Acetylcholine-induced constriction of angiographically normal coronary arteries is not time dependent in transplant recipients. Effects of stepwise infusion at 1, 6, 12 and more than 24 months after transplantation.

OBJECTIVES: The aim of this study was to evaluate whether acetylcholine may be a useful tool for detection of early angiographically undetectable coronary atherosclerosis in heart transplant recipients. BACKGROUND: Coronary artery disease is the main determinant of long-term prognosis in transplant recipients. Acetylcholine-induced constriction of angiographically normal coronary arteries in heart transplant recipients could be due to early atherosclerosis, and acetylcholine has been proposed for early detection of coronary artery disease. METHODS: The responses of large coronary arteries to stepwise intracoronary infusion of acetylcholine (10(-8) to 10(-5) mol/liter) were compared in five control subjects and in four groups of transplant recipients 1, 6, 12 and > 24 months postoperatively (group 1, n = 6; group 2, n = 7; group 3, n = 6; group 4, n = 6, respectively). All patients had normal coronary arteriographic findings. Vessel dimensions were measured in four segments in each patient. RESULTS: In control subjects, acetylcholine increased diameters significantly at 10(-8), 10(-7) and 10(-6) mol/liter (all p < 0.001 vs. basal value). No significant variation was observed at 10(-5) mol/liter. Intracoronary isosorbide dinitrate increased diameters of all segments (p < 0.001). In transplant recipients, vessel diameters did not vary significantly from baseline at 10(-8) and 10(-7) mol/liter concentrations in groups 1 and 3 and at 10(-8) mol/liter in group 4. Vessels constricted significantly in all the other cases. Comparisons of each group with control subjects showed that responses were significantly different for all concentrations but 10(-8) mol/liter in groups 3 and 4. Intracoronary isosorbide dinitrate elicited coronary vasodilation similar to that of control subjects in all groups of transplant recipients. CONCLUSIONS: This study indicates that the acetylcholine response is persistently abnormal in transplant recipients compared with that in normal control subjects and that this abnormality may not be related simply to the presence of atherosclerosis. Thus, acetylcholine may not be a useful tool for early detection of coronary atherosclerosis in heart transplant recipients.

Effects of time and previous acute rejection episodes on coronary vascular reserve in human heart transplant recipients.

OBJECTIVES: This study examined whether previous rejection episodes may have deleterious effects on coronary vascular reserve of heart transplant recipients months after transplantation. BACKGROUND: Coronary reserve has been demonstrated to be within the normal range in long-term transplant patients without previous episodes of rejection. Conversely, acute rejection is associated with a dramatic reduction of coronary reserve, which is rapidly restored after therapy. METHODS: Coronary flow velocity was measured by intracoronary Doppler catheter before and after a maximally vasodilating dose of intracoronary papaverine in 16 control subjects and in 59 transplant patients classified into three groups with respect to time after transplantation: 1 to 6 months (group 1, n = 17), 7 to 18 months (group 2, n = 22) and > 18 months (group 3, n = 20). Coronary vascular reserve was evaluated through peak/rest coronary flow velocity ratio and minimal coronary vascular resistance index. All patients had normal findings on left ventricular angiography and coronary arteriography and a normal left ventricular mass. RESULTS: Arterial pressure was normal in all groups. Heart rate in the three groups of transplant patients, mean aortic pressure in groups 1 and 2, left ventricular systolic pressure in group 2 and rate-pressure product in groups 1 and 2 were higher than in control subjects. Average number of rejection episodes per patient was similar in the three groups of patients (group 1, 2.4 +/- 1.4; group 2, 2.5 +/- 1.9, and group 3, 2.1 +/- 1.3). Results showed no difference between each group of transplant patients and control subjects for peak/rest coronary flow velocity ratio (control subjects, 5.2 +/- 0.8; group 1, 5.3 +/- 1.5; group 2, 4.9 +/- 1.2, and group 3, 4.4 +/- 1.6) and for minimal coronary vascular resistance index (control subjects, 0.18 +/- 0.03; group 1, 0.18 +/- 0.04; group 2, 0.20 +/- 0.06, group 3, 0.23 +/- 0.11). In addition, patients with zero or one rejection episode had similar values of peak/rest coronary flow velocity ratio and minimal coronary vascular resistance index (4.3 +/- 1.3 and 0.23 +/- 0.10, respectively, n = 22) as did those with one or two rejection episodes (5.1 +/- 1.5 and 0.19 +/- 0.07, respectively, n = 24), and those with four or more episodes (5.2 +/- 1.4 and 0.19 +/- 0.05, respectively, n = 13). CONCLUSIONS: This study showed that coronary vascular reserve remains within normal range and is independent from the number of previous episodes of rejection until late after transplantation in human heart transplant patients with angiographically normal coronary arteries.

