The isolation and characterization of a novel collagenolytic serine protease allergen (Der p 9) from the dust mite Dermatophagoides pteronyssinus

BACKGROUND

Dust mites have been shown to contain a serine protease distinct from the previously reported trypsin and chymotrypsin. The latter enzymes have been shown to be allergens, but the allergenic importance of the former is unknown.

OBJECTIVE

This study was performed to isolate and characterize the novel mite serine protease and determine its allergenicity.

METHODS

The mite serine protease was isolated from feces-enriched extracts of Dermatophagoides pteronyssinus by ion-exchange chromatography and affinity chromatography, and its physicochemical properties were determined. The allergenicity of the protease was assessed by using the RAST.

RESULTS

The protease was enzymatically similar to chymotrypsin and cathepsin G-like enzymes from a variety of sources and was shown to cleave collagen. It had a molecular mass of 23,780 d. N-terminal sequence analysis (18 residues) indicated homology with the mite tryptic allergen, Der p 3, and the chymotryptic allergen, Der p 6. RAST analyses showed that the frequencies of reactivity to the novel allergen and to Der p 1, Der p 2, Der p 3, and Der p 6 were 92%, 97%, 100%, 97%, and 65%, respectively (n = 35). RAST inhibition studies showed some cross-reactivity between the protease and Der p 3 but not Der p 6.

CONCLUSIONS

A novel mite serine protease was isolated from D. pteronyssinus and found to be a major allergen. This allergen has been tentatively designated Der p 9.

Pretreatment of human myocardium with adenosine during open heart surgery

BACKGROUND

Depressed myocardial performance after cardiac surgery can be contributed to ischemic reperfusion injury (IRI) incurred during and following the cardiopulmonary bypass (CPB). Myocardial preconditioning (PC) achieved by brief ischemia and subsequent reperfusion appears to be a clinically useful method of improved cardiac protection during surgery involving CPB by retarding IRI. Based on animal studies, activation of cardiac adenosine (ADO) receptors prior to the prolonged ischemic period appears to mimic this PC phenomenon.

AIMS AND METHODS

We investigated whether the human myocardial PC can be mimicked with ADO in the setting of the coronary artery bypass graft (CABG). The specific proposed objective of this study was to determine whether ADO infusion just prior to starting the CPB can improve post-CPB myocardial hemodynamics. Patients undergoing elective CABG with poor ventricular function (ejection fraction approximately 30%), and with at least three-vessel disease were selected for this study (n = 7 ADO, and n = 7 control).

RESULTS

Our results show that ADO infusion (250-350 micrograms/kg X 10 min) just prior to CPB resulted in an immediately improved postbypass cardiac index (CI) in the OR (CI increase of 41.5% +/- 11.1% for ADO vs 9.7% +/- 6.0% for control, p < 0.05). Forty hours postoperatively in the intensive care unit, ADO patients had improved CI (3.3 +/- 0.2 L/min per m2 for ADO, vs 2.6 +/- 4 L/min per m2 for control, p < 0.05). ADO patients maintained lowered resting heart rate (90 +/- 6 for ADO, vs 108 +/- 4 for control, p < 0.05) 40 hours after surgery. ADO patients also released significantly less CPK during the first 24 hours of the postoperative period.

CONCLUSION

Based on these measurements, ADO pretreated patients had improved ventricular performance postoperatively. It also appears that ADO pretreatment results in lowered postoperative myocardial energy demand and less myocellular injury during CPB. To our knowledge, this is the first study to demonstrate that human myocardium can be hemodynamically improved with ADO pretreatment, and may be protected against IRI incurred during and following the CPB. We believe that a cardiac surgeon may now have the unique opportunity to confer myocardial protection during and after a cardiac surgical procedure.

Immediate-early gene expression in human saphenous veins harvested during coronary artery bypass graft operations

Saphenous vein graft occlusion is a common late complication of coronary bypass grafting. Intimal smooth muscle cell hyperplasia is a component of this pathobiology, but the underlying molecular events are poorly understood. Immediate-early genes are activated shortly after growth stimulation and subserve cellular functions, which may contribute to intimal smooth muscle cell accumulation. In the present study, human saphenous vein grafts were harvested with minimal manipulation during coronary bypass and processed for isolation of total ribonucleic acid to examine change in immediate-early gene expression of messenger ribonucleic acid by Northern blotting techniques. Thirty saphenous vein grafts were incubated at 4 degrees C in Dulbecco's modified Eagle media from 30 minutes to 10 hours. The messenger ribonucleic acids for immediate-early genes c-fos and c-myc were weak or undetectable in controls but were increased (> 10 times controls) within 1 hour (c-fos) and persisted for at least 6 hours (c-myc) after harvest. Our results demonstrate, for the first time in human vascular tissue, incipient immediate-early gene induction. This information may lead to molecular therapies to control saphenous vein graft disease.

