Does an invasive approach benefit patients with stable coronary disease when compared to a conservative approach?

The study assessed whether an initial invasive strategy (IS) for treating stable coronary artery disease (CAD) in patients with moderate or severe ischemia (reduced blood supply to the heart) have a better outcome when compared to a conservative strategy (CS). The study concluded that over the course of 3.2 years, invasive treatment did not bring an additional benefit to patients when compared to conservative treatment. 

CAD is caused by blocked blood vessels that supply blood to the heart. This can lead to a heart attack or death. These are called major cardiac events (MCE). Treatment for patients with stable CAD has a goal of decreasing the risk of MCE and improving patient quality of life (QoL). Standard treatment for patients with CAD is medical treatment. This is called a conservative strategy (CS). 

Previous studies have shown that more intensive strategy (IS) resulted in a lower rate of death from cardiac causes. IS involves a minimally invasive surgery in which stents (small tubes) are inserted into blood vessels of the heart to open them up or prevent them from closing). IS can also involve coronary artery bypass grafting (CABG) which is surgery to divert blood flow from the blocked blood vessels. However, whether an IS is better at reducing the risk of MCE compared to a CS in patients with stable CAD and moderate to severe ischemic is still unknown.

There were 5179 patients included in this study. Patients were randomly assigned to receive either medical treatment alone (CS group) or an invasive procedure and medical treatment (IS). The main outcome measured was the occurrence of MCEs. Patients were followed up for an average of 3.2 years.

At 6 months 5.3% of patients in the IS group and 3.4% of the CS group experienced a MCE. At 3 years, the rate of MCEs was 11.3% in the IS group compared to 12.7% in the CS group. At 5 years, the rate of MCEs was 16.4% in the IS group compared to 18.2% in the CS group. The average time that both groups were at risk of a MCE was similar in both groups. 

The authors concluded that in patients with stable CAD, an initial IS did not bring an additional benefit when compared to initial CS. 

This study had a rather short follow-up. The method used in IS varied among patients. This might have influenced the outcomes.