Absorption and elution of anti-DLA-A and B antibodies with acetone-dried dog spleen powder.

Acetone-dried powders were prepared from the spleens of DLA-serotyped dogs and assayed for their specific absorptive properties for anti-DLA-A and B antisera. The specific activity of two different antisera (anti-DLA-A9 and anti-DLA-B13) was readily absorbed with acetone-dried powders prepared from the spleens of dogs of the corresponding DLA types. This specific activity was recovered by the elution of the powder used for the serum absorption. The same method was used to narrow the specificity of a highly polyspecific antiserum. The comparison of the absorption properties of acetone-dried spleen powder versus fresh spleen cells shows that the treatment with acetone does not modify qualitatively and quantitatively the DLA specificities.

Maximal coronary vasodilator capacity of orthotopic heart transplants in patients with and without rejection.

In cardiac allograft rejection, histopathologic changes suggesting that myocardial ischemia is a component of the rejection process have been documented. To further define the coronary vascular reactivity of human heart transplant, coronary sinus blood flow and coronary resistance were measured before and after intravenous dipyridamole within the first year after transplantation in 8 patients without rejection (group II) and in 5 patients with rejection (group III). All had normal coronary arteriograms. Results were compared to those of 8 control subjects (group I). After dipyridamole, coronary sinus blood flow was increased in groups I, II and III by 303, 212 (p less than 0.01 vs group I) and 45%, respectively (p less than 0.001 vs groups I and II). Coronary resistance was reduced by 77, 73 (not significant vs group I) and 36%, respectively (p less than 0.001 vs groups I and II). Concomitantly, coronary sinus blood oxygen content was increased by 172, 145 (not significant vs group I) and 78%, respectively (p less than 0.001 vs group I, not significant vs group II). Thus, the coronary flow reserve evaluated by the dipyridamole/basal coronary sinus blood flow ratio and the coronary resistance reserve evaluated by the basal/dipyridamole coronary resistance ratio were dramatically impaired in group III (1.56 +/- 0.09 and 1.63 +/- 0.30, respectively, p less than 0.001 vs groups I and II). In contrast, they were almost normal in group II (3.11 +/- 0.42 vs 4.03 +/- 0.52 in group I, p less than 0.02, and 3.83 +/- 0.78 vs 4.45 +/- 0.81 in group I, difference not significant). Thus, the impairment of coronary reserve during heart rejection should be linked to abnormalities of the coronary microvaculature. This emphasizes the important involvement of the coronary circulation in the rejection process.

Effect of plasma volume expansion on hemodynamics and atrial natriuretic factor release in heart-transplant recipients.

Plasma atrial natriuretic factor (ANF), plasma cyclic guanosine monophosphate (cGMP), plasma aldosterone, plasma-renin activity (PRA) and hemodynamic parameters were measured in heart-transplant recipients and control patients (chest pain syndrome) during right-sided heart catheterization under basal conditions and in response to an intravenous saline load. Basal plasma ANF and cGMP were higher in heart-transplant recipients than in control patients, whereas PRA and plasma aldosterone did not differ. The high plasma ANF levels in heart-transplant recipients did not result from high atrial pressures but appeared to be related with elevated atrial dimensions and cyclosporine-induced renal failure. During volume expansion, plasma ANF increased in control patients and remained elevated during the postinfusion period. In heart-transplant recipients, the changes in plasma ANF were less marked despite identical increases of atrial pressures. The sluggish response of plasma ANF in this group was associated in the postinfusion period with a nonreturn of the hemodynamic parameters to their basal values in contrast with what was observed in control patients.

