Giuseppe Nasso

The −174G/C Interleukin-6 Polymorphism Influences Postoperative Interleukin-6 Levels and Postoperative Atrial Fibrillation. Is Atrial Fibrillation an Inflammatory Complication?

Background—It has been suggested that inflammation can have a role in the development of atrial arrhythmias after cardiac surgery and that a genetic predisposition to develop postoperative complications exists. This study was conceived to verify if a potential genetic modulator of the systemic inflammatory reaction to cardiopulmonary bypass (the −174 G/C polymorphism of the promoter of the Interleukin-6 gene) has a role in the pathogenesis of postoperative atrial fibrillation (AF). Patients and Results—In 110 primary isolated coronary artery bypass patients the −174G/C Interleukin-6 promoter gene variant was determined. Interleukin-6, fibrinogen and C-reactive protein plasma levels were determined preoperatively, 24, 48, and 72 hours after surgery and at discharge. Heart rate and rhythm were continuously monitored for the first 36 to 48 hours; daily 12-lead electrocardiograms were performed thereafter until discharge. GG, CT, and CC genotypes were found in 62, 38, and 10 patients, respectively. Multivariate analysis (which included genotype, age, sex, and classical risk factors for AF) identified the GG genotype as the only independent predictor of postoperative AF. The latter occurred in 33.9% of GG versus 10.4% of non-GG patients (hazard ratio 3.25, 95%CI 1.23 to 8.62). AF patients had higher blood levels of Interleukin-6 and fibrinogen after surgery (P <0.001 for difference between the area under the curve). Conclusion—The −174G/C Interleukin-6 promoter gene variant appears to modulate the inflammatory response to surgery and to influence the development of postoperative AF. These data suggest an inflammatory component of postoperative atrial arrhythmias and a genetic predisposition to this complication.

Prospective Randomized Comparison of Coronary Bypass Grafting With Minimal Extracorporeal Circulation System (MECC) Versus Off-Pump Coronary Surgery

Background— We aimed to evaluate the clinical results and biocompatibility of the minimal extracorporeal circulation system (MECC) compared with off-pump coronary revascularization (OPCABG). Methods and Results— In a prospective randomized study, 150 patients underwent coronary surgery with the use of MECC and 150 underwent OPCABG. End points were (1) circulating markers of inflammation and organ injury, (2) operative results, and (3) outcome at 1-year follow-up. Operative mortality and morbidity were comparable between the groups. Release of inflammatory markers was similar between groups at all time points (peak interleukin-6 167.2±13.5 versus 181±6.5 pg/mL, P=0.14, OPCABG versus MECC group, respectively). Peak creatine kinase was 419.3±103.5 versus 326±84.2 mg/dL (P=0.28), and peak S-100 protein was 0.13±0.08 versus 0.29±0.1 pg/mL (P=0.058, OPCABG versus MECC group, respectively). Length of hospital stay and use of blood products were similar between groups. Two cases of angina recurrence at 1 year in the MECC group were observed versus 5 cases observed in the OPCABG group (P=0.44). A residual perfusion defect at myocardial nuclear scan was less frequent among patients in the MECC group (3 versus 9 cases, P=0.14; odds ratio 0.32, 95% confidence interval 0.07 to 1.32). Six (OPCABG group) versus 3 (MECC group) coronary grafts were occluded or severely stenotic at 1 year (P=0.33, odds ratio 0.47, 95% confidence interval 0.09 to 2.14). Conclusions— Clinical results of coronary revascularization with MECC are optimal when this procedure is performed by experienced teams. Postoperative morbidity is comparable to that with OPCABG. MECC is associated with little pump-related systemic and organ injury. It may achieve the benefits of OPCABG (less morbidity in high-risk patients) while facilitating complete revascularization in the case of complex lesions unsuitable for OPCABG.

