advisory committee for this particular organ is being assembled, and it is anticcipated that within the next year or so data on lung transplants comparable to that now available in cardiac transplants will be compiled by the registry.

ARTIFICIAL HEART DEVELOPMENT

Mr. FLOOD. Would you also comment on the development of an artificial heart for the record?

Dr. COOPER. Yes, sir.

(The information follows:)

ARTIFICIAL HEART DEVELOPMENT

The medical devices applications program (MDAP) of the National Heart and Lung Institute is aimed at the development of devices to assist or replace the heart and/or lungs in diseased patients. The goal is to achieve maximum rehabilitation of cardiac and pulmonary disease patients through the development of a family of devices designed to render emergency, temporary, or permanent assistance, or total heart replacement with a permanently implanted artificial heart. A goal-oriented program of contractual research, the MDAP uses a modified systems development approach whereby all subsystems are considered concurrently and their design, development, testing and assemblage into complete, workable systems is achieved by the coordinated efforts of various contractors, each concentrating on specific problems lying within a particular area of expertise. By thus bringing together the biomedical skills in the medical schools and hospitals and the talents of university scientists in physics and engineering, the chemical industry, engineering and actuarial firms, and other groups from private industry-and coordinating the efforts of these participants-the MDAP hopes to produce the most reliable and beneficial types of systems at minimal cost in time and money.

Areas of research and development by investigators working under the terms of 78 currently active MDAP contracts include: development of circulatory and pulmonary assist devices, physiologic effects of devices in animals, development and evaluation of materials for use in assist devices, effects of additional endogenous heat, cardiac control parameters, blood flow studies, development and testing of oxygenators, instrumentation, biological fuel cells, and energy systems, among others.

Although progress has been made in all areas under investigation, the following two developments are of particular interest: permanent heart-assist devices and a new capillary blood oxygenator (artificial lung).

An important goal of the MDAP is the development of improved blood oxygenators for the heart-lung machines used in open heart surgery and also oxygenators suitable for use with heart assist devices in patients requiring not only circulatory support but also temporary respiratory assistance as well. This is often the case in victims of massive heart attacks or with heart conditions resulting from or complicated by chronic respiratory disorders such as emphysema. The aim is to develop oxygenators with very high gas-exchange efficiencies that also cause very little damage to blood. In addition, they should be light, compact devices that require very little blood for priming, are easily sterilized, and, ideally, cheap enough to be disposable.

A membrane capillary blood oxygenator which may meet these specifications has been developed and evaluated under a program contract to the point where limited clinical trials are anticipated in the next several months. The device has been demonstrated to function adequately as a gas exchanger, to be atraumatic to blood for total heart-lung bypass for 8 hours, and for partial heart-lung bypass for 36 hours.

In the capillary oxygenator, blood entering the device is forced to flow through thousands of tiny, gas-permeable tubes-only a few thousandths of an inch in diameter. The capillary tubes are surrounded by a moving atmosphere of pure oxygen, which diffuses through the tubing to refresh the blood flowing through them. Carbon dioxide from the blood diffuses out through the tubing and is swept

out of the oxygenator on the moving oxygen stream. The capillary oxygenator thus works very much like the human lung.

The capillary oxygenator provides a very large surface area for gas exchange in a compact package and eliminates a direct blood-gas interface, which is damaging to blood components. Also damaging to blood, but unavoidable, is blood contact with the foreign surface of the gas-exchange membrane. Surprisingly, however, compared with conventional membrane oxygenators, the capillary oxygenator actually may reduce the extent of blood-membrane contact. Implantable heart assist devices have been developed which function synchronously with sick and irregular hearts, and are capable of reversing the lethal hemodynamic problems resulting from heart failure. The hydraulically driven blood pump components of these systems have been designed to render permanent assistance to either or both of the heart's main pumping chambers, the ventricles.

One of these devices is a double-valved blood pump that is connected at its inlet end to the left ventricle and at its outlet end to the body's main artery, the aorta. The pump is synchronized with the heart so as to effect counterpulsation, i.e., the assist pump ejects blood into the aorta while the left ventricle is filling and receives blood during the ventricle's pumping phase. The device thus minimizes left ventricular work by reducing the pressure against which the ventricle must pump.

