Left main coronary artery compression in precapillary pulmonary hypertension

Pulmonary hypertension (PH) is a progressive and invalidating condition despite available therapy. Addressing complications such as left main coronary artery compression (LMCo) due to the dilated pulmonary artery (PA) may improve symptoms and survival. Nevertheless, clear recommendations are lacking. The aim of this study is to analyze the prevalence, characteristics, predictive factors and impact of LMCo in a heterogenous precapillary PH population in a single referral center. Two hundred sixty-five adults with various etiologies of precapillary PH at catheterization were reviewed. Coronary angiography (CA) was performed for LMCo suspicion. Revascularization was performed in selected cases. Outcomes were assessed at a mean follow-up of 3.9 years. LMCo was suspected in 125 patients and confirmed in 39 (31.2%), of whom 21 (16.8%) had 50%-90% stenoses. Nine revascularizations were performed, with clinical improvement. The only periprocedural complication was a stent migration. LMCo was associated with PH etiology (p 0.003), occuring more frequently in congenital heart disease-associated PH (61.5% of all LMCo cases, 66.6% of LMCo ≥ 50%). Predictors of LMCo ≥50% were PA ≥ 37.5 mm (Sn 81%, Sp 74%) and PA-to-aorta ≥1.24 (Sn 81%, Sp 69%), with increased discrimination when considering RV end-diastolic area. LMCo ≥ 50% without revascularization presented clinical deterioration and worse survival (p 0.019). This analysis of a heterogeneous pre-capillary PH population provides LMCo prevalence estimation, predictive factors (PA size, PA-to-aorta, RV end-diastolic area and PH etiology) and long-term impact. While LMCo impact on survival is inconclusive, untreated LMCo ≥ 50% has worse prognosis. LMCo revascularization may be performed safely and with good outcomes.