Post #24: Diagnostic testing for Coronary Artery Disease – Testing after Revascularization – Guideline variations

Authorization criteria used by the major radiology benefits management (RBM) companies claim to conform to guidelines from national organizations such as the American College of Cardiology, however, each of the 3 RBMs may have slight guideline differences and exceptions. Imaging stress testing (either with myocardial perfusion imaging (MPI) or stress ECHO) can be performed after revascularization in the following scenarios: 

1.    New or worsening cardiac symptoms: any time after revascularization  (although if symptoms are typical of ischemia, coronary arteriography may be more appropriate than MPI as initial study). 
2.    Patients with no symptoms, a routine imaging stress test can be performed, depending upon the revascularization employed:

  • after CABG:  one MPI or stress ECHO may be approved after 5 years.   No follow up imaging is supported unless new signs/symptoms develop.                                 
  • after PCI: one MPI or stress ECHO may be approved after 2 years. No follow up imaging is supported unless new signs/symptoms develop.                                                                                          

Exceptions and Differences in Guidelines            

  1. Time Frame to first post-procedure imaging:  Cardiac guidelines differ from one RBM to the next For      example, the time frame for imaging with one RBM is 5 years (for CABG) and 2 years (for stent), while       another RBM’s guidelines call for imaging at 2 years for CABG and 2 years post stent. A third RBM states the follow up imaging may be done 3 years after stentand 5 after CABG. The Guideline from one RBM        allows imaging at one year if the artery stented was the left main coronary artery while other guidelines do not mention this.                                         
  2. Repeat imaging: After the initial imaging post-procedure study, most guidelines do no support repeating a stress ECHO or MPI without symtoms, but one RBM states if the vessel stented was left main coronary artery or proximal LAD, imaging can be approved every 2 years.                  
  3. Associated co-morbidities: One RBM allows continued imaging every 2 years if the ejection fraction is        less than 50%, while the other two RBMs omit this criterion.  One RBM allows   imaging in the evaluation    of new onset atrial fibrillation in patients with known CAD if no     imaging study has been performed within the past 2 years.   Other RBMs do not list this as a criterion for imaging.                                             
  4. Occupational Risk of CAD:  Some RBMs specify that patients at high occupational risk (airline or boat     pilots, bus and train drivers, bridge and tunnel workers, police officers and firefighters) or high personal risk (scuba divers) may have MPI or stress ECHO, with frequency as required by DOT, union or other recommendations.  Other RBMs do not include this criterion. One RBM states these high-risk individuals can be screened with a non-imaging ETT rather than an imaging study.

In an earlier post (#3) I mentioned that there are only 4 major radiology benefits management companies nationally.  The 3 largest RBMs publish their guidelines on their website and make them available to the public.  I suggested that the guidelines can be copied and pasted on your desktop, and referred to whenever you are uncertain as to which imaging study would be approved. Because these guidelines are taken from the medical standards created and maintained by national organizations (such as American College of Cardiology, NCCN, American College of Physicians and others) the working guidelines used by the 3 radiology benefits managers all 3 should be quite similar.  Post-revascularization imaging guidelines are exceptions.  

The only way to know for certain which imaging study to request and how often a study may be approved is to paste all 3 sets of guidelines to your desktop (instructions are on post #3).  The patient’s insurance ID card should contain the name of the radiology benefits manager to call for prior authorization.  That company’s guideline is the one to refer to for imaging rules post stent or CABG.

Lesson #24:  Guidelines support at least one follow-up imaging stress test after re-vascularization in asymptomatic patients but some do not support repeating imaging unless new signs or symptoms occur or unless the procedure was complex.  Different RBMs have slightly different guidelines and provisions. Refer to Blog #3 for detailed instructions on how to access these guidelines.