The pump's ability to reduce left ventricular pressures in both normal and failing hearts was established by implantation experiments in 124 calves. The investigators achieved continuous pumping with the left ventricular assist pump for periods up to 140 days with no significant damage to blood, other tissues or organs, and with no evidence of thromboembolism (formation on pump surfaces of blood clots that break loose to block arteries "downstream" from the pump). Similar results, with survival times of up to 92 days, have been achieved with a right ventricular assist device (connecting the right ventricle to the pulmonary artery which leads to the lungs); and of up to 60 days in calves equipped with a combined right- and left-sided circulatory assist device.

Future research includes the development of nuclear powered heart pacemakers and instrumentation (flowmeters, pressure transducers, and so forth) for monitoring the performance of pulmonary and heart assist devices. Additional research is needed for the clinical evaluation of these devices as well as of artificial heart valves, blood oxygenators, and intraaortic balloon pumps for providing temporary assistance to failing hearts.

INFORMATION ON OTHER HEART AND LUNG DISEASES

Mr. FLOOD. I think I should add emphysema, black lung, miner's asthma and arteriosclerosis. Develop them at your leisure in the record. Dr. COOPER. Yes.

(The information follows:)

ARTERIOSCLEROSIS

A degenerative blood-vessel disease characterized by the deposition in the inner walls of arteries of fatty materials and other substances from the blood, arteriosclerosis is present to a greater or lesser degree in most American adults. Arteriosclerosis of the arteries that nourish the heart muscle, or coronary heart disease, is the primary cause of an estimated 1.25 million heart attacks and nearly half a million heart-disease deaths each year. Arteriosclerosis of vessels supplying the brain, or cerebral vascular disease, is the major cause of strokes that cause nearly 300,000 deaths annually and disable two to three times as many others.

Last year, the NHLI Task Force on Arteriosclerosis, a 13-member panel of experts drawn from key cardiovascular research and clinical fields was convened to develop plans for a comprehensive, integrated research assault on arteriosclerosis to be waged by the Institute during the next decade. The final report, due this July, is expected to figure importantly in future decisionmaking and program planning by NHLI and its advisory bodies.

Present NHLI programs aimed at reducing morbidity and mortality from arteriosclerosis and its clinical consequences are emphasizing the development and wider application of countermeasures against factors known to increase susceptibility to the disease. Two of the most potent risk factors are elevated blood lipids and high blood pressure.

Elevated blood lipids may stem from any of five distinct lipid-transport disorders called hyperlipoproteinemias. These are readily identifiable-sometimes from birth and almost invariably by age 40-and once the specific hyperlipoproteinemia has been identified, the associated blood-lipid abnormality can nearly always be corrected or substantially improved by appropriate therapy. The newly established NHLI Lipid Metabolism Branch will attempt to improve the detection and clinical management of hyperlipoproteinemias in the U.S. population through the establishment and support of lipid research clinics at a number of medical centers around the country. Also scheduled to get underway in the near future at NHLI is a definitive study to determine whether correcting or ameliorating the elevated blood cholesterol levels of type II hyperlipoproteinemia reduces the threat of clinical coronary heart disease in type II subjects or favorably affects the clinical course of the established disease.

Elevated blood pressure greatly increases susceptibility to coronary heart dis ease and is more important than elevated blood lipids as a determinant of stroke risk. The Institute proposes to support clinical trials to determine whether and to what extent the detection and control of hypertension by blood-pressure-lowering drugs during its early, milder stages reduces the subject's risk of developing coronary heart disease and cerebral vascular disease.

Sudden cardiac death, occurring before the patient can be hospitalized, currently account for nearly half of all deaths from arteriosclerotic heart disease. In order to develop new knowledge needed to cope with this catastrophic consequence, the NHLĨ Myocardial Infarction Branch has awarded research contracts to (1) learn more about factor underlying sudden, unexpected cardiac death; (2) seek means of identifying the high-risk individual before he is stricken; (3) identify "trigger" factors that convert coronary arteriosclerosis into a full-blown heart attack; and (4) seek out warning symptoms that may alert the individual or his physician of a threatened attack, or, failing that, hospitalize the patients before it occurs.

