To Stress or Not to Stress?

One of the challenges I have on the inpatient service is the amount of stress tests we perform. Everyone knows the admission: some guy with atypical chest pain gets admitted, we don’t think it is cardiac but go ahead and stress them and send them home. The question I have is whether we should be stressing these patients. If a patient has chest pain that does not sound like it is cardiac in etiology, if they have a positive stress test does that suddenly mean the chest pain was cardiac in origin, or did we just happen to find an incidental finding. I suspect it is the latter. Then the question comes up, do we need to fix incidental findings?

A NEJM study in June 2009 may help answer this question. In this large, randomized trial, 2368 type II diabetics with proven CAD but PCI were randomized to either revascularization or intensive medical therapy. Interestingly, the randomization occurred after the PCI! After PCI, the patient was placed in the CABG group or stenting group. Those two groups were then randomized to either intensive medical therapy or immediate intervention. The randomization of the CABG group was surprising since this represents the worst of the worst. All of these patients were either asymptomatic or had stable disease. The end points were death, myocardial infarction, and CVA. The hypothesis of the study was that the early intervention group would show benefit. 
The results did not show this. When looking at the stenting group vs intensive medical therapy, there wasn’t any benefit noted for any of the end points. What surprised me was that the CABG group did not show any mortality benefit, although it did show a significant benefit in major cardiovascular events (22.4 vs 30%).

What does this mean? Well, it is clear that if a patient is asymptomatic, then don’t look unless you do not have them on medical therapy already, which all of our diabetics often do. Second, medical management is incredibly powerful. But, back to my first question. At this point, I am not ready to stop doing stress test on them, but I am moving closer to that point.