STICHES (STICH Extension Study)

Surgical Treatment for Ischemic Heart Failure (STICH) Extension Study.

Eric J. Velazquez, Kerry L. Lee, Robert H. Jones, Hussein R. Al-Khalidi,James A. Hill et al. Coronary-Artery Bypass Surgery in Patients with Ischemic Cardiomyopathy. N Engl J Med 2016;374:1511-20.

CLINICAL QUESTION

Is there a benefit of a strategy of coronary artery bypass graft (CABG) added to the guideline directed medical therapy as compared to medical therapy alone in patients with coronary artery disease (CAD), heart failure and left ventricular systolic dysfunction?

METHOD

This is a follow up trial of Surgical Treatment for Ischemic Heart Failure (STICH) trial. Enrollment was done from July 2002 to May 2007, 1212 patients in to the STICH trial.

Inclusion criteria

• Patients with an ejection fraction£ 35% measured by Cardiovascular magnetic resonance (CMR) ventriculogram, gated Single-photon emission computed tomography (SPECT) ventriculogram, Echocardiography (ECHO), or contrast.

• Women who are not of childbearing potential and men.

• Age ≥18 years.

• CAD suitable for revascularization.

Exclusion Criteria

• Aortic valvular heart disease clearly indicating the need for aortic valve repair or replacement.

• Cardiogenic shock (within 72 hours of randomization), as defined by the need for intra-aortic balloon support or the requirement of intravenous inotropic support.

• Recent acute MI judged to be an important cause of LV dysfunction.

• Non-cardiac illness with a life expectancy of less than 3 years.

• Previous heart, kidney, liver, or lung transplantation.

• Medial Therapy Eligibility Criteria

• Absence of left main CAD as defined by an intraluminal stenosis of ≥50%

• Absence of Canadian cardiovascular society (CCS III) angina or greater (angina markedly limiting ordinary activity

• Surgical Ventricular Reconstruction Eligibility Criterion

• Dominant akinesia or dyskinesia of the anterior LV wall amenable to SVR

Groups

1. CABG group, 610 patients

2. Medical-therapy group, 602 patients

The median duration of follow-up, including the STICH study was 9.8 years.

Outcomes

Primary outcome –

• Death from any cause

Secondary outcomes -

• Death from cardiovascular causes

• Death from any cause or hospitalization for cardiovascular causes

• Death from any cause or hospitalization for heart failure

• Death from any cause or hospitalization for any cause

• Death from any cause or revascularization.

 

RESULTS

Among 602 patients who are in medical therapy group 119 (19.8%) had CABG performed (cross over).

Primary outcome-

• Death from any cause occurred in 359 of 610 patients in the CABG group (58.9%) compared to 398 of 602 patients (66.1%) in medical therapy group. Median survival was 1.44 years longer in CABG group with a number needed to treat of 14 patients (95% CI, 8 to 55).

Secondary outcomes-

• 247 in CABG group (40.5%) and 297 in medical therapy group (49.3%) died from cardiovascular causes (p=0.006). Other secondary outcomes were also significantly favoured CABG group.

• When analysing the crossover population, they found that a combined crossover from medical group in first year and patients in CABG group had a mortality of 57.2% compared to 68% in only medical therapy group (p<0.001).

 

CONCLUSION

• Overall CABG had a better outcome in terms of median survival and saving 1 life in every 14 patients and significant survival benefit, with a rate of death from any cause that was 16% lower than that associated with medical therapy alone (an 8-percentage-point absolute difference in the Kaplan–Meier rate) at 10 years.

• STICH study reported that CABG was associated with three times increased risk of mortality compared to medical therapy alone in first 30 days of surgery. Similar difference in risk persisted up to two years after which significant benefit was noted. The operative risk of CABG is negated by significant clinical benefit by 10 years of follow up. Moreover, the cross over from medical to CABG group also yielded indirect benefit and a proposed 20 to 25% lowering of mortality in total.

• Use of LIMA graft and higher use of statin as compared to previous studies in the past were proposed to account for better outcome with CABG.

• Greater benefit of CABG was noted in patients with three vessels coronary artery disease compared to one or two vessel disease.

STRENGTHS

•  The clinical context in which the study is conducted is relevant to the general population.

•  Excellent follow up and very low dropout rate.

•  The current Class IIb recommendation [American college of cardiology foundation (ACC) & American heart association (AHA)] for CABG in similar patient population (LVEF <35%) is more strengthened by this study.

•  

LIMITATIONS

•     Revascularization procedure may have been affected due to lack of blinding.

•     This study didn’t include percutaneous intervention (PCI) as a therapy option. So, PCI may have comparable or better outcome as compared to CABG.

 

TAKE HOME MESSAGE

The findings of this trial may change our approach for evaluation and treatment of heart failure due ischemic cause. Subjecting these patients to early CABG may improve the survival outcome. Risk-benefit ratio of higher postoperative mortality to proposed long tem benefit and survival with CABG has to be evaluated in an individual basis.

 

 

DR Sananta K Dash

MD, FNB, FCCP,EDIC