Leon Resnekov

Unstable angina pectoris: National cooperative study group to compare surgical and medical therapy: II. In-Hospital experience and initial follow-up results in patients with one, two and three vessel disease

Abstract A prospective randomized study comparing intensive medical therapy with urgent coronary bypass surgery for the acute management of patients with unstable angina pectoris was carried out by nine cooperating medical centers under the auspices of the National Heart, Lung, and Blood Institute. Between 1972 and 1976, a total of 288 patients were entered into the study. All patients had transient S-T or T wave changes, or both, in the electrocardiogram during pain; 90 percent had pain at rest in the hospital, and 76 percent had multivessel coronary disease. The medically and surgically treated patients were comparable with respect to clinical, electrocardiographic and angiographic characteristics and left ventricular function. During the total study period, the hospital mortality rate was 5 percent in the surgical group and 3 percent in the medical group (difference not significant). The rate of in-hospital myocardial infarction was 17 and 8 percent in the respective groups (P In the 1st year after hospital discharge class III or IV angina (New York Heart Association criteria) was more common in medically than in surgically treated patients with one vessel disease (22 percent versus 3 percent, P The results indicate that patients with unstable angina pectoris can be managed acutely with intensive medical therapy, including the administration of propranolol and long-acting nitrates in pharmacologic doses, with adequate control of pain in most patients and no increase in early mortality or myocardial infarction rates. Later, elective surgery can be performed with a low risk and good clinical results if the patients angina fails to respond to intensive medical therapy.

Cardiac rupture--challenge in diagnosis and management.

Previous studies of the incidence, natural history, pathogenesis and diagnosis of cardiac rupture are presented, and 20 additional cases described. Progressive cardiorrhexis after myocardial infarction causes death in possibly more than 25,000 persons a year in the United States, and more frequent antemortem diagnosis is needed. Suggestions for future clinical and experimental studies are described and possible means of early diagnosis and therapy are outlined.

Newer catecholamines for treatment of heart failure and shock: An update on dopamine and a first look at dobutamine

T HE pharmacology and clinical uses of dopamine were reviewed in this journal in 1969.’ At that time, only a few therapeutic investigations had been completed, and the clinical literature was sparse. Since dopamine has now been administered to large numbers of patients with a variety of cardiovascular conditions and is widely used by the practicing physician, an up-dated review was needed. Recently, the chemically related but pharmacologically different catecholamine, dobutamine, was released for clinical investigations. Because initial studies demonstrated that dobutamine exhibited a different spectrum of activity, we have included a review of this potentially useful drug.

Unstable angina pectoris: National cooperative study group to compare medical and surgical therapy

A preliminary report is presented of a prospective randomized trial conducted by eight cooperative institutions under the auspices of the National Heart and Lung Institute to compare the effectiveness of medical and surgical therapy in the management of the acute stages of unstable angina pectoris. To date 150 patients have been included in the randomized trial, 80 assigned to medical and 70 to surgical therapy; the clinical presentation, coronary arterial anatomy and left ventricular function in the two groups are similar. Some physicians have been reluctant to prescribe medical or surgical therapy by a random process, and the eithical basis of the trial has been questioned. Since there are no hard data regarding the natural history and outcome of therapy for unstable angina pectoris, randomization appears to provide a rational way of selecting therapy. Furthermore, subsets of patients at high risk may emerge during the process of randomization. The design of this randomized trial is compared with that of another reported trial. Thus far, the study has shown that it is possible to conduct a randomized trial in patients with unstable angina pectoris, and that the medical and surgical groups have been similar in relation to the variables examined. The group as a whole presented with severe angina pectoris, either as a crescendo pattern or as new onset of angina at rest, and 84 percent had recurrence of pain while in the coronary care unit and receiving vigorous medical therapy. It is anticipated that sufficient patients will have been entered into the trial within the next 12 months to determine whether medical or surgical therapy is superior in the acute stages of unstable angina pectoris.Abstract A preliminary report is presented of a prospective randomized trial conducted by eight cooperative institutions under the auspices of the National Heart and Lung Institute to compare the effectiveness of medical and surgical therapy in the management of the acute stages of unstable angina pectoris. To date 150 patients have been included in the randomized trial, 80 assigned to medical and 70 to surgical therapy; the clinical presentation, coronary arterial anatomy and left ventricular function in the two groups are similar. Some physicians have been reluctant to prescribe medical or surgical therapy by a random process, and the ethical basis of the trial has been questioned. Since there are no hard data regarding the natural history and outcome of therapy for unstable angina pectoris, randomization appears to provide a rational way of selecting therapy. Furthermore, subsets of patients at high risk may emerge during the process of randomization. The design of this randomized trial is compared with that of another reported trial. Thus far, the study has shown that it is possible to conduct a randomized trial in patients with unstable angina pectoris, and that the medical and surgical groups have been similar in relation to the variables examined. The group as a whole presented with severe angina pectoris, either as a crescendo pattern or as new onset of angina at rest, and 84 percent had recurrence of pain while in the coronary care unit and receiving vigorous medical therapy. It is anticipated that sufficient patients will have been entered into the trial within the next 12 months to determine whether medical or surgical therapy is superior in the acute stages of unstable angina pectoris.

