Among local treatments, percutaneous coronary intervention (PCI) with drug-eluting stents is the standard of care for patients with obstructive coronary artery disease.1 However, stent-related complications, such as stent thrombosis and in-stent restenosis, may occur.2 Drug-coated balloons (DCB) offer an alternative to drug-eluting stents, based on the concept of “leaving nothing behind”, which may help preserve vessel vasomotion and potentially reduce the risk of adverse cardiac events.3,4 Nevertheless, the wall healing processes, plaque remodeling, and the impact of DCB-PCI on the coronary microcirculation remain unknown.

The PLAMI study (NCT06080919) is an investigator-initiated, single-center, single-arm, open-label pilot study that aimed to evaluate coronary arterial response to paclitaxel DCB-PCI (Pantera Lux, BIOTRONIK AG, Switzerland). The full study design, including inclusion and exclusion criteria, has been previously described.5 Briefly, all-comer de novo lesions with no limitations regarding vessel size or lesion characteristics, were included, except for patients presenting with ST-segment elevation myocardial infarction. The patients underwent paclitaxel DCB-PCI under intravascular ultrasound (IVUS) guidance (Opticross HD 60MHz; Boston Scientific, United States) according to current guidelines.1 IVUS and adenosine-free angiographic microvascular resistance (AMR) using uFR software (AngioPlus Core, Shanghai Pulse Medical Technology, Shanghai, China) were performed before, immediately after DCB-PCI, and at 3 months of follow-up (3M-FU). All IVUS and AMR data were analyzed by an independent core lab.

The primary endpoint was the change in percentage atheroma volume (PAV) evaluated by IVUS from baseline to the 3-month follow-up (3M-FU). Secondary endpoints included: a) changes in lumen area and external elastic membrane from baseline to post-DCB-PCI and to the 3M-FU (minimum, maximum, and average), b) the percentage of remodeling types (neutral, negative, and positive), and c) changes in uFR and AMR from baseline to post-DCB-PCI and the 3M-FU.

Continuous data are presented as mean±standard deviation and were compared using analysis of variance. A P value <.05 was considered statistically significant. Analyses were performed using SAS V 18 (SAS Institute, United States).

Thirty native coronary lesions were treated with paclitaxel-coated drug-eluting balloons (DCB). The mean age of the patients was 71.1 years, 29% were women, and diabetes mellitus was present in 32%. A total of 54.8% of the patients presented with non–ST-segment elevation myocardial infarction, and the most commonly treated vessel was the left anterior descending artery (51.6%). The mean treated vessel diameter was 3.04±0.46mm, with a mean lesion length of 24.8±5mm, and 16.6% of the lesions were severely calcified. After DCB-PCI, 6 type A, 3 type B, and 2 type C dissections were identified, none of which were flow-limiting. No bailout stenting was required in any of the patients. At the 3M-FU, only 1 nonischemia-driven target lesion revascularization occurred.

Primary and secondary endpoints are shown in table 1. A significant 9% reduction in mean PAV was observed at the 3M-FU (95% confidence interval [95%CI], 4.83-12.94; P<.001). Additionally, paclitaxel DCB-PCI resulted in a significant increase in minimum lumen area of 2.3 mm2 and mean lumen area of 1.9 mm2, without significant changes in mean vessel area or vessel volume (table 1). Positive vessel remodeling occurred in 76.5% of cases. Regarding the impact of paclitaxel DCB-PCI on microcirculation and coronary physiology, a significant increase in AMR was observed immediately after DCB-PCI, which normalized at 3M-FU. Conversely, a significant increase in uFR from baseline and post-PCI to 3M-FU was noted (table 1).

In conclusion, paclitaxel DCB-PCI was associated with a significant reduction in PAV at the 3M-FU. Additionally, paclitaxel DCB-PCI induced positive remodeling and late lumen enlargement, which were maintained in the mid- term, translating into a significant increase in the angio-derived index for the functional evaluation of the disease, without impacting the microcirculation. The main limitation of this study is its pilot design and limited sample size. However, based on these findings, paclitaxel DCB-PCI may not only treat coronary stenosis from a mechanical perspective but also influence the progression of atherosclerotic plaque by reducing its size. Further randomized studies are needed to evaluate the potential impact of these intracoronary imaging findings on mid- and long-term clinical outcomes in patients undergoing DCB-PCI.