D. Glenn Pennington

Results of internal thoracic artery grafting over 15 years: single versus double grafts

One hundred consecutive patients who had coronary artery bypass grafting using both internal thoracic arteries (ITAs) and saphenous veins, operated on during a 3-year period between 1972 and 1975, have been compared retrospectively with a series of 100 patients operated on during the same period who had one ITA graft along with saphenous vein grafts. The two groups were similar with respect to age, sex, risk factors for coronary artery disease, angina class, extent of coronary artery disease, left ventricular function, number of coronary bypass grafts performed, and completeness of revascularization. Single ITA operative mortality was 2% and double ITA, 9% (p = NS). The mean follow-up of hospital survivors was 14.4 +/- 2.7 years; all but 7 patients had follow-up for at least 10 years. At 13 years, the actuarial patency of the right ITA was 85% and the left ITA, 82%. These data strongly suggest a survival benefit for patients with double ITA grafts among hospital survivors (74% versus 59%; p = 0.05). Patients receiving two ITA grafts had a significant freedom from subsequent myocardial infarction (75% versus 59%, p less than 0.025), recurrent angina pectoris (36% versus 27%, p less than 0.025), and subsequent total ischemic events (32% versus 18%, p less than 0.01). These data also suggest improved freedom from coronary artery interventional therapy (percutaneous transluminal coronary angioplasty and reoperation) when two ITA grafts were used. These results support the use of bilateral internal thoracic artery grafting in selected patients.

Preoperative and postoperative comparison of patients with univentricular and biventricular support with the thoratec ventricular assist device as a bridge to cardiac transplantation

OBJECTIVES The goal of this study was to determine whether there are differences in populations of patients with heart failure who require univentricular or biventricular circulatory support. METHODS Two hundred thirteen patients who were in imminent risk of dying before donor heart procurement and who received Thoratec left (LVAD) and right (RVAD) ventricular assist devices at 35 hospitals were divided into three groups: group 1 (n = 74), patients adequately supported with isolated LVADs; group 2 (n = 37), patients initially receiving an LVAD and later requiring an RVAD; and group 3 (n = 102), patients who received biventricular assistance (BiVAD) from the beginning. RESULTS There were no significant differences in any preoperative factors between the two BiVAD groups. In the combined BiVAD groups, pre-VAD cardiac index (BiVAD, 1.4 +/- 0.6 L/min per square meter, vs LVAD, 1.6 +/- 0.6 L/min per square meter) and pulmonary capillary wedge pressure (BiVAD, 27 +/- 8 mm Hg, vs LVAD, 30 +/- 8 mm Hg) were significantly lower than those in the LVAD group, and pre-VAD creatinine levels were significantly higher (BiVAD, 1.9 +/- 1.1 mg/dl, vs LVAD, 1.4 +/- 0.6 mg/dl). In addition, greater proportions of patients in the BiVAD groups required mechanical ventilation before VAD placement (60% vs 35%) and were implanted under emergency conditions than in the LVAD group (22% vs 9%). The survival of patients through heart transplantation was significantly better in patients who had an LVAD (74%) than in those who had BiVADs (58%). However, there were no significant differences in posttransplantation survival through hospital discharge (LVAD, 89%; BiVAD, 81%). CONCLUSION Patients who received LVADs were less severely ill before the operation and consequently were more likely to survive after the operation. As the severity of illness increases, patients are more likely to require biventricular support.

Implantable electrical left ventricular assist systems: Bridge to transplantation and future

An implantable left ventricular assist system (LVAS) utilizing an electromechanically driven dual pusher-plate blood pump has been employed in a multiinstitutional trial as a bridge to cardiac transplantation. Under development for permanent circulatory support in patients with end-stage heart disease, the LVAS, in this application, derives power and control from an external console via a percutaneous lead. The LVAS was implanted in 20 patients (16 men, 4 women) who were hemodynamically unstable or in refractory cardiogenic shock. The mean age was 44.9 years (range, 25 to 63 years). Preoperative diagnosis was evenly divided between end-stage ischemic disease, cardiomyopathy, and acute myocardial infarction. Implanted in the left upper quadrant within the anterior abdominal wall, the blood pump was connected between the left ventricular apex and ascending aorta. Total support of the systemic circulation and substantial left ventricular unloading were achieved with synchronous counterpulsation for periods up to 90 days (mean, 22.7 days). All patients were stabilized hemodynamically. The mean preoperative cardiac index of 1.5 L/min/m2 increased by a factor of 2. Pulmonary arterial pressures decreased substantially. Serious complications occurred in 16 patients, precluding cardiac transplantation in 10. Most complications (greater than 70%) were in patients who did not receive transplants; the most common complication was bleeding. Twelve of 13 patients with LVAS implants for more than seven days were mobilized, and 4 were fully ambulatory and completely rehabilitated. Orthotopic cardiac transplantation was performed in 10 patients after implants ranging from two to 90 days (mean, 30.3 days).(ABSTRACT TRUNCATED AT 250 WORDS)

High incidence of myocarditis by endomyocardial biopsy in patients with idiopathic congestive cardiomyopathy.

