Appeal type: Medical necessity
Decision: Upheld

Diagnosis: Shortness of breath; Abnormal stress test

Treatment: Myocardial Perfusion Imaging (MPI) Procedure Code-78452

The insurer denied the Myocardial Perfusion Imaging (MPI) Procedure Code-78452

The denial was upheld.   

This female patient was recommended a stress nuclear scan due to her recent abnormal stress test and the development of dyspnea which was suspicious for angina. The patient underwent a Bruce protocol stress test. The study was abnormal as she developed shortness of breath. There was 1 millimeter (mm) ST segment depression seen at peak stress. Due to these findings a stress nuclear scan was highly recommended. An electrocardiogram (EKG) showed segment depression, which was not horizontal, and was rapidly up-sloping. Another EKG showed no ST segment depression and only T-wave inversion in lead III. Another EKG showed sinus tachycardia at approximately 150 bpm.

According to the literature, the major clinical application of myocardial perfusion imaging using single-photon emission computed tomography (SPECT) technology is for detection of coronary artery disease (CAD) in patients presenting with chest pain or other symptoms considered reflective of angina. Either exercise or pharmacologic stress is employed, and most commonly, one of the Tc-99m-labeled tracers is used. Numerous studies have assessed the relative accuracies of stress imaging using nuclear cardiology techniques, and some review articles have reported pooled data. For stress SPECT, pooled sensitivity is 87% with a specificity of 73%. The latter is derived when comparing SPECT data with coronary angiography. This may yield a biased value since it requires patients to go onto cardiac catheterization after the noninvasive stress study. 

Considering the pretest likelihood of coronary artery disease (CAD), patients with a stable condition and intermediate risk have good indications for stress myocardial perfusion imaging (MPI). The Duke Treadmill Score has proven valuable in predicting future cardiac events, but there remains uncertainty of cardiac event risk especially in patients with intermediate risk according to their Duke Treadmill Score. As previously addressed, stress MPI can determine the cardiac event risk in this population and so these patients may benefit from stress MPI. 

It was imaging, however, that made it possible, for the first time, to visualize coronary atherosclerosis and its effects on myocardial perfusion. Therefore, MPI, at rest and under stress, paved the way for the next groundbreaking advance: the concept of myocardial ischemia from hemodynamically significant obstructive CAD. Revascularization therapy was finally able to target lesions, based on their hemodynamic significance. Noninvasive imaging of myocardial perfusion, illuminated - both metaphorically and literally - the path to tailored management and radically improved clinical outcomes. 

When symptoms are present and there is sufficient suspicion of heart disease to warrant cardiac evaluation, the clinician should make a probability estimate of the likelihood of CAD prior to selecting testing. By comparison to symptomatic patients, testing in asymptomatic patients was generally found to be "rarely appropriate," except for calcium scoring and exercise testing in intermediate and high-risk individuals and either stress or anatomic imaging in higher-risk individuals, which were all rated as "may be appropriate."

The literature review supports that the clinician should estimate the likelihood of this patient's CAD prior to selecting a test. The records from the stress test did not meet the criteria of a positive test. For these reasons, the myocardial perfusion imaging test was not considered medically necessary for this patient. 

The health plan acted reasonably with sound medical judgment, and in the best interest of patient. 

Based on the above, the medical necessity for Myocardial Perfusion Imaging (MPI) Procedure Code-78452 is not substantiated.  The insurer's denial should be upheld.