Prospective, Randomized Clinical Trial of the FloSeal Matrix Sealant in Cardiac Surgery

BACKGROUND Topical hemostatic agents composed of a gelatin-based matrix and thrombin have been reported to be effective, in addition to traditional means, in terminating bleeding during cardiac operations. We compared a hemostatic matrix sealant agent (FloSeal; Baxter Inc, Deerfield, IL) with alternative topical hemostatic agents in a mixed cohort of elective cardiac and thoracic aortic operations. METHODS Following sample size calculation, in a prospective randomized study design, 209 patients were treated with FloSeal matrix sealant (FloSeal group) and 206 patients received alternative agents as topical hemostatic materials (comparison group). FloSeal is composed of a self-expandable gelatin matrix component and purified bovine thrombin. Comparisons included hemostatic patches or sponges composed of either oxidized regenerated cellulose or purified porcine skin gelatin. Study endpoints were the following: rate of successful intraoperative hemostasis (identified by cessation of bleeding) and time required for hemostasis; overall postoperative bleeding; rate of transfusion of blood products; rate of surgical revision for bleeding; postoperative morbidity; and intensive care unit stay. RESULTS Statistically higher rates of successful hemostasis and shorter time-to-hemostasis were observed in the FloSeal group (p < 0.001 both). Time-to-event analysis confirmed this finding (p = 0.0025). Postoperative bleeding and rate of transfusion of blood products were statistically decreased in the FloSeal group (p < 0.001 both). Rates of revision for bleeding and of minor complications were not statistically different among groups in the overall cohort, but were significantly lesser in the FloSeal group if only patients with overt intraoperative bleeding are considered (p = 0.04 both). The advantages observed in the FloSeal group were not offset in patients undergoing systemic hypothermia. CONCLUSIONS The topical hemostatic agent used in the FloSeal group is effective in terminating intraoperative bleeding as an adjunct to traditional surgical methods for stopping bleeding. Its judicious use is associated with lesser need for transfusion of blood products and rate of revision for bleeding. Its cost-utility profile should be addressed in dedicated trials.

Genetic control of postoperative systemic inflammatory reaction and pulmonary and renal complications after coronary artery surgery.

BACKGROUND Although some data suggest that the individual genetic predisposition for developing major or minor degrees of postoperative systemic inflammatory reaction may influence postoperative morbidity, this hypothesis has not been clinically tested to date. Methods and results The -174 G/C polymorphism of the promoter of the interleukin 6 gene was determined preoperatively in 111 consecutive patients submitted to primary isolated coronary artery bypass. The results of the genetic analysis were then correlated with the postoperative interleukin 6 levels and the development of postoperative renal and pulmonary complications. G homozygotes had significantly higher interleukin 6 levels postoperatively (P <.0001 for the difference between areas under the curve). These patients also had worse postoperative pulmonary and renal function. The mean perioperative difference in serum creatinine, potassium, and nitrogen was 0.82 +/- 0.34, 0.99 +/- 0.44, and 10.1 +/- 7.8 mg/dL versus 0.18 +/- 0.14, 0.15 +/- 0.48, and 2.6 +/- 4.1 mg/dL for GG versus non-GG carriers (P <.0001), respectively. The mean respiratory index at 6 and 12 hours was 2.9 +/- 0.8 and 2.8 +/- 0.3 versus 2.1 +/- 0.5 and 1.3 +/- 0.1, respectively (P <.0001). The mean duration of mechanical ventilation was 22.5 +/- 2.1 versus 12.7 +/- 6.7 hours (P <.01). A correlation was found between postoperative interleukin 6 levels and renal and pulmonary complications. CONCLUSION The interleukin 6 -174 G/C polymorphism modulates postoperative interleukin 6 levels and is associated with the degree of postoperative renal and pulmonary dysfunction and in-hospital stay after coronary surgery.

Preoperative C-reactive protein level and outcome following coronary surgery

OBJECTIVE It has been suggested that a preoperative level of C-reactive protein (CRP)>5mg/l is predictive of postoperative complications in cardiac surgery patients. MATERIAL AND METHODS Among 113 primary isolated coronary artery bypass patients, CRP was determined preoperatively and fibrinogen, interleukine 6, plasminogen activator inhibitor-1, prothrombin time, activated partial thromboplastin time, platelets and white blood cells count measured before surgery, 24, 48 and 72h thereafter and at hospital discharge. The clinical course of all cases was prospectively recorded. Data were then analysed according to the preoperative CRP level by dividing the patients into two groups (CRP>5mg/l or CRP<5mg/l). RESULTS The in-hospital results were similar between the two patients groups. Even the postoperative haematic inflammatory markers did not significantly differ according to the preoperative CRP level. CONCLUSION In this prospective study, a preoperative level of CRP>5mg/l did not predict in-hospital postoperative complications nor influence the extent of the inflammatory activation in primary isolated coronary bypass patients.