NF-Y activates mouse tryptophan hydroxylase transcription

Tryptophan hydroxylase catalyses the rate-limiting step in the biosynthesis of serotonin, a neurotransmitter which has been implicated in the etiologies of clinically important psychiatric illnesses. Tryptophan hydroxylase is expressed in a tissue-specific manner, but little is known about its transcriptional regulation. By analysing transcriptional activities of a set 5'-deletion constructs of promoter-reporter plasmids in P815-HTR mastocytoma cells, we found that transcription was activated by sequences between nucleotides -343 and -21. DNase I footprint analysis, using nuclear protein extracts from P815-HTR cells, revealed a protein-DNA interaction between nucleotides -77 and -46. A double stranded oligonucleotide, representing this binding site, specifically bound nuclear protein in a gel shift assay. Methylation interference analysis of this complex revealed that nuclear protein interacted with an inverted GGCCAAT element, which is a high-affinity binding motif for the transcription factor NF-Y (also known as CP1 or CBF). An NF-Y specific antibody abolished protein binding in a gel shift assay. Mutagenesis of specific base pairs abolished protein binding in vitro, and mutagenesis of the same base pairs in a reporter gene construct resulted in a 65% decrease in transcriptional activity. Our results suggest that the transcription factor NF-Y binds to a GGCCAAT motif in the tph proximal promoter and activates transcription.

Experience with the Mitroflow aortic bioprosthesis

From October 1985 to May 1990, the Mitroflow bovine pericardial valve was placed in the aortic position in 168 patients (97 men, 71 women) with a mean age of 69.7 years. Eighty-nine patients had isolated aortic valve replacement, and 79 had aortic valve replacement and additional procedures. Follow-up over 7 1/2 years includes 781 patient years (426 for isolated aortic valve replacement). Mean follow-up time is 56 months. Peak-to-peak gradients (in millimeters of mercury) measured in the intraoperative period averaged 11.0 +/- 8.7, 11.8 +/- 10.8, and 8.6 +/- 8.2 for 19 mm, 21 mm, and 23 mm valves, respectively. Hospital mortality was 7.3% (14 patients); all deaths were non-valve related. Late mortality of 20.1% in 31 patients resulted from cardiac failure (n = 8), sepsis (n = 4), valve reoperation (n = 1), non-cardiac causes (n = 15) and sudden, unknown causes (n = 3). Fifteen thromboembolic episodes occurred, but only three late thromboembolic episodes occurred in isolated aortic valve replacement without other risk factors. Four early and four late episodes of endocarditis occurred. Seven patients had clinical valve dysfunction, and five others required reoperation for structural deterioration, with one death. At 94 months, overall survival was 64% +/- 5%. Freedom from thromboembolic episode was 87% +/- 3% and 90% +/- 4% for isolated aortic valve replacement. Freedom from combined reoperation or clinical dysfunction was 75% +/- 8%: 64% +/- 15% for those under 70 years of age, and 87% +/- 7% for those 70 years of age and older. The valve has favorable hemodynamics. Durability begins to decline during the sixth year after implantation, possibly at a slower rate in patients older than 70 years of age.

Repair of coronary sinus rupture secondary to retrograde cardioplegia

Coronary sinus injuries related to retrograde cardioplegia administration are uncommon, but can be a lethal complication of this technique. This report describes a major coronary sinus disruption during retrograde cardioplegia administration and details a method of repair with suggestions for possible prevention of this complication.

Safety and efficacy of autologous blood donation before elective aortic valve operation

Although the use of preoperative autologous blood donations for patients undergoing elective cardiac operations has increased dramatically in recent years, patients awaiting elective aortic valve replacement have traditionally been denied access to preoperative autologous blood collection programs. We report our experience with 79 patients, each of whom donated 1 to 3 units of autologous blood before an aortic valve operation. All patients had serious aortic valve disease as evidenced by symptoms and preoperative catheterization data. The patients collectively made 129 blood donations. One patient had a syncopal episode within 2 hours of donation and recovered without difficulty. Of the patients who gave autologous blood preoperatively, 68% avoided any homologous blood donor exposure during their subsequent hospitalization for aortic valve replacement. In contrast, in a group of 298 patients who did not give autologous blood preoperatively, only 31% avoided homologous blood exposure during aortic valve replacement (p < 0.0001). Our experience suggests that preoperative autologous blood donation by patients awaiting elective aortic valve replacement is both safe and effective. Patients with aortic valve disease should not be routinely excluded from preoperative blood services.

Primary cardiac tumors. Diagnosis and management in 14 cases

In our experience over a 10-year period at Westchester County Medical Center (Valhalla, NY), we diagnosed 11 left atrial myxomas and three primary cardiac malignancies in ten females and four males, aged 18-74 years. Two-dimensional echocardiography enabled the correct diagnosis of these lesions. Detailed characteristics of the cardiac tumors were provided by magnetic resonance imaging (MRI) scanning in five patients. Two of three malignancies were only biopsied; the myxomas were completely excised. We emphasized removal of tumor and its attachments to the atrial wall, accomplished by left or biatrial incision, full-thickness excision of the area of attachment, and pericardial patch closure of the atrial or free-wall defects. Associated procedures included mitral valve repair (three) and coronary artery bypass grafting (two). There was no mortality associated with the surgery. Two patients with malignancy died three and 36 months after surgery; a third is alive at 30 months after surgery. No patients with myxoma has had recurrence from 16 to 100 months. Preoperative diagnosis of cardiac tumors is enhanced by MRI scanning and may help in planning the surgical procedure. Complete and timely removal of these tumors contributes to long-standing patient survival.

