Predictors of late cardiac events following treatment with Sr-90 beta-irradiation for instent restenosis.
BACKGROUND
Intracoronary radiation therapy (IRT) with Sr-90 using the Novoste Beta-Cath system has been shown to be an effective therapy for instent restenosis (ISR), but the temporal occurrence of cardiac events and the predictors of late complications require further investigation.


METHODS
We analyzed the demographics, lesion characteristics and clinical outcomes of 138 consecutive patients with ISR treated with IRT from September 1998 to March 2002. Major adverse cardiac events (MACE) were defined as death, myocardial infarction (MI) or target vessel revascularization (TVR). Characteristics of early (< or =8 months) and late (>8 months) failures were analyzed.


RESULTS
Thirty-two (23.1%) of 138 patients had MACE on follow-up; 25% (8/32) of failures occurred late after treatment with IRT. A comparison of the clinical and angiographic profile of early and late failures using univariate analysis indicates no correlations to late failure following IRT. Duration to failure after IRT was 14.25+/-3.69 months in the late group compared to 4.63+/-2.86 months in the early group (P<.001).


CONCLUSIONS
Late MACE after IRT with Sr-90 for ISR occur beyond the traditional period for clinical restenosis in 25% of cases and are difficult to predict. Further study is warranted to identify patients at risk for the development of late complications after IRT.
Chua
Dave C Y
DC
Rush Heart Institute, Rush-Presbyterian-St. Luke's Medical Center, 1653 West Congress Parkway, Chicago, IL 60612, USA.
Almeda
Francis Q
FQ
Senter
Shaun
S
Haynie
Justin
J
Nguyen
Cam
C
Chu
James C H
JC
Kavinsky
Clifford J
CJ
Snell
R Jeffrey
RJ
Schaer
Gary L
GL
D000368:Aged; D015906:Angioplasty, Balloon, Coronary / Q000009:adverse effects*; D001918:Brachytherapy / Q000009:adverse effects* / Q000379:methods; D023903:Coronary Restenosis / Q000209:etiology / Q000532:radiotherapy*; D003643:Death; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009203:Myocardial Infarction / Q000209:etiology; D009204:Myocardial Revascularization; D011237:Predictive Value of Tests; D011446:Prospective Studies; D015607:Stents / Q000009:adverse effects*; D013326:Strontium Radioisotopes / Q000009:adverse effects* / Q000627:therapeutic use; D016896:Treatment Outcome
D013326:Strontium Radioisotopes