Time course and extent of improvement of dysfunctioning myocardium in patients with coronary artery disease and severely depressed left ventricular function after revascularization: correlation with positron emission tomographic findings.

OBJECTIVES: This study was performed to evaluate the prevalence, time course of recovery and extent of improvement of segments with a positron emission tomographic (PET) flow-metabolism mismatch and match pattern, as well as of PET segments with normal perfusion but with impaired myocardial function. BACKGROUND: Previous studies have shown that scintigraphic techniques evaluating myocardial viability provide predictive information about the improvement of regional wall motion. However, there are little data concerning the time course and extent of improvement of segments according to preoperative scintigraphic patterns. METHODS: Twenty-nine patients with ischemic cardiomyopathy (ejection fraction 18% to 35%) underwent preoperative PET viability assessment and were functionally assessed by two-dimensional echocardiography preoperatively and at 11 days, 14 weeks and >12 months after coronary artery bypass graft surgery. RESULTS: In 168 (70%) of 240 dysfunctional segments, a "normal" scintigraphic pattern was present, whereas a "mismatch" pattern was observed in 24% (p<0.01). Mismatch areas were associated with more severe preoperative wall motion abnormalities and incomplete postoperative recovery. After one year, 31% of normal scintigraphic segments, compared with only 18% of mismatch segments, showed complete functional restoration (p<0.05). CONCLUSIONS: These data suggest that in patients with severe left ventricular dysfunction, a scintigraphic pattern of normal perfusion and normal metabolism is more prevalent than a flow-metabolism mismatch pattern. Functional recovery is more frequent in normal scintigraphic segments, whereas in mismatch segments, postoperative recovery remains incomplete even after one year.

Long-term survival and functional follow-up in patients after the arterial switch operation.

BACKGROUND: For many years, the arterial switch operation (ASO) has been the therapy of choice for patients with transposition of the great arteries (TGA). Although excellent short- and mid-term results were reported, long-term results are rare. METHODS: Between May 1983 and September 1997, ASO was performed on 285 patients with simple TGA (n = 171), TGA with ventricular septal defect (VSD) (n = 85), and Taussig-Bing (TB) anomaly (n = 29). This retrospective study describes long-term morbidity and mortality over a 15-year period. RESULTS: Hospital mortality was 3.5% for simple TGA, 9.4% for TGA with VSD, and 13.8% for TB anomaly. Late death occured in 2 patients, 1 with simple TGA and 1 with TGA and VSD. The cumulative survival for all patients at 5 and 10 years is 93%, and at 15 years is 86%. Reoperations were required in 31 patients and were most common for stenosis of the right ventricular outflow tract (RVOT). However, no correlation was found between technical variations on pulmonary artery reconstruction and this type of complication. Forty-six patients underwent follow-up angiography, which revealed five cases with coronary occlusion or stenosis. Follow-up is complete in 96% of the patients from 1 to 15.2 years. Sinus rhythm is present in 97%; 88% of the patients show no limitations on exertion. CONCLUSIONS: The ASO can be performed with low early mortality, almost absent late mortality, and infrequent need for reoperation. The favorable long-term results demonstrate that the ASO can be considered as the optimal approach for patients with TGA and special forms of double-outlet right ventricle.

Results after surgical repair of Ebstein's anomaly.

BACKGROUND: Ebstein's anomaly of the tricuspid valve is a complex malformation. Various operations have been undertaken with varying results. Because valve replacement yielded poor results, surgical treatment has focused on valvuloplasties. METHODS: Between April 1974 and February 1995, 60 patients with Ebstein's anomaly underwent surgical repair. Age ranged from 5 months to 54 years. In 56 patients (93.3%), tricuspid valvuloplasty was feasible, mainly by creating a monocusp valve with the single-stitch technique. The other 4 patients had valve replacement with a bioprosthesis. Six reoperations were necessary (10.0%): four valve replacements and two repeat valvuloplasties. RESULTS: There were two hospital deaths (3.3%) and a late mortality rate of 10.0% (6 patients). Forty-nine (94.2%) of 52 survivors were followed for 5 months to 18.6 years (median follow-up, 5.0 years; mean follow-up, 6.9 years). The actuarial survival rate (Kaplan-Meier) was 96.5% +/- 2.4% at 1 year and 83.3% +/- 5.6% at 18 years. At follow-up evaluation, nearly all patients showed substantial improvement (93.9% were in functional class I or II) compared with their preoperative status. Doppler echocardiographic studies demonstrated good tricuspid valve function in most patients. CONCLUSIONS: Valvuloplasty using the single-stitch technique is a rewarding operation. It yields good long-term results with substantial improvement in functional performance and clinical status.

