The consequences of under-use of coronary revascularization; results of a cohort study in Northern Italy.

AIM: To assess whether under-use of coronary artery bypass graft (CABG) or percutaneous transluminal coronary angioplasty (PTCA) affects patient outcome.

PATIENTS AND METHODS: A prospective observational study was performed following up a cohort of patients, candidates for a revascularization procedure (either CABG or PTCA) after an index angiogram. A total of 1258 patients, candidates -- according to explicit criteria -- for either CABG or PTCA entered the study enrolled by 16 hospitals located in a Northern Italian region (Lombardia). Information on demographic and clinical characteristics, type of care received (i.e. CABG or PTCA performed Yes/No) and vital status was obtained from revascularization laboratories, patients' hospital medical records and local census offices of the town of patients' residence. The main outcome measure was total unadjusted and adjusted mortality at a minimum follow-up of 9 months after the index cardiac angiogram.

RESULTS: Patients who received CABG or PTCA (n=863) had lower mortality than those who did not (n=350) (4.8% vs 10.6%, P=0.001). This held true after adjustment for relevant risk factors between the two groups such as extent of coronary artery disease, clinical symptoms, and cardiac surgical risk index (adjusted odds ratio=0.48; 95% confidence intervals=0.30--0.77) and after performing a survival analysis (adjusted hazard ratio=0.31; 95% confidence intervals=0.19--0.50).

CONCLUSIONS: Failure to perform a revascularization procedure when it was indicated led, in this study, to a significantly increased mortality showing that under-use of effective procedures may represent a significant quality of care problem even in areas where health care systems are well developed. Although the study was not specifically designed to identify determinants of under-use (i.e. reduced capacity leading to waiting lists, physicians' competence or patients' refusal to undergo a recommended procedure) our data suggest that limited capacity could have been the most important reason. Our findings also provide further evidence of the validity of the RAND method to assess the impact of under-use of coronary revascularization procedures.