Francesco Macrina

Left ventricular aneurysmectomy ; comparison between two techniques ; early and late results

OBJECTIVE The aim of the present study was to evaluate early and late results of two different surgical techniques for left ventricular aneurysms repair. The conventional aneurysmectomy and direct closure of the ventricular wall and the endoventricular patch plasty. METHODS We retrospectively reviewed 118 patients operated on for postinfarction left ventricular aneurysm from 1981 to 1994. Eighty-seven patients (Group A) were operated upon between 1981 and 1991 with the conventional technique and 31 patients (Group B) between 1992 and 1994 with the endoventricular patch plasty technique. Preoperative clinical, hemodynamic and echocardiographic evaluation with operative procedures and early postoperative results of all patients are reported. We also analyzed results of late clinical and echocardiographic controls of 34 patients of Group A and all patients of Group B after a mean follow-up of 42 and 28 months, respectively. RESULTS Mean number of by-pass grafts was 1.9 in Group A and 2.6 in Group B (P = 0.01). The left anterior descending coronary artery was revascularized in 27 patients of Group A (34.6%) and 26 of Group B (89.7%) (P < 0.001); the left internal mammary artery was used in seven patients of Group A (8.9%) and 24 of Group B (82.8%) (P < 0.001). Hospital mortality in Group A was 10.3% (9/87), in Group B there was no hospital mortality (P > 0.05). Thirty-two patients of Group A (36.8%) and 3 of Group B (9.7%) suffered of low cardiac output syndrome (P = 0.01). At late control, improvements observed in NYHA and CCS classes, left ventricular ejection fraction (all P < 0.001 in both groups versus preoperative values) and left ventricular end-diastolic diameter (P > 0.05 in Group A and P < 0.001 in Group B) proved to be statistically higher in patients of Group B. CONCLUSIONS Endoventricular patch plasty associated with a complete myocardial revascularization, in particular of the anterior descending coronary, and a larger use of the internal mammary artery, permits, by means of reconstruction of the left ventricular geometry, a better outcome for patients undergoing left ventricular aneurysmectomy.

Short-term results of a randomized trial examining timing of carotid endarterectomy in patients with severe asymptomatic unilateral carotid stenosis undergoing coronary artery bypass grafting

OBJECTIVE This study evaluated the timing of carotid endarterectomy (CEA) in the prevention of stroke in patients with asymptomatic carotid stenosis >70% receiving a coronary artery bypass graft (CABG). METHODS From January 2004 to December 2009, 185 patients with unilateral asymptomatic carotid artery stenosis >70%, candidates for CABG, were randomized into two groups. In group A, 94 patients received a CABG with previous or simultaneous CEA. In group B, 91 patients underwent CABG, followed by CEA. All patients underwent preoperative helical computed tomography scans, excluding significant atheroma of the ascending aorta or aortic arch. Baseline characteristics of the patients, type of coronary artery lesion, and preoperative myocardial function were comparable in the two groups. In group A, all patients underwent CEA under general anesthesia with the systematic use of a carotid shunt, and 79 patients had a combined procedure and 15 underwent CEA a few days before CABG. In group B, all patients underwent CEA, 1 to 3 months after CABG, also under general anesthesia and with systematic carotid shunting. RESULTS Two patients (one in each group) died of cardiac failure in the postoperative period. Operative mortality was 1.0% in group A and 1.1% in group B (P = .98). No strokes occurred in group A vs seven ipsilateral ischemic strokes in group B, including three immediate postoperative strokes and four late strokes, at 39, 50, 58, and 66 days, after CABG. These late strokes occurred in patients for whom CEA was further delayed due to an incomplete sternal wound healing or because of completion of a cardiac rehabilitation program. The 90-day stroke and death rate was 1.0% (one of 94) in group A and 8.8% (eight of 91) in group B (odds ratio [OR], 0.11; 95% confidence interval [CI], 0.01-0.91; P = .02). Logistic regression analysis showed that only delayed CEA (OR, 14.2; 95% CI, 1.32-152.0; P = .03) and duration of cardiopulmonary bypass (OR, 1.06; 95% CI, 1.02-1.11; P = .004) reliably predicted stroke or death at 90 days. CONCLUSIONS This study suggests that previous or simultaneous CEA in patients with unilateral severe asymptomatic carotid stenosis undergoing CABG could prevent stroke better than delayed CEA, without increasing the overall surgical risk.

