Diastolic properties of the Sorin Solo, ATS 3F, Edwards Prima Plus and Medtronic Freestyle stentless valves: an independent in-vitro comparison.

BACKGROUND AND AIM OF THE STUDY: Currently, little is known of the diastolic properties of stentless valves that affect stress and strain on leaflets and, hence, their durability. In a pressurized aortic root model, a series of in-vitro tests was conducted to determine how stentless valves behave in diastole, and how they adapt to different annulus-to-sinotubular junction (STJ) ratios. METHODS: Sixteen 25 mm stentless aortic valves (four each of the Sorin Solo, ATS 3F, Edwards Prima Plus and Medtronic FreeStyle) were sutured into a 32 mm Valsalva graft, suspending the commissures into the expandable region (42 mm). The neoaortic root was pressurized and the size of the STJ progressively reduced by wrapping the neocommissural ridge with Dacron rings. Endoscopic views and ultrasound imaging were used to observe the geometry of the leaflets, regurgitation, and the height and level of leaflet coaptation at different annulus-to-STJ ratios. RESULTS: Pericardial prostheses built to mimic a cylinder (ATS 3F and Sorin Solo) showed the greatest tolerance to STJ dilatation and a larger coaptation surface, but also a tendency to roll in on themselves in an italic S-shape if oversized. Valves built to mimic native aortic leaflets (porcine Prima Plus and Medtronic Freestyle) showed a reduced tolerance to STJ dilatation, resulting in regurgitation and a smaller coaptation surface, but also a reduced tendency to roll if oversized. CONCLUSION: Despite similar systolic performances, stentless prostheses behave differently during diastole. The 3F and Solo valves benefit from a better tolerance to STJ dilatation, while the Prima Plus and Freestyle benefit from a more stable shape of closure under conditions of oversizing.

Preoperative very short-term, high-dose erythropoietin administration diminishes blood transfusion rate in off-pump coronary artery bypass: a randomized blind controlled study.

OBJECTIVE: Human recombinant erythropoietin has been used to obtain a rapid increase in red blood cells before surgery. Previously, the shortest preparatory interval has been 4 days, but at the European Hospital only 2.4 days on average separate hospitalization and surgery. We therefore proposed a randomized blind trial to test the efficacy of high-dose erythropoietin for very short-term administration. METHODS: All patients presenting with a diagnosis of isolated coronary vessel disease were randomized to either erythropoietin therapy or a control group. Patients with a creatinine level greater than 2 mg/dL or hemoglobin level greater than 14.5 g/dL were excluded. Hemoglobin values were collected preoperatively and on postoperative days 1 and 4. Blood loss and blood transfusion rate were recorded at the time of discharge. RESULTS: We enrolled 320 consecutive patients in the study. No significant difference was found in preoperative parameters, postoperative blood loss, or mean preoperative hemoglobin levels. On postoperative day 4, mean hemoglobin was 15.5% higher in the erythropoietin group (10.70 +/- 0.72 g/dL vs 9.26 +/- 0.71 g/dL; P < .05). This group required 0.33 units of blood per patient, whereas the controls required 0.76 units per patient (risk ratio 0.43, P = .008). CONCLUSION: A significant reduction in transfusion rate and a significant increase in hemoglobin values were observed in the erythropoietin group. No adverse events related to erythropoietin administration were recorded. A very short preoperative erythropoietin administration seems to be a safe and easy method to reduce the need for blood transfusions.

Long-term survival and quality of life of patients with prolonged postoperative intensive care unit stay: unmasking an apparent success.

OBJECTIVE: Our objective was to evaluate the long-term survival and quality of life of patients who faced a prolonged (>10 days) postoperative stay in the intensive care unit and were discharged from the hospital. METHODS: Among 3125 consecutive patients who underwent cardiac operations in a 5-year period, we prospectively identified 57 who faced a prolonged postoperative intensive care unit stay and were discharged alive from the hospital. Patients were enrolled in a prospective follow-up protocol and evaluated every 6 to 12 months both clinically and instrumentally. RESULTS: Mean intensive care unit stay was 34 +/- 9 days (range 11-141 days). Follow-up was complete and mean follow-up time was 71 months. Overall survival was 12 (21%) of 57, and the majority of follow-up deaths were cardiac related. Of the surviving patients, only a small minority (4/12) regained full autonomy and returned to their previous lifestyle. Risk factors for prolonged intensive care unit stay were age, New York Heart Association/Canadian Cardiovascular Society class, hypertension, diabetes, low ejection fraction, aortic surgery, preoperative renal failure, nonelective surgery, prolonged cardiopulmonary bypass time, and perioperative use of aortic counterpulsator. CONCLUSIONS: Patients who face a prolonged postoperative intensive care unit stay and who were discharged from the hospital have a very poor long-term outcome and even worse quality of life. These data lead to a consideration of the wisdom of using heroic treatment in patients who face a prolonged postoperative intensive care unit stay in view of the dismal clinical results and enormous use of hospital and human resources.

