Noninvasive Cardiac Testing vs. Clinical Evaluation Alone in Acute Chest Pain: Less is more

These researchers from St. Louis wanted to see if “nothing” was a good diagnostic strategy for the evaluation of low risk acute chest pain.

Ok… not really nothing. But they hypothesised that non-invasive testing (i.e. CTCA, treadmill, stress echo, SPECT) would provide no benefit beyond the typical evaluation using history, physical examination, ECG and troponins.

To try to answer this research question, they got their hands on de-identified data from the Boston led ROMICAT II study. This was a 1000 patient RCT looking at CTCA vs. standard practice in the evaluation of chest pain performed in 9 ED’s in the USA. This robust prospectively collected data was subsequently analysed by these new researchers using a different angle.

They found that 118 (12%) of the 1000 patients did not undergo non-invasive stress testing and they had better outcomes than those who got testing. Specifically, they had shorter lengths of stay, less downstream testing, less radiation exposure and less cost with no change in clinical outcomes.

Apparently there no advantage to performing these non-invasive tests. Less is more.

I love this message.

We never get congratulated for the tests we do not order. Perhaps now is the time for a cultural shift that emphasises the potential harms of these non-specific tests; radiation, cost, time, and most of all overdiagnosis. Let’s clap our hands together for doing nothing!

But unfortunately, my evidence-based bones just can’t completely embrace the conclusions of this study.

This subanalysis was not an RCT. It was up to the physician judgement as to who got non-invasive testing in the usual care arm. It is very likely that the cohort of patients that got nothing were at less risk for bad outcomes. (To be fair, they did try an adjusted analysis, but these are always fraught with problems.)

What are we to think?

It is likely true that over zealous non-invasive testing in low risk patients with chest pain is potentially harmful. A targeted approach for higher risk patients is probably better.

In the end, this study has raised a decent hypothesis for prospectively testing in a proper RCT. If you are a patient with chest pain, perhaps nothing can be a real cool hand.

Covering:

Reinhardt SW, Lin CJ, Novak E, et al. Non-invasive Cardiac Testing vs Clinical Evaluation Alone in Acute Chest Pain. JAMA Intern Med. 2018;178(2):212-19.