Gennaro Ismeno

Variables predicting adverse outcome in patients with deep sternal wound infection

BACKGROUND Mortality after deep sternal wound infection (DSWI) ranges between 5% and 47%. Variables predicting hospital mortality and prolonged hospital stay are still to be assessed. METHODS Among 13,420 patients who underwent cardiac surgery in our institution between 1979 and 1999, DSWI developed in 112 cases (0.8%). Multiple variables were recorded prospectively and analyzed retrospectively as predictors of hospital death and prolonged (>30 days) hospital stay. The analyzed variables were divided into three groups: (1) related to the patient, including demographic variables and preoperative conditions; (2) related to cardiac operation; and (3) related to infection. Predictive variables were assessed by univariate and multivariate logistic regression analysis. RESULTS Hospital mortality was 16.9%. The hospital stay of the 93 discharged patients ranged between 16 and 180 days (mean 31.3 +/- 15.2). Length of cardiac operation, length of stay in intensive care unit, interval between symptoms of DSWI and wound debridement were found to be the most significant predictors of bad outcome following DSWI. CONCLUSIONS In our study demographic variables and preoperative conditions did not affect the prognosis of DSWI. Lower mortality rate and shorter hospital stay could be achieved with earlier and aggressive treatment of DSWI.

Intravascular hemolysis after mitral and aortic valve replacement with different types of mechanical prostheses

Heart valve replacement with mechanical prosthesis is associated with mild intravascular hemolysis. In this study we evaluated the incidence of hemolysis in patients with different combinations of two mechanical valves. Between 1974 and 1996, 680 patients underwent mitral and aortic valve replacement with mechanical prostheses; we selected 90 patients, divided into six groups according to the prosthetic model (Group A, ball and tilting disc; Group B, ball and bileaflet; Group C, tilting disc and tilting disc; Group D, tilting disc and bileaflet; Group E, bileaflet and tilting disc; Group F, bileaflet and bileaflet; respectively, in mitral and aortic position). Blood tests were performed to check blood hemoglobin, serum lactic dehydrogenase, percent-correlated reticulocyte fraction, serum haptoglobin, and schistocytes. Chi square test was performed for categorical data. ANOVA and Bonferroni tests were performed in order to evaluate significant statistical differences between media and variance of the hematological data. A mild degree of intravascular hemolysis was observed in 30% of patients with double mechanical prostheses. LDH values were above the normal values in all groups, although a significant difference was found only between Group B versus Groups C and D. Reticulocytes and schistocytes and serum haptoglobin values were within the normal range and no differences were found between the groups. Low levels of blood hemoglobin were found in Groups D and F. The difference was statistically significant when compared with Groups A and E. In conclusion, hemolysis is frequent but never severe in patients with mitral and aortic mechanical prostheses. A higher incidence of subclinical hemolysis was found in patients with bileaflet valves regardless of the position of the implant.

Are blood and valve cultures predictive for long-term outcome following surgery for infective endocarditis?

OBJECTIVE To evaluate whether perioperative bacteria identification in blood and/or in valve cultures can predict early and late outcome of surgery for infective endocarditis, a retrospective study was performed. METHODS Between January 1978 and December 1998, 232 patients, 79 (34.1%) female and 153 (65.9%) male with mean age of 44. 95+/-1.03 years (range 8-79) underwent surgery for infective endocarditis on a native (162 cases) or prosthetic (70 cases) valve. Patients were divided into three groups according to the perioperative x of microbiological tests: Group A: patients with preoperative positive blood cultures (83 cases); Group B: patients with positive valve cultures (35 cases); Group C: patients with negative blood and valve cultures (114 cases). Categorical values were compared by chi(2) analysis, whereas continuous data were compared by ANOVA and Bonferroni correction for post hoc comparisons. Analysis of late survival and complications was performed with Kaplan-Meier and Log Rank test. Late mortality, reoperation, perivalvular leak, recurrence of infection were considered as treatment failure. All data were presented as mean+/-standard error. RESULTS Hospital mortality was 10.8% (9/83) in Group A, 8.6% (3/35) in Group B, and 14.9% (17/114) in Group C (P=0.52; not significant (NS)). Ten-year survival was 62.7+/-8% in Group A, 43.9+/-19% in Group B and 62.7+/-7% in Group C (P=0.38; NS). Ten-year freedom from reoperation was 85.2+/-6% in Group A, 37.9+/-20% in Group B and 80+/-6% in Group C (P=0.0034). Ten-year freedom from treatment failure was 56.3+/-8% in Group A, 31.6+/-16% in Group B and 55. 3+/-7% in Group C (P=0.46; NS). CONCLUSIONS Positive blood and tissue cultures are not predictive for hospital mortality and late treatment failure in patients with infective endocarditis. Positive valve cultures, a common finding in patients with staphylococcal endocarditis, are predictive for a higher risk of reoperation.