Analysis of gunshot residue test results in 112 suicides

The results of gunshot residue (GSR) tests in 112 suicide cases investigated by the U.S. Army Criminal Investigation Command over a ten-year period are described. Only suicide cases in which there was certainty that the victim fired a weapon were examined in an effort to reduce ambiguous results. Previous case work research by Rudzitis indicated that positive GSR test results were encountered in suicides 62% of the time using various combinations of neutron activation analysis (NAA) and atomic absorption spectrophotometry (AAS). Threshold values of 0.2-micrograms antimony and 0.3-micrograms barium (0.2-micrograms antimony and 0.5-micrograms barium after 1985) used by the U.S. Army Criminal Investigation Laboratory resulted in positive GSR results in suicide cases 38% of the time. The effects of time, location of body, handling of the body, weapon type, caliber, and condition of the hands on GSR results are examined. Case studies involving suicides by unit armorers are discussed.

Simplified method for reoperation on the mitral valve

Reoperation on the mitral valve is becoming more common because of the degeneration of bioprosthetic valves, endocarditis, and malfunction or thrombosis of mechanical valves. We advocate a technique that transforms a technically difficult operation into one that is much less tedious, time-consuming, and dangerous than reopening a sternal-split operative site the second, third, or fourth time. Favorable experience in 11 patients using right anterolateral thoracotomy without aortic or right atrial cannulation and without aortic cross-clamping or cardioplegia is presented.

Prevention of ventricular fibrillation after aortic declamping during cardiac surgery

Ventricular fibrillation is common after aortic declamping during cardiac surgery, and the metabolic demands of such fibrillation, or its treatment by means of countershock, may contribute to myocardial injury. To determine the effects of administering intravenous lidocaine just before aortic declamping, we randomly divided 194 cardiac surgery patients into 2 groups. One hundred patients (group A) received lidocaine, 200 mg intravenously, 3 minutes before aortic declamping; and 94 patients (group B) received no medication before declamping. Multiple baseline variables, including clamp times, medications, electrolyte values, ventricular function, and the extent and type of surgery, were similar for both groups. After aortic declamping, 31 of the 100 patients in group A had ventricular fibrillation, as did 57 of the 94 patients in group B (p < 0.001). Of those who fibrillated, the group-A patients required a mean of 1.76 countershocks, whereas the group-B patients required a mean of 2.68 countershocks (p < 0.05). Serum potassium level also affected the incidence of ventricular fibrillation, independently of lidocaine. Elevated serum potassium levels were associated with a lower incidence of ventricular fibrillation. Although lidocaine was independently protective at all potassium levels, the combination of lidocaine and a high serum potassium level had the greatest effect in preventing fibrillation. In patients who had potassium levels higher than 5.1 mEq/l and who were also given lidocaine, the incidence of ventricular fibrillation was lower than 15%.

Predictors, prevention, and long-term prognosis of atrial fibrillation after coronary artery bypass graft operations

Multiple trials have suggested the use of digoxin, digoxin and propranolol, or timolol to prevent atrial fibrillation after coronary artery bypass grafting. No trial has evaluated the efficacy of digoxin verus propranolol. Furthermore, the predictors of postoperative atrial fibrillation and the long-term consequence of atrial fibrillation that reverts to sinus rhythm have not been established. One hundred fifty patients were randomized to receive no drug, propranolol (20 mg every 6 hours), or digoxin (0.5 mg followed by 0.25 mg daily). Twenty-seven patients were excluded from data analysis. In the remaining 123 patients, no preoperative parameter (age, sex, diabetes, hypertension, smoking, electrocardiographic p wave morphology, or preoperative digoxin or propranolol therapy), intraoperative parameter (bypass time, aortic cross-clamp time, or number of vessels bypassed), or postoperative parameter (peak creatinine kinase, congestive heart failure, or pericarditis) by univariate or multivariate analysis predicted patients at risk for atrial fibrillation. Sustained atrial fibrillation developed in 37.5% of control and 32.6% of digoxin-treated patients. Only 16.2% of propranolol-treated patients had sustained atrial fibrillation (p less than 0.03). There were no in-hospital complications in those patients with atrial fibrillation. After 26 +/- 7 months follow-up, those patients with postoperative atrial fibrillation had no increased incidence of angina, cerebral vascular accident, myocardial infarction, or sudden death. Therefore, in this select population, propranolol prophylaxis is effective but discretionary.

