Michele Musci

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.

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.

Surgical management of acute aortic root endocarditis with viable homograft: 13-year experience.

OBJECTIVE Cryopreserved homograft valves have been used for acute infective aortic root endocarditis with great success but it is compounded by its availability in all sizes. The long-term clinical results of geometric mismatched homografts are not well defined and addressed. METHODS Over a 15-year period (April 1986-June 2001), 816 patients presented with active infective endocarditis. One hundred and eighty-two of the patients aged between 9 and 78 years (mean: 51.0 +/- 1.13 years) consisting of 142 males and 40 females received homograft aortic valves. One hundred and ten patients were in NYHA functional class III and 72 in class IV and in cardiogenic shock. Of the patients, 2.7% suffered from septic embolism. One hundred and twenty-four (68.1%) patients presented with periannular abscesses and 58 (31.9%) with no abscess while 107 native valve (NVE) and 75 prosthetic valve (PVE) endocarditis were diagnosed preoperatively by transesophageal echocardiography (TEE) and confirmed intraoperatively. Freehand subcoronary implantation (FSCI) was used in 106 patients and root replacement in 76 patients. RESULTS The operative death was 8.5% and for patients in NYHA functional class IV and in cardiogenic shock was 14.5%. Late mortality rate was 7.9%. Patient survival after discharge from hospital at 1 year was 97% and at 10 years was 91%, respectively. Thirty-one (22.1%) patients underwent reoperation after 1.7 years (mean) with two deaths (6.4%). Early (< or = 60 days) and late reinfection rate was 2.7 and 3.6%, respectively. Freedom from reoperation for matched and undersized homografts at 10-13 years was 85 and 55%, respectively. The univariate model identified undersized homograft (P=0.002), FSCI (P=0.09) and reinfection (P=0.0001) as independent risk factors for developing early and late valve dysfunction resulting in reoperation and homograft explant. CONCLUSION Early aggressive valve replacement with homograft for active infective aortic root endocarditis with periannular abscesses is more successful than delayed last resort surgery. Homografts exhibit excellent clinical performance and durability with a low rate of reinfection, if properly inserted. Undersized homograft is an incremental risk factor for early and late reoperation.

Transient sinus node dysfunction after the Cox-maze III procedure in patients with organic heart disease and chronic fixed atrial fibrillation

OBJECTIVES This prospective study examined types, frequency and time dependency of the electrophysiologic manifestation of the sinus node dysfunction after the Cox-maze III procedure--the technique of choice for the management of medically refractory atrial fibrillation-in patients with organic heart disease, chronic fixed atrial fibrillation and no preoperatively overt dysfunction of the sinus node. BACKGROUND The original maze procedure was modified twice in order to reduce the high incidence of the sinus node inability to generate an appropriate sinus tachycardia in response to maximal exercise, and occasional left atrial dysfunction. Despite these modifications, postoperative disturbance of sinus node function can be frequently observed. METHODS In 15 adult patients, standard electrocardiogram, 24-h Holter monitoring, power spectral analysis of heart variability, exercise testing, Valsalva maneuver and rapid positional changes were performed 3, 6 and 12 months after the Cox-maze III procedure and mitral valve surgery or closure of atrial septal defect. RESULTS Electrocardiographic manifestations of sinus node dysfunction were identified in 12 patients at 3 months, in 6 patients at 6 months, and in 0 patients at 12 months after surgery. The heart rate response to exercise during the first 6 months was reduced in the maze group and became fully normal at 12 months. Power spectral analysis of heart rate variability showed very low power values at 1 month with inhibited cardiac autonomic activity and no response on sympathetic stress. A potential of recovery of cardiac autonomic activity was documented 12 months after surgery. CONCLUSIONS The manifestations of sinus node dysfunction following the Cox-maze III procedure were time dependent and their frequency and intensity progressively decreased and disappeared within 12 months after surgery.

