Miralem Pasic

Transapical Aortic Valve Implantation: Incidence and Predictors of Paravalvular Leakage and Transvalvular Regurgitation in a Series of 358 Patients

OBJECTIVES The aim of this study was to evaluate the results when the surgical concept of not accepting intraprocedural paravalvular leakage was applied for transcatheter aortic valve implantation (TAVI). BACKGROUND The surgical strategy of conventional aortic valve replacement does not accept paraprosthetic leakage and requires immediate action to eliminate it. However, paravalvular leakage is the major concern after TAVI. METHODS A total of 358 patients underwent transapical TAVI with balloon-expandable prostheses. The modified procedural strategy consisted of precise positioning of the prosthesis using a modified TAVI technique and immediate additional intraprocedural treatment to eliminate relevant paravalvular leakage. RESULTS Balloon redilation of the transcatheter valve was performed in 18 patients (5%), and additional second valves were implanted in 13 (4%). At the end of the procedure, 186 patients (52%) had no paravalvular or transvalvular regurgitation. In the remaining 172 patients, paravalvular leakage was observed in 113 (32%), transvalvular leakage in 47 (13%), and both in 12 (3%). Leakage was trace in 88 patients (25%), mild in 82 (23%), and moderate in 2 (0.6%). Multivariate analysis identified male sex, New York Heart Association functional class IV, and no previous aortic valve replacement as predictors of post-procedural leakage. Cumulative survival was not dependent on post-procedural regurgitation rate. Overall mortality was 5 ± 1% at 30 days, 14 ± 2% at 6 months, 17 ± 2% at 1 year, and 33 ± 4% at 2 years. CONCLUSIONS The modified procedural strategy of transapical TAVI with a balloon-expandable prosthesis was associated with a low incidence of relevant prosthetic regurgitation.

Morphometric analysis of aortic media in patients with bicuspid and tricuspid aortic valve.

BACKGROUND Patients with bicuspid aortic valves tend to develop dilatation of the ascending aorta. The aim of this study was to analyze whether or not there is any histologic difference in the aortic media of patients with a bicuspid aortic valve or a tricuspid aortic valve. METHODS A morphometric analysis of the wall of the ascending aorta was performed in 107 patients with bicuspid aortic valves undergoing aortic valve operations. The thickness of the elastic lamellae of the aortic media and the distances between the elastic lamellae were measured with the use of an image analysis system. The histologic specimens of the ascending aorta from 61 surgical patients with tricuspid aortic valve disease served as a control. RESULTS The patients with bicuspid aortic valves had thinner elastic lamellae of the aortic media (2.71 +/- 0.23 microm) of the ascending aortic wall than the patients with tricuspid aortic valve disease (2.83 +/- 0.23 microm) (p = 0.006). The patients with bicuspid aortic valves also had greater distances between the elastic lamellae (27.21 +/- 8.69 microm) of the ascending aortic wall in comparison with the patients with tricuspid aortic valve disease (24.34 +/- 5.32 microm) (p = 0.033). There was no difference in the total thickness of the aortic media between the groups (p = 0.62). CONCLUSIONS Patients with a bicuspid aortic valve had thinner elastic lamellae of the aortic media and greater distances between the elastic lamellae than patients with a tricuspid aortic valve.

Risk and benefit of low systemic heparinization during open heart operations

Heparin surface-coated perfusion equipment with improved thromboresistance was evaluated in 104 consecutive patients undergoing open heart operation in a prospective, randomized trial with low versus full systemic heparinization. Surgical procedures included coronary artery revascularization in 47 of 54 (87%) for low versus 44 of 50 patients (88%; not significant [NS]) for full, valve repair/replacement in 8 of 54 (15%) for low versus 5 of 50 patients (10%; NS) for full, left ventricular aneurysm repair in 1 of 54 (2%) for low versus 2 of 50 patients (4%; NS) for full, and other in 3 of 54 (6%) for low versus 3 of 50 patients (6%; NS) for full. Cross-clamp time was 39.2 +/- 10.7 minutes for low versus 39.5 +/- 10.5 minutes for full (NS). Cardiopulmonary bypass time was 68.6 +/- 20.1 minutes for low versus 69.3 +/- 16.6 minutes for full (NS). Lowest activated coagulation time during perfusion was 255 +/- 75 seconds for low versus 537 +/- 205 seconds for full (p < 0.0005). In the low group, the target activated coagulation time of more than 180 seconds was not reached during perfusion in 4 of 54 patients (7%), the lowest value being 164 seconds. No oxygenator failure occurred. Hospital mortality was 0 of 54 (0%) for low versus 1 of 50 patients (2%) for full (NS). Bleeding required surgical revision in 0 of 54 (0%) for low versus 4 of 50 patients (8%) for full (p = 0.05). Drainage (24 hours) was 790 +/- 393 mL for low versus 1,039 +/- 732 mL for full (p < 0.025).(ABSTRACT TRUNCATED AT 250 WORDS)

