From Randomized Trials to 'Real World'
The initial DES approvals by the FDA were made on the basis of randomized controlled trials (RCTs) enrolling patients with mostly stable CAD and relatively noncomplex, single, de novo coronary artery lesions. However, DES are now routinely used 'off label' in higher risk patients and in more complex lesions, and concerns have arisen about the safety and efficacy of DES in the 'real-world', nonselected population.
A recent meta-analysis was performed in order to estimate the relative impact of DES versus BMS on safety and efficacy end points, particularly for non-FDA-labeled indications. Data were obtained from 9470 patients in 22 RCTs and from 182,901 patients in 34 observational studies. In RCTs, DES were associated with no detectable differences in overall mortality compared with BMS or MI, with a significant 55% reduction in TVR (hazard ratio [HR]: 0.45). In observational studies, DES were associated with significant reductions in mortality (HR: 0.78), MI (HR: 0.87) and TVR (HR: 0.54) compared with BMS. The authors concluded that DES is safe and efficacious in both on-label and off-label use but highlighted differences between RCTs and observational data comparing DES and BMS. The reduced death and MI observed in real-world, nonrandomized observational studies might be due to the fact that nearly 20-times more patients had been studied in the observational registries as in the RCTs, providing much more power to detect differences in low-frequency safety events. Nonetheless, observational analyses are subject to confounding with respect to the nonrandomized choice of either DES or BMS. Conventional statistical approaches used in observational analyses have limited ability to address the influence of unmeasured confounders on the overall effect estimate. For example, the decision to use DES may be based on unmeasured patient characteristics and may sobsfantially affect subsequent treatment decisions, including medication use. The longer duration of dual antiplatelet therapy required with DES may reduce long-term adverse event rates independently of stent selection.
Expert Rev Pharmacoeconomics Outcomes Res. 2010;10(1):49-61. © 2010 Expert Reviews Ltd.
Cite this: Long-term Outcomes in Patients Undergoing Percutaneous Coronary Intervention with Drug-eluting Stents - Medscape - Feb 01, 2010.