A fluttering coronary event

Assessment of serum phenylalanine and tyrosine isomers in patients with ST-segment elevation vs non-ST-segment elevation myocardial infarction

Background

Under conditions of oxidative stress, hydroxyl radicals can oxidize phenylalanine (Phe) into various tyrosine (Tyr) isomers (meta‐, ortho‐, and para‐tyrosine; m‐, o‐, and p‐Tyr), depending on the location of the hydroxyl group on the oxidized benzyl ring. This study aimed to compare patients with ST‐segment elevation myocardial infarction (STEMI) and non‐STEMI (NSTEMI) and the serum levels of Phe and Tyr isomers at the aortic root and distal to the culprit lesion in both groups.

Methods

Forty‐four patients participated in the study: 23 with STEMI and 21 with NSTEMI. Arterial blood samples were taken from the aortic root through a guiding catheter and from the culprit vessel segment distal from the primary lesion with an aspiration catheter, during the percutaneous coronary intervention. Serum levels of Phe, p‐Tyr, m‐Tyr, and o‐Tyr were determined using reverse‐phase high‐performance liquid chromatography.

Results

Serum levels of Phe were significantly higher distal to the culprit lesion compared to the aortic root in patients with STEMI. Serum p‐Tyr/Phe and m‐Tyr/Phe concentration ratios were both lower distal to the culprit lesion than at the aortic root in patients with STEMI. There were no statistically significant differences with respect to changes in serum Phe and Tyr isomers distal to the culprit lesion compared to the aortic root in patients with NSTEMI.

Conclusion

Our data suggest that changes in serum levels of different Tyr isomers can mediate the effects of oxidative stress during myocardial infarction.

Acute Coronary Syndrome (ACS) due to Coronary Artery Embolism in a Patient with Atrial Fibrillation

Acute coronary syndrome (ACS) secondary to a coronary embolism is an unusual occurrence, yet an important consideration given the difficult diagnosis. We report a case of a 69-year-old male with a medical history of paroxysmal atrial fibrillation who presented with chest pain and shortness of breath. A coronary angiogram was significant for three focal transluminal and translucent areas in the ostial, mid, and distal circumflex artery consistent with embolic disease. The patient was subsequently managed medically with anticoagulation. Despite being a relatively rare entity, thromboembolism into the coronary arteries can provoke an acute myocardial infarction, with atrial fibrillation being the most common risk factor. Treatment modalities for ACS secondary to thromboembolism include stent placement, intracoronary thrombolysis, and thrombus aspiration.