Acute effects of beating heart coronary surgery on left ventricular performance.

BACKGROUND The increasing use of off-pump bypass grafting (OPCABG), requires an evaluation of its effects on left ventricular (LV) performance. METHODS In 8 patients with multivessel coronary disease who were undergoing to off-pump coronary artery bypass grafting, LV performance was analyzed from the pressure-volume (P-V) plane by the conductance catheter technique. Measurements were performed at base line, after the exposure of the vessels, after the application of the stabilization system, and at the end of the procedure. RESULTS No significant changes in heart rate, LV end-systolic volume, LV end-diastolic pressure, mean pulmonary artery, and mean systemic blood pressure were observed in the various stages of the procedure. Cardiac index decreased during left anterior descending coronary artery grafting after application of the stabilizer with a concomitant decrease in LV end-diastolic volume, together with decreases in LV peak negative -dP/dt and increases in tau, indicating an impairment of LV relaxation but without a change in preload recruitable stroke work, indicating preserved LV contractile state. Exposure of posterior and lateral vessels induced a decrease in cardiac index and preload recruitable stroke work without a decrease in LV preload, indicating a decrease in LV contractile state together with a decrease in peak -dP/dt and increase in tau, indicating an impairment in LV relaxation CONCLUSIONS Off-pump coronary artery bypass grafting can be performed without decreasing LV performance. Major cardiac displacement like that used for posterior and lateral exposure induces acutely significant decrease in LV contractile state.

Surgery for tricuspid valve endocarditis: A selective approach

SummaryThe authors report their 18-year experience in the surgical treatment of infective tricuspid endocarditis. Between January 1981 and January 1999, 238 cases of infective endocarditis were seen, with a tricuspid involvement in 21 cases (8.8%). Tricuspid valve repair was performed in 9 patients with infective lesions involving one single leaflet. The surgical principle of the repair was to avoid any prosthetic material implantation. Posterior leaflet vegetectomy was performed in another 2 patients with infected intracavitary leads. Tricuspid valve replacement was performed in 10 patients with involvement of the whole valvular apparatus. One patient died of septic shock 3 days postoperatively. All the other patients had a good postoperative recovery. Follow-up ranged between 12 and 155 months (mean 68.9 ± 55 months). Five cases of late mortality were observed: 3 for cardiac reasons and 2 of cancer. All the other patients are alive. Late postoperative echocardiography in the patients with tricuspid repair showed tricuspid regurgitation to be absent in 6 patients, mild in 2, moderate in 1, and severe in 1. No recurrent infections were observed either in patients with valve repair or in those with valve replacement. Good early and long-term results can be achieved in the surgical treatment of tricuspid endocarditis as long as complete excision of the infected tissue is performed and risk factors are controlled.

Long-term follow-up of open commissurotomy versus bileaflet valve replacement for rheumatic mitral stenosis.

OBJECTIVE Despite the achievements of third generation mechanical cardiac valve prostheses, conservative procedures are still considered the best surgical option for rheumatic mitral valve stenosis. To compare long-term results of open mitral commissurotomy (Group A) and mitral valve replacement with bileaflet prostheses (Group B) a 15-year follow-up study was carried out. METHODS From January 1981 to May 1996, 540 consecutive patients with pure isolated rheumatic mitral stenosis underwent mitral valve surgery: 300 had mitral commissurotomy and 240 valve replacement. The follow-up was 99.05% complete and ranged between 1 and 185 months in Group A and from 1 to 171 months in Group B. RESULTS Hospital mortality was 2% in Group A and 2.08% in Group B. Late mortality was 1% in Group A and 3% in Group B. The 10-year survival rates were 98.7% +/- 1% in Group A and 93.7% +/- 3% in Group B. There was a statistically significant difference of freedom from reoperation in Group B (97.7% +/- 1%) versus Group A (88.1% +/- 2%) (P = 0.04). In group A 14 embolic events occurred (93.7% +/- 2%), and 15 (6.52%) in Group B (83.9% +/- 7%). Haemorrhagic events were observed in 2 patients (0.68%) of Group A (99.3% +/- 0.5%) and in 3 patients (1.3%) of Group B (98.4% +/- 1%). CONCLUSIONS Long term results of mitral commissurotomy were more satisfactory than those obtained with bileaflet valves. Reoperation rate was higher in mitral commissurotomy.

