Clinical and biomechanical behavior of a platinum-cromium stent platform in a large all-comers single centre PCI population: insights from the Novara-PROMETEUS registry

Abstract

Aims: Recent reports have described cases of longitudinal deformation in new generation thin-strut coronary stents and biomechanical analyses have suggested increased susceptibility for such a complication for the novel platinum chromium (PtCr) Elements™ coronary stent platform. The present study assesses the incidence of longitudinal stent deformation for PtCr stents in a large single centre all-comers population. Methods and results: Quantitative angiographic analysis (QCA) of 337 PtCr stents deployed in 253 consecutive all-comers patients treated in our Laboratory from January 2011 to August 2012 was performed. QCA: nominal stent length ratio (QCA:NSLR) was considered as surrogate estimate of longitudinal stent deformation. The risk profile of the studied population was high, with 265 lesion (75.3%) classified as ACC/AHA type B2/C. QCA:NSLR averaged 0.95±0.04 in the whole population. The small post-deployment reduction of stent length had no clinical relevance, with only 3 cases (0.9%) of trivial geographical miss which did not required further interventions. Plaque prolapsed, usually small and focal, through the stent struts was observed in 19 cases (5.6%). No case of typical concertina effect was observed, while in 3 cases (0.9%) a large prolapsed plaque mimicked longitudinal stent deformation. Minor grades of stent deformation were more common and correlated with tortuous and calcified lesions, as expression of great stent conformability. Actually blinded a posteriori re-examination of the angiograms corresponding to the 20 lowest and highest ratios did not identify any cases of severe stent deformation. Logistic regression analysis identified a significant correlation between the need for predilation and lower QCA:NSLR values, while postdilation independently predicted higher QCA:NSLRs. Conclusions: Systematic QCA analysis of a large single centre population of all-comer PCI patients treated with PtCr stents failed to detect clinically relevant longitudinal stent deformations. Need for predilation was associated with a reduced stent length ratio, even if this did not substantially influenced PCI outcomes. Conversely postdilation was associated with QCA stent measures closest to nominal. (Clinicaltrials.gov ID: [NCT01759719][1]) [1]: /lookup/external-ref?link_type=CLINTRIALGOV&access_num=NCT01759719&atom=%2Fehj%2F34%2Fsuppl_1%2FP3017.atom