Procalcitonin is useful whereas C-reactive protein is not, to predict complications following coronary artery bypass surgery

Background: The respective value of procalcitonin (PCT) and C-reactive protein (CRP) as markers of postoperative complications after coronary bypass surgery is unclear. Therefore, complications during one week after surgery were studied to evaluate the predictive role of PCT and CRP changes during the immediate postoperative period. Methods: Thirty-two patients, in whom an uneventful immediate postoperative course was anticipated, were prospectively enrolled and followed-up to the 7th postoperative day. At the end of the follow-up, patients were divided into two groups. Group A were patients with an uncomplicated postoperative course and Group B were patients with a complicated postoperative course. Results: Serum samples were drawn for PCT and CRP determination after induction of anesthesia (baseline), at the end of surgery and daily until postoperative day 2. Baseline serum PCT concentrations were 0.119 ± 0.09 and 0.209 ± 0.21 ng/mL in Groups A and B, respectively (NS). Serum PCT concentration increased compared with baseline in both groups during the first two days after surgery. The increase in serum PCT concentration was significantly greater in Group B than A patients (p<0.0002). Considering a perioperative abnormal cut-off value of > 0.5 ng/mL, there were none in Group A versus 57% in Group B (p<0.0001). Baseline serum CRP concentrations were 1.449 ± 1.30 and 1.589 ± 1.35 ng/mL in Groups A and B, respectively (NS). After surgery, CRP increased significantly compared with baseline in both groups. When changes in time-varying variables were included in a logistic model, complications were predicted by changes (between baseline and end of surgery values) of PCT (coefficient=9.410; t=2.18) and heart rate (coefficient=0.075; t=1.57), whereas changes of CRP, white blood cells, mean blood and central venous pressures did not contribute statistically. The model constant was -4.827 (t= -2.43) and the ROC curve area was 0.8971. Thus, absolute PCT changes of 0.20, 0.40 and 0.60 ng/mL carry an approximate risk of 5, 26 and 69%, respectively, of postoperative complications in the time frame of this study. Conclusions: A postoperative serum PCT concentration of >0.5 ng/mL is highly suggestive of a postoperative complication. CRP changes do not contribute to predictive information.

Nitroglycerin-induced changes in myocardial sestamibi uptake to detect tissue viability: radionuclide comparison before and after revascularization

BackgroundNitroglycerin (NTG) is known to increase the blood supply to the myocardium, and would thus increase the delivery of a perfusional tracer such as sestamibi (MIBI) to the tissue. The latter, in turn, would take up and concentrate the tracer to a greater extent than in basal conditions only if energy-dependent mechanisms were still available — that is, only if the cells were still viable. MethodsWe evaluated the changes that intravenous administration of NTG induced on the uptake of MIBI by akinetic myocardial areas, using tomographic perfusional imaging in 23 patients with previously ascertained anterior myocardial infarction who were undergoing myocardial revascularization procedures. Changes in uptake were compared with echocardiographic and perfusional changes occurring after operation. ResultsThe improvement of MIBI uptake after NTG correctly identified 12 of the 16 patients (75%) showing postoperative wall motion improvement; they comprised 12 of the 14 (86%) patients with NTG-induced increase in MIBI uptake who showed improved wall motion after operation. A close correlation (r = 0.88, P< 0.001) was found between the increase in myocardial MIBI uptake induced by NTG infusion and that induced by revascularization. The presence of collaterals to the akinetic area was associated with a significantly (P<0.01) greater increase in MIBI uptake both during NTG infusion and after operation. ConclusionsThe results of this study suggest that MIBI perfusional myocardial scintigraphy during infusion of NTG is capable of detecting viable but chronically hypoperfused myocardium, predicting postoperative wall motion and perfusional improvement, and reflecting the postoperative pattern of perfusion. The best results were achieved in patients with evidence of collateral circulation supplying the infarcted area.