Tricuspid valve dysfunction and surgery after orthotopic cardiac transplantation

OBJECTIVE The study examines the prevalence of tricuspid regurgitation and biopsy-induced flail tricuspid leaflets after orthotopic heart transplantation and evaluates the results of the tricuspid valve surgery. METHODS By a computerized search of the databases 647 of 889 patients who survived heart transplantation for more than 30 days were identified for this study. The primary tool for rejection monitoring in our institution is the daily observation of intramyocardial ECG (IMEG) based on day-by-day changes of the maximal QRS complex amplitude. Endomyocardial biopsy with 45-cm-long sheath bioptome was performed only in doubtful IMEG and echocardiographic data and at times of annual routine heart catheterization. Tricuspid regurgitation was diagnosed clinically and by echocardiography as mild, moderate and severe. Eleven patients received prosthetic valve replacements (four bioprostheses and seven mechanical valves) and six patients underwent valve reconstruction. The choice of xenograft valve was dictated by the condition of renal function. Patient survival and incidence of tricuspid regurgitation and freedom from operation for severe tricuspid regurgitation were analyzed with Kaplan-Meier method. RESULTS The prevalence of tricuspid regurgitation was 20.1%. Mild and moderate tricuspid regurgitation was seen in 14.5 and 3.1% of the patients, respectively, who were responsive to medical therapy and remained clinically stable in NYHA class I-II. Severe tricuspid regurgitation was seen in 16 (2.5%) patients who presented signs of an acute right heart dysfunction. Tricuspid valve pathology at operation revealed biopsy-induced rupture of the Chordae tendineae at various valve segments mostly the anterior and posterior leaflets. There was one hospital death (<30 day) and five late deaths due to infection, arrhythmia and trauma and no procedural-related or directly cardiac related death. Ten patients (62.5%) are alive at a mean follow-up time of 29.9 months (range 4-81 months) and nine survivors are in NYHA class I-II and one in class III. CONCLUSIONS Severe tricuspid regurgitation in transplanted hearts is associated mainly with biopsy-induced injury or endocarditis. Other regimes of rejection monitoring may help to eliminate this complication. Apart from our preference of valve repair, the choice of valve substitute may be influenced by the presence or the prospect of chronic renal failure. Heart transplant patients can safely undergo valve surgery with acceptable mortality, low morbidity and excellent intermediate-term clinical results. Mild to moderate functional tricuspid regurgitation is responsive to medical therapy and non-progressive and occur in 17.6% of orthotopic transplanted hearts without having a detrimental effect on the right ventricular performance.

Medium-term results of heart transplantation using donors over 63 years of age

BACKGROUND The continual shortage of hearts for transplantation (HTx) led to the expansion of the donor pool by accepting older donors. We compared the medium-term follow-up of patients after HTx with older hearts (over the age of 63 years) with those of patients after HTx with younger hearts. PATIENTS AND METHODS Since April 1994 we have used hearts for HTx from donors older than the age of 63 years. Until November 1998, 309 HTx and 9 re-HTx were performed in 309 adults with a mean age of 50.7+/-10.9 years (range 17-68 years). There were 252 men and 57 women. The patients were divided into two groups: group I--donor age under 63 years (296 patients, mean age 50.4+/-11 years; mean donor age 38.1+/-13 years; mean follow-up 1.7+/-1.6 years); group II-donor age of more than 63 years (13 patients, mean age 57.4+/-5.6 years; mean donor age 65.1+/-2.1; mean follow-up 2.2+/-1.6 years). There were no differences in the etiology of heart failure, gender, or ischemia time between the groups. The patients in group II were significantly older (P = 0.008). Multiple factors were analyzed in the groups, which included changes in the left/right ventricle ejection fraction, early postoperative mortality (up to 30 days), cumulative survival rates and cardiac-dependent morbidity [myocardial infarction, malignant arrhythmias, coronary stenosis (>50% in one of the main coronary arteries) and transplant vasculopathy]. Additionally, freedom from cytomegalovirus infection (rise of titer or seroconversion) and freedom of acute rejection episodes grade > or =2 (International Society of Heart & Lung Transplantation [ISHLT]) were analyzed. RESULTS After 1 year mean left and right ventricle ejection fraction were good in both groups and did not significantly change for up to 2 years. No Re-HTx was performed in group II. The early postoperative mortality was similar in both groups (P = 0.8). Also, the cumulative survival rates were similar in both groups (P = 0.87). Long-term cardiac morbidity was lower in group I (P = 0.03). The long-term freedom from cytomegalovirus infection in group I was significantly higher when compared with group II (P = 0.0002). The long-term freedom from severe rejection episodes was similar in both groups (P = 0.3) CONCLUSION The study found a significant increase in long-term cardiac morbidity due to more focal coronary stenosis in group II, and freedom from cytomegalovirus infection, but did not find significant differences in the long-term survival between patients who received hearts from donors of up to 63 years of age and from those more than 63 years. The acceptance of donors older than 63 years old for HTx does not worsen the outcome of the recipients. The careful selection of older donors, with close monitoring of the coronary situation after HTx and expanded indications for revascularization of older hearts, could make HTx with older hearts, even in older recipients, a safe option.

