BACKGROUND/AIMS: Although drug-eluting stents (DESs) effectively reduce restenosis following percutaneous coronary intervention (PCI), they also delay re-endothelialization and impair microvascular function, resulting in adverse clinical outcomes. Endothelial progenitor cell (EPC) capturing stents, by providing a functional endothelial layer on the stent, have beneficial effects on microvascular function. However, data on coronary microvascular function in patients with EPC stents versus DESs are lacking. METHODS: Seventy-four patients who previously underwent PCI were enrolled in this study. Microvascular function was evaluated 6 months after PCI based on the index of microvascular resistance (IMR) and the coronary flow reserve (CFR). IMR was calculated as the ratio of the mean distal coronary pressure at maximal hyperemia to the inverse of the hyperemic mean transit time (hTmn). The CFR was calculated by dividing the hTmn by the baseline mean transit time. RESULTS: Twenty-one patients (age, 67.2 +/- 9.6 years; male:female, 15:6) with an EPC stent and 53 patients (age, 61.5 +/- 14.7 years; male:female, 40:13) with second-generation DESs were included in the study. There were no significant differences in the baseline clinical and angiographic characteristics of the two groups. Angiography performed 6 months postoperatively did not show significant differences in their CFR values. However, patients with the EPC stent had a significantly lower IMR than patients with second-generation DESs (median, 25.5 [interquartile range, 12.85 to 28.18] vs. 29.0 [interquartile range, 15.42 to 39.23]; p = 0.043). CONCLUSIONS: Microvascular dysfunction was significantly improved after 6 months in patients with EPC stents compared to those with DESs. The complete re-endothelialization achieved with the EPC stent may provide clinical benefits over DESs, especially in patients with microvascular dysfunction.
Aged ; Blood Flow Velocity ; Coronary Angiography ; Coronary Artery Disease/diagnosis/physiopathology/*therapy ; *Coronary Circulation ; Coronary Vessels/*physiopathology/radiography ; Drug-Eluting Stents ; *Endothelial Progenitor Cells/radiography ; Female ; Humans ; Male ; Microvessels/*physiopathology/radiography ; Middle Aged ; Percutaneous Coronary Intervention/*instrumentation ; Prosthesis Design ; *Re-Epithelialization ; *Stents ; Time Factors ; Treatment Outcome ; Vascular Resistance

This was designed to assess the outcomes of side branch (SB) stenosis after implantation of three drug-eluting stents (DES). From 2,645 patients in the ZEST (Comparison of the Efficacy and Safety of Zotarolimus-Eluting Stent with Sirolimus-Eluting and PacliTaxel-Eluting Stent for Coronary Lesions) Trial, 788 patients had 923 bifurcation lesions with SB > or = 1.5 mm were included. SB was treated in 150 lesions, including 35 (3.8%) receiving SB stenting. Of untreated SB with baseline stenosis < 50%, the incidences of periprocedural SB compromise was similar in the zotarolimus (15.8%), sirolimus (17.2%), and paclitaxel (16.6%) stent groups (P = 0.92). At follow-up angiography, delayed SB compromise occurred in 13.9%, 3.2%, and 9.4% (P = 0.010) of these groups. When classified into four groups (< 50%, 50%-70%, 70%-99%, and 100%), 9.0% of untreated SB were worsened, whereas improvement and stationary were observed in 9.6% and 81.4%. In a multivariable logistic regression model, main branch (MB) stenosis at follow-up (%) was the only independent predictor of SB stenosis worsening (odds ratio, 1.03; 95% confidence interval, 1.01-1.04; P < 0.001). After MB stenting in bifurcation lesions, a minority of SB appears to worsen. DES with strong anti-restenotic efficacy may help maintain SB patency.
Acute Disease ; Aged ; Blood Vessels/physiopathology ; Cardiovascular Agents/*therapeutic use ; Coronary Angiography ; Coronary Stenosis/*drug therapy/physiopathology/radiography ; Drug-Eluting Stents/*adverse effects ; Female ; Follow-Up Studies ; Humans ; Logistic Models ; Male ; Middle Aged ; Myocardial Infarction/etiology/radiography ; Myocardial Revascularization ; Odds Ratio ; Paclitaxel/*therapeutic use ; Predictive Value of Tests ; Sirolimus/*analogs & derivatives/*therapeutic use ; Thrombosis/etiology ; Treatment Outcome