Intraoperative radiofrequency maze ablation for atrial fibrillation: the Berlin modification

BACKGROUND The Cox-maze procedure combined with an operation for organic heart disease is highly successful in the elimination of chronic atrial fibrillation. However, it prolongs significantly the aortic cross-clamp and operating time. In this study, a simplified left atrial maze procedure, which is a short procedure performed using a surgical radiofrequency ablation probe, is added to elective open heart procedures in patients with atrial fibrillation. METHODS Forty-eight adults with atrial fibrillation (duration, 6 months to 36 years) underwent elective open heart operations (isolated valve procedures or coronary artery bypass grafting, n = 27 patients; combined procedures, n = 21 patients) combined with intraoperative radiofrequency ablation of the left atrium. The postoperative follow-up period ranged from 1 to 11 months (mean, 4 months). Possible predictors for persistent postoperative atrial fibrillation were determined among 40 variables by univariate and multivariate analyses. RESULTS Intraoperative radiofrequency ablation prolonged the aortic cross-clamp time for 6 to 14 minutes (mean, 11 minutes). Freedom from atrial fibrillation was 100% intraoperatively, 25% at 1 week after operation (12 of 48 patients), 59% at 1 month postoperatively (16 of 27 patients), 64% at 3 months postoperatively (16 of 25 patients), and 92% at 6 months postoperatively (12 of 13 patients). The only predictor of postoperative atrial fibrillation was the presence of coronary artery disease (odds ratio, 7.5; 80% confidence interval, 2.24-25.13). CONCLUSIONS Intraoperative radiofrequency ablation of the left atrium combined with an operation for organic heart disease effectively eliminates atrial fibrillation without significant prolongation of the aortic cross-clamp and operative time. The presence of coronary artery disease decreases the success rate during the first 6 postoperative months.

Aortic valve replacement with the Mitroflow pericardial bioprosthesis: Durability results up to 21 years

OBJECTIVE The study aim was to analyze the performance profile of a large series of Mitroflow pericardial valves (Sorin Group Canada Inc. Mitroflow Division) in the very long term. METHODS Data from 1513 patients with isolated aortic valve replacement who received pericardial bioprostheses between 1986 and 2007 were analyzed. Cumulative duration of follow-up was 6164 patient-years with a maximum duration of 21 years. Actuarial rates of valve-related events were calculated by the Kaplan-Meier method and the Cox multivariate analysis to identify independent determinants of outcome. RESULTS Hospital mortality for elective surgery was 2.5%. Late death was 40.6%. Reoperation was required in 86 (5.7%) patients and was valve related in 83: structural valve deterioration in 64 (4.2%) patients, prosthetic valve endocarditis in 17 patients (1.1%), valve thrombosis in 1, and periprosthetic leak in 1. Rates of 20-year actuarial freedom from valve-related morbidity were as follows: structural valve deterioration 84.8% (actual 96.6%) in patients 70 years of age or older; thromboembolism 94.1%; and prosthetic valve endocarditis 96.8%. Twenty-year actual risk of reoperation for structural valve deterioration was 11.4% in all patients and 3.4%, in patients 70 years or age or older. Advanced age, renal insufficiency, pulmonary disease, and low body mass index were independent risk factors for late outcome (P < .001). CONCLUSIONS After 2 decades of follow-up, the Mitroflow pericardial aortic valve continues to be a valve of choice with a predictable low rate of valve-related events, particularly for patients over the age of 65 to 70 years and others with comorbidities.