Early postoperative spasm in left internal mammary artery bypass grafts

Two patients with early postoperative spasm of a left internal mammary artery bypass graft are described. To our knowledge, this entity has not been reported previously. Both patients were characterized by vasomotor collapse secondary to intractable spasm responsive only to local application of vasodilator agents. Although the mechanism of graft spasm is not clear, prophylactic nifedipine therapy in appropriate dose may be of some value. The profound hemodynamic effect of internal mammary artery spasm in the immediate postoperative period may allow no time for anything other than emergency reoperation to assess the nature of the problem and treat it appropriately.

Delayed sternal closure as a safe adjunct to support biventricular failure after open heart surgery

Over a four-year period, 22 patients of 2495 undergoing open heart surgery sustained severe biventricular failure (BVF) and would not tolerate primary sternal closure. Reasons for BVF included intraoperative injury, perioperative infarction, global dysfunction, cardiopulmonary edema, and intractable arrhythmia. Mechanical assist devices were required in nine patients. Average cardiac index fell to 1.1 L/min/m2 with attempts to close the chest, then stabilized at 1.9 with the sternum open and only soft tissue closed. After 3 to 11 days, cardiac index rose to 2.5 when assist devices were removed, inotropic agents decreased, and the sternum closed. Three early deaths (5-12 days) were caused by progressive biventricular failure. Five later deaths (19-64 days) were associated with renal and respiratory failure, superinfection, and sepsis. All of these required tracheostomy. Survival of 14 patients was not related to early low cardiac output, preoperative status, timing of sternal closure, or age, but was associated with early recovery of respiratory function without need for tracheostomy, avoidance of renal failure, and satisfactory alimentation. Sternal infection occurred in three patients, resulting in one death. The hospital stay ranged from 12 to 230 days. There was one death resulting from respiratory failure 14 months postoperatively. Our findings show that delayed sternal closure lessens early cardiac instability during BVF, helps allow recovery, and does not produce long-term disability.

Coronary revascularization in young patients

From 1978 to 1982, 92 of our 1704 patients undergoing coronary bypass surgery were 40 years of age or younger. Eighty-six were male and six were female. The main indications for surgery were refractory angina and unstable angina. A family history of heart disease, smoking, and hypertension were major risk factors. The majority of patients had triple vessel disease, and six had left main lesions. Left ventricular function was moderately or severely impaired in 24. Coronary revascularization was performed with internal mammary and saphenous vein conduits, with a mean of 3.7 grafts per patient (range, 1 to 7). There was no operative mortality, but one patient required an intraaortic balloon pump. Perioperative infarction determined by Q waves occurred in one patient, while eight had enzymatic evidence of infarction. Late follow-up to 60 months showed three late deaths of cardiac origin. Eighty-three survivors were greatly improved, and 50 were asymptomatic. Sixty-five patients returned to work. Seventy percent of smokers stopped smoking; half the patients exercised regularly, and half maintained dietary modifications. Coronary bypass grafting is an effective rehabilitation procedure in the young. Long-term attention to risk factors and life style is required to maintain a beneficial outcome.

Endothelial loss due to leukocytes in canine experimental vein-to-artery grafts

Vein-to-artery grafts develop areas of endothelial loss with fibrin and leukocytes which lead to early thrombosis and may lead to subsequent atherosclerosis of the graft. En face monolayers were prepared which removed greater than 90% of vascular intima. Unevenly distributed leukocytes and endothelial cells were counted using a standardized sampling of calibrated oil immersion fields of 0.01 mm2. Nongrafted veins had 14 +/- 1 evenly arranged endothelial cells per field without gaps or leukocytes, while 10-min grafts had 13 +/- 2 with rare leukocytes. Four-hour grafts from normal dogs had 9 +/- 2 endothelial cells with gaps and 97 +/- 37 neutrophils and 44 +/- 25 monocytes. Leukopenic dogs (vinblastine-treated) had normal numbers of endothelial cells (14 +/- 1) with scanty leukocytes. We conclude that leukocytes cause endothelial loss in vein-to-artery grafts that can be prevented by intense leukopenia. This may lead to practical approaches to protecting such grafts in humans.

Ventricular arrhythmias after coronary artery bypass graft surgery: incidence, risk factors and long-term prognosis

The incidence, risk factors and long-term prognosis of complex ventricular arrhythmias after coronary artery bypass graft surgery are not known. Complex ventricular arrhythmias are defined as Lown grades 4a (couplets), 4b (ventricular tachycardia) and 5 (R on T phenomenon). Ninety-two patients with normal left ventricular function who underwent elective coronary artery bypass graft surgery were prospectively evaluated. Ventricular arrhythmias were documented by predischarge 24 hour ambulatory electrocardiographic monitoring; 43% of patients had no or simple ventricular arrhythmias (Lown grades 1 to 3) and 57% had complex ventricular arrhythmias. Risk factors analyzed included age, sex, diabetes, hypertension, smoking, preoperative digoxin or propranolol therapy, cardiopulmonary bypass time, aortic cross-clamp time, number of vessels bypassed, peak creatine kinase (CK) elevation and pericarditis. No risk factor identified patients at higher risk for complex ventricular arrhythmias. Patients were followed up for 6 to 24 months (mean 16). Patients with complex ventricular arrhythmias did not have a higher incidence of sudden death, cardiac death, syncope, angina, myocardial infarction or cerebrovascular accident. It was concluded that: Complex ventricular arrhythmias are common after coronary artery bypass graft surgery. None of the risk factors considered identify high risk patients. Complex ventricular arrhythmias after coronary artery bypass graft surgery do not indicate a poor prognosis in patients with normal left ventricular function.