Repeat valvular operations: bench optimization of conventional surgery.

BACKGROUND: Repeat heart valve operations have become a quite common procedure. We reviewed our experience with reoperative valvular surgery during a 6-year period to assess the risk factors affecting in-hospital mortality and medium-term survival. METHODS: A series of 316 redo procedures performed on a total of 290 patients in the period between 1997 and 2002 at our institution was retrospectively analyzed. Univariate and multivariable analyses were performed. RESULTS: In-hospital mortality was 3.8%; overall mortality at the end of a 30-month follow-up was 9.3%. We identified advanced New York Heart Association class, advanced age, depressed ejection fraction, emergent or urgent presentation, impairment of renal function, and involvement of tricuspid valve as predictors of mortality. In contrast, duration of cardiopulmonary bypass and multiple valve procedure were not associated with increased short-term risk. CONCLUSIONS: The present study is characterized by particular attention in reducing confounding variables and biases correlated to heterogeneities. The main determinants of mortality are related to the degree of patients' illness rather than to inherent technical factors of reoperations. Although highest-risk individuals (previous coronary artery bypass grafting or coexistence of aortic aneurysm) were excluded from the study, our data suggest that patients undergoing isolated redo valvular procedures now face operative risks that are comparable to primary intervention.

Skeletonization does not influence internal thoracic artery innervation.

BACKGROUND: This study was designed to compare the effect of surgical harvesting on internal thoracic artery innervation and to assess the eventual presence of denervation supersensitivity in skeletonized grafts. METHODS: Nineteen patients who underwent primary isolated coronary artery bypass grafting were randomly assigned to receive a skeletonized (n = 9) or pedicled (n = 10) internal thoracic artery graft. Immunohistochemical nerve localization using anti-S-100 protein, anti-160-kd neurofilament polypeptide and anti-tyrosine hydroxylase antibodies was performed on distal specimens of arteries to study vascular innervation. Moreover, endovascular vasoactive challenges using serotonin and methylergometrine were performed at early angiographic control to evaluate the eventual presence of denervation supersensitivity. RESULTS: Quantitative analysis of immunohistochemical specimens revealed lack of difference in the number of positive cells between skeletonized and pedicled arteries for all the antibodies used. No difference in the reaction to serotonin and methylergometrine was found between skeletonized and pedicled arteries. CONCLUSIONS: Skeletonization does not influence internal thoracic artery innervation.

Composite Y internal thoracic artery-saphenous vein grafts: short-term angiographic results and vasoreactive profile.

BACKGROUND: The angiographic patency of composite Y internal thoracic artery-saphenous vein grafts has not been investigated in detail. METHODS: Twenty-five patients who received composite Y internal thoracic artery-saphenous vein grafts had control angiography and vasoactive challenges with serotonin, acetylcholine, and isosorbide dinitrate at a mean of 2.5 +/- 1.2 years after surgery. RESULTS: The perfect patency rate of composite Y internal thoracic artery-saphenous vein grafts was 72% (18/25). The distal portion of the internal thoracic artery was stringed in 4 patients and occluded in 2. The saphenous branch of the composite Y internal thoracic artery-saphenous vein grafts was found patent in all patients except 1. No failures were reported in the proximal tract of the internal thoracic artery. The distal tract of the internal thoracic artery showed reduced capacity of endothelium-mediated relaxation. CONCLUSION: The short-term patency of composite Y internal thoracic artery-saphenous vein grafts is suboptimal and markedly influenced by distal runoff and native flow competition.

Myocardial ischemia, stunning, inflammation, and apoptosis during cardiac surgery: a review of evidence.

Cardiac surgery (CS), in particular cardiopulmonary bypass and cardioplegia, have been reported to trigger myocardial inflammation and apoptosis. This surgery-related inflammatory reaction appears to be of extreme complexity with regard to its molecular, cellular and tissue mechanisms. Both experimental and clinical studies have ascertained the role of several hormonal mediators, mitochondria, cardioplegia and extracorporeal circulation temperature, apoptosis and even genetic modulators of damage. However, the correlations between these factors in vivo and post-surgery outcome and prognosis have not yet been systematically investigated. In animal models of myocardial cardioplegia and/or ischemia-reperfusion, experimental drugs such as antioxidants have been documented to provide amelioration of post-intervention cardiac performance and reduction of apoptosis suggesting the possibility of new therapeutic strategies. However, these findings have been only partially confirmed in humans. Moreover, markers for the differential detection of early and late phases of apoptosis are subjects of intense investigations. This review will provide an overview of the major studies about the link between ischemia, myocardial inflammation and apoptosis during and after CS, with particular regard to the markers and methods for apoptosis detection.