Mid-ventricular obstruction: a variant of obstructive cardiomyopathy.

In two patients with clinical and catheterization findings of hypertrophic obstructive cardiomyopathy, the level of intraventricular obstruction was found to be in the mid-ventricular area rather than at the junction of the inflow and outflow tracts. One patient died suddenly shortly after unsuccessful outflow tract myectomy. In vivo recognition of this probably rare variant form of obstructive cardiomyopathy rests mainly on the angiograhic appearance of the left ventricle and on the recording of pressures in multiple sites of the left ventricular cavity. Surgical relief of the obstruction in these patients is not likely to be obtained by a transaortic left ventricular outflow myectomy but may require either papillary muscle resection by the transatrial or transventricular approach or mid-ventricular septectomy, or both.

Relationship of the Pulmonary Artery End-Diastolic Pressure to the Left Ventricular End-Diastolic and Mean Filling Pressures in Patients With and Without Left Ventricular Dysfunction

The relationship of the left ventricular end-diastolic pressure (LVEDP) and the pulmonary arterial “wedge” mean pressure (PAWMP) to the pulmonary artery end-diastolic pressure (PAEDP) was investigated by cardiac catheterization in 71 subjects. Pressure records were obtained simultaneously or immediately consecutively. In 15 subjects with normal LV function (LVEDP, 4 to 12 mm Hg) PAEDP was within 3 mm Hg of LVEDP (r = 0.70, P < 0.01) and within 3 mm Hg of PAWMP (r = 0.69, P < 0.01) in every instance.In 56 patients with LV dysfunction (LVEDP, 12 to 55 mm Hg), PAEDP was lower than LVEDP in 42, equal to LVEDP in six, and higher than the LVEDP in eight, who were in atrial fibrillation or had increased pulmonary vascular resistance (PVR). PAEDP correlated closely with PAWMP (r = 0.92, P < 0.001).In 30 patients with LV dysfunction in sinus rhythm, an a wave was identified in the PA pressure tracing (PA a) prior to systole which coincided in time and magnitude to the PAW a wave and was considered to represent retrograde transmission of the left atrial contraction wave. The PA a pressure was within 5 mm Hg of the LVEDP (r = 0.94, P < 0.001) in all except four patients, two of whom had elevated PVR.Thus, in the presence of LV dysfunction and elevated LVEDP, PAEDP correlated well with PAWMP, but failed to represent LVEDP accurately, while PA a wave pressure closely reflected LVEDP except when PVR was markedly increased.

Unstable angina pectoris: National cooperative study group to compare medical and surgical therapy. I. Report of protocol and patient population

A preliminary report is presented of a prospective randomized trial conducted by eight cooperative institutions under the auspices of the National Heart and Lung Institute to compare the effectiveness of medical and surgical therapy in the management of the acute stages of unstable angina pectoris. To date 150 patients have been included in the randomized trial, 80 assigned to medical and 70 to surgical therapy; the clinical presentation, coronary arterial anatomy and left ventricular function in the two groups are similar. Some physicians have been reluctant to prescribe medical or surgical therapy by a random process, and the eithical basis of the trial has been questioned. Since there are no hard data regarding the natural history and outcome of therapy for unstable angina pectoris, randomization appears to provide a rational way of selecting therapy. Furthermore, subsets of patients at high risk may emerge during the process of randomization. The design of this randomized trial is compared with that of another reported trial. Thus far, the study has shown that it is possible to conduct a randomized trial in patients with unstable angina pectoris, and that the medical and surgical groups have been similar in relation to the variables examined. The group as a whole presented with severe angina pectoris, either as a crescendo pattern or as new onset of angina at rest, and 84 percent had recurrence of pain while in the coronary care unit and receiving vigorous medical therapy. It is anticipated that sufficient patients will have been entered into the trial within the next 12 months to determine whether medical or surgical therapy is superior in the acute stages of unstable angina pectoris.Abstract A preliminary report is presented of a prospective randomized trial conducted by eight cooperative institutions under the auspices of the National Heart and Lung Institute to compare the effectiveness of medical and surgical therapy in the management of the acute stages of unstable angina pectoris. To date 150 patients have been included in the randomized trial, 80 assigned to medical and 70 to surgical therapy; the clinical presentation, coronary arterial anatomy and left ventricular function in the two groups are similar. Some physicians have been reluctant to prescribe medical or surgical therapy by a random process, and the ethical basis of the trial has been questioned. Since there are no hard data regarding the natural history and outcome of therapy for unstable angina pectoris, randomization appears to provide a rational way of selecting therapy. Furthermore, subsets of patients at high risk may emerge during the process of randomization. The design of this randomized trial is compared with that of another reported trial. Thus far, the study has shown that it is possible to conduct a randomized trial in patients with unstable angina pectoris, and that the medical and surgical groups have been similar in relation to the variables examined. The group as a whole presented with severe angina pectoris, either as a crescendo pattern or as new onset of angina at rest, and 84 percent had recurrence of pain while in the coronary care unit and receiving vigorous medical therapy. It is anticipated that sufficient patients will have been entered into the trial within the next 12 months to determine whether medical or surgical therapy is superior in the acute stages of unstable angina pectoris.

