Search PubMed⌕ Search

Biomedical subjects

G Thiene

Publications and source records attributed to G Thiene.

At least 145 records · Page 8Linked to original sources
PubMed1994

Mid-term results of heart transplantation in diabetic patients.

BACKGROUND: Diabetes mellitus (DM) has been considered a relative contraindication to heart transplantation (HTx) because of possible increased infection rates and worsening DM with prednisone immunosuppression. The introduction of cyclosporine has allowed us to reduce the dosage of oral steroids and to accept DM patients (pts) for HTx. We reviewed the mid-term outcome of our DM pts who had undergone HTx. MATERIALS AND METHODS: Out of 257 HTx recipients, 19 males and 3 females, aged 53 +/- 8 years, were diabetic. Prior to HTx, DM was controlled with insulin in 5, with oral hypoglycemic agents in 7 and with diet in the remaining patients. Immunosuppression consisted of cyclosporine and azathioprine; low-dose prednisone was added in 10 patients because of repeated rejections. RESULTS: All patients survived HTx and were followed 2 to 75 (mean 38 +/- 21) months. There were 4 late deaths, with actuarial survival of 84% at 5 years. DM was more difficult to control after HTx (12 patients requiring insulin vs 5 pre-HTx), but comparison of diabetic vs non diabetic patients following HTx showed no significant difference in frequency of rejection or infection during the 1st year (2.6 +/- 1.6 vs 2.1 +/- 1.5; 0.5 +/- 0.4 vs 0.4 +/- 0.3 episode/patient respectively) and in 5-year actuarial survival (84% vs 77%). Renal function is preserved in all DM patients, hypertension has developed in 11/18 (61%); annual post-HTx cardiac catheterisation has shown normal graft function and coronary arteries in all but 2 patients. CONCLUSIONS: Mid-term results indicate that HTx can be safely performed in diabetic patients; a longer follow-up is required to determine whether DM is no longer a contraindication to HTx.

Actuarial Analysis↗
PubMed1994

Early and late outcome after reoperation for prosthetic valve dysfunction: analysis of 549 patients during a 26-year period.

Factors influencing operative mortality and late survival of 549 patients undergoing a first reoperation for prosthetic valve failure during the interval from 1966 to 1992 were analyzed; 347 patients had reoperation on a mitral prosthesis, 173 on an aortic prosthesis and 29 on both aortic and mitral prostheses. Univariate analysis showed that hospital mortality was higher in patients in functional class IV compared with those in class II-III (35% vs. 8%, p < 0.001), in those who required emergency reoperation (57% vs. 11%, p < 0.001), in those reoperated for endocarditis (59%) or valve thrombosis (43%) compared with those reoperated for structural valve deterioration (9%, p < 0.001), and in those with a failing mechanical prosthesis compared to patients with a bioprosthesis (21% vs. 10%, p < 0.05). Furthermore, operative mortality decreased from 41% in the period from 1966 to 1977, to 12% from 1977 to 1983 and to 8% from 1984 to 1992 (p < 0.001). Hospital survivors were followed from 0.1 to 22 years (mean follow-up 11 +/- 5 years) with an overall actuarial survival at 15 years of 24 +/- 5%. At 15 years actuarial survival is 24 +/- 5% for patients in preoperative functional class II-III and 20 +/- 6% for those in functional class IV (p < 0.05). It is concluded that in prosthetic valve recipients both early and late outcome is greatly influenced by preoperative clinical status. Increasing surgical experience, better myocardial protection and patient management have contributed to reducing the operative risk. More accurate patient follow up and possibly earlier reoperation might also improve the long term outcome.

Adolescent↗
PubMed1994

Donor shortage in heart transplantation. Is extension of donor age limits justified?