Long-term mortality prediction after operations for type A ascending aortic dissection

BackgroundThere are few long-term mortality prediction studies after acute aortic dissection (AAD) Type A and none were performed using new models such as neural networks (NN) or support vector machines (SVM) which may show a higher discriminatory potency than standard multivariable models.MethodsWe used 32 risk factors identified by Literature search and previously assessed in short-term outcome investigations. Models were trained (50%) and validated (50%) on 2 random samples from a consecutive 235-patient cohort. NN were run only on patients with complete data for all included variables (N = 211); SVM on the overall group. Discrimination was assessed by receiver operating characteristic area under the curve (AUC) and Ginis coefficients along with classification performance.ResultsThere were 84 deaths (36%) occurring at 564 ± 48 days (95%CI from 470 to 658 days). Patients with complete variables had a slightly lower death rate (60 of 211, 28%). NN classified 44 of 60 (73%) dead patients and 147 of 151 (97%) long-term survivors using 5 covariates: immediate post-operative chronic renal failure, circulatory arrest time, the type of surgery on ascending aorta plus hemi-arch, extracorporeal circulation time and the presence of Marfan habitus. Global accuracies of training and validation NN were excellent with AUC respectively 0.871 and 0.870 but classification errors were high among patients who died. Training SVM, using a larger number of covariates, showed no false negative or false positive cases among 118 randomly selected patients (error = 0%, AUC 1.0) whereas validation SVM, among 117 patients, provided 5 false negative and 11 false positive cases (error = 22%, AUC 0.821, p < 0.01 versus NN results). An html file was produced to adopt and manipulate the selected parameters for practical predictive purposes.ConclusionsBoth NN and SVM accurately selected a few operative and immediate post-operative factors and the Marfan habitus as long-term mortality predictors in AAD Type A. Although these factors were not new per se, their combination may be used in practice to index death risk post-operatively with good accuracy.

Preoperative Identification of Viable Myocardium: Effectiveness of Nitroglycerine-Induced Changes in Myocardial Sestamibi Uptake

In order to predict tissue viability in infarcted myocardial areas, changes induced by nitroglycerine infusion on Sestamibi myocardial uptake were evaluated in 37 patients with previously confirmed myocardial infarction undergoing coronary artery bypass grafting, and compared with echocardiographic and perfusional changes occurring after the operation. The improvement of Sestamibi uptake after nitroglycerine correctly classified 24/26 (92%) patients showing postoperative improvement of wall motion in the infarcted area, whereas 24/31 (77%) patients with nitroglycerine-induced increase in Sestamibi uptake had improved wall motion after operation. The presence of collateral flow to the infarcted area was associated with a significantly (P < 0.01) higher increase in Sestamibi uptake both during nitroglycerine infusion and postoperatively. An increase in wall motion score after operation was associated with a significantly higher (P < 0.05) increase in Sestamibi uptake score during nitroglycerine infusion. Thus, the results of this study suggest that Sestamibi perfusional myocardial scintigraphy during nitroglycerine infusion is capable of assessing viable but chronically hypoperfused myocardium and predicting postoperative wall motion and perfusional improvement, to yield the best results in patients with evidence of collateral circulation that supplies the infarcted area.

Artificial Neural Networks Versus Multiple Logistic Regression to Predict 30-Day Mortality After Operations For Type A Ascending Aortic Dissection§

Background: There are few comparative reports on the overall accuracy of neural networks (NN), assessed only versus multiple logistic regression (LR), to predict events in cardiovascular surgery studies and none has been performed among acute aortic dissection (AAD) Type A patients. Objectives: We aimed at investigating the predictive potential of 30-day mortality by a large series of risk factors in AAD Type A patients comparing the overall performance of NN versus LR. Methods: We investigated 121 plus 87 AAD Type A patients consecutively operated during 7 years in two Centres. Forced and stepwise NN and LR solutions were obtained and compared, using receiver operating characteristic area under the curve (AUC) and their 95% confidence intervals (CI) and Gini’s coefficients. Both NN and LR models were re-applied to data from the second Centre to adhere to a methodological imperative with NN. Results: Forced LR solutions provided AUC 87.9±4.1% (CI: 80.7 to 93.2%) and 85.7±5.2% (CI: 78.5 to 91.1%) in the first and second Centre, respectively. Stepwise NN solution of the first Centre had AUC 90.5±3.7% (CI: 83.8 to 95.1%). The Gini’s coefficients for LR and NN stepwise solutions of the first Centre were 0.712 and 0.816, respectively. When the LR and NN stepwise solutions were re-applied to the second Centre data, Gini’s coefficients were, respectively, 0.761 and 0.850. Few predictors were selected in common by LR and NN models: the presence of pre-operative shock, intubation and neurological symptoms, immediate post-operative presence of dialysis in continuous and the quantity of post-operative bleeding in the first 24 h. The length of extracorporeal circulation, post-operative chronic renal failure and the year of surgery were specifically detected by NN. Conclusions: Different from the International Registry of AAD, operative and immediate post-operative factors were seen as potential predictors of short-term mortality. We report a higher overall predictive accuracy with NN than with LR. However, the list of potential risk factors to predict 30-day mortality after AAD Type A by NN model is not enlarged significantly.