Experience with over 1000 Implanted Ventricular Assist Devices

Abstract  Purpose: The use of ventricular assist devices (VADs) in patients with chronic end‐stage or acute heart failure has led to improved survival. We present our experience since 1987. Subjects and Methods: Between July 1987 and December 2006, 1026 VADs were implanted in 970 patients. Most of them were men (81.9%). The indications were: cardiomyopathy (n = 708), postcardiotomy heart failure (n = 173), acute myocardial infarction (n = 36), acute graft failure (n = 45), a VAD problem (n = 6), and others (n = 2). Mean age was 46.1 (range 3 days to 78) years. In 50.5% of the patients the VAD implanted was left ventricular, in 47.9% biventricular, and in 1.5% right ventricular. There were 14 different types of VAD. A total artificial heart was implanted in 14 patients. Results: Survival analysis showed higher early mortality (p < 0.05) in the postcardiotomy group (50.9%) than in patients with preoperative profound cardiogenic shock (31.1%) and patients with preoperative end‐stage heart failure without severe shock (28.9%). A total of 270 patients were successfully bridged to heart transplantation (HTx). There were no significant differences in long‐term survival after HTx among patients with and without previous VAD. In 76 patients the device could be explanted after myocardial recovery. In 72 patients the aim of implantation was permanent support. During the study period 114 patients were discharged home. Currently, 54 patients are on a device. Conclusions: VAD implantation may lead to recovery from secondary organ failure. Patients should be considered for VAD implantation before profound, possibly irreversible, cardiogenic shock occurs. In patients with postcardiotomy heart failure, a more efficient algorithm should be developed to improve survival. With increased experience, more VAD patients can participate in out‐patient programs.

Homograft aortic root replacement in native or prosthetic active infective endocarditis: Twenty-year single-center experience

OBJECTIVE We compared early and long-term results of cryopreserved homograft aortic root replacement in native valve endocarditis or prosthetic valve endocarditis associated with periannular abscess. METHODS Between May 1986 and December 2007, 1163 patients with endocarditis were operated upon. Of these, 221 patients (n = 185 men, median age 55 years) had homograft aortic root replacement due to 99 cases of native valve endocarditis (45%) and 122 of prosthetic valve endocarditis (55%). Perinannular abscess developed in 189 patients (86%), and aortoventricular dehiscence in 120 (63.5%) of them. Perioperative characteristics, probability of survival, freedom from recurrence, and reoperation were analyzed. Follow-up (mean 5.2 +/- 0.4 years, maximum 18.4 years) was completed in 96.8% with a total of 1127 patient-years. RESULTS Overall native valve endocarditis survival at 30 days and 1, 5, and 10 years was 83.8% +/- 3.7%, 76.6% +/- 4.3%, 66.5% +/- 4.9%, and 47.3% +/- 5.6%, respectively, significantly better than for patients with prosthetic valve endocarditis, who had a greater tendency toward abscess formation (P = .029). Thirty-one patients (14.0%) required reoperation either for structural valve deterioration (n = 19, 8.6%), with a greater tendency in patients aged <40 years, or for recurrent endocarditis of the homograft (n = 12, 5.4%). One-year reoperation mortality rate was 16.1% (n = 5). CONCLUSIONS Homograft aortic root replacement in active infective endocarditis with periannular abscess formation shows satisfactory early and long-term results with significantly better survival in native valve endocarditis than prosthetic valve endocarditis. It is associated with a low recurrence rate, although the risk of structural valve deterioration increases over time, especially in young patients, and reoperation remains a challenge. In our institution, the homograft remains the preferred valve substitute in active infective endocarditis with periannular abscess formation.

Reduction aortoplasty for dilatation of the ascending aorta in patients with bicuspid aortic valve