Chronic shortage of donor organs for heart transplantation led us to extend donor age limits. To verify the effectiveness of such a policy we have compared the results of heart transplantation in 45 patients with donors more than 40 years of age (group 1) with those of 72 patients older than 50 years of age who had heart transplantation with younger donors (group 2) between November 1985 and December 1992. The two groups were comparable in terms of mean recipient age, recipient and donor sex, and indication for heart transplantation. Mean donor age was 46 +/- 4 years (range 41 to 59 years) in group 1 and 23 +/- 7 years (range 8 to 39 years) in group 2 (p < 0.001). In group 1 cerebrovascular accidents were more common as the cause of donor death (60% versus 16%, p = 0.001), and no difference was found in ischemic time (144 +/- 47 minutes versus 140 +/- 48 minutes, p = not significant). There were 6 early (< 30 days) deaths in group 1 (13%) and 10 in group 2 (14%; p = not significant). Fatal acute graft failure was more prevalent, but not significantly so, in group 1 (10% versus 5.5%, p = not significant). Mean follow-up was 29 +/- 20 months (range 3 to 78 months) in group 1 and 30 +/- 20 months (range 3 to 80 months) in group 2 (p = not significant). At 5 years actuarial survival was 80% +/- 6% in both groups with comparable graft performance at echocardiographic and hemodynamic control studies. A significant difference was found in freedom from any type of coronary artery abnormality between group 1 (49% +/- 13%) and group 2 (77% +/- 8%) at 5 years (p < 0.05); however, freedom from coronary stenotic lesions only was similar. Major conduction disturbances have occurred more frequently in patients of group 1 (37% versus 12%; p = 0.003) without any difference in the need for permanent pacing. Donors older than 40 years of age can be accepted for heart transplantation with early and long-term results comparable with those obtained with younger donors. The impact of a higher incidence of coronary abnormalities on late performance of older grafts must be assessed at longer follow-up. Our results indicate that, because of the current organ shortage, extension of donor age limits is justified, even up to the sixth decade of life in selected cases.

Actuarial Analysis↗
PubMed1993

Endomyocardial biopsy in right ventricular cardiomyopathy.

Right ventricular cardiomyopathy is characterized by a progressive myocyte loss and fibro-fatty substitution of the right ventricle. The aim of our study was to assess the diagnostic accuracy of right ventricular endomyocardial biopsy. Using an imaging analyser system, histomorphometric parameters of myocytes, interstitium, fibrous tissue and fatty tissue were evaluated on endomyocardial biopsy from 30 patients with arrhythmogenic right ventricular cardiomyopathy, 29 patients with dilated cardiomyopathy and 30 control patients. The percent area of myocytes decreased from 78.10 +/- 7.34 in control to 63.39 +/- 9.22 in dilated cardiomyopathy (P < 0.05) and to 47.28 +/- 15.01 in arrhythmogenic right ventricular cardiomyopathy (P < 0.01). Fibrous tissue increased from 8.10 +/- 3.89 in control to 21.80 +/- 9.29 in dilated cardiomyopathy (P < 0.05) and to 24.60 +/- 11.37 in arrhythmogenic right ventricular cardiomyopathy (P < 0.05). Fatty tissue varied from 0.33 +/- 1.44 in control and 0.07 +/- 0.31 in dilated cardiomyopathy to 13.30 +/- 17.30 in arrhythmogenic right ventricular cardiomyopathy (P < 0.05). Fatty tissue was a feature of arrhythmogenic right ventricular cardiomyopathy (67% of patients vs. 6% of control and dilated cardiomyopathy patients). Diagnostic values typifying arrhythmogenic right ventricular cardiomyopathy, obtained by excluding any overlapping between confidence intervals in the three groups, were: myocytes < 44.95%; fibrous tissue > 40.38%, and fatty tissue > 3.21%, with 67% sensitivity and 91.53% specificity for at least one parameter. In conclusion, a significant difference between arrhythmogenic right ventricular cardiomyopathy, dilated cardiomyopathy and control exists in terms of amount of myocytes, fibrous tissue and fatty tissue. Presence of fatty tissue and fibrous tissue exceeding 3.21% and 40.38%, respectively should be considered highly suspect for arrhythmogenic right ventricular cardiomyopathy in right ventricular endomyocardial biopsy.

Adipose Tissue↗
PubMed1993

Endomyocardial biopsy in heterotopic heart transplant recipients via the femoral vein.

The results of endomyocardial biopsy (EMB) via the femoral vein in heterotopic heart transplant recipients were retrospectively analyzed and compared with those obtained using the right internal jugular vein approach. A total of 139 EMB were performed in 8 patients using the femoral (35) or the jugular (104) approach. Twenty three (64.7%) of the procedures performed via the femoral vein were part of the yearly hemodynamic and coronary artery study, and 12 (35.3%) constituted a routine postoperative evaluation of the myocardium rejection state in patients with imperviousness of the right internal jugular vein. Comparing the results obtained with the femoral approach, we observed a higher overall success rate (94.3 vs 88.5%, NS) and obtained more samples that were useful for histologic evaluation (95.5 vs 85.9%, NS); with the jugular procedure, the fragments were significatively larger in diameter (1.28 +/- 0.55 vs 1.61 +/- 0.85 mm, mean +/- SD) and in area (1.49 +/- 1.16 vs 2.28 +/- 2.24 mm2, mean +/- SD). No cardiac or local complications were noted when the femoral approach was used, while two attempts to perform biopsy via the jugular vein resulted in obstruction of this vessel. Our data suggest that the femoral venous approach for endomyocardial biopsy in heterotopic heart transplant recipients is a valid alternative to the more commonly used routes.

