Coronary stents for failed balloon pulmonary angioplasty in patients with chronic thromboembolic disease: a case series of 16 patients with long-term follow-up

Abstract Background Balloon pulmonary angioplasty (BAPA) became a standard therapy for patients with distal chronic thromboembolic pulmonary hypertension (CTEPH). However, use of stents to treat failure of BAPA remains unknown. Aims The purpose of this study is to evaluate long-term efficacy and safety of using coronary stents for the treatment of BAPA failures. Patients and methods Sixteen patients with CTEPH were included in whom coronary stents were implanted into pulmonary arteries after failure of BAPA procedure. The failure of BAPA was defined as the presence of high-grade stenosis (90%) after repeated BAPA (at least 3 attempts with 2 balloons with different diameters) with non-optimal peripheral lung perfusion (slow flow without adequate peripheral blush and venous phase). All patients had repeated interventions after the initial implantation of stents and the last visualization of stent was used for the determination of time for the patency of stents. All periprocedural and long-term complications were recorded (reperfusion injury, local pulmonary bleeding events, early and late stent thrombosis or occlusion). Results Among 38 CTEPH patients who were treated with BAPA with 172 interventions (3-5 arteries per procedure was treated) in four centers in Serbia from 2016-2025, in sixteen patients we implanted 21 drug-eluting coronary stents (median diameter of stents were 4 mm) after repeated unsuccessful BAPA (19 patients had high-grade stenosis without adequate peripheral lung perfusion, one patient had subacute thrombosis of subsegmental PA after BAPA, and one patient had occlusive dissection of organized thrombotic lesion after BAPA). In all patients stents achieved significant improvement of flow, peripheral blush and venous contrast return, which mean successful reperfusion. Two patients had severe lung reperfusion injury in lung segments below stents which were successfully treated with high-flow oxygen, diuretics and antibiotics. All patients received a combination of oral anticoagulants with clopidogrel for 3-6 months after the procedure and proceeded with anticoagulants after that period. The median time from stent implantation to the last stent visualization was 26 months (range from 1-92 months), and 14 out of 16 patients had angiographic follow-up for more than 12 months. On the last pulmonary angiography all stents except one was fully patent with complete perfusion of the segmental or subsegmental pulmonary areas beneath the stents. One stent was patented, but with high-grade „restenosis" which was successfully treated with repeated BAPA. Conclusion Coronary stents implanted into segmental or subsegmental PA after failed BAPA are safe and efficacious procedures to achieve adequate pulmonary perfusion with durable patency on oral anticoagulant therapy.