Identification of high risk subsets of acute myocardial infarction

To Identify the patient at high risk after acute myocardial Infarction data on 400 patients obtained from the Myocardial Infarction Research Units Cooperative Data Bank were examined. Patients were grouped according to clinical findings as follows: uncomplicated (class 1, 81 patients); mild to moderate failure (class II, 150 patients); severe failure with pulmonary edema (class III, 17 patients); and severe failure with shock (class IV, 152 patients). Hemodynamic data Including pulmonary capillary wedge pressure and cardiac output were available In all patients. High risk subsets within clinical classes I, II and IV were Identifiable. In class I, nonsurvivors had significantly (P <0.05) higher values for pulmonary capillary wedge pressure (16 mm Hg) and heart rate (96 beats/min); nonsurvivors In class II also had a significant (P <0.01) elevation In pulmonary capillary wedge pressure (23 mm Hg); and In class IV the high risk subset was characterized (P <0.01) by pulmonary capillary wedge pressure (21 mm Hg), heart rate (100 beats/min), cardiac Index (1.6 liters/min per m2), stroke index (14 cc/m2) and stroke work index (12 g-m/m2). Discrimlnant function analysis using pulmonary capillary wedge pressure and heart rate predicted mortality In classes I to III with 72 percent accuracy; a similar equation representing stroke work index, pulmonary capillary wedge pressure and cardiac Index had an 83 percent rate of accuracy in class IV patients. interclass comparison of the last three measurements indicated that the data differed significantly among classes, thus signifying a spectrum of ventricular impairment after Infarction that was commensurate with the clinical presentation. However, in individual patients the clinical examination did not consistently reflect the degree of ventricular dysfunction. Thus, careful bedside examination together with hemodynamic monitoring of wedge pressure, cardiac output and heart rate serve to identify the high risk patient after acute myocardial infarction.

Unstable angina pectoris: National cooperative study group to compare surgical and medical therapy: III. Results in patients with S-T segment elevation during pain

Abstract A prospective randomized study comparing intensive medical therapy with urgent coronary bypass surgery for the acute management of patients with unstable angina pectoris was carried out by nine cooperating medical centers under the auspices of the National Heart, Lung, and Blood Institute. Between 1972 and 1976, a total of 288 patients were entered into the study; 79 of these (27 percent of the total study group) with 70 percent or more fixed obstruction in one or more coronary arteries had episodes of pain at rest associated with transient S-T segment elevation. Forty-two were randomized to medical and 37 to surgical therapy. The hospital mortality rate was 4.8 percent for the medical and 5.4 percent for the surgical group (difference not significant). The rate Of in-hospital myocardial infarction was 12 percent in the medical and 14 percent in the surgical group (difference not significant). During the 1st and 2nd years of follow-up, 25 percent in the medical and 15 percent in the surgical group complained of New York Heart Association class III or IV angina (difference not significant). During an average follow-up period of 42 months 45 percent of the medically treated patients later underwent surgery to relieve unacceptable angina. In the medical group 65 percent were working full- or part-time at the end of 1 year and 61 percent at the end of 2 years of follow-up; comparable figures for the surgically treated group were 63 and 68 percent. The results indicate that patients with unstable angina pectoris with transient S-T segment elevation during pain at rest with fixed obstruction of 70 percent or more in one or more coronary arteries do not differ significantly from patients with pain at rest associated with transient S-T segment depression or T wave inversion. The condition of such patients can be stabilized, and they can be managed with a maximal medical program including propranolol and long-acting nitrates in pharmacologic doses with good control of pain in most and no increase in rate of early mortality or myocardial infarction. Later, elective surgery can be performed with a lower risk and good clinical results if the patients angina fails to respond to intensive medical therapy.

Clinical myocardial imaging with nitrogen-13 ammonia

Myocardial infarcts may be clearly imaged using intravenous nitrogen-13 as carrier-free ammonia in doses of 10–30 mCi. This positron emitter is well imaged with the Nuclear Chicago HP Anger Camera with heavy collimation. The rapid blood disappearance of the agent gives good image contrast, and the short half-life and high isotope dosage give high-count density images with little radiation absorbed dose (5 mrad∕mCi total body).