Early impairment of acetylcholine-induced endothelium-dependent coronary vasodilation is not predictive of secondary graft atherosclerosis.

STUDY OBJECTIVE: To test the hypothesis that the magnitude of early constriction of coronary arteries to acetylcholine might be a useful predictor of secondary graft atherosclerosis. DESIGN: The responses of epicardial coronary arteries to stepwise intracoronary infusion of acetylcholine (10(-8)M to 10(-5)M) were compared in 7 control subjects and in 18 patients who had undergone transplants within 2 months after surgery. MEASUREMENTS AND RESULTS: Vessel dimensions (percent basal diameter) were measured by quantitative angiography. Follow-up at 1 year showed angiographically normal coronary arteries in 12 patients (group 1) and coronary atherosclerosis in 6 patients (group 2). In control subjects, acetylcholine induced a dose-dependent dilation from 10(-8)M to 10(-6)M. No significant variation was observed at 10(-5)M. In patients with transplants early after surgery, diameters did not vary significantly from base at 10(-8)M in either group and constricted significantly at higher concentrations. Vasodilator responses to intracoronary isosorbide dinitrate were similar in both groups with transplants early after surgery, and at 1 year in group 1, but significantly lower than in control subjects. CONCLUSIONS: In patients who had undergone transplants, acetylcholine-induced endothelium-dependent coronary artery dilation is similarly impaired early after surgery (within 2 months) in patients with and without coronary atherosclerosis at 1-year follow-up. Thus, response to acetylcholine is not a predictor of secondary atherosclerosis in patients with heart transplants.

Ventricular septal defect after acute myocardial infarction: Early repair.

Thirty-eight patients have been operated upon early after acute myocardial infarction with rupture of the ventricular septum. Preoperative management included bedside hemodynamic evaluation, mechanical left heart support, and pharmacologic agents. The results of the surgical repair reflected both the effectiveness and the duration of preoperative treatment. Operation was performed in 14 patients with refractory cardiogenic shock, 10 of whom died (71%). Hemodynamic and clinical stability was achieved in 24 patients. Early operation (average 46 hours of medical management) in 17 patients permitted accurate repair, even with friable tissues; four of these patients died (23%). Delayed operation (average 12 days of monoperative treatment) was performed in seven patients and resulted in a higher mortality rate, three patients dying (43%). The location of the ventricular septal defect (VSD) also influenced the operative risks, the prognosis for posterior defects being worse than that for anterior defects. Optimal myocardial preservation during the entire procedure is of crucial importance to the success of the operation.

Evaluation of direct effects of enoximone on systemic and pulmonary vascular bed in animals with a Jarvik total artificial heart.

Enoximone, a phosphodiesterase inhibitor, has positive inotropic and vasodilating actions. To evaluate specific effects of this drug on the systemic and pulmonary vascular bed, we administered enoximone as a 10-minute intravenous bolus at two different doses of 2 and 3 mg/kg of body weight, at different days, to five Holstein calves with a Jarvik 7-70 ml total artificial heart (Symbion, Inc., Salt Lake City, Utah). The calves were monitored for aortic pressure, right atrial pressure, pulmonary arterial pressure, and left atrial pressure. For each experiment cardiac output was maintained constant, and systemic and pulmonary vascular resistances were calculated at 0, 15, 30, and 60 minutes and every hour for 8 hours after infusion. Statistical analysis used analysis of variance and the paired t test with Bonferroni's correction. Data showed the following: (1) a marked systemic vasodilating action of enoximone at peak effect at 30 minutes with a 20% decrease in systemic vascular resistance from baseline value under constant cardiac output, returning progressively to normal values throughout the 8 hours; (2) a comparable effect for the two separate doses tested; (3) no specific action on the pulmonary vascular bed with "nonunidirectional" changes in pulmonary vascular resistance. This model was validated by the infusion of prostaglandin I2 in the same animals, at different days, which significantly decreased pulmonary vascular resistance of 50% at peak effect, under constant cardiac output. In summary, enoximone showed a proper systemic vasodilating effect with no specific action on the pulmonary vascular bed in an animal model of the total artificial heart. Decrease in pulmonary vascular resistances obtained with enoximone in clinical practice seems more related to the inotropic properties of the drug. Enoximone should not be administered in pulmonary hypertension, as suggested before.