Biopsy↗
PubMed1993

Heart rate variability in patients with orthotopic heart transplantation: long-term follow-up.

To evaluate heart rate variability (expressed as the standard deviation of RR intervals) within 5 years of follow-up, we studied 20 patients (14 males, 6 females, mean age 44 +/- 12 years) who underwent orthotopic heart transplantation. Six measurements were taken: one in the first 3 weeks after transplantation, and the others once annually, for 5 years. Twenty healthy subjects (mean age 44 +/- 7 years) constituted the control group. Heart rate variability increased significantly in the first 3 years of follow-up (7.2 +/- 1 vs. 11.1 +/- 4, p < 0.001; 11.1 +/- 4 vs. 15.2 +/- 4, p < 0.01; 15.2 +/- 4 vs. 18.9 +/- 5, p < 0.05); in the following years this trend slackened and values did not reach a statistically significant difference (18.9 +/- 5 vs. 21.4 +/- 5; 21.4 +/- 5 vs. 22.5 +/- 5). The mean standard deviation was invariably greater in the control group (63.6 +/- 12). These findings show that sinus rhythm variability in the denervated heart progressively increased over 5 years of follow-up. The absence of presynaptic uptake, which is responsible for adrenergic hypersensitivity to circulating catecholamines and intrinsic cardiac reflexes, does not appear to cause this phenomenon, since these mechanisms are not able to evolve in time after cardiac transplantation. Therefore, an enhanced beta-adrenergic receptors density or affinity to circulating catecholamines or a limited sympathetic reinnervation may be the more probable underlying mechanism.

Electrocardiography, Ambulatory↗
PubMed1993

When and why do heart transplant recipients die? A 7 year experience of 1068 cardiac transplants.

This mortality study deals with the 1068 heart transplants (1054 patients) performed in Italian Units from November 1985 to April 1992. The death rate was 19.7% and the actuarial survival was 89% at 1 month, 83% at 1 year and 74% at 6.5 years. Recipients who died had been less often transplanted for dilated cardiomyopathy, were older (44.1 vs. 41.7 years) and more often male (84.5 vs. 72.7%). Analysis of the causes of death was restricted to orthotopic transplantations (1029/1068 procedures, 195/208 deaths). Deaths were grouped within four intervals: peri-operative (< or = 1 month, 50.0% of deaths), early (> 1 month < or = 3 months, 17.2%), intermediate (> 3 months < or = 2 years, 22.6%) and late (> 2 years, 10.2%). The prime causes of death were mostly postoperative graft failure (whose effects brought about 64% of peri-operative deaths, 28% of early and 7% of intermediate deaths), post-operative complications (10% of peri-operative deaths), acute rejection (10% of total deaths, distributed in all the periods), graft arteriopathy (6% of early, 36% of intermediate and 58% of late deaths), infections (17% of deaths, occurring in all periods but late) and malignant tumours (7% of deaths), lymphomas being the first to occur and Kaposi's sarcoma occurring only in the intermediate period. Repeat transplantation had a poor outcome (death rate 71.4%), two-thirds of the re-transplanted patients' deaths being due to early graft failure and a third to late relapsing graft vasculopathy.

Adult↗
PubMed1993

Right ventricular cardiomyopathy in identical and nonidentical young twins.

We describe the first sets of identical and nonidentical twins with right ventricular cardiomyopathy (RVC). Pair A: A 12-year-old boy was referred because of palpitation and syncope. Clinical and instrument examinations revealed an enlarged and depressed right ventricle (end-diastolic volume = 110 ml/m2; ejection fraction = 44%), spontaneous ventricular tachycardia, and fatty-fibrous infiltrates in the biopsy specimens. His asymptomatic, monozygotic twin showed localized involvement of the right ventricle with isolated, ventricular extrasystoles. Pair B: These 18-year-old nonidentical twin boys showed diffuse right ventricular involvement (end-diastolic volume = 110 ml/m2 and 114 ml/m2; ejection fraction = 30% and 24%, respectively), induction of sustained and nonsustained ventricular tachycardia, respectively, and fibrosis on endomyocardial biopsy. One of the boys died suddenly at rest after documented ventricular fibrillation. These cases support the hypothesis of a genetic etiology with a minor role for genotype and point to the important influence of environmental factors in determining the clinical features of the disease.

Adolescent↗
PubMed1993

Clinical results of steroid-free induction immunosuppression after heart transplantation.

