While invasive procedures to improve chest pain and quality of life have been found in some patients, a number of key outcomes are not significantly different – namely, subsequent heart attack, hospitalization for unstable chest pain or heart failure, heart attack resuscitation and cardiovascular death.
"Patients want to know, will this treatment make me live longer?" Said study chair Dr. Judith Johann, senior associate dean of clinical sciences at New York Long Health. "Based on what we have seen, we have not seen evidence that will make them live longer."
Stents and bypass surgeries are commonly used for patients with heart attack, but whether to intervene in stable patients – who have blockage or chest pain during exercise but not acute heart attack – has been hotly debated.
Patients with heart attack were not included in the study, nor were other groups included, including those with poor heart muscle function or those with narrowing of the coronary heart artery.
But when it comes to patients with stable heart disease, "we chose patients with a very abnormal stress test," explained Hochmann. "Was it considered that if anyone would benefit from an invasive strategy for stenting or bypass surgery, it would be the patients who would benefit."
The international trial, launched in 2012, covered more than 5,000 patients in 37 countries, making it the largest study of its kind, researchers said. Hochmann said it was based on two previous studies that made similar conclusions, but partly as designed, failed to gain widespread acceptance by doctors.
If asymptomatic patients give up invasive therapies, Hohmann estimates the savings could be in the hundreds of millions of dollars in the United States, based on previous research.
"The implications are quite large globally and in the United States," she said.