Biomedical subjects

M Pettinger

Publications and source records attributed to M Pettinger.

22 records · Page 2Linked to original sources

PubMed1985

A test of the National Death Index using the Coronary Artery Surgery Study (CASS).

The National Death Index (NDI) is a central, computerized index of death record information compiled from records submitted by the Vital Statistics Office of each state to the National Center for Health Statistics. A selection of 1180 cases, including 370 decedents, from the Coronary Artery Surgery Study was sent to the NDI to test the reliability of the index in identifying decedents. Five possible matching rules are considered: an NDI match with soundex included, an NDI match without soundex matches, an NDI match on social security number, an NDI match on personal data (first name, last name, sex, race, and month, day, and year of birth), and an NDI match on social security number or personal data. In determining death, the greatest positive predictive value was given by a match on social security number, while the greatest negative predictive value was given by an NDI match with soundex included. Further comparisons of sensitivity and specificity, and figures that relate predictive values to the population mortality rate, are given to assist potential users in determining an optimal matching rule.

Coronary Disease↗

PubMed1985

The effect of clinical characteristics on the comparison of medical and surgical therapy in the Coronary Artery Surgery Study (CASS) and the Veterans Administration Cooperative trial.

The CASS randomized trial was compared with the Veterans Administration (VA) randomized study of coronary bypass surgery with respect to the influence of clinical characteristics on the comparison of medical and surgical therapy. With regard to clinical baseline characteristics, the CASS population was overall at lower risk than the VA population. Average percent survival for years 1 through 6 were greater in the CASS than in the VA study for patients in both the medical and surgical groups. In the VA population, a multivariate risk index was developed with the use of presence or absence of New York Heart Association functional class III or IV, history of hypertension, history of myocardial infarction, and ST depression on the resting electrocardiogram. Low-, middle-, and high-risk terciles in the VA study population were determined based on this index. In the low-risk tercile, VA patients treated medically had a greater percent survival at 6 years than those treated surgically. In the high-risk tercile, VA patients treated surgically had markedly improved survival compared with those treated medically. These results were not replicated by the CASS study. In CASS, there were no significant differences between patients assigned to medical and surgical treatment within the terciles. Other noninvasive risk indexes were explored in CASS, but no subgroups defined solely by clinical features could be found wherein patients assigned to medical and surgical therapy were significantly different. Basic differences in the populations sampled are the most probable reason for the different results in the CASS and VA trials.

Clinical Trials as Topic↗

PubMed1984

Design of comparative clinical studies of percutaneous transluminal coronary angioplasty using estimates from the Coronary Artery Surgery Study.

The design of a prospective randomized trial of PTCA is discussed. It is suggested that patients with proximal subtotal occlusion of 1 or more vessels may be candidates for such a trial. Medical therapy as a control of 1-vessel CAD, medical or surgical therapy as a control for 2-vessel CAD (with 1 dilatable vessel) cases and surgical therapy as a control for 3-vessel CAD are most congruent with current practice. Possible criteria for comparison of PTCA with a control therapy include vital status, angina with daily activities, angina upon maximal exercise testing, MI, hospitalization, work status, cost, follow-up angiographic assessment, follow-up radionuclide ventriculography, measurement of immediate anatomic or hemodynamic change during initial treatment and quality-of-life indexes. These 10 measures are evaluated with respect to 9 desirable attributes for outcome criteria: the importance of the quantity measured, reproducibility, accuracy, low influence of investigator bias, low influence of subject bias, the measure is inexpensive and easy to obtain, sufficient occurrence to detect important differences, convenient to patients and measuring impairment due to disease. Examination of data from the Coronary Artery Surgery Study suggests that (1) a trial based on mortality alone is not feasible (because of a needed sample size in the thousands); (2) a trial using a combined death and/or MI end point would need approximately 1,000 cases even for patients with multivessel CAD; (3) approximately 950 patients would be needed in a trial to evaluate return to work (within 10%); (4) a trial based on pain relief (within 15% of the control group) would need 500 subjects.(ABSTRACT TRUNCATED AT 250 WORDS)

Angina Pectoris↗

PubMed1983

Follow-up of patients from the coronary artery surgery study (CASS) potentially suitable for percutaneous transluminal coronary angioplasty.

To determine the proper place for percutaneous transluminal coronary angioplasty (PTCA) among the therapeutic options available for patients with coronary heart disease, one must compare the results of PTCA with those obtained by conventional medical and surgical therapy. To develop a cohort comparison group, we interrogated the Coronary Artery Surgery Study (CASS) registry, and patients with proximal discrete subtotal stenosis (70% to 99%) involving the right, left anterior descending, circumflex, or left main coronary artery, singly or with stenoses in two of the three major coronary arteries, were selected; 796 patients (3.7% of all patients enrolled in CASS from 1975 to 1979) met these selection criteria. Surgical therapy was chosen in 53.3%; surgical mortality was low and there was excellent 4-year actuarial survival. There was significant improvement in functional class. Survival was also excellent in medically treated patients. Medically treated patients also had significant improvement in functional class in comparison with baseline values. The data presented here characterize a cohort group against which the clinical results of PTCA can be evaluated and compared.

Angina, Unstable↗