The NHLI Medical Devices Applications Branch continues their support of research to develop effective devices to provide temporary or permanent assistance to hearts heavily damaged by acute heart attacks or chronic heart failure due to any number of cardiovascular diseases. Various types of intra-aortic balloon pumps for providing temporary circulatory assistance have been developed and clinically tested against cardiogenic shock, currently the leading cause of death among hospitalized heart-attack victims. Results thus far, while not spectacular, have been sufficiently promising to warrant further evaluation of these and similar heart-assist devices.

The individual who has experienced and survived an acute heart attack remains a prime candidate for recurrent attacks. The NHLI Coronary Drug Project is evaluating the effectiveness of lipid-lowering drugs as a means of protecting against recurrent heart attacks and reducing 5-year mortality rates among recovered heart-attack victims, hopefully by 25 percent or more. During the most recent fiscal year for which figures are available (1970), NHLI also awarded 312 research grants totaling $14,234,160 for studies on arteriosclerosis. Major research areas included:

Studies on lipid metabolism and metabolic disorders that predispose to the development of arteriosclerosis;

The development and/or evaluation of therapeutic diets and drugs for the correction of blood-lipid abnormalities;

Epidemiological studies to identify and quantitate factors increasing risk of coronary heart disease and assessment of the effectiveness of countermeasures against salient risk factors;

Studies to develop and evaluate improved techniques for detecting and following the progress or regression of arteriosclerosis, especially in asymptomatic individuals;

Improved monitoring techniques, resuscitation procedures, drugs, and other therapeutic measures for coping with the acute heart attack and its

complications, such as cardiogenic shock, acute heart failure, and arrhythmias; and

Development and clinical evaluation of drugs and surgical procedures for the relief of angina pectoris, a common clinical manifestation of coronary artery disease.

During 1971 a new "managed" grants program was initiated to establish specialized centers of research. Four particular disease areas are to be attacked via this mechanism. Something more than 40 percent of the available dollars in this line item will be awarded to centers approaching the problem of arteriosclerosis in many different ways. While not a geographic network, such specialized research programs will be established in at least nine States.

EMPHYSEMA AND OTHER CHRONIC RESPIRATORY DISEASES

Chronic respiratory diseases, mainly emphysema and chronic bronchitis, afflict an estimated 5.3 million Americans and currently cause more than 33,000 deaths per year. Emphysema ranks second only to coronary heart disease as a cause of disability among the Nation's workers, incapacitating approximately 1 out of 14 persons aged 40-65.

In December 1969, the National Heart Institute was redesignated the National Heart and Lung Institute and assigned broadened responsibility for the conduct, support, and coordination of research and training activities directed against chronic lung disease. During the past year, the Institute appointed an associate director for lung programs to plan, organize, and administer an expanded NHLI effort against chronic lung disease.

In June of last year, the Institute sponsored a meeting of pulmonary program directors that was attended by 150 biomedical scientists from 97 medical schools and 12 Federal agencies to discuss current and foreseeable research and training needs in the pulmonary disease field. The report and recommendations of this group should prove highly useful to the Institute in shaping its pulmonary disease programs, and the Institute is hopeful that this meeting will be the first in what will become a continuing dialog between the Institute and all segments of the pulmonary disease community.

A critical and steadily increasing need is evident for additional highly trained research workers, clinicians, and teachers in the field. To help meet this need, the Institute is currently inaugurating a program of pulmonary academic awards to schools of medicine or osteopathy to (1) attract high-quality students into this field to provide them with superior training in the most modern techniques of prevention, diagnosis, and treatment and (2) strengthen the pulmonary training staffs of recipient institutions by attracting promising young teacher-investigators into academic careers in the respiratory-disease field.

