Simultaneous Coronary and Pulmonary Angiography to Diagnose Critical Left Main Coronary Artery Stenosis Secondary to Dilated Pulmonary Artery

Left main coronary artery compression in pulmonary hypertension

Extrinsic compression of the left main coronary artery (LMCA) by a dilated pulmonary artery (PA) in the setting of pulmonary arterial hypertension (PAH) is an increasingly recognized disease entity. LMCA compression has been associated with angina, arrhythmia, heart failure, and sudden cardiac death in patients with PAH. Recent studies suggest that at least 6% of patients with PAH have significant LMCA compression. Screening for LMCA compression can be achieved with computed coronary tomography angiography, with a particular emphasis on assessment of PA size and any associated downward displacement and reduced takeoff angle of the LMCA. Indeed, evidence of a dilated PA (>40 mm), a reduced LMCA takeoff angle (<60°), and/or LMCA stenosis on CCTA imaging should prompt further diagnostic evaluation. Coronary angiography in conjunction with intravascular imaging has proven effective in diagnosing LMCA compression and guiding subsequent treatment. While optimal medical therapy and surgical correction remain in the clinician's arsenal, percutaneous coronary intervention has emerged as an effective treatment for LMCA compression. Given the prevalence of LMCA compression, its associated morbidity, and mortality, and the wide array of successful treatment strategies, maintaining a high degree of suspicion for this condition, and understanding the potential treatment strategies is critical.

Extrinsic compression of left main coronary artery by aneurysmal pulmonary artery in severe pulmonary hypertension: its correlates, clinical impact, and management strategies

Aims

Although left main coronary artery (LMCA) compression (Co) by pulmonary artery (PA) aneurysm (A) has been reported in some pulmonary hypertension (PH) series, clinical importance and management of this complication remain to be determined. In this single-centre prospective study, we evaluated correlates, clinical impact, and management strategies of LMCA-Co in patients with PH.

Methods and results

Our study group comprised 269 (female 166, age 52.9 ± 17.3 years) out of 498 patients with confirmed PH who underwent coronary angiography (CA) because of the PAA on echocardiography, angina or incidentally detected LMCA-Co during diagnostic evaluation with multidetector computed tomography. The LMCA-Co ≥ 50% was documented in 22 patients (8.2%) who underwent CA, and stenosis were between 70% and 90% in 14 of these. Univariate comparisons revealed that a younger age, a D-shaped septum, a higher PA systolic, diastolic, and mean pressures and pulmonary vascular resistance, a larger PA diameter, a smaller aortic diameter and pulmonary arterial hypertension associated with patent-ductus arteriosus, atrial or ventricular septal defects were significantly associated with LMCA-Co. Bare-metal stents were implanted in 12 patients and 1 patient underwent PAA and atrial septal defect surgery and another one declined LMCA stenting procedure.

Conclusion

Our study demonstrates that LMCA-Co is one of the most important and potentially lethal complications of severe PH, and alertness for this risk seems to be necessary in specific circumstances related with PAA. However, long-term benefit from stenting in this setting remains as a controversy.