Description of a methodological approach to verify the outcome-optimization of tailored therapeutic choices and test application to PCI vs. CABG.

Abstract

Background.

The decision process between Percutaneous Coronary Intervention (PCI) and Bypass Graft Surgery (CABG) is based on inconclusive evidence. Yet, it is generally regarded as capable of optimizing patient outcomes.

Objectives.

To verify this belief through a statistical approach investigating effect modification by propensity score (PS).

Methods

The probability of receiving PCI as the revascularisation strategy – PS - was calculated for all the 11750 patients with severe coronary disease who underwent coronary revascularization between 2002 and 2008 in Emilia-Romagna, Italy. Long-term risks of PCI vs. CABG for death, myocardial infarction, repeat revascularization and stroke were calculated by Cox regression in each decile of PS. The homogeneity of the Hazard Ratios (HR) across deciles was assessed with a likelihood ratio test and by visual inspection.

Results.

Repeat revascularization was the only outcome that significantly differed across deciles of PS (p=0.05) and whose trend supported a favorable effect of the decision process.

Conclusions

In agreement with the current scientific uncertainty, but contrary to common opinion, the medical decision process between PCI and CABG based on demographic and clinical factors is marginally capable of optimizing the post-procedural outcomes. The proposed methodology is limited by the assumption that clinicians considered only the variables that entered the PS calculation.

Keywords

Outcome And Process Assessment (Health Care), Coronary Disease, Coronary Artery Bypass, Angioplasty, Patient Selection, Propensity Score