Coexisting carotid stenosis in patients undergoing cardiac surgery: indications and guidelines for simultaneous operations

The coexistence of critical carotid stenosis with coronary artery or valvular heart disease occurs in a small percentage of patients requiring open heart surgical procedures. Recognition of such combined lesions by noninvasive carotid testing identifies patients at risk for neurologic events. Our experience with 62 patients having combined simultaneous carotid and cardiac operations among 2,400 open heart surgery patients was compared with the results in 110 patients with only carotid endarterectomy operations. The outcomes indicated that carotid endarterectomy can be performed simultaneously with open heart surgical procedures with morbidity and mortality rates similar to those of isolated cervical artery operations. Thus, patients with significant coexisting carotid artery disease defined with specific criteria and coronary artery disease need not be exposed to cerebral ischemic events or to myocardial infarctions that often accompany staged operations.

Hemodynamic comparison of albumin and hydroxyethyl starch in postoperative cardiac surgery patients

The hemodynamic effects of 2 plasma volume expanders were compared in postoperative open heart surgery patients. Albumin 5% (A) or hydroxyethyl starch 6% (HES) solutions were infused according to indications based on cardiac index (CI) and pulmonary wedge pressure (WP), and their effects evaluated by physiologic profile measurements. Both groups demonstrated significant increases with volume infusion in CI (A from 2.37 to 2.84; HES from 1.97 to 2.49 L/min X m2) and WP (A from 9.4 to 13.7 mm Hg; HES from 11.9 to 13.2 mm Hg). Stroke index and stroke work increased similarly. Mean systemic arterial pressure (MAP) and mean pulmonary arterial pressure (MPAP) remained unchanged. No significant difference for any variable was demonstrated between the A and HES groups. In the volume used, from 250 to 750 ml, HES caused no bleeding abnormalities. HES is as effective as A as a plasma volume expander in postoperative cardiac surgery patients.

Prosthetic heart valves: a review

There are a number of difficulties inherent in the analysis of such a large and diverse quantity of data. In a substantial number of clinical trials, there is no significant effort made to evaluate prosthetic performance as a function of preoperative cardiac anatomy. Hemodynamics have not been systematically studied in relation to preexisting left ventricular size, shape, or configuration, mitral annular orientation, or left atrial size. Postoperative anticoagulation protocols vary from one institution to another and occasionally within study groups themselves. Less tangible variables such as alteration in surgical technique over time and differential familiarity of cardiovascular surgeons with the prostheses employed are chronic problems in any study of this sort. Perhaps the greatest variable in evaluating the postoperative performance of valvular prostheses over the past 20 yr is the radical improvement in techniques of intraoperative myocardial preservation. Notwithstanding, comparisons are possible within the confines of certain criteria. The caged ball value remains in use after 20 years of clinical experience. It has sustained the greatest number of modifications, probably because it has been the most extensively studied. Hemodynamics are adequate although its centrally obstructed design is responsible for increased turbulence, hemolysis, and neointimal proliferation, particularly in the aortic position. The device has been shown to be durable with virtually no reports of ball variance since the alteration of the silicone curing procedure in 1965. Thromboembolic rates are acceptable in the anticoagulated patient while prosthetic thrombosis is not a grave threat in the non-close clearance device. Incidence of endocarditis is not particularly different from that associated with all nonbioprosthetic valves, although there is a much greater published volume of clinical experience concerning recognition and treatment of late prosthetic valve endocarditis in patients with caged ball valves than there is for any other replacement device. Perhaps the most serious disadvantage to caged ball design is its size. Its large spatial requirements have led to anatomic complications in patients with small aortic roots, isolated mitral stenosis, left ventricular hypertrophy, and double valve replacement, among others. Nevertheless, this is still the valve of choice in some centers.(ABSTRACT TRUNCATED AT 400 WORDS)