Effect of target artery location and severity of stenosis on mid-term patency of aorta-anastomosed vs. internal thoracic artery-anastomosed radial artery grafts.

OBJECTIVE: To verify the effect of location and severity of stenosis of the target coronary artery (TCA) on mid-term patency of aorta-anastomosed vs. internal thoracic artery (ITA)-anastomosed radial artery (RA) graft. METHODS: During a 3-year period 228 consecutive patients received an RA graft at our institution. In 131 cases the RA was anastomosed to the aorta whereas in 97 the proximal anastomosis was performed on a mammary graft. The two groups were comparable in terms of preoperative variables and TCA characteristics. At a mean follow-up of 6.5 years 128 cases of the aorta-anastomosed and 95 of the mammary-anastomosed group were submitted to control angiography. RESULTS: Mid-term patency and perfect patency rates were 92.1 and 89.8% (118/128 and 115/128) for aorta-anastomosed RA vs. 86.3 and 84.2% for mammary-anastomosed grafts (82/95 and 80/95; P=0.81 and 0.82). The location of TCA did not influence graft patency in the two groups. The severity of the TCA stenosis strongly influenced graft patency in both groups but the threshold for failure was clearly higher in the mammary-anastomosed group. CONCLUSIONS: ITA-anastomosed RA grafts are more vulnerable to the detrimental effect of chronic native competitive flow and should be used only for target vessel with subocclusive stenosis. The location of the distal anastomosis does not influence long-term RA patency.

Effect of surgical revascularization of a right coronary artery tributary of an infarcted nonischemic territory on the outcome of patients with three-vessel disease: a prospective randomized trial.

BACKGROUND: We evaluated the in-hospital and long-term effects of surgical grafting of a dominant graftable right coronary artery tributary of an infarcted nonischemic territory in patients with triple-vessel disease who were undergoing coronary artery bypass grafting. METHODS: Of 303 consecutive patients undergoing coronary artery bypass grafting with 3-vessel coronary disease and a dominant right coronary artery tributary of an infarcted nonischemic territory, 154 were randomized to right coronary artery revascularization and 149 to no right coronary artery grafting. In all cases, standard on-pump surgical myocardial revascularization was performed. RESULTS: Overall hospital mortality was 2 of 154 versus 1 of 149 (P =.97); no difference in in-hospital outcome was observed between the 2 groups. At follow-up, cardiac event-free survival was 84 of 152 in the right coronary artery grafting series and 62 of 148 in the non-right coronary artery grafting group (P =.20). However, when the analysis was limited to surviving patients without new scintigraphic evidence of ischemia (to avoid confounding factors derived from ischemia in the left coronary system or right coronary artery graft malfunction), we found that patients who received a right coronary artery graft had fewer cardiac events, a lower incidence of arrhythmia, and less left ventricular dilatation than did the non-right coronary artery revascularized series. CONCLUSIONS: Surgical grafting of a right coronary artery tributary of an infarcted nonischemic territory in patients with 3-vessel coronary artery disease submitted to coronary artery bypass grafting improved late electric stability, ventricular geometry, and event-free survival but did not affect in-hospital or 10-year survival.

Atherosclerotic involvement of the radial artery in patients with coronary artery disease and its relation with midterm radial artery graft patency and endothelial function.

BACKGROUND: The radial artery has recently been proposed as an alternative arterial conduit for surgical myocardial revascularization. This study was conceived to evaluate the degree of atherosclerotic involvement of the radial artery in patients with coronary artery disease and the eventual influence of a subtle degree of preoperative atherosclerosis on the midterm results of radial artery grafts. METHODS AND RESULTS: The intima-media thickness of the radial artery, common carotid artery, and internal thoracic artery was evaluated in 42 coronary artery disease patients and in 26 control patients. All radial arteries were then used for myocardial revascularization; 30 patients submitted to control angiography after 5 years. The mean intima-media thickness was 0.92 +/- 0.22 mm for the common carotid artery, 0.54 +/- 0.16 mm for the internal thoracic artery, 0.55 +/- 0.11 mm for the radial artery in coronary artery disease patients versus 0.79 +/- 0.14 mm, 0.52 +/- 0.11 mm, and 0.56 +/- 0.09 mm, respectively, in control patients (P =.001 only for the common carotid artery). No correlation was found between the intima-media thickness of the carotid, internal thoracic, and radial artery. No correlation was found between the preoperative intima-media thickness of the radial artery and the midterm patency and endothelial-mediated vasodilating capacity of radial artery grafts. CONCLUSION: In coronary artery disease patients, radial artery atherosclerotic involvement is more frequent than that of the gold standard internal thoracic artery but still by far less severe than that of the common carotid artery. The early atherosclerotic signs often observed in the radial artery do not seem to have the potential to influence radial artery graft patency and endothelial function.

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.