Comparison between two strategies for the prevention of heart attack in stable coronary artery disease

The present study compares the effectiveness of two approaches – conservative and interventional – with relation to heart attack prevention in patients with a stable coronary heart disease (CAD). The conservative strategy consists of optimal drug therapy; the interventional approach is based on percutaneous coronary intervention (PCI), also called angioplasty.

CAD is a condition caused by the narrowing of the coronary arteries that supply the heart. This is usually the result of a process called atherosclerosis; the accumulation of fatty deposits in artery walls. A CAD is defined as 'stable' if symptoms can be managed with lifestyle changes and medications alone.The optimal drug therapy (ODT) aims to reduce risk factors (blood clots, cholesterol), and alleviate symptoms. Alternatively, stable CAD can be treated by an intervention (PCI) that opens the narrowed arteries and restores blood supply to the heart. However, PCI may entail complications, such as 'procedural-heart attack', which is indicated by the elevation of specific markers of heart muscle injury in the blood.  

The ultimate goal of both strategies is to delay disease progression and prevent 'spontaneous' heart attacks (not related to any procedure). A heart attack occurs when a narrowed coronary artery becomes completely blocked, depriving the heart muscle of oxygen.

This study examined which strategy better protects CAD patients from a prospective heart attack.

The authors reviewed 12 different trials that compared PCI with ODT. The trials included altogether 8,070 patients who were monitored for an average of 5 years. ODT was defined by the researchers as the use of at least three drugs: an anti-platelet (reduce blood clot formation), an anti-angina (reduce chest pain), and a lipid-lowering drug. Regardless of whether or not stenting was performed during PCI, PCI reduced the likelihood of a spontaneous heart attack by 24%. On the other hand, PCI was associated with 317% increase in the risk of 'procedural-related heart attack'. Despite reducing the risk of a spontaneous heart attack, PCI did not significantly reduce the rate of death due to any cause, or due to cardiovascular causes. However, the authors note that spontaneous- mora than procedural-heart attacks are associated with higher death rates. 

PCI is associated with a significant reduction in risk for spontaneous heart attacks, at the risk of procedural ones.

This study is correlational. Therefore, it is not clear that PCI itself definitively caused the reduction in spontaneous heart attacks. The studies included used various techniques of PCI, some of which yielded better results compared to others. Larger trials, comparing ODT with each PCI method are needed to determine which strategy better protects patients with stable CAD. 

If you have a stable CAD discuss with your cardiologist your treatment options, including drug therapies and interventions.