Collaborative research activities planned for the near future include

Epidemiological studies on hereditary deficiencies of the plasma protein alpha-1-antitrypsin, which appear to predispose to the development of emphysema and to render persons with this deficiency unusually susceptible to the harmful effect of cigarette smoking. These studies will attempt to ascertain the prevalence of this deficiency in the U.S. population and to assess its importance in the genesis of emphysema and also as a factor to be considered in preventive measures and in the treatment and rehabilitation of emphysema patients.

Studies seeking improved procedures for the rehabilitation of patients partially or completely disabled by emphysema, currently estimated to number more than 200,000.

Establishment of pulmonary intensive care units (1) to develop new clinical knowledge about acute respiratory crises resulting from chronic lung disorders, hyaline membrane disease in the newborn, and other causes and (2) to evaluate new or improved modes of therapy, including respiratoryassist devices.

The NHLI Medical Devices Applications Branch is supporting research to develop respiratory assist devices and blood oxygenators for heart-lung machines; for use with heart-assist devices in victims of massive heart attacks or heart failure resulting from or complicated by chronic respiratory disease; and for temporary respiratory support during acute respiratory crises, such as respiratory distress resulting from hyaline membrane disease, which causes some 25,000 in

fant deaths per year. The goal is light, compact devices that do not damage blood, have very high gas-exchange efficiencies, require very little blood for priming, are easily sterilized, and hopefully cheap enough to be disposable.

During 1970 NHLI also supported 152 research grants totaling $5,594,436 for research into the causes, prevention, diagnosis, and clinical management of emphysema and related lung disorders. Major research areas included:

Epidemiological studies to identify factors in the person or his environment that increase his susceptibility to emphysema or aggravate the course of the disease.

Development of techniques for evaluating lung function, measuring pulmonary gas exchange and bloodflow, and other parameters useful in detecting chronic lung disease, assessing the extent of the resulting damage, and evaluating the results of therapy.

Development and evaluation of drugs and other therapeutic procedures for relieving the distressing symptoms of emphysema and for the rehabilitation of patients partially or completely disabled by this disease.

Development of more effective means of dealing with circulatory complications of chronic lung disease, such as right heart failure and/or pulmonary hypertension.

Basic research on pulmonary physiology and biochemistry and on the interrelationships of the pulmonary and cardiovascular systems in health and disease.

Research on lung transplantation and associated surgical, immunological, and organ-storage problems.

The particular problems of miner's asthma and black lung disease are of interest and concern to several different agencies and divisions within the Federal Government. Within the context of its lung program, the National Heart and Lung Institute is concerned with basic studies which may help to identify those at particular risk of developing the diseases, of determining how many such people there are in the country and where they tend to live, how their predisposition may be determined before the disease sets in so that prevention rather than therapy may be offered to them. While the elimination of asthma-producing antigens and the control of air pollutants contributing to black lung disease are of categorical concern to other Institutes in the NIH, the patient with lung disease is of prime interest to the NHLI, not solely because his disease is undoubtedly interrelated with other lung diseases such as chronic bronchitis and emphysema, but because once his illness is manifest, he will require the services of highly trained pulmonary, specialists and the resources of pulmonary care units to alleviate his suffering.

Thus many of the Institute's current lung programs are of direct relevance to miners' asthma and black lung as well as to chronic bronchitis emphysema, and respiratory distress syndrome. However, by no means do we feel that all of the potentially fruitful research is being undertaken nor that more effective and more efficient screening systems, prevention programs, and therapeutic modalities could not be instituted. In this context it might be noted that in the NHLI's new line item for specialized centers of research, some 11 pulmonry centers are being established at a cost of approximately $4,700,000 per year. While these are in no way intended to be primarily a regional network, they are located in some 10 of the 50 States, are concerned with a multiplicity of pulmonary problems, and will have the potential to serve many different groups of patients in the country with many different types of pulmonary disorders.

Mr. FLOOD. Mr. Michel.

INCIDENCE OF HEART FAILURE DEATHS

Mr. MICHEL. Doctor, how many people died last year because of heart failure?

Dr. COOPER. The usual designation on a death certificate is coded as probably not heart failure but arteriosclerotic heart disease. Of that total number of 800,000 to 900,000, probably the predominant group would be due to what is called heart attack, some of which may be