| Abstrakt: |
Invasive management of coronary artery disease (CAD) includes Percutaneous Transluminal Coronary Angioplasty (PTCA) and Coronary Artery Bypass Graft surgery (CABG). Indications for CABG and PTCA are well established. Whether PTCA alters the incidence of CABG is unknown. If PTCA is an effective invasive alternative to CABG, then where PTCA is aggressively performed, rates of CABG should be lower than in other locations with lower PTCA rates. We tested whether the performance of PTCA decreases the incidence of CABG comparing practice patterns in all 50 States. We examined the Medicare volume of PTCA from 805 hospitals and of CABG from 783 hospitals in the United States (US) from the Health Care Financing Administration (HCFA) database for 1992. Volumes of procedures were aggregated by State. Census data for population age>65 was obtained from the US Census Bureau for 1990. For all 50 States, as the rate of PTCA per 100,000 population age>65 (PTCA/l00,000) increased, there was an increase in the rate of CABG per 100,000 population age>65 (CABG/l00,000) (r2=0.67, P<0.0001) with rates of PTCA/l00,000 and CABG/l00,000 ranging from 89 to 831 and 299 to 1108 respectively. For the 10 States with the greatest population age >65 years, the relationship was similar (r2=0.84, P=0.0002) with rates of PTCA/l00,000 and CABG/l00,000 ranging from 130 to 503 and from 378 to 764 respectively. We conclude: 1) Rates of PTCA/100,000 and CABG/l00,000 vary considerably from State to State despite established indications, 2) High rates of PTCA/100,000 are associated with high rates of CABG/l00,000 suggesting that PTCA does not substitute for CABG in the invasive treatment of CAD, 3) Among the 10 most populous States, low rates of both procedures were associated with a Certificate of Need program and public disclosure of hospital and physician volume and mortality results for CABG surgery, 4) Appropriateness studies for PTCA and CABG should be performed on an individual statewide basis to further investigate the considerable inter-state variability. |