Between January 1987 and September 1991, 112 operative survivors of heart transplantation were initially immunosuppressed with cyclosporin A and azathioprine without prednisone. Eighty-eight patients (79%) remained on a regimen of double therapy for a mean follow-up of 25 +/- 15 months (range, 1 to 54 months), whereas 24 patients (21%) had oral prednisone, 5 mg/day, added to maintenance therapy for persistent or repeated rejection. There were 5 early deaths (4%) because of acute rejection (4 patients) or infection (1 patient). Only 1 patient died late after heart transplantation of chronic rejection. Actuarial survival was 95% +/- 2% and 94% +/- 3% at 12 and 48 months, respectively. Mean rate of acute rejection was 1.7 +/- 1.0 episodes per patient, with a 5% +/- 2% freedom from rejection at 48 months. Ten patients (9%) required in-hospital treatment for infection; the actuarial freedom from infectious episodes was 85% +/- 4% at 48 months. Actuarial freedom from hypertension was 43% +/- 7% at 48 months. At annual catheterization, mean left ventricular ejection fraction was 0.64 +/- 0.08 and 0.62 +/- 0.05 at 1 year and 4 years, respectively, with evidence of coronary lesions in 9 patients (8%). In conclusion, steroid-free immunosuppression after heart transplantation is associated with a high incidence of acute rejection. However, the excellent medium-term survival and the low incidence of both infection and chronic rejection seem to justify a wider use of such treatment.

Adolescent↗
PubMed1993

Fatal obstruction of the left ventricular outflow tract caused by low-profile bioprostheses in the mitral valve position.

Two cases of fatal left ventricular outflow tract obstruction following mitral valve replacement with low-profile bioprostheses are described. This unfortunate experience shows that correct orientation of the prosthesis is mandatory also when using low-profile bioprosthetic valves to avoid this complication, particularly in patients with a small left ventricular cavity.

Aged↗
PubMed1993

[The early and late complications after percutaneous balloon coronary angioplasty].

The coronary arteries from the hearts of 7 patients, 6 male and 1 female, age ranging from 39 to 69 years (mean 56), who died early or in the mid term from percutaneous transluminal coronary angioplasty (PTCA), were investigated by histology, immunohistochemistry and electron microscopy. Atherosclerotic coronary artery disease was present in all: single vessel disease in 2 and double vessel disease in 5. Indication to PTCA was stable angina in 1 patient, unstable angina in 2, postinfarction angina in 2 and acute myocardial infarction in the remaining 2. Thrombolysis was an associated procedure in 3 cases. Time interval between PTCA and death was less than 48 hours in 6, and 4 months in 1. Cause of death was myocardial infarction due to coronary occlusion complicating PTCA in 3 patients, and myocardial infarctions preceding PTCA in 4 patients. 9 coronary segments underwent dilatation: 5 in the anterior descending coronary artery, 3 in the right coronary artery and 1 in the left circumflex artery. Angiographically, the PTCA had been effective (decrease of stenosis > or = 40%) in 5 and failed in 4. Basically, the atherosclerotic plaques were eccentric in 3 and concentric in 6; the histotype was fibrotic in 4, atheromatous in 4 and fibro-atheromatous in 1. Only one case did not show any complication and the dilatation was effective as a consequence of plaque compression and stretching of the underlying tunica media. Complications observed in the other cases with early death consisted of: a) plaque cracks with intimal flaps and hematomas in all 6; b) laceration of the tunica media, even of the disease-free wall, with dissecting hematoma in 2; c) occlusive thrombosis in 3 and d) atheroembolism in 1. The 4 coronary segments, which appeared occluded angiographically soon after PTCA, were clinically interpreted as dissection in 3 and thrombosis in 1, whereas at histology the closing mechanism was an intimal hematoma with flap in 2, occlusive thrombosis in 1, and medio-adventitial dissecting hematoma with thrombosis in 1. Only ruptures of atheromatous plaques were complicated by thrombosis. The patient who died at 4 months exhibited a pattern of restenosis due to intimal smooth muscle cell proliferation. In conclusion, our postmortem study shows that PTCA may be associated with severe damage of the coronary artery consisting of plaque crack and laceration even of the disease-free wall, intimal and medial hematomas, thrombosis and atheroembolism.(ABSTRACT TRUNCATED AT 400 WORDS)

Adult↗
PubMed1993

Cardiac fibroma and heart transplantation.

Successful orthotopic heart transplantation was performed in a 38-day-old child with a fetal echocardiographic diagnosis of a left ventricular mass and in a 40-year-old woman with cardiac murmur since childhood and an echocardiographic diagnosis of asymmetric septal hypertrophy. Pathologic examination of the removed hearts, consisting of gross, histologic, immunohistochemical, and ultrastructural studies, led to the final diagnosis of cardiac fibroma. Both patients were alive and in good condition at 35 and 28 months, respectively, after operation.

Adult↗