Effects of bimakalim on human cardiac action potentials: comparison with guinea pig and nicorandil and use-dependent study.

Electrophysiologic effects of K(ATP) channel openers (KCOs) are rarely studied for tissue and species specificity, and use-dependent investigations in human tissues are lacking. We therefore investigated in vitro the concentration-dependent effects of the KCO bimakalim [from 10 nM to 10 microM, at 1,000 ms of cycle length (CL) and 37 degrees C] on human (atrium, n = 4, and ventricle, n = 6) and guinea pig (atrium, n = 7, and ventricle, n = 6) transmembrane action potential (AP). The frequency relation (from CL 1,600 to 300 ms, 31 degrees C) of human atrial AP duration 90% (APD90) shortening (10 microM vs. baseline, n = 7) also was determined. A parallel study was performed with the KCO nicorandil (from 10 nM to 1 mM, n = 3) in human atrial APs, at 31 degrees C. Resting membrane potential and maximal upstroke velocity of AP were not modified by bimakalim at maximal concentration, whereas AP amplitude was decreased in both guinea pig preparations (p < 0.05); APD90 was shortened in all tissues (p < 0.01). Median effective concentration (EC50) for APD90 shortening at 37 degrees C was 0.54 and 2.74 microM in atrial and ventricular human tissue, respectively, and 8.55 and 0.89 microM in atrial and ventricular guinea pig tissue, respectively. In human atrial tissue at 31 degrees C, EC50 with bimakalim was 0.39 microM; a much higher value was seen with nicorandil (210 microM). Bimakalim (10 microM)-induced APD90 shortening as a function of stimulation rate was greatest at longest CL. Evidence is provided for (a) species (human vs. guinea pig) and tissue (atrium vs. ventricle) differential AP sensitivity to bimakalim; (b) an approximately 500-fold higher efficacy of bimakalim versus nicorandil to shorten human atrial APD90; and (c) normal use-dependence of human atrial APD90 shortening with bimakalim at 10 microM.

Extracardiac left to right shunt in a patient with biventricular postinfarction rupture and pseudoaneurysm

A 68 year old man had a diaphragmatic myocardial infarction and 9 months later was admitted with severe congestive heart failure (functional class IV). Cardiac catheterization demonstrated a postinfarction pseudoaneurysm. Because of a massive left to right shunt (pulmonary to systemic flow ratio = 2.7), concomitant rupture of the ventricular septum was suspected. At surgery the pseudoaneurysm communicated with the right ventricle through two different orifices and with the left ventricle through another ostium. The ventricular septum was intact. Therefore, the shunt was extracardiac through the pseudoaneurysm (left ventricle----pseudoaneurysm----right ventricle). The unique combination of lesions allowed the patient to survive. The false aneurysm was excised and primary repair was performed in the orifices of the right and left ventricular walls. The postoperative course was uneventful and 10 months later the patient was in functional class I.

A simple circuit for cerebral perfusion during cardiopulmonary bypass surgery of the ascending aorta and the aortic arch.

Introduction A circuit was developed to allow for rapid reaction to the needs of perfusion during extracorporeal circulation (ECC) in surgery of the aortic arch and ascending aorta. Method From January 2008 through January 2010, a home-designed circuit was used on 30 patients with aortic dissection who underwent surgery to replace the ascending aorta and the aortic arch and, in some cases, the aortic valve and re-implant of the coronary arteries using Bentall’s technique.