Results of combined valvular and myocardial revascularization operations

A total of 105 patients underwent combined coronary artery and valvular operations. Sixty-six had combined coronary artery bypass grafting (CABG) and aortic valve replacement (AV), 28 had CABG and mitral valve operations (MV), and 11 patients had CABG and double or triple valve operations (DTV). An average of 3.0 bypasses was done, range one to seven. These patients were compared to a similar group of patients who underwent valve replacement(s) only, without CABG. Bypass time was increased for the combined groups, as was ischemic cross-clamp time. Early mortality was 3.0% AV, 3.5% MV, and 9.1% DTV in the combined groups and 1% in the valve only groups. The higher mortality for the combined groups was almost entirely due to the 23% mortality in women over 70 years of age. Perioperative myocardial infarction (MI) was higher in the combined groups (5% MI, 9% probable MI versus 2.9% MI, 4.1% probable MI). All survivors were in improved clinical condition and free of angina. Mortality and improvement were unrelated to perioperative infarction. The small increase in risk compared to the significant improvement from the combined approach has led to the following principles: coronary arteriography on all adult patients requiring valvular operations; bypass of all significant coronary lesions; restoration of valvular function and hemodynamics; and myocardial preservation with cold cardioplegia during a single period of cross clamping, topical cold, and systemic hypothermia.

Durability of measured mitral annuloplasty: seventeen-year study

This report describes the technique and results of measured mitral annuloplasty performed in 196 patients having isolated mitral valve disease during the 17 years between January, 1961, and January, 1978. These patients represent 35% of all of those operated upon for isolated mitral valve disease during this period. Ages ranged from 3 to 70 years. Annuloplasty was performed in 115 patients and both commissurotomy and annuloplasty in another 81 patients. The operative mortality rate was 4.5% and the late mortality rate 8.7%. There were six arterial embolic episodes during the 17 years. Reoperation was required in 8% with another repair of the valve being possible in one third of them. This study suggests that measured repair of mitral regurgitation resulted in lower operative mortality, late mortality, and incidence of embolization when contrasted with mitral valve replacement. This operation appears to be the preferred procedure for certain subsets of patients (1) who require operation during infancy or childhood, including during active carditis; (2) who require operation during the childbearing age; and (3) in whom anticoagulation poses a severe threat to life or quality of life.

Release of nucleosides from canine and human hearts as an index of prior ischemia

During ischemia, myocardial adenosine triphosphate is degraded to adenosine, inosine and hypoxanthine. These nucleosides are released into coronary venous blood and may provide an index of ischemia; adenosine may also participate in the autoregulation of coronary flow. In dogs, the temporal relations between reactive hyperemic flow and nucleoside concentrations in regional venous blood were correlated after brief occlusions of a segmental coronary artery. Reactive hyperemia and adenosine release peaked together in 10 seconds, persisted for 10 to 30 seconds and then decreased in a pattern consistent with the hypothesis that they are related. During initial reflow after 45 seconds of ischemia, mean concentrations of adenosine, inosine and hypoxanthine increased, respectively, to 52, 67 and 114 nmol/100 ml plasma; after 5 minutes of ischemia, the respective levels increased to 58, 1,570 and 1,134 nmol and fell quickly. In nine patients there was a similar release of nucleosides into coronary sinus blood during reperfusion after 59 to 80 minutes of ischemic arrest during cardiac surgery. With initial reflow, adenosine, inosine and hypoxanthine levels reached 65, 655 and 917 nmol/100 ml of blood, respectively. Inosine and hypoxanthine concentrations remained high for 5 to 10 minutes after cardiac beating resumed, often when production of lactate had decreased. The results indicate that postischemic release of nucleosides reaches significant levels in man as well as animals, is parallel with the duration of ischemia, is temporary and may be a useful supplement to measurement of lactate as an index of prior myocardial ischemia.

Chylothorax as a manifestation of rheumatic mitral stenosis: its postoperative management with a diet of medium-chain triglycerides

Chylothorax occurred as a manifestation of severe congestive heart failure resulting from rheumatic mitral stenosis. Following replacement of the mitral valve, chylothorax recurred and was treated by thoracocentesis initially and then resolved during six months of therapy with a diet of medium-chain triglycerides. Ultimately, the patient resumed a regular diet with no further accumulation of pleural fluid.

Long-term results in 1375 patients undergoing valve replacement with the Starr-Edwards cloth-covered steel ball prosthesis

The two principal considerations with prosthetic valves are durability and thromboembolism. With the widespread interest in recently developed prosthetic valves (porcine, tilting disc, Cooley), the long-term results at one institution with a single prosthesis were considered of particular importance. Accordingly, a 97% follow-up has been completed on 1375 patients (pts) undergoing prosthetic valve replacement with the Starr-Edwards cloth-covered steel ball prosthesis at New York University between October 1967 and December 1975. Operative procedures were as follows: aortic valve replacement (AVR): 470 pts; mitral valve replacement (MVR): 362 pts; combined AVR and MVR: 129 pts; other combined procedures: 414 pts. Overall operative deaths were 13.7%, 9% for AVR, 10.8% for MVR, and 18.6% for combined AVR and MVR. At seven years, AVR survival was 64%, and MVR survival 64.5%. There has been widespread pessimism, usually without significant data, about the cloth-covered prosthesis, because of concern of cloth wear, hemolysis and other complications. Therefore, a particularly significant finding by actuarial analysis was that 85% of surviving patients with isolated AVR remained free of emboli for five years. In pts surviving isolated MVR, 80% remained free of emboli for five years. Of those having embolic episodes, 33% were not on anticoagulants. Fatal hemorrhage from anticoagulants occurred in 0.8% of pts. Endocarditis occurred in 5.7% of the entire group, with 1.3% requiring reoperation. Clinically significant hemolysis occurred in 5.1% of the group, with only 0.2% requiring reoperation. Hence, the total frequency of clinically significant cloth-wear was less than 0.5%. These data indicate both the reliability and the limitations of the Starr-Edwards cloth-covered steel ball valve and can be used in comparing experiences with the more recently developed prostheses.

