Background and study objectives
The RAVEL trial was the first randomized, double blind drug-eluting-stent trial comparing sirolimus eluting stent (SES) with an identical bare metal stent (BMS, BX Velocity). Six-month angiographic follow-up showed complete suppression of late loss resulting in 0% restenosis in the SES group. The long term safety and efficacy of the SES was assessed by clinical follow-up (FU) over 5 years. This abstract presents the final long-term data.
Patient population and methods
238 patients with a single de novo native coronary artery lesion were enrolled. Survival free from target lesion revascularization (TLR), target vessel failure (TVF) and MACE were compared until 5 year FU.
Results
Rates of survival free from all TLR, and all TVF at 5 years follow-up are 89.7% and 82.0% in the SES group respectively, versus 74.0 (TLR), and 64.8% (TVF) in the BMS group. The differences were significant at 5 years (P = 0.0004 for TLR, and P = 0.001 for TVF, Log-rank test). Freedom from MACE at 5 years was 74.2% in the SES group, versus 64.8% in the BMS group (P = 0.034, Log-rank test). There were no stent thromboses observed in the trial.
Conclusion
The beneficial anti-restenotic effect of SES is sustained over 5 years of follow-up.
Background and study objectives
The RAVEL trial was the first randomized, double blind drug-eluting-stent trial comparing sirolimus eluting stent (SES) with an identical bare metal stent (BMS, BX Velocity). Six-month angiographic follow-up showed complete suppression of late loss resulting in 0% restenosis in the SES group. The long term safety and efficacy of the SES was assessed by clinical follow-up (FU) over 5 years. This abstract presents the final long-term data.
Patient population and methods
238 patients with a single de novo native coronary artery lesion were enrolled. Survival free from target lesion revascularization (TLR), target vessel failure (TVF) and MACE were compared until 5 year FU.
Results
Rates of survival free from all TLR, and all TVF at 5 years follow-up are 89.7% and 82.0% in the SES group respectively, versus 74.0 (TLR), and 64.8% (TVF) in the BMS group. The differences were significant at 5 years (P = 0.0004 for TLR, and P = 0.001 for TVF, Log-rank test). Freedom from MACE at 5 years was 74.2% in the SES group, versus 64.8% in the BMS group (P = 0.034, Log-rank test). There were no stent thromboses observed in the trial.
Conclusion
The beneficial anti-restenotic effect of SES is sustained over 5 years of follow-up.
Session Number : 710007
Session Title: Clinical Trial Update I
Conclusion
DISCUSSANT: De Bruyne
What does RAVEL reveal?
RAVEL is a multicentric randomized study conducted in 238 patients with one vessel disease. The study investigated whether the Sirolimus eluting stent (SES) decreased in-stent angiographic late loss after 6 months as compared to the corresponding bare metal stent (BMS).
This primary end-point (late loss) was reached in a spectacular manner confirming indisputably that SES virtually abolishes in-stent neointimal hyperplasia. In this regard RAVEL will remain an historical study.
At the first glance, there seems to exist a ‘catch up’ phenomenon, the number of adverse events in the BMS group remaining quite stable while there is an increase in the number of events in the SES group.
Paradoxically, the very choice of this angiographic surrogate end-point makes it difficult to gauge 5-year clinical outcome, for at least two reasons: first, the study was powered to reach the angiographic end point but not to investigate the clinical effects of SES implantation on patient outcome. Therefore, the clinical follow-up results presented today should only be taken as indicative. Second, the need for a repeat angiogram induces at least 50% re-intervention driven, not by clinical reasons, but by the so-called occulo- stenotic reflex. This makes it even more difficult to evaluate the long-term clinical outcome of the patients.
When reported, this long-term outcome should be limited to “hard end points” i.e death and myocardial infarction or – even preferably – only total death, without distinction between cardiac and non-cardiac and Q-wave myocardial infarction. From the data presented, it appears that there is a trend towards a higher death / MI rate in patients treated with a SES than in patients treated with a BMS. And whether or not this trend is driven by non-cardiac death does not change anything for the patients.
As long as this is not clarified by larger studies (without repeat angiogram and reporting mainly on total death rates and Q-wave myocardial infarction) the suspicion will remain that SES cures the stenosis but harms the patient.