Arterial Versus Venous Bypass Grafts in Patients With In-Stent Restenosis

Background—In patients who develop in-stent restenosis, successful revascularization can be difficult to achieve using percutaneous methods. This study was designed to verify the surgical results in this setting and to evaluate the potential beneficial role of arterial bypass conduits. Methods and Results—Sixty consecutive coronary artery bypass patients with previous in-stent restenosis and 60 control cases were randomly assigned to receive an arterial conduit (either right internal thoracic or radial artery; study group) or a great saphenous vein graft (control group) on the first obtuse marginal artery to complete the surgical revascularization procedure. At a mean follow-up of 52±11 months, patients were reassessed clinically and by angiography. Freedom from clinical and instrumental evidence of ischemia recurrence was found in 19 of 60 subjects in the study group versus 45 of 60 in the control series (P=0.01). The results of the arterial grafts were excellent in both the study and control groups (right internal thoracic artery patency rate, 19 of 20 for both, and radial artery patency rate, 20 of 20 versus 19 of 20; P=0.99). Saphenous vein grafts showed lower patency rate than arterial grafts in both series and had extremely high failure rate in the study group (patency rate, 10 of 20 in the study group versus 18 of 20 in the control group; P=0.001). Use of venous graft was an independent predictor of failure in the study group, whereas hypercholesterolemia was associated with graft failure in both series. Conclusions—Venous grafts have an high incidence of failure among cases who previously developed in-stent restenosis, whereas the use of arterial conduits can improve the angiographic and clinical results. Arterial grafts should probably be the first surgical choice in this patient population.

Coronary artery bypass grafting in type II diabetic patients: a comparison between insulin-dependent and non-insulin-dependent patients at short- and mid-term follow-up

BACKGROUND Diabetes is a well-established risk factor for coronary artery disease, and it is associated with an increased rate of early and late adverse events after myocardial revascularization by coronary artery bypass grafting. METHODS A prospective follow-up study was done to evaluate the short-term and mid-term outcomes of type II diabetic patients who had coronary artery bypass grafting at our institution between 1996 and May 1999. A total of 200 patients, 100 insulin-dependent diabetic patients (group I) and 100 non-insulin-dependent diabetic patients (group II), met the inclusion criteria of the study and were included in the clinical follow-up study. RESULTS The characteristics of the patients of the two groups were similar for baseline clinical angiographic and operative characteristics. In particular, no significant differences in cardiopulmonary bypass and aortic cross-clamping times were noted between the two groups. The number grafts per patient was similar between the two groups. There were no in-hospital deaths, but postoperative complications were different among the two series. In fact, 33% of patients in group I had at least one major complication compared with 20% in group II (p = 0.037). The cumulative number of complications was 148 in group I and 69 in group II, and the mean number of complications per patient was 4.5 and 3.5 in groups I and II, respectively. The major differences in perioperative complication rates were found in the need for prolonged (> 24 hours) ventilation, occurrence of respiratory or renal insufficiency, and mediastinitis. The mean length of stay in the intensive care unit and for total hospitalization were longer in group I than group II (4.3 +/- 2.8 days versus 2.8 +/- 2.7 days [p = 0.010] and 11.1 +/- 2.2 days versus 7.2 +/- 2.4 group II [p < 0.05], respectively). At long-term follow-up, group I patients had a significantly higher mortality rate (29% versus 10%, p < 0.001). Moreover, overall late cardiac and noncardiac complication rates were significantly higher in group I than II (37% versus 22%, p = 0.02). In the multivariate analysis including several preoperative and operative variables, treatment by insulin, advanced age (> 75 years), left ventricular dysfunction (left ventricular ejection fraction < 35%), and complex lesions at coronary angiography (American Heart Association lesion classification type C lesion) were found as independent predictors of increased mortality. CONCLUSIONS Our data show that patients with insulin-dependent type II diabetes who had coronary artery bypass grafting have a significantly higher rate of major postoperative complications with an extremely unfavorable short- and long-term prognosis. Diabetic patients on insulin treatment should be considered high-risk candidates for coronary artery bypass grafting and require intense perioperative and long-term monitoring. Further studies will be necessary to investigate whether such conclusions may be appropriate for newer surgical strategies such as off-pump operation.