Infective endocarditis. An analysis of 54 surgically treated patients

One hundred seventy-seven patients were admitted to the New York University Medical Center from 1970 through 1975 with infective endocarditis. Fifty-four of these patients required surgical treatment. The over-all mortality rate was 28 per cent. Two thirds of the deaths were early (10 patients) and one third late (5 patients). The mortality rate was 90 per cent in 10 patients treated for 4 to 6 weeks in whom the infection was uncontrolled and the clinical condition was deteriorating. However of the 12 patients with uncontrolled infection who were operated upon promptly within 10 days, 83 per cent survived. The fact that fungal and gram-negative infections responded poorly to medical therapy suggests the need for prompt, early surgical intervention. The mortality rate in the 32 patients operated upon in whom the infection was controlled was 12.5 per cent. It is our conclusion that all patients with infective endocarditis who develop progressive congestive failure, recurrent embolization, or progressive sepsis, despite treatment, shold have prompt valve replacement within 7 days of the institution of appropriate antimicrobial therapy.

Operative management of tricuspid regurgitation

From January 1968 to June 1975 tricuspid regurgitation was encountered in 238 patients of a total of 1074 patients undergoing operations on the mitral valve. During this time tricuspid annuloplasty (TA) was performed in 137 patients and the tricuspid valve was replaced (TVR) in 101 patients. Comparison of hospital mortality of 15% (20 of 137) for TA as against 40% (40 or 101) for TVR suggests the superiority of repair over replacement. A new technique for repair makes this operation even more attractive. It satisfies the dual objectives of producing competency but not obstruction by creating a measured orifice. As experience with TA was gained, the incidence of valve replacement dropped from 69% (22 of 32) in the first 2 years of the study to 16% (11 of 70) for the last 2 years.

Measured tricuspid annuloplasty: a rapid and reproducible technique

A technique for repairing the tricuspid valve that involves principles successfully used in operative repair of the mitral valve is described. A measured orifice produces competence but not obstruction and eliminates the trial-and-error aspects of annuloplasty. The procedure can be performed with the heart beating, though it can be transiently fibrillated so that the suture may be tied without tension.

The influence of diabetes and hypertension on the results of coronary revascularization

The effects of diabetes and hypertension on the early postoperative course of patients undergoing coronary revascularization were studied by reviewing the records of 177 patients operated upon in 1972. There were 121 nondiabetic, nonhypertensive; 32 hypertensive; ten diabetic; and 14 diabetic-hypertensive patients. The incidence of postoperative low cardiac output, renal insufficiency and arrhythmia was significantly higher in the hypertensive patient. Operative mortality ranged from 0 in diabetic patients, to 0.8 per cent in nondiabetic, nonhypertensives, to 7.1 per cent in diabetic-hypertensives and 12.5 per cent in hypertensive patients, suggesting an increased risk for the hypertensive patient. The one- to two-year follow-up results documented symptomatic improvement in 90.7 per cent of patients with little adverse effect apparent from diabetes or hypertension. Pre- and postoperative coronary angiography was carried out in 103 patients between 1968 and 1973 with a mean elapsed time between operation and postoperative angiogram of 9.3 months. The progression of atherosclerosis was graded on a 0-4 basis in both grafted and ungrafted coronary arteries. While hypertension appeared to contribute to disease progression, the incidence of vein graft and internal mammary artery bypass occlusion was not significantly affected by either diabetes or hypertension. This study has shown that while hypertension contributes to increased morbidity and mortality in the early postoperative period and an increased rate of progression of atherosclerosis, neither diabetes nor hypertension appeared to influence the one- to two-year results of coronary revascularization.

Cystic thymoma simulating contrictive pericarditis. The role of echocardiography in the differential diagnosis

A case is presented of a 60-year-old woman with fatigue, dyspnea, and chest pain. A chest x-ray film revealed an abnormal cardiac silhouette. Echocardiography revealed a large, echo-free area with well-demarcated, discrete borders adjacent to the right heart border. This structure decreased in size with inspiration and did not show pulsatile cardiac motion. Cardiac catheterization confirmed the extracardiac nature of the lesion and also showed a "constrictive" pattern with equalization of diastolic pressures. Surgical exploration revealed a large cystic thymoma. With removal of the tumor, intracardiac pressures returned to normal.

