Case Presentation Corner
13N-Ammonia myocardial blood flow quantitation in patient with aneurismal coronary artery disease

https://doi.org/10.1007/s12350-021-02642-6Get rights and content

Abstract

Aneurysmal coronary artery disease includes coronary artery aneurysms and ectasia; this condition has been associated with poor long-term outcomes. Few studies have explored myocardial blood flow 13N-ammonia PET/CT MPI added value. We present a 45-year-old man who came to the emergency department with chest pain. After a physical examination and laboratory studies, he was diagnosed with very high-risk unstable angina and referred to the catheterization laboratory. Coronary angiography showed the culprit lesion in the LCx and was treated by angioplasty and stent. LAD was found with coronary artery ectasia (TIMI 2 flow grade) and the RCA with aneurysmal disease in the proximal and middle segments (TIMI 3 flow grade). Medical treatment was decided for these findings and the patient was discharged. Two weeks later, we performed a 13N-ammonia PET/CT MPI founding apical, inferior, and inferoseptal severe ischemia, and reduced hyperemic coronary blood flow and coronary flow reserve in the RCA territory. Flow was normal in the LAD territory. Although coronary angiography remains the gold standard for evaluating these coronary abnormalities, it does not show the physiological compromise. Therefore 13N-ammonia PET/CT MPI should be performed as a complementary noninvasive imaging approach.

Introduction

Aneurysmal coronary artery disease (ACAD) is a vascular phenotype that is observed infrequently in patients who undergo coronary angiography (CA),1 includes coronary artery aneurysms (CAA) and coronary artery ectasia (CAE).2 Clinical presentations range from an incidental finding on cardiac imaging to an acute coronary syndrome.3 Poor long-term outcomes are associated with CAA or CAE. Management of these patients presents a dilemma to the clinician due to the lack of randomized trials.

Noninvasive functional studies are not usually considered as a routine ACAD approach. Our report suggests that 13N-ammonia PET/CT myocardial perfusion imaging study (MPI) should be mandatory because it demonstrates hemodynamic alterations that are not routinely assessable in the angiographic study. These findings allow defining a more appropriate therapeutic management.

Section snippets

Case report

A 45-year-old male presented to the emergency department with typical acute oppressive chest pain and dyspnea in the last five hours. His past medical history included smoking habits, hypertension, dyslipidemia, and familiar history of coronary artery disease. No previous cardiac history was known.

His physical exam, electrocardiogram and cardiac biomarkers (high sensitive troponins) were normal; diagnosis of unstable angina was made. Despite treatment with nitrates, the patient continued with

Discussion

CAA is defined as a localized irreversible dilatation of the coronary vascular lumen with a diameter ≥ 1.5 times that of the adjacent normal coronary segment. CAE describes diffuse dilatation of the coronary arteries that involves ≥ 50% of the artery’s length.2,4 Both conditions can be simultaneously present, generating disturbed coronary blood flow, which potentially promotes thrombogenicity and inflammatory reactions associated with coronary artery disease.5

The reported prevalence of ACAD

Conclusions

Controversies regarding the optimal approach to ACAD persist. Although coronary angiography is the standard study of choice to characterize anatomical coronary abnormalities, these patients must be studied with a noninvasive imaging to evaluate their functional impact. In our case, the use of 13N-ammonia PET/CT MPI to assess the degree of ischemia and the CBF and CFR reduction helped determine the CAA’s functional impact. We suggest that PET/CT MPI with flow quantitation should be mandatory in

References (14)

There are more references available in the full text version of this article.

Cited by (0)

View full text