Bioprosthetic and mechanical valves in the elderly: benefits and risks.

There is controversy over whether elderly patients benefit from the durability of mechanical valves when balanced against the risk of anticoagulation. From 1976 to 1993, 576 patients 65 years old or older underwent isolated valve replacement with mechanical (n = 250) or bioprosthetic valves (n = 326). Total follow-up was 2,222 patient-years. Probability of survival and freedom from thromboembolism and prosthetic valve endocarditis were not different between the two groups. There was a significant difference (p = 0.015) in freedom from anticoagulant-related hemorrhage. Two patients with mechanical prostheses and 7 patients with bioprostheses were reoperated. However, actuarial freedom from reoperation was not different (p = 0.73) in both groups, with no hospital mortality, whereas mortality from thromboembolic events and anticoagulant-related hemorrhage was three times higher in patients with mechanical prostheses as compared with patients with bioprostheses (1.08% versus 0.36% per patient-year). The benefit from the durability of mechanical valves, compared with bioprostheses, is smaller than expected because of the limited number of patients exposed to the onset of bioprosthetic structural deterioration. Elderly patients without absolute indication for anticoagulation should preferentially receive bioprostheses for valvular replacement.

Repair of interrupted aortic arch: results after more than 20 years.

BACKGROUND: This study focused on the influence of concomitant anomalies, the individual surgical approach, and the probability for reinterventions. METHODS: Between 1975 and 1999, 94 patients with interrupted aortic arch were evaluated for short- and long-term results after surgical treatment. RESULTS: Interrupted aortic arch was associated mainly with a ventricular septal defect (85%) and left ventricular outflow tract obstruction (LVOTO, 13%). Mean follow-up was 6.7 years (median 6.9 years, 628.4 patient years). A single-stage operation was performed in 76 cases. Early mortality for two-stage procedures was 37% and late mortality was 26%, compared with single-stage procedures, with an early mortality of 12% and a late mortality of 20%, respectively. Early mortality in patients with additional LVOTO was 42% and late mortality was 50%. Freedom from reoperation at 5 years was 62%, and at 10 years was 49%. Reinterventions were performed mainly for residual arch stenosis, also with bronchus or tracheal compression, or LVOTO. CONCLUSIONS: Arch continuity and repair of associated anomalies can be achieved with an acceptable overall risk in this often complex entity. Associated anomalies play an important role in the outcome. Single-stage repair with primary anastomosis of the arch should be the surgical goal. The long-term probability for reoperation is high.

Ischemically compromised myocardium displays different time-courses of functional recovery: correlation with morphological alterations?

OBJECTIVE: It has been demonstrated that positron emission tomography (PET) predicts the functional recovery of viable but ischemically compromised myocardium. Reversible contractile dysfunction after revascularization has been reported for 'hibernating myocardium' and stunned myocardium, however, there are little data concerning the time-course and the extent of improvement of the two different pathophysiological conditions. METHODS: Twenty-nine patients with advanced coronary artery disease and severely reduced left ventricular function (EF 18--35%) who were referred for isolated coronary artery bypass grafting underwent preoperative PET viability assessment and were functionally assessed by two-dimensional echocardiography preoperatively at 11 days, 14 weeks, and more than 12 months after surgical revascularization. Intraoperative biopsies were taken from dysfunctional areas defined by PET as segments of normal perfusion and normal metabolism (stunned myocardium) and from areas with a 'mismatch' between perfusion and metabolism (hibernating myocardium). The degree of morphological alterations was evaluated by electron microscopy. RESULTS: In 70% of the 240 dysfunctional segments, 'stunned myocardium' was present whereas 'hibernating myocardium' could be detected in only 24% (P < 0.01). Hibernating myocardium was associated with more severe preoperative wall motion abnormalities and incomplete postoperative recovery. After 1 year, 31% of 'stunned' segments vs. only 18% of 'hibernating' segments showed complete functional restoration (P < 0.05). This incomplete improvement was associated with more severe morphological alterations including depletion of sarcomeres, accumulation of glycogen, loss of sarcoplasmatic reticulum, and cellular sequestration. CONCLUSIONS: These data indicate that in patients with severe ischemic left ventricular dysfunction 'stunned myocardium' is more prevalent than 'hibernation'. Functional normalization is more frequent in 'stunned' segments, whereas areas of 'hibernation' showed more severe tissue injury and protracted recovery. Different degrees of myocardial injury coexist in most patients, which determines the time-course and the extent of improvement after revascularization.

