Friday January 25, 2008
Drug-Eluting Stents vs. CABG in Multivessel Coronary Disease
Very important obsevational study published from New York in this week issue of The New England Journal of Medicine, comparing Drug-Eluting Stents vs. Coronary-Artery Bypass Grafting in Multivessel Coronary Disease 1.
Patients compared: CABG (N = 7437) vs Stent (N = 9963)
The end points of the study: Death in the hospital or within 30 days after treatment and death, death or myocardial infarction, and revascularization up to 18 months after treatment.
Conclusions: For patients with multivessel disease, CABG continues to be associated with lower mortality rates than does treatment with drug-eluting stents and is also associated with lower rates of death or myocardial infarction and repeat revascularization.
Arguments against study in editorial of NEJM (Joseph P. Carrozza, Jr., M.D.):
1. "......For example, dementia is not a covariate in this risk-adjustment model and would be likely to influence a clinician to choose PCIinstead of CABG. When confounders are associated with an increased risk of the measured outcome (e.g., death), bias becomes clear. Factors precluding CABG include coexisting conditions that are linked to poor prognosis (e.g., dementia), whereas those precluding PCI are often lesion- based (e.g., chronic total occlusion) and have a lesser effect on prognosis after CABG. Thus, the presence of these unmeasured confounders may bias the outcome in favor of CABG".
2. "....It is important to remember that in this observational study, the physician, and sometimes the patient, chose the treatment and thus introduced selection bias. In a randomized design,patients must qualify for both treatments and assignment is by chance. This allows a purer comparison of two treatments but has practical limitations. Is it appropriate to remove physicianand patient preferences from decision makingwhen they are such important features of “realworld” medicine?"
3. "Patients were enrolled before widespread use of extended dual antiplatelet therapy as prophylaxis against latestent thrombosis".
4. "The mean follow-up times for both treatments were only 19 months,a period that captures the majority of clinical events related to the major hazards of stenting — thrombosis and restenosis — but does not include events driven by atherosclerosis of saphenous- vein grafts, a process that begins several years after surgery."
Final words in editorial:
"The New York State registries affirm that CABG remains the standard of care for patients who require multivessel coronary revascularization. However, stents may be an alternative for patients at high risk for surgical complications or when an informed patient chooses a less invasive option".
References: click to get abstract / article if available
1. Drug-Eluting Stents vs. Coronary-Artery Bypass Grafting in Multivessel Coronary Disease - Volume 358:331-341, Number 4, Jan. 24 2008
2. Drug-Eluting Stents — Pushing the Envelope beyond the Labels? - Editorial, n engl j med 358;4 www.nejm.org january 24, 2008