Angina Relief by Ranolazine Identifies False-Negative SPECT Myocardial Perfusion Scans in Patients with Coronary...

Area of Science:

• Cardiology
• Nuclear Cardiology
• Interventional Cardiology

Background:

• Normal myocardial perfusion imaging (MPI) can underestimate coronary disease (CD) in patients with angina.
• Ranolazine (RAN) is used to treat angina, but its effectiveness in patients with normal MPI requires further investigation.
• A significant dilemma exists for patients with angina and normal MPI whose symptoms are relieved by RAN.

Purpose of the Study:

• To confirm the indication for coronary angiography (CA) in patients with class 3-4 angina relieved by RAN despite normal myocardial single-photon emission computed tomography (SPECT) MPI.
• To evaluate the diagnostic utility of RAN in identifying significant coronary stenoses in patients with initially normal MPI.

Main Methods:

• Retrospective chart review of patients with stable class 3-4 angina and normal MPI (LVEF ≥50%, segmental score = 0).
• Coronary angiography (CA) was performed on patients with complete angina relief on RAN and non-responders with unexplained angina.
• Flow-restrictive stenoses were defined as >70% diameter stenosis by quantitative CA or 50-70% with fractional flow reserve (FFR) ≤0.80.

Main Results:

• RAN relieved angina in 67% (36/54) of patients.
• Of those with angina relief, 69% (25/36) had significant stenoses (≥50%), with 66% mean stenosis severity.
• Flow-restrictive stenoses were found in 67% (29/43) of stenoses identified, present in 72% (18/25) of these patients.

Conclusions:

• Ranolazine's effectiveness in relieving angina is valuable in identifying patients with potentially falsely negative SPECT MPI.
• Approximately 50% of patients with angina relief from RAN and normal MPI have significant, flow-restrictive coronary stenoses.
• Coronary angiography is indicated for patients with class 3-4 angina relieved by RAN, even with normal MPI, to detect obstructive coronary disease.