Results of biventricular repair of congenital cardiac malformations: definitive corrective surgery?

OBJECTIVES: Congenital cardiac malformations are usually corrected in the neonatal period or in early infancy. Corrective surgery may not always be definitive, especially in complex malformations. Long-term morbidity is influenced by reoperations and their risk. METHODS: This study analyzes our single-center experience over more than 20 years in a selected group of patients. Data were gathered, with special focus on causes and incidence for reoperations, respectively. RESULTS: Freedom from reoperation after 5, 10, and 15 years for each cardiac malformation was determined. The numbers describe in the following order patient years (y), number of patients (n), and freedom from reoperation at follow-up interval (%), respectively: atrial septal defect (15,864y, n=1198, 99+/-0/99+/-0/99+/-0), partial atrioventricular septal defect (2506y, n=234, 95+/-2/93+/-2/93+/-2), total anomalous pulmonary venous connection (742y, n=141, 93+/-1/91+/-0/91+/-0), complete atrioventricular septal defect (1715y, n=377, 81+/-3/76+/-3/72+/-4), tetralogy of Fallot <1 year (1503y, n=197, 94+/-4/85+/-1/74+/-3), transposition of great arteries (1459y, n=375, 88+/-2/83+/-4/73+/-7), interrupted aortic arch (IAA) (481y, n=98, 63+/-6/52+/-7/45+/-8), common arterial trunk (CAT) (599y, n=109, 64+/-6/24+/-6/11+/-5). CONCLUSIONS: In most congenital malformations surgical correction is definitive and the rate of reoperations is low. In complex anomalies, such as CAT and IAA, reoperations at long-term are more common. Analysis of such results and recognition of a sometimes inevitable operative morbidity helps to predict long-term outcome and influences the follow-up.

Assessing the benefit of biological valve prostheses: cumulative incidence (actual) vs. Kaplan-Meier (actuarial) analysis.

OBJECTIVE: The standard method of analysing structural valve degeneration (SVD) of biological prostheses is the Kaplan-Meier method. In order to assess SVD with regard to competing risks (e.g. death particularly in elderly patients) cumulative incidence (actual analysis) was compared to Kaplan-Meier (actuarial analysis). METHODS: We retrospectively analysed 257 patients older than 60 years, who underwent mitral valve replacement with different biological prostheses between 1974 and 2000. Reoperation-free survival was determined, both according to Kaplan-Meier and cumulative incidence analysis. RESULTS: For the total group of patients older than 60 years, the 10- and 15-year freedom from reoperation was 79+/-5 and 55+/-8%, respectively, according to Kaplan-Meier and 90+/-2 and 83+/-3% according to cumulative incidence analysis. For patients older than 65 years of age (n=170), Kaplan-Meier analysis revealed 85+/-7% freedom from reoperation at 10 years vs. 94+/-3% according to cumulative incidence analysis. For those between 60 and 65 years of age (n=87), Kaplan-Meier freedom from reoperation was 76+/-7% at 10 years and 48+/-9% at 15 years vs. 86+/-4 and 75+/-5% according to cumulative incidence analysis. CONCLUSIONS: Kaplan-Meier analysis overestimates the 10- and 15-year risk of SVD compared to cumulative incidence analysis, thus underestimating the benefit of biological valve replacement. Cumulative incidence analysis may lead to a more complete evaluation of risk and benefit and thus better patient management.

Mitral-valve replacement in children under 6 years of age.

