Chest pain: surgery, balloon dilation, drugs

The following questions are addressed:

1. To what extent did the indications for coronary artery interventions coincide with the scientific evidence?
2. To what extent were these indications uniformly adhered to throughout Sweden?
3. To what extent did these interventions lead to the intended improvement in symptoms?

To answer these questions, we used a method developed at the RAND Corporation in the United States to determine the indications for the various interventions (RAM, ie, RAND Appropriateness Method). When the Swedish study commenced, there were no previous examples where results from the RAM method had been compared to actual outcomes in a representative patient group.

Hence, additional purposes of the study were:

• to identify the relationship between the appropriateness of the indications (according to RAM) with the final outcomes for the patients, and
• to gain experience concerning RAM as a method to register and assess indications.

Assessment Strategy

From the extensive body of literature, nine medical experts used RAM to assess the appropriateness of nearly 2000 indications for bypass surgery (CABG) and balloon dilation, ie, percutaneous transluminal coronary angioplasty (PTCA). Clinical practices were studied via a survey of almost 3000 patients during the autumn of 1994. The results of the survey were compared with the opinions of the expert panel, and the patients were followed for almost 2 years concerning survival, the onset of symptoms and their intensity, and physical and emotional functionality.

Primary Data Collection

Systematic review of the literature. Systematic review and perspectives on indications for coronary artery interventions. Survey of patients (mainly those with chronic, stable angina) who had been referred for cardiovascular investigation.

Conclusions and Recommendations

The study addressing the utilization of coronary artery interventions in Sweden, which provides the basis for this report from SBU, was managed and analyzed by a project group appointed by SBU. The project group worked independently from the physician group responsible for selecting patients and providing the procedures. The participants on the panel, consistent with the modified Delphi method from RAND, determined the appropriate indications for intervention with assistance from the Swedish Medical Society, and without direct involvement from the hospitals/departments of surgery. SBU conducted both the literature review and the analysis of the panels decisions. Followup was also managed by SBU. Hence, to the extent possible, the findings concerning the indications for intervention, implementation, and followup are free from potentially preconceived conclusions from the specialties having a direct interest in reviewing this field of activity. Consequently, this study should have a high level of reliability.

The main objective of this analysis has been to compare the judgment of the multidisciplinary group that assessed each patient prior to potential intervention (the heart conferences) with the statistical analysis of the collective judgment of the nine specialists (Delphi panel) who gave their views about the indications for intervention based on their extensive review of the literature combined, to some extent, with their own experiences. This addresses a disease that often leads to death due to advanced sclerosis of the coronary arteries.

The analysis has revealed weaknesses in RANDs modified Delphi method for determining the indications for intervention. Hence, this method cannot be accepted unequivocally as the "golden standard" for assessing the indications for new technologies.