Thirty-five patients with unexplained congestive heart failure were evaluated with endomyocardial biopsy. Utilizing microscopic, ultrastructural and immunofluorescent studies, samples were classified as exhibiting either no inflammation (cardiomyopathy) or active lymphocytic myocarditis, grade I to IV. Twenty-two (63%) of the patients had inflammatory changes. Of these 22 patients, 18 had low grade I or II inflammation, 7 were treated with immunosuppressive agents with improvement in 5 and stabilization in 1. One patient died of progressive congestive heart failure. Three of four patients with high grade III or IV myocarditis died after a fulminant course. The results suggest that inflammatory myocarditis may be more common than previously suspected and add evidence that there may be ongoing inflammation in many cases of congestive cardiomyopathy.

Conservative versus surgical management of chylothorax

Chylothorax is a potentially life-threatening disorder that has profound respiratory, nutritional, and immunologic consequences. Treatment for this problem is controversial, and the results have been variable. From 1985 to 1990, 29 patients (16 males, 13 females; mean age: 20.1 years; range: 5 days to 76.8 years) were diagnosed as having chylothorax (18 right, 6 left, 5 bilateral). Etiologies included surgical trauma (26) and nonsurgical trauma (3). Initial conservative treatment consisted of tube thoracostomy drainage (mean duration: 13.3 days; range: 1 to 62 days; mean total volume: 4,030 mL) and dietary modification (low-fat diet, total parenteral nutrition). This resulted in resolution of the chylothorax in 23 patients (79% success), although 2 patients died of unrelated causes while hospitalized (myocardial infarction and cardiopulmonary arrest). Five adult patients and one infant (21%) required ligation of the thoracic duct, with resolution of the chylothorax in all six (100% success). Despite successful duct closure, one infant died of respiratory failure unrelated to the operation, and one adult died as the result of a cerebrovascular accident 6 weeks postoperatively, yielding an operative mortality of 33% and an overall mortality of 14% (4 of 29). Our experience demonstrates that initial treatment of chylothorax with thoracostomy drainage and dietary modification is successful in the majority of patients and is not associated with high morbidity or mortality rates. Surgical intervention for chylothoraces that fail to respond to initial conservative measures will be required in a minority of patients but appears to be associated with a higher risk of complications.

The changing profile of the patient undergoing coronary artery bypass surgery

The first 100 consecutive patients undergoing isolated coronary artery bypass surgery in 1975 were evaluated with respect to the incidence of operative risk factors and outcome. When compared with an identically selected group from 1985, there was significant worsening of the preoperative condition over the decade with regard to mean age (p less than 0.0005), presence of congestive heart failure (p less than 0.05), left ventricular dysfunction (p less than 0.05), severity of coronary artery disease (p less than 0.001) and incidence of emergency operation (p less than 0.05). More patients in 1985 had associated medical diseases such as diabetes (p less than 0.01) and chronic lung disease (p less than 0.005). There was an increase in the occurrence of vascular diseases (hypertension, renal dysfunction, peripheral vascular and cerebrovascular disease) (p less than 0.05). Overall operative mortality increased from 1 to 8% (p less than 0.05) over the decade. Despite the deterioration in the clinical profile of the patient undergoing coronary bypass surgery, elective procedures were still performed with low mortality. The significant increase in overall mortality was chiefly in patients undergoing emergency operation (p less than 0.05). There were also increases in operative morbidity including low output syndrome (p less than 0.01) and respiratory (p less than 0.005) and neurologic (p = 0.06) complications.