OBJECTIVE: In patients with congenital mitral-valve disease, reconstructive surgery is the primary goal. However, in cases with severely dysplastic valves or failed repair, mitral-valve replacement (MVR) is the only option. We analyzed, retrospectively, data of 35 patients younger than 6 years of age, who underwent MVR at our institution. METHODS: Between 1974 and 1997, 35 children underwent MVR. The ages ranged from 2.7 months to 5.5 years (mean=1. 9+/-1.7 years) and body weight varied between 3.2 and 16.7 kg (mean=8.2+/-4 kg). The main indication (57%) for valve replacement was severe mitral-valve insufficiency. Eighteen patients (51%) had undergone at least one previous reconstructive operation (mean=1. 46+/-1.86 years) before the MVR. In 29 cases (83%), mechanical prostheses were implanted. Six patients received a bioprosthesis. The size of the prostheses ranged between 14 and 27 mm. RESULTS: The overall hospital mortality was 17.1% (6/35), and decreased from 33 (1974-1985) to 11.5% (1986-1997). Seven children died late. The actuarial survival after 20 years was 51.2+/-13.3%. Eight patients (23%) required 10 reoperations (8.2%/100 patient-years). Freedom from reoperation at 10 years was 50+/-22%. Valve-related complications were thrombo-embolism (n=2; 1.6%/100 patient-years), hemorrhage (n=1; 0.8%/100 patient-years), structural deterioration (n=3; 2.5%/100 patient-years) and non-structural dysfunction (n=3; 2. 5%/100 patient-years). Follow-up is 96% complete, with a total of 122 patient-years (mean=4.2+/-4.7 years). Eighty six percent of the patients are in New York Heart Association (NYHA) class I, 95% have sinus rhythm and 59% do not need medication. All survivors, except for those who received a bioprosthesis, were placed on a regimen of Phenprocoumon (Marcumar((R))), aiming to maintain the International Normalized Ratio (INR) between 2.5 and 3.5. In one third of these children, self-management of oral anticoagulation was performed either by the patients or their parents. CONCLUSIONS: MVR in small children still carries a high risk. In our experience, the long-term results are satisfying. After failed reconstructive surgery, or as a primary procedure, we prefer mechanical prostheses. They are well tolerated and the incidence of anticoagulation-related complications is low.

Aortic valve replacement in children: are we on the right track?

OBJECTIVE: The choice of the ideal prosthesis for aortic valve replacement (AVR) in children is still controversial. Early degeneration of bioprostheses and the potential risks related to anticoagulation in the child have renewed the interest of many surgeons towards the Ross operation. This study concerns our 22-year experience with AVR in children. METHODS: Forty-six children, aged 4 months to 16 years (mean 11.6 years), had AVR between April 1974 and December 1996. Preoperative diagnosis revealed aortic regurgitation (AR) in 25 cases, aortic stenosis (AS) in ten, combined AS and AR in nine and LVOTO in two patients. Of the 46 patients, 26 had 37 previous procedures. Isolated AVR was performed in 19 cases, 27 children underwent 36 concomitant intracardiac procedures. Mechanical prostheses were implanted in 30 children, bioprostheses in eight, aortic homografts in three. Five patients underwent a Ross procedure. RESULTS: There was one hospital death in the latter group (2.1%). Six of seven late deaths occurred in patients who underwent complex intracardiac procedures (15.2%). Reoperation rate was 19.5% (n = 10), differentiating 16.6% for mechanical (5/30 patients) and 50% (4/8 patients) for bioprostheses. The mean follow-up period was 8.01 years, ranging from 0.45 to 21.66 years (304.04 patient-years). There was one hemorrhagic event (2.1%) due to anticoagulation, thrombosis of the mechanical valve occurred in two patients (4.2%). CONCLUSIONS: AVR can be performed with acceptable mortality rate and good long-term results in children. We perform the Ross operation only in selected cases. According to our experience, mechanical prostheses show excellent performances in children with a low incidence of complications related to anticoagulation.

Single centre experience on primary correction of common arterial trunk: overall survival and freedom from reoperation after more than 15 years.

OBJECTIVE: To identify predictors of early and late outcomes of common arterial trunk (CAT) after primary surgical correction, such as clinical state prior to surgery, age and weight at presentation, implications of truncal valve abnormalities and associated anomalies of this complex congenital malformation. METHODS: A consecutive series of 106 patients, operated between 1976 and 1998, were reviewed retrospectively. Using the 'Van Praagh' classification, 59 patients presented as A1, 33 as A2, six as A3, and eight as A4. The mean age at operation was 8.6 months (range, 14 days-8.9 years; median, 4.4 months), and the mean weight was 5.2 kg (range, 2.5-30.8 kg; median, 4.4 kg). At the time of operation, 32 patients had congestive heart failure, five were on ventilator support for less than 1 week, and 21 for more than 1 week. RESULTS: Between 1976 and 1989, the early mortality was 21%, and between 1990 and 1998, it dropped to 13%. After 1, 10 and 15 years, the overall survival was 66, 61 and 59%. The 1, 5, 10 and 15 year freedom from reoperation was 82, 60, 22 and 10%, respectively. Clinical condition prior to intervention, truncal valvar dysfunction, and coronary anomalies were significantly associated with poor surgical outcome, whereas weight and age at presentation in our series were not. CONCLUSIONS: In the current era of paediatric cardiac surgery, primary surgical repair of CAT can be carried out with reasonable early and late mortality. However, our data suggest that a high incidence of reoperation, mainly due to the outgrowth and failure of the conduit, has to be expected. The patient's clinical state after diagnosis is decisive for the timing of intervention.