Antiplatelet versus oral anticoagulant therapy as antithrombotic prophylaxis after mitral valve repair

OBJECTIVE To verify the rate of thromboembolic and hemorrhagic complications during the first 6 months after mitral valve repair and to assess whether the type of antithrombotic therapy influenced clinical outcome. METHODS Retrospective data were retrieved from 19 centers. Inclusion criteria were isolated mitral valve repair with ring implantation. Exclusion criteria were ongoing or past atrial fibrillation and any combined intraoperative surgical procedures. The study cohort consisted of 1882 patients (aged 58 ± 15 years; 36% women), and included 1517 treated with an oral anticoagulant (VKA group) and 365 with antiplatelet drugs (APLT group). Primary efficacy outcome was the incidence of arterial thromboembolic events within 6 months and primary safety outcome was the incidence of major bleeding within 6 months. Propensity matching was performed to obtain 2 comparable cohorts (858 vs 286). RESULTS No differences were detected for arterial embolic complications in matched cohort (1.6% VKA vs 2.1% APLT; P = .50). Conversely, patients in the APLT group showed lower incidence of major bleeding complications (3.9% vs 0.7%; P = .01). Six-month mortality rate was significantly higher in the VKA group (2.7% vs 0.3%; P = .02). Multivariable analysis in the matched cohort found VKA as independent predictor of major bleeding complications and mortality at 6 months. CONCLUSIONS Vitamin K antagonist therapy was not superior to antiplatelet therapy to prevent thromboembolic complications after mitral valve repair. Our data suggest that oral anticoagulation may carry a higher bleeding risk compared with antiplatelet therapy, although these results should be confirmed in an adequately powered randomized controlled trial.

Surgery of rheumatic mitral stenosis: comparison of different techniques.

Objective — The breakthrough of percutaneous transvenous mitral commissurotomy (PTMC) has dramatically changed the indications for the surgical treatment of rheumatic mitral stenosis over the last decade. No recent studies comparing long-term results of PTMC, open mitral commissurotomy (OMC) and mitral valve replacement (MVR) with bileaflet prostheses are available in medical literature. Methods and results — Between January 1991 and December 1997, 313 patients with pure and isolated rheumatic stenosis were treated in our department. One hundred and eleven patients underwent PTMC, 82 OMC and 120 MVR.There was no statistical difference (p>0.05) between the mortality rates of the three groups of patients. No cases of hospital mortality were observed in the patients who underwent PTMC and OMC, whereas two patients (1.6%) died within 30 days after MVR. Seven year actuarial survival results are: 95.41±2(SE)% (PTMC), 98.05±1% (OMC) and 92.82±33% (MVR) (p=NS). Freedom from embolism was 98.78±1% in PTMC, 98.78±1% in OMC and 92.52±2% in MVR (p>0.05); freedom from reoperation was 88.43±8% in PTMC, 96.35%±2% in OMC and 97.72±1% in MVR (p>0.05).The mean NYHA class at the end of follow-up was lower in OMC (1.14±0.3) versus PTMC (1.39±0.6) and MVR (1.41±0.71) (p=0.001). Conclusions — Even though conservative techniques are the first option to consider in treating mitral valve stenosis, valve replacement with bileaflet prostheses no longer represents a limiting factor to survival and quality of life.

Cardiac Rupture Due to Mitral Valve Endocarditis

A 66-year-old lady with a history of mitral valve endocarditis and recent onset of low-output syndrome, underwent successful emergency surgery for myocardial rupture with hemopericardium. Visualization of the abscess cavity was not possible with transthoracic echocardiography and a definitive diagnosis was made by transesophageal echocardiography. Diagnostic and therapeutic aspects of mitral valve abscess are reviewed.

Echocardiographic Appearance of Normally Functioning Sorin Bicarbon Valve Prostheses

A clinical and echocardiographic study was carried out to evaluate the performance of the Sorin Bicarbon bileaflet valve. From December 1990 to December 1994, 100 patients underwent isolated mitral (64) or aortic (36) valve replacement. There were 39 males and 61 females, with ages ranging from 21 to 73 years (mean 62 ± 9.6 years). Forty-three patients underwent a transthoracic continuous pulsed color Doppler echocardiogram at 3 and 6 months postoperatively. For mitral prostheses, the parameters calculated were valve area, pressure half-time and mean gradient; for aortic prostheses, peak and mean gradients were measured. Results were compared by analysis of variance to those obtained in patients matched for sex, body surface area, cardiac rhythm, site, and size of the prosthesis who had St. Jude Medical or CarboMedics valves implanted. No statistically significant differences were found among the 3 prosthetic heart valves. The operative mortality was 7%; 3 cases of fatal cerebral hemorrhage occurred in the early postoperative period. There was 1 late mortality, 1 case of transient cerebral ischemia, and 1 of gastric bleeding, all occurring inpatients with mitral prostheses. Midterm follow-up was satisfactory, although a larger series is required to confirm these results.