic sustained VT, or who present with VT storm and have failed or are intolerant of amiodarone (LOE: B-R).S7.1.3-4 or other antiarrhythmic medications (LOE: B-NR) S7.1.3-5–S7.1.3-9, catheter ablation is recommended S7.1.3-10–S7.1.3-12 B-NR

IIb C-LD 3. In patients with ischemic heart disease and ICD shocks for sustained monomorphic VT or symptomatic sustained monomorphic VT that is recurrent, or hemodynamically tolerated, catheter ablation as first-line therapy may be considered to reduce recurrent VA.S7.1.3-10,S7.1.3-11

III: Harm B-R 4. In patients with prior MI, class IC antiarrhythmic medications (eg, flecainide and propafenone) should not be used.S7.1.3-13

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