Operative and Middle-Term Results of Cardiac Surgery in Nonagenarians A Bridge Toward Routine Practice

Background— Age >90 years represents in many centers an absolute contraindication to cardiac surgery. Nonagenarians are a rapidly growing subset of the population posing an expanding clinical problem. To provide helpful information in regard to this complex decision, we analyzed the operative and 5-year results of coronary and valvular surgical procedures in these patients. Methods and Results— We retrospectively reviewed 127 patients aged ≥90 years who underwent cardiac surgery within our hospital group in the period 1998 to 2008. Kaplan–Meier and multiple logistic regression analyses were performed. A longer follow-up than most published studies and the largest series published thus far are presented. Mean age was 92 years (range, 90 to 103 years). Mean logistic EuroSCORE was 21.3±6.1. Sixty patients had valvular surgery (including 11 valve repairs), 49 patients had coronary artery bypass grafting, and 18 had valvular plus coronary artery bypass grafting surgery (55 left mammary artery grafts implanted). Forty-five patients (35.4%) were operated on nonelectively. Operative mortality was 13.4% (17 cases). Fifty-four patients (42.5%) had a complicated postoperative course. There were no statistically significant differences in the rate and type of complications between patient strata on the basis of type of surgery performed. Nonelective priority predicted a complicated postoperative course. Predictors of operative mortality were nonelective priority and previous myocardial infarction. Kaplan–Meier survival estimates at 5 years were comparable between patient groups on the basis of procedure performed. Conclusions— Although the rate of postoperative complications remains high, cardiac surgery in nonagenarians can achieve functional improvement at the price of considerable operative and follow-up mortality rates. Cardiac operations in these very elderly subjects are supported if appropriate selection is made and if the operation is performed earlier and electively. Our results should contribute to the development of guidelines for cardiac operations in nonagenarians.

Arterial revascularization in primary coronary artery bypass grafting: Direct comparison of 4 strategies—Results of the Stand-in-Y Mammary Study

OBJECTIVE It is unclear (1) whether the use of 2 arterial conduits rather than a single conduit in multivessel coronary artery bypass grafting significantly improves results despite the concomitant use of saphenous vein grafts and (2) whether any among different configurations of composite grafts (left/right thoracic arteries and radial artery) offers an advantage over the others. METHODS Eight hundred fifteen patients were randomized to one of 3 different strategies of revascularization by using the left thoracic artery plus the right thoracic artery or using the left thoracic artery plus the radial artery. Venous grafts were used for the remaining targets. Patients randomized to receive 1 arterial graft served as control subjects. Operative mortality and morbidity were comparable among groups. RESULTS The rate of cerebrovascular complications was not statistically lower among patients receiving 2 arterial grafts. At 2 years, overall survival was not significantly different among groups (P = .59). Cardiac event-free survival was significantly better in patients receiving 2 arterial grafts versus control subjects (P < .0001), even among elderly patients (P = .022). The 3 investigated strategies using 2 arterial conduits were similar concerning early and midterm results. CONCLUSIONS Revascularization with 2 arterial conduits offers better midterm event-free survival than a single arterial graft, irrespective of which second-choice arterial conduit is used (radial artery or right thoracic artery), the simultaneous use of saphenous vein grafts, and the patients age.

Results of mitral valve repair for Barlow disease (bileaflet prolapse) via right minithoracotomy versus conventional median sternotomy: a randomized trial.

OBJECTIVE The results of mitral repair for complex Barlow valves are adequate and support earlier intervention. It is unknown whether these results are reproducible in the context of minimally invasive surgery via right minithoracotomy. METHODS We randomized patients with Barlow mitral disease (bileaflet prolapse) to have conventional open repair via median sternotomy (MS group) or minimally invasive (MI group) repair. Repair was done using polytetrafluoroethylene chordal reimplantation for both leaflets. In the MI group, we adopted right minithoracotomy, peripheral cannulation, external aortic clamping, and surgery under direct vision. RESULTS Both groups comprised 70 patients. The operative and the cardiopulmonary bypass times were significantly longer in the MI group (P = .003 and P = .012). Mitral repair was successful in 98.5% MI patients and 100% MS patients. Operative mortality was comparable. The mean mechanical ventilation time, intensive care unit stay, and hospital stay were lower in the MI group (P = .014, P =.02, and P = .03,). Mean pain score was lower in the MI group at postoperative days 2 and 4. At follow-up, the freedom from moderate (2+) or severe (3+ or 4+) mitral regurgitation was 98% versus 97% (P = .9). Two patients underwent reoperation (1 in each group) for late failure of repair. The Kaplan-Meier analysis confirmed these results. CONCLUSIONS Our data indicate that the optimal standard-of-care results of mitral repair for complex disease (Barlow) are reproducible in the minimally invasive settings through right minithoracotomy and direct vision. The minimally invasive technique can be proposed for complex mitral disease and early referral of these patients can be encouraged.