Surgical management of acute dissections involving the ascending aorta. Early and late results in 38 patients.

Thirty-eight patients (32 men and six women, mean age 48.1 years) were operated upon for acute dissection involving the ascending aorta. The surgical procedure included multiple peripheral arterial cannulations, resection of the initial intimal tear if found (35 cases), and obliteration of the false channel by double cuffing with Teflon of the two layers of the dissecting process proximally and distally. When present (29 cases), aortic regurgitation was usually (21 cases) managed by conservative remodeling of the aortic anulus; 34 prosthetic replacements of the ascending aorta and four replacements of the arch were achieved. The operative mortality was 7.9% (3138) and the overall hospital mortality was 23.7% (9138). Nonfatal complications occurred in 11 patients (29%). There were three late deaths (10.3%). Mean follow-up was 3.4 years (2 months to 8 years, 8 months). Twenty-three (88.5%) of the 26 patients were asymptomatic. Contrast tomodensitometry was performed in 14 patients; in type II (two patients), the aorta was normal; in type I (12 patients), residual abnormalities were noted: patency of the false channel (10 cases), aneurysmal dilatation (seven cases), and reduction of the true lumen by the false channel (four cases). These results emphasize the need for scrupulous long-term follow-up in surgically treated aortic dissections.

Mitroflow pericardial valve: long-term durability.

Isolated aortic (n = 107), mitral (n = 63), and tricuspid (n = 1) valve replacement and 28 double-valve replacements were performed with a second generation of pericardial valves, the Mitroflow valve, in 199 patients from March 1983 to December 1986. Follow-up (total, 1,058 patient-years) was extended to 106 months and 91.5% complete. Mean age was 58 +/- 13 years. The operative mortality included 22 deaths, non-cardiac-related in 7. The actuarial probability of survival for all patients was 66% +/- 4% at 8.5 years. There were no significant differences between patients with aortic valve replacement, mitral valve replacement, or double-valve replacement. The rate of thromboembolic events, antithromboembolic therapy-related hemorrhage, periprosthetic leak, and endocarditis is extremely minimal. Structural valve dysfunction occurred at a rate of 3.2% +/- 0.5%/patient-year. Actuarial freedom from the event was 94.6% +/- 1.7% at 5 years and 63.7% +/- 6.5% at 8.5 years for all valves. There were no difference in structural valve dysfunction rate between patients having aortic, mitral, or double-valve replacement. Thirty-five patients were reoperated on (3.4 +/- 0.6%/patient-year for all). The rate of all valve-related morbidity and mortality was 5.6% +/- 0.7%/patient-year for all patients, actuarial freedom from the event being 44% +/- 7% at 8.5 years. These data suggest that the excellent hemodynamic characteristics of the valve are balanced by a risk of valve failure that is slightly increased when compared with porcine valves.

Severe aortic stenosis in octogenarians: is operation an acceptable alternative?