Surgical treatment for active infective prosthetic valve endocarditis: 22-year single-centre experience §

OBJECTIVE We retrospectively analysed the profile and outcome of surgically treated patients with active infective prosthetic valve endocarditis (PVE) over a period of 22 years. METHODS Between May 1986 and December 2008, a total of 1313 patients with active infective endocarditis (AIE) were operated on, 349 (26.6%) of them for PVE. Of these, 77 (22.1%) had to be operated upon due to early PVE (≤60 days, n=55 men, median age: 58 years) and 272 (77.9%) due to late PVE (n=200 men, median age: 63 years). A large proportion of patients were referred to our department with advanced endocarditis and in a condition of cardiac and pulmonary decompensation. A total of 226 (64.8%) patients developed periannular abscess. Operations consisted of 80 aortic valve, 45 mitral valve, 39 double valve and 165 aortic root replacements, 134 of them with a homograft. Perioperative characteristics, probability of survival, freedom from recurrence and predictors for hospital mortality were analysed. Follow-up (maximum: 19.4 years) was completed in 96.3% (total: 1118 patient-years). RESULTS There was high early and late mortality. Overall in-hospital mortality was 28.4% (99/349). The 30-day, 1-, 5- and 10-year survival for the whole PVE study population was 71.4 ± 2.4%, 58.7 ± 2.7%, 44.5 ± 3% and 31.7 ± 3.5% with no significant differences between the early and late PVE patients: 67 ± 5.4%, 55.9 ± 5.8%, 49.4 ± 6.2% and 29.7 ± 7.6%, compared to 72.4 ± 3%, 60 ± 3%, 43.5 ± 3.3% and 31.1 ± 3.8% (p=0.93). Predictors of early mortality were mechanical support (risk ratio (RR): 4.3), emergency operation (RR: 2.1), preoperative high doses of catecholamines (RR: 1.8), mitral valve replacement (RR: 1.5) and age at operation (RR: 1.1). Freedom from re-operation due to recurrent endocarditis at 10 years was 85.8 ± 5.6% for early PVE compared to 92.1 ± 2.3% for late PVE patients (p=0.17). Staphylococcus aureus (S. aureus) (18.1%) was the most frequent causative micro-organism. CONCLUSIONS Surgery for active infective PVE continues to be challenging. It not only carries a high in-hospital mortality but is also associated with a high long-term mortality risk. Early PVE patients were in a more severe condition than late PVE patients. Preoperative status, complications and co-morbidity of PVE patients strongly predict early outcome. Because of the potential risk of late complications, PVE patients need close clinical follow-up.