BACKGROUND Individuals with bicuspid aortic valve tend to develop a dilatation of the ascending aorta. It is controversial whether the dilated ascending aorta should be replaced with a tube graft or whether the diameter of the aorta should be reduced by reduction aortoplasty. Furthermore, it is unclear whether an external prosthetic support of the reduction aortoplasty is necessary. The aim of this study is to analyze the results of reduction aortoplasty with and without external prosthetic support. METHODS Between 1985 and 1999, a total of 115 patients with bicuspid aortic valve and dilatation of the ascending aorta underwent reduction aortoplasty in combination with other types of open-heart procedure at our institution. The diameter of the ascending aorta was measured before and early after surgery and then later between 12 and 144 months (mean 40 months) postoperatively using echocardiography and computed tomography. RESULTS The reduction aortoplasty decreased the internal diameter of the aorta from 48.7+/-5.1 mm preoperatively to 36.9+/-3.6 mm early after surgery (p = 0.0001). During follow-up, there was no increase of the aortic diameter either in patients with external prosthetic support or in 97 of 106 patients without external prosthetic support. The diameter increased only in 9 (8.5%) of 106 patients without external aortic support by 4 to 8 mm. In patients with postoperative diameter increase, the aortic diameter after operation had been higher than in patients without a postoperative increase of the aortic diameter (41.4+/-3.1 mm vs 36.6+/-3.4 mm; p < 0.0001). CONCLUSIONS Reduction aortoplasty showed good long-term results in patients with bicuspid aortic valve and dilatation of the ascending aorta. Redilation of the aorta occurred only in patients with a suboptimal diameter reduction.

The influence of leukocyte filtration during cardiopulmonary bypass on postoperative lung function. A clinical study.

The accumulation of activated leukocytes in the pulmonary circulation plays an important role in the pathogenesis of lung dysfunction associated with cardiopulmonary bypass. Animal studies have demonstrated that the elimination of leukocytes from the circulation reduces postoperative lung injury and improves postoperative pulmonary function. We conducted a prospective randomized clinical study to evaluate whether postoperative lung function could be improved by use of a leukocyte filter during cardiopulmonary bypass. Elective coronary artery bypass grafting was done with a leukocyte-depleting arterial blood filter incorporated in the extracorporeal circuit (14 patients, leukocyte filter group) or without the filter (18 patients, control group). Blood samples collected at intervals before, during, and after operation were used for analysis of blood cell counts, elastase concentrations, and arterial blood gases. The use of the leukocyte filter caused no significant reduction in leukocyte count (p = 0.86). There were no differences in postoperative lung function between the groups, as assessed through (1) oxygenation index (290 for leukocyte filter group compared with 329 for control group, 95% confidence interval, 286 to 372, p = 0.21), (2) pulmonary vascular resistance (p = 0.10), and (3) intubation time (16.6 hours for leukocyte filter group versus 15.7 hours for control group, 95% confidence interval, 12.1 to 19.1 hours, p = 0.72). The levels of neutrophil elastase were significantly higher at the end of cardiopulmonary bypass in the leukocyte filter group (460 microgram/L in leukocyte filter group versus 230 microgram/L in control group, 95% confidence interval, 101 to 359 microgram/L, p = 0.003). We conclude that the clinical use of the present form of leukocyte-depleting filter did not improve any of the postoperative lung function parameters analyzed in this study.

Cannulation of the right axillary artery for surgery of acute type A aortic dissection

OBJECTIVE The optimal choice of the arterial inflow site during operations for type A aortic dissection is not clearly defined. The aim of the prospective study was to identify whether cannulation of the right axillary artery instead of the femoral artery may improve the results of surgery for acute type A aortic dissection. METHODS Seventy consecutive patients were operated on because of acute type A aortic dissection from January 2000 to February 2002. The only difference in surgical strategy was the site of arterial cannulation: the right axillary artery was used in 20 patients [axillary group] and the left femoral artery in 50 patients [femoral group]. All patients had aortic surgery with open distal anastomosis during deep hypothermic arrest and retrograde cerebral perfusion. The mean age was 58.7 +/- 12 years with a range from 28 to 88 years (axillary group, 56.6 +/- 13 years; femoral group, 59.4 +/- 12 years; P = 0.435). Preoperatively evident organ malperfusion was identified in five (25%) patients of the axillary group and in seven (14%) of the femoral group. RESULTS There was no perioperative death. The hospital mortality rate was 5.0% for the axillary group and 22% for the femoral group (all patients, 17%). Major neurological complications occurred postoperatively in 5% of patients from the axillary group (one out of 20 patients) and in 8% of patients from the femoral group (four out of 50 patients) (all patients, 7%). CONCLUSION Cannulation of the right axillary artery improved the outcome of surgery for acute type A aortic dissection. However, postoperative complications occurred after both axillary and femoral artery cannulation.