Brookline Conference on Longitudinal Cardiovascular Studies
June 17-19, 1957
The Brookline conference was called at the behest of the National Heart Institute and the American Heart Association and was held near the site of the Framingham Heart Disease Epidemiology Study. The discussion was confined to diagnostic criteria and procedures used in surveys and longitudinal studies, and was chaired by T. Roy Dawber, Medical Director of the Framingham Study.
Most of the active groups in CVD epidemiology at the time were represented, including the 1,000 Aviators Study in Pensacola, the California State Department of Health Longshoremen Survey, the University of Illinois Observation of Male Employees, Michael Reece Hospital evaluation of periodic physical examinations in industry, the Framingham Study itself, the University of Michigan School of Public Health Survey of a large sibship and the Tecumseh Community Study, the University of Minnesota with its Professional and Businessmen’s Study and U.S. Railroad Study, the Albany Cardiovascular Health Center study in male civil service employees of New York State, and the Health Insurance Plan of Greater New York.
This group of investigators was already heavily involved in longitudinal studies and each study had its own diagnostic criteria. Some were set in their ways; some were open-minded, and some were actively interested in improving the objectivity of diagnostic criteria and measurement.
There was general discussion of the measurement and definition of hypertension and hypertensive heart and vascular disease and ventricular hypertrophy. But the most discussion was of terminology and criteria for diagnosis of the various manifestations of coronary heart disease, including a decision to use that term in preference to ischemic or atherosclerotic heart disease. There was a great deal of discussion about electrocardiographic findings consistent with or diagnostic of coronary disease.
The general absence of diagnostic criteria or systematic methods applicable to population studies became apparent. Few of the centers had written manuals of operation or had tested their own repeatability of measurements and diagnosis. Nevertheless, certain criteria for definite coronary heart disease and hypertensive cardiovascular disease were arrived at by the conferees and everyone left with clear ideas and intent to exchange detailed methodology. Plans were begun to develop laboratory standards and repeat testing of clinical methods.
Specific agreement was reached on issues of blood pressure cuff size, use of a mercury manometer, and sitting posture and a desire was expressed for further standardization of procedure. Reportable classes of high blood pressure were agreed upon.
The chairman of the Subcommittee on Electrocardiographic Criteria, Joseph Doyle, based in academic cardiology, was skeptical about standardized strategies or “even the desirability to amalgamate these viewpoints.” His state of his mind was characterized by such statements as these in his report:
“I think, speaking for myself alone, I would reiterate that the pother over the significance of so-called Q3 patterns is unnecessary.
I cannot accept certain electrocardiographic criteria for coronary heart disease proposed by the Pensacola group, that is, . . . Etc.
It appears that the heart has only limited modes of electrical expression for a great variety of metabolic vicissitudes . . . It is therefore improbable that an elaborate study of the scalar electrocardiogram would yield significantly more information than is apparent from inspection.”
The Albany/Framingham axis was opposed in general to defined, objective, reliable, and mutually exclusive criteria. Rather, they were accepting of the powerful authority of their Boston specialists.
The conference achieved a distinct recommendation to establish a central agency for the calibration of laboratory procedures and it proposed internal secular, and external reproducibility, plus the preparation of central pooled, lyophilized serum and dry paper strip standards for blood lipids.
In general, it seemed that the investigators seeking an open exchange of criteria and procedure were differentiated from those who were wedded to existing protocols, but all were willing to exchange materials and records and to support a centralized standardized chemistry laboratory as well as some testing of electrocardiographic readings. (Henry Blackburn)