Coronary vasomotor function and myocardial flow with bioresorbable vascular scaffolds or everolimus-eluting metallic stents: a randomised trial

Drug-Coated Balloon vs. Drug-Eluting Stents for De Novo Unprotected Left Main Stem Disease: The SPARTAN-LMS Study

The objective of this study is to compare the outcomes of patients treated with drug-coated balloons (DCBs) or second-generation drug-eluting stents (DESs) for de novo unprotected left main stem (LMS) disease. Previous studies comparing the treatment of LMS disease suggest that the mortality for DES PCI is not worse than CABG. There are limited data from studies investigating the treatment of de novo LMS disease with DCB angioplasty. We compared the all-cause and cardiac mortality of patients treated with paclitaxel DCB to those with second-generation DES for de novo LMS disease from July 2014 to November 2019. Data were analysed using Kaplan-Meier analyses and propensity-matched analyses. A total of 148 patients were treated with either a DCB or DES strategy. There was no significant difference in all-cause mortality in the DCB group (19.5%) compared to the DES group (15.9%) (HR 1.42 [0.61-3.32], p = 0.42). Regarding cardiac mortality, 2 (4.9%) were recorded for the DCB group and 7 (6.5%) for the DES group (HR 1.21 [0.31-4.67], p = 0.786); for target vessel myocardial infarction, there were 0 (0%) for the DCB group and 7 (6.5%) for the DES group; and for target lesion revascularisation, there were 3 (7.3%) in the DCB group and 9 (8.3%) in the DES group (HR: 0.89 [0.24-3.30]). p = 0.86. These remained not significant after propensity score matching. We found no difference in the mortality outcomes with DCB angioplasty compared to second-generation DES, with a median follow-up of 33 months. DCB can therefore be regarded as a safe option in the treatment of LMS disease in suitable patients.

Coronary Endothelium-Dependent Vasomotor Function After Drug-Eluting Stent and Bioresorbable Scaffold Implantation

Background Early generation drug-eluting stents (DESs) showed a high grade of coronary endothelial dysfunction that was attributed to lack of stent reendothelialization. Endothelium-dependent vasomotor response of current DESs and bioresorbable scaffolds (BRSs) remains unknown. This study sought to assess the device-related endothelial function of current devices and to correlate neointima healing with endothelial function. Methods and Results A total of 206 patients from 4 randomized trials treated with the durable-polymer everolimus-eluting Xience (n=44), bioresorbable-polymer sirolimus-eluting Orsiro (n=35), polymer-free biolimus-eluting Biofreedom (n=24), bioactive endothelial-progenitor cell-capturing sirolimus-eluting Combo DES (n=25), polymer-based everolimus-eluting Absorb (n=44), and Mg-based sirolimus-eluting Magmaris BRS (n=34) underwent endothelium-dependent vasomotor tests and optical coherence tomography imaging, as per protocol, at follow-up. Crude vasomotor responses of distal segments to low-dose acetylcholine (10^-6 mol/L) were different between groups: bioresorbablepolymer DEShad the worst (-8.4%±12.6%) and durable-polymer DES had the most physiologic (-0.4%±11.8%; P=0.014). High-dose acetylcholine (10^-4 mol/L) showed similar responses between groups (ranging from -10.8%±11.6% to -18.1%±15.4%; P=0.229). Device healing was different between devices. Uncovered struts ranged from 6.3%±7.1% (bioresorbable-polymer DES) to 2.5%±4.5% (bioactive DES; P=0.056). In multivariate models, endothelium-dependent vasomotor response was associated with age, bioresorbable-polymer DES, and angiographic lumen loss, but not with strut coverage nor plaque type. Endothelial dysfunction (defined as ≥4% vasoconstriction) was observed in 46.6% of patients with low-dose and 68.9% with high-dose acetylcholine, without differences between groups. Conclusions At follow-up, endothelial dysfunction was frequently observed in distal segments treated with current stents without remarkable differences between devices. Although neointima healing was different between devices, poor healing was not associated with endothelial dysfunction.

Coronary endothelial and microvascular function distal to polymer-free and endothelial cell-capturing drug-eluting stents. The randomized FUNCOMBO trial

INTRODUCTION AND OBJECTIVES

The vasomotor function of new-generation drug-eluting stents designed to enhance stent healing and reendothelialization is unknown. This study aimed to compare the endothelial function of the infarct-related artery (IRA) treated with bioactive circulating endothelial progenitor cell-capturing sirolimus-eluting stents (COMBO) vs polymer-free biolimus-eluting stents (BioFreedom) in ST-segment elevation myocardial infarction patients at 6 months. Secondary objectives were to compare the microcirculatory function of the IRA and stent healing at 6 months.

METHODS

Sixty patients were randomized to bioactive sirolimus-eluting stent vs polymer-free biolimus-eluting stents implantation. At 6 months, patients underwent coronary angiography with vasomotor, microcirculatory and optical coherence tomography examinations. Endothelial dysfunction of the distal coronary segment was defined as ≥ 4% vasoconstriction to intracoronary acetylcholine infusion.

RESULTS

Endothelial dysfunction was similarly observed between groups (64.0% vs 62.5%, respectively; P=.913). Mean lumen diameter decreased by 16.0 ±20.2% vs 16.1 ±21.6% during acetylcholine infusion (P=.983). Microcirculatory function was similar in the 2 groups: coronary flow reserve was 3.23 ±1.77 vs 3.23±1.62 (P=.992) and the index of microcirculatory resistance was 24.8±16.8 vs 21.3±12.0 (P=.440). Optical coherence tomography findings were similar: uncovered struts (2.3% vs 3.2%; P=.466), malapposed struts (0.1% vs 0.3%; P=.519) and major evaginations (7.1% vs 5.6%; P=.708) were observed in few cases.

CONCLUSIONS

Endothelial dysfunction of the IRA was frequent and was similarly observed with new-generation drug-eluting stents designed to enhance stent reendothelialization at 6 months. Endothelial dysfunction was observed despite almost preserved microcirculatory function and complete stent coverage. Larger and clinically powered studies are needed to assess the role of residual endothelial dysfunction in ST-segment elevation myocardial infarction patients. Registered in ClinicalTrials.gov: NCT04202172.

Endothelial Dysfunction and Coronary Vasoreactivity - A Review of the History, Physiology, Diagnostic Techniques, and Clinical Relevance

The fervency for advancement and evolution in percutaneous coronary intervention has revolutionised the treatment of coronary artery disease. Historically, the focus of the interventional cardiologist was directed at the restoration of luminal patency of the major epicardial coronary arteries, yet whilst this approach is evolving with much greater utilisation of physiological assessment, it often neglects consideration of the role of the coronary microcirculation, which has been shown to clearly influence prognosis. In this review, we explore the narrative of the coronary circulation as more than just a simple conduit for blood but an organ with functional significance. We review organisation and physiology of the coronary circulation, as well as the current methods and techniques used to examine it. We discuss the studies exploring coronary artery endothelial function, appreciating that coronary artery disease occurs on a spectrum of disorder and that percutaneous coronary intervention has a latent effect on the coronary circulation with long-term consequences. It is concluded that greater recognition of the coronary artery endothelium and mechanisms of the coronary circulation should further guide revascularisation strategies.