Clinical trials are essential for evaluating medical treatments and improving patient care. In cardiovascular medicine, large-scale trials have significantly advanced understanding of heart conditions. The Surgical Treatment for Ischemic Heart Failure (STICH) trial is a key example, addressing a complex area of heart disease.
The STICH Trial’s Purpose
The STICH trial aimed to clarify the optimal treatment for patients with ischemic heart failure and severe left ventricular dysfunction. This patient population experiences a weakened heart muscle due to reduced blood flow from coronary artery disease, leading to heart failure symptoms. Before STICH, limited randomized trial data compared different treatment strategies for these patients.
The trial compared comprehensive medical therapy alone against medical therapy combined with coronary artery bypass grafting (CABG). CABG is a surgical procedure that improves blood flow to the heart by creating new pathways around blocked arteries. The study investigated whether adding CABG would improve patient outcomes, specifically by reducing all-cause mortality, decreasing cardiovascular hospitalizations, and improving quality of life.
How the Trial Was Conducted
STICH was a large-scale, randomized clinical trial, a design known for minimizing bias. It enrolled 1,212 patients internationally to compare medical therapy versus medical therapy plus CABG. Participants had coronary artery disease suitable for CABG and a left ventricular ejection fraction of 35% or less, indicating severe heart muscle weakness.
Patients were randomly assigned to either optimal medical therapy alone or with CABG. This randomization balanced patient characteristics, ensuring observed differences were due to treatment. The trial collected extensive data on survival, hospitalizations, and functional status over a median 56-month follow-up.
What the STICH Trial Revealed
The STICH trial’s initial findings at 56 months showed that adding CABG to medical therapy did not significantly reduce all-cause mortality compared to medical therapy alone. All-cause mortality was 36% in the CABG group versus 41% in the medical therapy group. However, a positive trend was observed for cardiovascular mortality.
The trial also found a significant reduction in the combined outcome of all-cause mortality or hospitalization for cardiovascular causes in the CABG group. This was primarily due to fewer cardiovascular hospitalizations, especially for heart failure. Specific analyses on modes of death showed that CABG significantly reduced sudden death and fatal pump failure events, although periprocedural deaths were initially higher in the surgical group.
Patients who received CABG alongside medical therapy experienced meaningful improvements in quality of life. These improvements were observed consistently over 36 months. Left ventricular function also showed greater improvement with CABG, indicating a positive structural change in the heart.
Impact on Clinical Practice
The STICH trial findings have influenced clinical guidelines for managing ischemic heart failure. While initial results did not show a significant all-cause mortality benefit at 56 months, the trial’s secondary outcomes, particularly regarding cardiovascular mortality and hospitalizations, provided valuable insights. This led to recommendations to consider CABG in patients deemed suitable for surgery, particularly those with multi-vessel coronary artery disease.
The STICHES (Surgical Treatment for Ischemic Heart Failure Extension Study), an extended follow-up of the original STICH cohort, further clarified the long-term benefits. After 9.8 years, STICHES demonstrated a significant reduction in all-cause mortality in the CABG group compared to the medical therapy group. This extended follow-up reinforced the long-term survival advantage of surgical intervention for these patients, influencing subsequent guideline updates. The trial’s detailed data helps clinicians and patients make more informed choices about whether to pursue surgical revascularization or continue with medical management, considering both short-term risks and long-term benefits.