From 1981 to 1989, 60 patients more than 80 years of age were referred for operation for severe calcific aortic stenosis. All patients were symptomatic: 13 in New York Heart Association (NYHA) functional class II, 28 in class III, and 19 in class IV. The preoperative mean cardiothoracic ratio was 0.58 +/- 0.09; the mean valve area, 0.52 +/- 0.14 cm2; and the mean aortic valve gradient, 62 +/- 18 mm Hg. Left ventricular function was impaired in 30 patients (ejection fraction less than 0.40). Coronary arteriography was performed in 10 patients. Aortic replacement used bioprosthesis in all 60 patients associated with aortocoronary bypass (in 5) and mitral valve replacement (in 1). One-month mortality rate was 28% (17 patients) due to cardiac failure (in 9), pulmonary complications (in 6), and neurological complications (in 2). Early mortality was not correlated with preoperative angina, cardiothoracic ratio, associated operation, and cross-clamping time. It was not obviously correlated with preoperative functional class but correlated positively with urgent operations and with left ventricular function (40% mortality in patients with ejection fraction less than 0.40 versus 16% mortality in others). Hospital morbidity was 68%. Mean hospitalization was 15 +/- 7 days. There were four late deaths. Thirty-nine patients are long-term survivors (3 months to 7 years): 27 in class I, 10 in class II, and 2 in class III due to primary valve failure. The actuarial survival probability is 65% at 1 year and 61% at 5 years. In summary, the good long-term quality of life justifies the high postoperative risk in octogenarians. Early operation before cardiac function impairment improves the results.

Intraoperative transesophageal echocardiography for pulmonary embolectomy without cardiopulmonary bypass.

This case report describes a patient with massive pulmonary embolism and acute circulatory failure in whom transesophageal echocardiography permitted the diagnosis of thrombi in the main pulmonary truncus and in the right branch and guided intraoperatively the surgical embolectomy performed under simple venous inflow occlusion because of a contraindication to heparin administration. Transesophageal echocardiography seems to be a very helpful technique to diagnose promptly massive pulmonary embolism and a very useful tool at the time of operation to guide the embolectomy.

Acute postinfarction septal rupture: long-term results.

From 1973 to 1989, 66 patients received early surgical repair for acute postinfarction ventricular septal rupture. Mean age was 64 +/- 7 years (range, 45 to 80 years). Ventricular septal rupture occurred soon after acute myocardial infarction (3.4 +/- 4 days), and the first medical treatment occurred 6.7 +/- 7 days after onset of acute myocardial infarction. Three patients had a previous myocardial infarction. The site of the rupture was anterior in 38 patients (57%) and posterior in 28 (43%). Forty-four patients (67%) were in shock at the time of admission. Intraaortic balloon pumping was used preoperatively in 28. Operation was performed at the time of maximal efficacy of medical treatment. The same technique was used in all cases. Associated procedures included coronary bypass grafting in 5 patients and valvar operation in 5. The patients have been carefully followed up for up to 16 years. Hospital mortality was 45% (30 patients) and was cardiac related or due to acute renal failure in 25 patients (83%). No correlation could be revealed between early death and age, sex, preoperative intraaortic balloon pumping, or year of operation. Location of the ventricular septal rupture (early mortality of 57% for posterior versus 37% for anterior ventricular septal rupture) and shock at the time of admission (52% versus 32%) showed a trend toward significance (0.08 less than or equal to p less than 0.10). Response to initial active therapy has a strong predictive value (mortality of 70% in unresponsive patients versus 14% in responders; p less than 0.001).(ABSTRACT TRUNCATED AT 250 WORDS)

Pharmacological bridge to cardiac transplantation: current limitations.

Addition of intravenous enoximone to sympathomimetic agents permits a rapid and drastic improvement in the clinical and hemodynamical condition of patients in cardiogenic shock referred for a mechanical bridge to transplantation. The present experience, based on the management of 52 patients, permits us to point out the current limitations of this pharmacological bridge: the rate of sudden death, the incompleteness of the physical rehabilitation of the patients, and the vanishing effect of intravenous enoximone.

Preservation of the aortic valve in acute aortic dissection: long-term echocardiographic assessment and clinical outcome.