Heterotopic prosthetic ventricles as a bridge to cardiac transplantation. A multicenter study in 29 patients

Heterotopic prosthetic ventricles were used to support the circulation in 29 candidates for heart transplantation who were expected to die before procurement of a donor heart. Twenty-one of these patients (average age, 36 years) underwent successful transplantation after 8 hours to 31 days of circulatory support. The other eight patients died because their condition could not be stabilized for transplantation, despite restoration of blood flow. Fourteen patients received biventricular support; 15 received only left ventricular support, with pharmacologic assistance of right heart function. Before transplantation, blood flow from the left prosthetic ventricle averaged 2.8 +/- 0.4 liters per minute per square meter of body-surface area, and from the right prosthesis 2.4 +/- 0.4 liters, as compared with an average flow of 1.6 +/- 0.5 liters per minute per square meter before implantation. Of the 21 patients who received heart transplants, 20 were discharged from the hospital after a median of 31 days. Nineteen patients were alive at 7 to 39 months, and 11 of the first 12 were alive at one year. We conclude that heterotopic placement of prosthetic ventricles as a bridge to transplantation provides an effective method of temporarily supporting cardiac function in critically ill patients without removing the natural heart. The early survival rate after transplantation is similar to that with elective cardiac transplantation.

The Importance of Biventricular Failure in Patients with Postoperative Cardiogenic Shock

To evaluate the importance of severe biventricular failure in patients with postcardiotomy ventricular failure, we analyzed the data from 30 patients treated with ventricular assist devices (VADs) over a five-year period. All patients had profound postoperative ventricular failure refractory to drugs and an intraaortic balloon (IAB). Evaluation of preoperative ventricular function did not allow prediction of which patients would require VADs. However, the development of perioperative myocardial infarction was an important determinant of the need for postoperative support with a VAD. Twenty patients received only a left VAD (LVAD). Four of them had isolated left ventricular failure; 3 were weaned, and 2 survived. None of the 16 patients with biventricular failure who received only an LVAD were weaned. Ten other patients with biventricular failure received biventricular support, either with a right VAD and IAB, or with two VADs. Of these 10 patients, 5 were weaned and 3 survived. Considering all 26 patients with biventricular failure, those receiving biventricular mechanical support (10) had a better chance (p less than 0.025) of being weaned (5/10) and surviving (3/10) than those who received only an LVAD (0/16). We conclude that biventricular failure is common in patients with postcardiotomy ventricular failure and is often the result of perioperative infarction. While patients with isolated left ventricular failure did well with an LVAD only, those with biventricular failure required biventricular mechanical support for survival.

Intraaortic Balloon Pumping in Cardiac Surgical Patients: A Nine-Year Experience

Abstract From March, 1973, to April, 1982, 378 of 5,546 patients (6.8%) undergoing cardiac operations had insertion of an intraaortic balloon pump (IABP). The 378 patients ranged in age from 19 to 84 years (mean, 58.2 years) and included 4.7% of patients undergoing coronary bypass grafting and 10.6% of patients undergoing valve replacement. An IABP was inserted preoperatively in 22 patients with unstable angina pectoris and in 33 patients with cardiogenic shock; intraoperatively in 252 patients who could not be weaned from cardiopulmonary bypass; and postoperatively in 71 patients who had hemodynamic deterioration. The IABP was inserted by femoral arteriotomy in 201 patients, by percutaneous femoral puncture in 161 patients, and by transthoracic aortotomy in 16 patients. All patients received daily infusions of low molecular weight dextran without heparin during the IABP period. Duration of IABP support ranged from 1 to 384 hours (mean, 37.3 hours). Out of 230 patients weaned from the IABP, 202 patients were discharged from the hospital for an overall survival rate of 53.4%. The overall incidence of complications was 11.6%. There were 8 IABP-related deaths (2.1%), which were due to ruptured aorta in 6 patients, aortic dissection in 1 patient, and helium embolus in 1. Survival was higher in patients with insertion by percutaneous femoral puncture (99/161; 61.5%) than in patients with insertion by femoral arteriotomy (99/201; 49.3%) ( p p p

Coronary artery bypass surgery in patients aged 80 years or older

Between August 1980 and January 1986, 23 patients aged 80 years or older underwent coronary artery bypass grafting (CABG) operations. These patients had a higher incidence of severe left main coronary artery narrowing (p less than 0.0001), 3-vessel coronary artery disease (p less than 0.05) and moderate to severe left ventricular dysfunction (p less than 0.05) than patients in the Coronary Artery Surgery Study registry older than 65 years. Of 14 patients undergoing elective simple CABG procedures, none died; of 19 elective cases overall, 2 patients died (11%). Three of 4 patients undergoing emergency procedures (75%) and 4 of 6 patients (67%) requiring intraaortic balloon counterpulsation died. Significant complications occurred in 9 of 18 survivors (50%). All operative survivors improved at least 1 New York Heart Association class, with a mean classification improvement of 3.7 to 1.6 (p less than 0.0001); 13 of 16 long-term survivors were in class I or II. Actuarial survival at 1 and 2 years is 94% and 82%, respectively. CABG can be performed electively in octogenarian patients with increased but acceptable mortality and morbidity risks. Functional improvement and long-term survival are excellent.