The long-term influence of coronary bypass grafts on myocardial infarction and survival

Approximately 1,000 coronary bypass procedures were performed at New York University between February 1968 and December 1973. This report reviews all elective operations performed for angina between 1968 and 1972, a total of 448 patients. In this five-year period the percentage of diseased arteries bypassed rose from 40% to 84%, and operative mortality decreased from 28% to less than 3%. There were a total of 28 operative deaths, mostly from myocardial infarction and low cardiac output. Operability was nearly 95%. The only fixed contraindication was chronic congestive failure. Over one-half of the patients had an abnormal ventriculogram, and there was some history of mild congestive failure in nearly 20%. Elevation of left ventricular end-diastolic pressure above 20 mm before operation was associated with a higher operative mortality, but the late mortality was similar to those with a normal preoperative end-diastolic pressure. In 383 surviving patients, angina was eliminated or greatly improved in 86%, unimproved in 12% and worse in 2%. Late angiograms were performed on 201 patients, studying a total of 445 venous grafts with an overall patency rate of 71%. Graft occlusion was sporadic and unpredictable, but over 90% of patients with multiple grafts remained with at least one patent graft. A late myocardial infarction occurred in 32 out of 420 patients surviving operation, and was fatal in eight. The cumulative incidence over a period of five years was 17%. Twenty-three deaths occurred following discharge from the hospital. Life-table analyses showed a five-year survival of 77% when all deaths were included, and a five-year cardiac survival of 81% when non-cardiac deaths were withdrawn alive at the time of death. The expected survival in a comparable population group without coronary disease was 92%, while data published by Sones of patients treated without operation showed a five-year cardiac survival of 66%. Current operative techniques have an operative mortality of 2-3% and a subclinical infarction rate of 5-10%. The ideal graft is yet evolving, but data with internal mammary artery grafts are most encouraging. A future goal should be a five-year graft patency of at least 80%. Because many infarcts probably develop from a relatively small decrease in coronary blood flow, either during rest or mild activity, the likelihood that future data will demonstrate a marked increase in longevity with bypass grafting is great.

Release of adenosine from human hearts during angina induced by rapid atrial pacing

This study was designed to determine whether human hearts release adenosine, a possible regulator of coronary flow, during temporary myocardial ischemia and, if so, to examine the mechanisms involved. Release of adenosine from canine hearts had been reported during reactive hyperemia following brief coronary occlusion, and we initially confirmed this observation in six dogs hearts. Angina was then produced in 15 patients with anginal syndrome and severe coronary atherosclerosis by rapid atrial pacing during diagnostic studies. In 13 of these patients, adenosine appeared in coronary sinus blood, at a mean level of 40 nmol/100 ml blood (SE = +/-9). In 11 of these 13, adenosine was not detectable in control or recovery samples; when measured, there was concomitant production of lactate and minimal leakage of K(+), but no significant release of creatine phosphokinase, lactic acid dehydrogenase, creatine, or Na(+). THERE WAS NO DETECTABLE RELEASE OF ADENOSINE BY HEARTS DURING PACING OR EXERCISE IN THREE CONTROL GROUPS OF PATIENTS: nine with anginal syndrome and severe coronary atherosclerosis who did not develop angina or produce lactate during rapid pacing, five with normal coronaries and no myocardial disease, and three with normal coronaries but with left ventricular failure. The results indicate that human hearts release significant amounts of adenosine during severe regional myocardial ischemia and anaerobic metabolism. Adenosine release might provide a useful supplementary index of the early effects of ischemia on myocardial metabolism, and might influence regional coronary flow during or after angina pectoris.

Lethal postoperative infections following cardiac surgery. Review of four years' experience

Seventeen of 1,494 patients (1.1%) succumbed to infection following open-heart operations at New York University Hospital between January, 1968 and December, 1971. All but two of these patients had Starr-Edwards ball-valve prostheses inserted. One had repair of a tetralogy of Fallot, and one had aortic commissurotomy and a double coronary bypass graft. The sites of infection were pulmonary (15 patients), urinary tract (14), mediastinum or pleura (10), and blood (15). Pulmonary infection appeared as the source of endocarditis in 13 patients and as a source of pleural or mediastinal infection in nine. Candida species infection was directly responsible for the deaths of 10 of the 17 patients, being the sole organism isolated in 5 of the 10.

Predisposing factors to infection were preoperative bacterial endocarditis 2 patients, prolonged cardiopulmonary bypass (>3½ hours) 6 patients, a "low output" state following operation 12 patients, postoperative cerebral dysfunction 6 patients, and postoperative disseminated intravascular coagulation 4 patients.

The debilitated state of the patients, multiple sites of infection, degree of tissue destruction, and the variety and resistance of the organisms involved all combined to produce treatment failure. Removal of the infected valvular prosthesis coupled with antimicrobial therapy is considered the treatment of choice in instances of bacterial endocarditis when chemotherapy fails and in all cases of established fungal endocarditis.