Heart failure develops when the heart struggles to pump blood out to the body. Over time, this added workload causes the left ventricle to enlarge and the heart muscle becomes weakened.
Weakness of the heart muscle causes problems especially for the left ventricle – the hardest working chamber of the heart. Heart failure affects about 5 million Americans and is the most common reason patients seek medical treatment at hospitals.
Doctors identify about 550,000 new heart failure patients each year. The economic impact of hospitalizations, office visits and medication to treat heart failure is considerable with cost estimated to exceed $20 billion.
From STICH to STICHES
Surgical Treatment for Ischemic Heart Failure (STICH), Initiated in 2002
This multicenter international project addressed two specific primary hypotheses in patients with clinical heart failure (HF) and left ventricular systolic dysfunction (LVSD) who had coronary artery disease amenable to surgical revascularization, and conducted as two parallel randomized trials.
Hypothesis 1 tested the myocardial revascularization hypothesis that improvement in myocardial perfusion by coronary bypass graft surgery (CABG) combined with intensive medical therapy (MED) improves long-term survival compared to MED alone (1,212 patients randomized 1:1 to continuing MED with or without CABG). Upon randomization, patients underwent a battery of baseline and follow-up testing overseen by 5 core laboratories for echocardiography, radionuclide myocardial perfusion and viability, cardiac magnetic resonance imaging, neurohormonal-cytokine-genetic blood testing, and economics and quality of life. The five-year follow-up results published in 2011 (N Engl J Med 2011(Apr 28);364:1607-1616, Epub 2011 Apr 4) showed that there was no significant difference between MED alone and MED plus CABG with respect to the primary endpoint of death from any cause. Patients assigned to CABG, as compared with those assigned to MED alone, had lower rates of death from cardiovascular causes and of death from any cause or hospitalization for cardiovascular causes.
Hypothesis 2 tested the hypothesis that surgical ventricular reconstruction (SVR) to a more normal LV size combined with CABG improves survival free of subsequent hospitalization for cardiac cause compared to CABG alone in patients who require CABG (1,000 patients randomized 1:1 to CABG with or without SVR). The results published in 2009 (N Engl J Med 2009;360:1705-1717) showed that adding SVR to CABG reduced the LV volume, as compared with CABG alone. However, this anatomical change was not associated with a greater improvement in symptoms, or exercise tolerance, or with a reduction in the rate of death or hospitalization for cardiac causes.
STICH Extended Study (STICHES), Initiated in 2011
This project extends the follow-up of surviving subjects randomized in the STICH trial myocardial revascularization hypothesis (Hypothesis 1) for an additional 5 years to acquire critically important longer-term (10-year average) information on patients with HF and LVSD treated with optimal MED with and without CABG. The primary endpoint of STICHES is all-cause mortality. Important secondary endpoints include (1) cardiovascular mortality, (2) cardiovascular morbidity defined by hospitalization for HF, myocardial infarction or need for coronary revascularization procedure), and (3) symptoms (NYHA functional class and CCS angina class). Patients currently in STICH follow-up will be asked to provide informed consent to continue with study visits (in person preferred, by phone allowable) for an additional 5 years at 6-month intervals to gather information on medical treatments and health outcomes. STICHES capitalizes on a unique and already exceptionally well-characterized cohort of patients with HF/LVSD and coronary artery disease amenable to CABG to address the following specific aims:
- To determine whether CABG with MED improves 10-year survival compared to MED alone and how treatment-related outcome differences seen at 5 years vary over time.
- To determine whether CABG with MED leads to differences in health outcomes, including functional status and symptoms, compared to MED alone at 10 years among important subgroups defined by baseline clinical status, symptoms, coronary anatomy, functional status, noninvasive measures of myocardial ischemia and viability, and/or genotype.
- To quantify the relative, incremental predictive value of baseline noninvasive cardiac imaging on long-term treatment-dependent results (relative to the short- and intermediate-term).
- To determine whether CABG with MED leads to changes in cardiac morphology, function, and hemodynamics over time (4 and 24 months) compared to MED alone and to define how these changes relate to 10-year health outcomes.