Late stent malapposition and marked positive vessel remodeling after sirolimus-eluting coronary stent implantation:

Comparison of intravascular ultrasonic imaging with versus without incomplete stent apposition at follow-up after drug-eluting stent implantation

BACKGROUND

Incomplete stent apposition (ISA) at follow-up has been reported to be more common after drug-eluting stent (DES) implantation than after bare-metal stent (BMS) implantation. The aim of this study was to use intravascular ultrasound (IVUS) to evaluate the coronary characteristics after drug-eluting stent implantation in patients with ISA at follow-up.

METHODS

From the IVUS database of our institute, a total of 89 patients with 125 native lesions who underwent DES implantation into de novo lesions with IVUS imaging at 6-month follow-up were identified, and 15 (16.9%) patients had documented ISA at follow-up by IVUS. The ISA group was compared with a matched control group of patients (n = 30) who had no evidence of ISA at follow-up.

RESULTS

Of the 15 documented ISA at follow-up after DES implantation, two located at the edge (within 5 mm from stent margin) while 13 in the body of the stent. The maximum area and arc of ISA measured 5.3 +/- 2.2 mm(2) and 163 +/- 67 degrees , respectively. In patients with ISA, the maximum EEM area of stent segment with ISA was significantly larger than the adjacent stent segment without ISA (24.1 +/- 3.3 vs. 20.1 +/- 3.1 mm(2), P = 0.002), while stent area, plaque plus media (P&M) area and intrastent lumen area were comparable (P > 0.05). Compared to the matched control cohort without ISA at follow-up, the maximum EEM area was also significantly larger (24.1 +/- 3.3 vs. 18.8 +/- 4.2 mm(2), P < 0.001), while the areas of reference EEM and lumen, stent, P&M behind the stent, intimal hyperplasia and intrastent lumen were all comparable between the two groups (P > 0.05).

CONCLUSION

ISA at follow-up after DES implantation for de novo coronary lesions was associated with a larger EEM area.