Case report: Dobutamine stress intracoronary physiology and imaging to examine the functional and dynamic properties of an apparent malignant intra-arterial right coronary artery

Abstract

Background

We present a case concerning a 64-year-old female with complaints of palpitations, chest pain, and an anomalous right coronary artery (RCA) from the opposite sinus (R-ACAOS) with a suspected malignant trajectory on computed tomography. She was referred to our clinic for a second opinion to re-assess the suggested treatment of coronary surgery.

Case summary

A coronary angiogram was performed demonstrating a RCA with a tapered ostium typical for an inter-arterial course. Dobutamine and adenosine stress test during simultaneous intracoronary flow, pressure, and ultrasound assessment, was performed to determine the functional significance. After 120 mcg adenosine, intracoronary baseline flow velocity increased from 14 cm/s to a peak flow velocity of 37 cm/s, demonstrating a sufficient coronary flow velocity reserve (CFVR) of 2.6. No intracoronary pressure drop during maximal hyperaemia was found. After maximum dobutamine stress, CFVR was measured 2.5. Fractional flow reserve measured 0.99. Cross-sectional area measurement through intravascular ultrasound demonstrated a diameter reduction from 14.6 mm² to 8.5 mm². Therefore, we concluded this aberrant trajectory was not of any functional relevance and should be considered non-malignant.

Discussion

There are several anatomic coronary anomalies which may contribute to coronary compression during exercise and are therefore correlated with sudden cardiac death. Right coronary artery from the opposite sinus is correlated with a low mortality rate of 0.2% in comparison to left-ACAOS at 6.3% over 20 years in participants of competitive sport. Therefore, strong evidence of ischaemia must be present before opting for surgery. Our pragmatic approach provided in our opinion enough evidence for a conservative treatment strategy.