The cox maze III procedure: Parallel normalization of sinus node dysfunction, improvement of atrial function, and recovery of the cardiac autonomic nervous system ☆ ☆☆ ★ ★★

OBJECTIVE The Cox maze III procedure includes isolation of the pulmonary veins and multiple incisions in both atria in what corresponds to partial autotransplantation and partial denervation of the heart. The aim of this prospective longitudinal study was to identify physiologic effects of reinnervation on changes in heart rate at rest and in response to various stimulations and on atrial function after the Cox maze III procedure. PATIENTS AND METHODS Power spectral analysis of heart rate variability, exercise testing, 24-hour Holter monitoring, electrocardiography, and transthoracic and transesophageal echocardiography were performed in 30 adult patients after the combined Cox maze III procedure and mitral valve surgery (maze group). They were prospectively followed up at 1, 3, 6, and 12 months after the operation. The results were compared with those of 15 heart transplant recipients (transplant group) and normal probands (healthy adults, n = 12). RESULTS The physiologic effects of denervation with no differences in cardiac autonomic activity between the groups were seen early after the operation. Later, evidence of autonomic reinnervation was observed only in the maze group but not in the transplant group. Inappropriate heart rate responses during physical exercise were clearly evident in both groups after 1 and 3 months, with progressive improvement seen between 6 and 12 months only in the maze group. Left atrial function after the Cox maze procedure improved parallel to the recovery of sinus node function. CONCLUSION Progressive improvement of sinus node function and atrial contractions with significant functional normalization 1 year after the Cox maze procedure corresponded to functional reinnervation and recovery of the autonomic nervous system.

Surgical therapy in patients with active infective endocarditis: seven-year single centre experience in a subgroup of 255 patients treated with the Shelhigh® stentless bioprosthesis

OBJECTIVE We investigated outcomes after surgical therapy in patients with active infective endocarditis (AIE) with regard to survival in relation to surgical urgency, valve position, number of valves implanted and abscess formation. We aimed to identify independent risk factors for early mortality. METHODS AND RESULTS Two hundred and fifty-five patients received Shelhigh bioprostheses between February 2000 and March 2007. A total of 74.1% had native and 25.9% prosthetic AIE. Surgery was regarded as urgent in 57.3% and as an emergency procedure in 38.4%. There was a highly significant difference in survival rate between patients who were operated on urgently versus in an emergency (p<0.0001), between single and double valve replacement (p=0.0206) and between patients with and without abscess formation (p=0.0245). There were two cases of early reinfection (0.78%) and six of late reinfection (2.35%) leading to re-operation. CONCLUSIONS The survival of patients differs significantly in dependence on their surgical urgency. Better outcome could have been achieved if patients had been referred earlier for surgery and operated upon before heart failure or septic shock developed. Long-term survival was better in patients without abscess formation. The low reinfection rate of Shelhigh bioprostheses in AIE is promising and the early and mid-term results achieved need to be verified in the long-term course.

Body mass index and outcome after ventricular assist device placement.

BACKGROUND The implantation of ventricular assist devices (VAD) is an established treatment for end-stage congestive heart failure. Extremes of body mass index (BMI) are associated with decreased survival after cardiac surgery. Many patients with congestive heart failure develop cardiac cachexia. In this study the association between BMI and outcomes after VAD implantation was investigated. METHODS Consecutive patients (n = 590) who underwent VAD placement between 1996 and 2006 were divided into five groups based on BMI (kg/m2) quintiles (<20; 20-24; 25-29; 30-35; and >35). In a multivariate analysis adjusted for age, sex, diagnosis, emergency level, and type of device (left ventricular or biventricular assist device), procedural success (recovery, transplantation, or 30-day survival) and complications were analyzed. The best group was set as reference category for calculation of odds ratios. RESULTS The groups with both extremes of BMI had the worst outcomes. The best procedural success was in the group with BMI 25 to 29 kg/m2. Underweight patients had similar survival rates to patients with normal weight. Overweight and obese patients did not have decreased survival. Extreme obesity at the time of VAD implantation showed elevated risk for postoperative death. There was no significant difference for BMI groups in the type of complications and cause of death. Cumulative survival curves for BMI category and overall VAD patient survival showed no significant differences. CONCLUSIONS Cardiac cachexia need not be an exclusion criterion for VAD placement. Underweight patients appear to have benefit from mechanical support. Severely obese patients should be carefully selected before VAD placement.