Relationship of late loss in lumen diameter to coronary restenosis in sirolimus-eluting stents.
BACKGROUND
Observed rates of restenosis after drug-eluting stenting are low (<10%). Identification of a reliable and powerful angiographic end point will be useful in future trials.


RESULTS
Late loss (postprocedural minimum lumen diameter minus 8-month minimum lumen diameter) was measured in the angiographic cohorts of the SIRIUS (n=703) and E-SIRIUS (n=308) trials. Two techniques, the standard normal approximation and an optimized power transformation, were used to predict binary angiographic restenosis rates and compare them with observed restenosis rates. The mean in-stent late loss observed in the SIRIUS trial was 0.17+/-0.45 mm (sirolimus) versus 1.00+/-0.70 mm (control). If a normal distribution was assumed, late loss accurately estimated in-stent binary angiographic restenosis for the control arm (predicted 35.4% versus observed 35.4%) but underestimated it in the sirolimus arm (predicted 0.6% versus observed 3.2%). Power transformation improved the reliability of the estimate in the sirolimus arm (predicted 3.2% [CI 1.0% to 6.7%]) with similar improvements in the E-SIRIUS trial (predicted 4.0% [CI 1.2% to 7.0%] versus observed 3.9%). In the sirolimus-eluting stent arm, in-stent late loss correlated better with target-lesion revascularization than in-segment late loss (c-statistic=0.915 versus 0.665).


CONCLUSIONS
Because distributions of late loss with a low mean are right-skewed, the use of a transformation improves the accuracy of predicting low binary restenosis rates. Late loss is monotonically correlated with the probability of restenosis and yields a more efficient estimate of the restenosis process in the era of lower binary restenosis rates.
Mauri
Laura
L
Brigham and Women's Hospital, Boston, Mass 02116, USA.
Orav
E John
EJ
O'Malley
A James
AJ
Moses
Jeffrey W
JW
Leon
Martin B
MB
Holmes
David R
DR
Teirstein
Paul S
PS
Schofer
Joachim
J
Breithardt
Günter
G
Cutlip
Donald E
DE
Kereiakes
Dean J
DJ
Shi
Chunxue
C
Firth
Brian G
BG
Donohoe
Dennis J
DJ
Kuntz
Richard E
RE
D023903:Coronary Restenosis / Q000175:diagnosis* / Q000473:pathology / Q000517:prevention & control; D005500:Follow-Up Studies; D006801:Humans; D011336:Probability; D011379:Prognosis; D016032:Randomized Controlled Trials as Topic; D012044:Regression Analysis; D020123:Sirolimus / Q000627:therapeutic use*; D015607:Stents
D020123:Sirolimus