The aim of the present study was to determine the long-term status of the native aortic valve after surgical treatment of acute aortic dissection involving the ascending aorta. From 1972 to 1991, 93 patients underwent operation for type I or II aortic dissection. There were 76 men and 17 women. Mean age was 54 +/- 13 years. Eighty patients (86%) had a conservative procedure regarding the aortic root and aortic cusps: 74 had prosthetic replacement of the ascending aorta and 6, complete replacement of the aortic arch. Thirteen patients (14%) had simultaneous replacement of the aortic valve and the ascending aorta. The overall hospital mortality rate was 29% (27/93). The overall actuarial survival rate was 60.2% +/- 5.2%, 49.7% +/- 6.1%, and 35.9% +/- 8.1% at 5, 10, and 15 years, respectively. The survival rates for patients who had an ascending aortic procedure only were 63% +/- 5.5%, 54% +/- 6.5%, and 39% +/- 8.5% at 5, 10, and 15 years, respectively, and for patients who required aortic valve replacement, 45% +/- 14% and 22% +/- 17.5% at 5 and 10 years, respectively. Fifty long-term survivors (94% follow-up) with preservation of the aortic valve and aortic root were studied. Among them, 9 (18%) died within a mean interval of 97 +/- 46 months after operation. Causes of death were ischemic cardiac failure (2), aortic rupture or extension of dissection (4), renal disease (1), stroke (1), and sudden death (1). Forty-one patients had long-term clinical and echocardiographic evaluation.(ABSTRACT TRUNCATED AT 250 WORDS)

Enoximone improves selection of candidates for urgent cardiac transplantation.

Immediate cardiac transplantation, or urgent implantation of devices for mechanical support of the failing heart, has been shown to be effective as life-saving procedures in patients with cardiogenic shock unresponsive to maximal sympathomimetic treatment. The intravenous administration of enoximone in these patients, in addition to previous inotropic support, should permit a 'buying of time' strategy, leading to a reduction in the need for complex, invasive and costly techniques, such as artificial hearts. In addition, it should permit improved selection of candidates for cardiac transplantation. A prospective study was started in 1985 to obtain data on the haemodynamic and clinical efficacy of intravenous enoximone in these critically ill patients, and to determine the time gained for evaluation of the need for urgent transplantation. Cardiac index rose from 1.82 +/- 0.26 litres/minute/m2 to 2.67 +/- 0.56 litres/minute/m2 after 30 minutes, while pulmonary capillary wedge pressure decreased from 29.9 +/- 7 mm Hg to 18.0 +/- 7 mm Hg (n = 30). This early beneficial effect waned progressively after 6 hours. Prior to the next intravenous infusion at 8 hours, cardiac index was 2.07 +/- 0.53 litres/minute/m2 and pulmonary capillary wedge pressure was 25 +/- 8.5 mm Hg. Only four patients could not wait for a biological graft and had to be implanted with a complete artificial heart (3 patients), or a ventricular assist device (1 patient). In all, 30 patients improved and their increased survival allowed a re-evaluation for cardiac transplantation itself; 13 were rapidly (1.7 days; range 0.5-5) confirmed as good candidates. As a whole, this strategy compares favourably with the results of a strategy based on mechanical bridging alone.

Are there indications for reconstructive surgery in severe mitral regurgitation after acute myocardial infarction?

From 1972 to 1988, early surgery were performed in 26 patients with acute mitral regurgitation (MR) unresponsive to medical management complicating a recent acute myocardial infarction (AMI). The indication was acute pulmonary oedema (11), major left ventricular insufficiency (5), cardiogenic shock (10). Surgery was performed within 3 weeks following AMI. Mitral lesions were as follows: rupture of chordae tendinae (9) of papillary muscle (6), haemorrhagic necrosis of one (17) or two (9) papillary muscles. The mitral annulus was never found to be enlarged. The LV posterior wall was necrotic in 23, with a septal rupture in 3 and a giant aneurysm in 5. Valve replacement was performed in all but one patient. The 30-day mortality included 8 patients (31%). The cause of death was myocardial insufficiency in 5, early thrombosis of a disk valve in 1 and unrelated complications in 2. One patient deteriorated rapidly and had a Jarvik device implanted. Late results (1 month-15 years) showed 4 cardiac related deaths within the first year. One patient had to be transplanted after 1 year. Two patients died of non-cardiac problems at 3 months and 5 years. The probability of survival at 5 years is 43% and at 10 years 22%. In conclusion, there are still indications for early surgery in MR post AMI. Anatomical lesions of both papillary muscles and ventricular wall do not allow conservative surgery and new non-invasive technics provide a more promising strategy in such desperately ill patients.