Impact of patient-prosthesis mismatch on exercise capacity in patients after bioprosthetic aortic valve replacement.

OBJECTIVE: It is presumed that patient-prosthesis mismatch (PPM) influences morbidity and mortality after aortic valve replacement (AVR). The aim of our study was to determine the impact of PPM on physical capacity. METHODS: Six months after AVR with a bioprosthesis, stress echocardiography was performed on a bicycle ergometer in 312 patients. Depending on gender, age and weight, the target exercise level for every patient was determined by a reference table. Maximum achieved workload is given as percentage of the predicted exercise capacity (PPEC). PPM was defined as an effective orifice area index

Timing of repair in ventricular septal defect with aortic insufficiency.

OBJECTIVE: Trusler's valvuloplasty technique and its modifications are the standard approach for the repair of aortic insufficiency in combination with ventricular septal defect. However, recurrent aortic insufficiency may occur after repair. The timing of surgical intervention in patients with ventricular septal defect and aortic insufficiency is still controversial. METHODS: Between 1985 and 2000, 33 patients were analyzed retrospectively focusing on echocardiographic findings. For statistical analysis, the patients were divided into two groups according to the grade of preoperative aortic insufficiency: there were 5 patients with preoperative severe aortic insufficiency and 28 patients with mild to moderate aortic insufficiency. RESULTS: The mean age at operation was 6.05 +/- 3.61 years. The aortic valve was repaired by means of Trusler's valvuloplasty in the majority of the patients. All but three had patch closure of the ventricular septal defect, with a transaortic approach in 54 %. Mean follow-up was 5.1 years with a maximum of 16.9 years (168.9 patient years). Rates for freedom from reoperation at 1, 3, and 8 years were 90 %, 85 %, and 75 %, respectively. In 3 patients, a mechanical prosthesis was implanted at the time of reoperation. One sudden death occurred after 3.6 years. Patients with preoperative severe aortic insufficiency were reoperated significantly more often (P < 0.03). In patients with preoperative severe aortic insufficiency, the underlying pathology (insufficiency) was detected earlier on in life (8.4 +/- 10 months) than in patients (45.0 +/- 30 months) with mild to moderate aortic insufficiency at the time of intervention (P < 0.05). CONCLUSION: Severe aortic insufficiency at the time of operation has less favorable long-term results. Therefore, early surgical intervention, even in young patients, seems warranted to avoid potential reoperation or valve replacement.

[Ebstein's anomaly: when should a patient have operative treatment?]. / Morbus Ebstein: Wann ist die Operation indiziert?

Ebstein's anomaly is a complex malformation of the tricuspid valve where the hinges of the septal and/or posterior leaflets are displaced downward into the right ventricle. The leaflets show variable deformations. In general, the anterior leaflet is enlarged. For those patients who have only mild symptoms, medical management is recommended, but operative treatment is indicated if progressive deterioration is evident. The timing of the surgical intervention is still a matter of controversy, especially since the results of surgical treatment were substantially improved by further development of repair techniques. Between 1974 and August, 1997, 69 patients with Ebstein's anomaly underwent surgical repair. In 65 patients (94.2%) tricuspid valvuloplasty was feasible, mainly by creating a monocusp valve with the "single-stitch technique", developed in our clinic by F. Sebening. Four patients required primary valve replacement with a bioprosthesis. Ten reoperations (14.5%) were necessary: 6 repeat valvuloplasties, 4 valve replacements. There were 2 hospital deaths (2.9%), the late mortality was 8.7% (6 patients). Since 1992, our valvuloplasties have been evaluated by intraoperative transesophageal echocardiography (TEE). Follow-up was obtained in 58 patients (95%) over a period of 4 months to 21.0 years (median 5.3 years, mean 7.6 years). The actuarial survival rate (Kaplan-Meier) was 96.5% +/- 2.4% at 1 year and 83.3% +/- 5.6% at 21 years. Pre-operatively, the majority of patients were in New York Heart Association functional Class III. At follow-up evaluation, nearly all patients showed substantial improvement of their pre-operative status, 94.8% were in NYHA Class I or II. Doppler echocardiographic studies demonstrated good tricuspid valve function in most patients. The valvuloplasty developed in our hospital using a single-stitch technique is a rewarding operation, which yields good long-term results. An analysis of the postoperative deaths revealed that all patients but one suffered from endstage cardiac disease and had a cardio-thoracic ratio greater than 0.65. This supports the importance of surgical intervention in time. In our opinion, operation is even indicated for those patients in functional Class II who reveal clinical deterioration.