Clinical relevance of adding intravascular ultrasound to coronary angiography for the diagnosis of extrinsic left main coronary artery compression by a pulmonary artery aneurysm in pulmonary hypertension

Abstract

Objectives We sought to assess the clinical value of adding intravascular ultrasound (IVUS) evaluation to coronary angiography (CA) to guide extrinsic left main coronary artery (LMCA) compression diagnosis and treatment in pulmonary hypertension (PH). Background LMCA compression due to a pulmonary artery aneurysm (PAA) is a severe complication of PH. Although guidelines encourage the use of IVUS for LMCA disease evaluation, it has hardly been used in this scenario. Methods We analyzed morbimortality of type 1 and 4 PH patients with clinically suspected LMCA compression by a PAA between 2010 and 2018 in a reference unit. LMCA compression was prospectively assessed with CA ± IVUS. Angiographic‐LMCA compression was considered conclusive when LMCA stenosis>50% was present in four predetermined projections; inconclusive, when LMCA stenosis>50% was present in <4 projections and negative if no stenosis>50% was present. Patients with conclusive and inconclusive CA underwent IVUS. IVUS‐LMCA compression was defined as systolic minimum lumen area < 6 mm2. Results LMCA compression was suspected in 23/796 patients (3%). CA was conclusive for compression in 7(30.5%), inconclusive in 9(39%), and negative in 7(30.5%). IVUS confirmed LMCA compression in 6/7(86%) patients with conclusive CA and in 2/9(22%) with inconclusive CA. Patients fulfilling IVUS criteria for LMCA compression underwent stent implantation. At 20 months follow‐up a composite end‐point of death, stent restenosis/thrombosis, or lung transplant was reported in three patients (13%). Conclusions CA can misdiagnose LMCA extrinsic compression. IVUS discriminates better whether significant compression by a PAA exists or not, avoiding unnecessary LMCA stenting. Patients treated following this strategy show a low rate of major clinical events at 20 months follow‐up.

2022 ESC/ERS Guidelines for the diagnosis and treatment of pulmonary hypertension

“…For patients with left main coronary artery compression syndrome, percutaneous coronary stenting is an effective and safe treatment [62]. For patients with asymptomatic left main coronary artery compression or non-severe compromise of its anatomy, evaluation with intravascular ultrasound or coronary pressure wire may help to avoid unnecessary interventions [494].…”

Acute Myocardial Infarction due to External Compression of the Left Main Coronary Artery by a Large Pulmonary Artery Aneurysm

“…It is therefore suggested that extrinsic compression by an aneurysmally dilated PA should be considered in the differential diagnosis of chest pain in patients with severe PAH. Coronary angiography alone can misdiagnose extrinsic LMCA compression, but IVUS can more accurately determine the extent of LMCA stenosis and is associated with lower rates of major clinical events [ 10 ].…”

Surgical correction of massive main pulmonary artery aneurysm due to giant cell arteritis causing left main coronary artery compression

“…Cases of symptomatic LMCA compression are typically evaluated with CT and coronary angiogram. IVUS is an emerging and highly sensitive tool in identifying extrinsic coronary artery compression 7 . Conservative treatment is indicated for asymptomatic patients and those with stable PAA diameter.…”

“…IVUS is an emerging and highly sensitive tool in identifying extrinsic coronary artery compression. 7 Conservative treatment is indicated for asymptomatic patients and those with stable PAA diameter. Cases due to PAH are initially managed with pulmonary vasodilators as first line therapy and vasculitides are treated with immunosuppressive therapy.…”