Combined heart and kidney transplantation using the same donor.

A 45-year-old man received a combined heart and kidney transplant provided by the same donor. The patient was in the terminal stage of renal failure and was submitted to 3 sessions of haemodialysis per week for 2 years before transplantation. A dilated cardiomyopathy with severe impairment of left ventricular (LV) function was discovered, precluding renal transplantation alone. In the postoperative course, a cardiac rejection episode was detected by echocardiography and documented by endomyocardial biopsy; no simultaneous rejection of the kidney could be detected. The patient was discharged after 2 months, and he resumed a normal and active life. The specific problems raised by the management of such multi-organ transplantation are briefly reviewed.

Pharmacological bridge to cardiac transplantation.

From September 1985 to August 1988, 32 patients were referred from various intensive care units throughout Paris for urgent cardiac transplantation or for a mechanical bridge to transplantation. At time of admission, under maximal sympathomimetic therapy, the cardiac index (CI) was 1.81 +/- 0.26 l/min per m2, the pulmonary capillary wedge pressure (PCWP 31 +/- 7 mmHg), systemic vascular resistances (SVR) 2053 +/- 469 dynes s cm-5. In 25, diuresis was less than 25 ml/h. Five were anuric. Prior to any final decision, a new inotropic agent, enoximone, was infused in addition to previous treatment as a 10 min bolus iv 1.5-2 mg/kg every 8 h. In 3, the situation further deteriorated, leading to a Jarvik 7-70 implantation within 12 h. In 29 however, within 3 h, the Cl increased to 2.69 +/- 0.56 as SVR dropped to 1410 +/- 453 and PCWP to 18 +/- 7. Diuresis increased to more than 100 ml/h in all. This permitted an indepth evaluation of the transplant candidates leading to contraindications to transplantation in 16. Nine patients could be weaned off iv enoximone. Four of these are still living (NYHA class III) with a follow up of 6-17 months. In 11, transplantation was performed within 2 days. Four died within a month, 2 with multiple organ failure. One patient died after 5 months. Six are back to normal life, NYHA class I (follow up 10 months-2.5 years). This protocol suggests that in patients with extreme heart failure, immediate survival may be increased by iv enoximone therapy, permitting a better selection of the recipients, more efficient pre-transplantation intensive care and consequently a decrease in the indications for a temporary mechanical bridge to a staged transplantation.

Centrifugal pump or pneumatic ventricle for short-term mechanical circulatory support?

Two comparable groups of four Holstein calves were implanted with different left ventricle assist devices: the Centrimed centrifugal pump (CP) (Sarns Inc.) or the UTAH 85 VAD pneumatic ventricle (University of Utah). Operative procedure, inflow and outflow cannulae, monitoring, heparinization, were identical in both groups. No transfusion was ever required. The study was terminated after three days and autopsy was performed on the calves. Left ventricular unloading provided by both devices was complete (LVEDP less than 1 mmHg) and identical. LV bypassed flow rate was higher in CP (0.045 L/min/kg) than in UTAH 85 VAD (0.035 L/min/kg) but with no statistical difference. Blood trauma was comparable in the two groups. Daily blood samples did not show any significant changes from baseline values in creatinine, hematocrit, fibrinogen. Platelet loss from initial level was 30%; serum lactate dehydrogenase rose 150% with no significant difference in the two groups; plasma free hemoglobin never reached significant values. At autopsy, thrombotic deposits on cannuale and renal infarction rate were similar. CP housing had to be changed every day, whereas no technical failure was ever observed with the UTAH 85 VAD. Clinical response and blood damage of the two pumps used as LVAD were the same. Considering the CP has to be replaced every 24 h, the cost of three CP's would be comparable to one Utah UVAD-85 if polyurethane tricusp semi-lunar valves are used in the latter. Until the UTAH-85 VAD becomes commercially available, simple valveless low-cost CP are very attractive for short-term mechanical support.