Diagnostic accuracy of pre-operative NT-proBNP level in predicting short-term outcomes in coronary surgery: a pilot study.

BACKGROUND: B-type natriuretic peptides (BNP) are acknowledged markers of acute and chronic heart failure. Insufficient data exist, however, regarding their diagnostic usefulness in cardiac surgery, particularly in coronary patients. AIM: To assess diagnostic accuracy of preoperative value of NT-proBNP level as a predictor of short-term postoperative complications in subjects undergoing coronary artery bypass grafting (CABG). METHODS: This pilot study included 100 consecutive patients scheduled for elective CABG, including 24 females and 76 males (mean age 65.9 ± 9.1 years). Exclusion criteria were: significant valvular disorders, off-pump procedure, renal failure (GFR < 60 mL/min/1.73 m2), low ejection fraction (< 30%), intra-aortic balloon pump counterpulsation (IABP), use of inotropic agents, atrial fibrillation (AF), and implanted pacemaker or defibrillator. The NT-proBNP level was measured on the day of the surgery before induction of anaesthesia. We investigated short-term postoperative complications, defined as those occurring within 30 days or before hospital discharge. RESULTS: Median NT-proBNP concentration was 526.0 pg/mL (IQR 156.0-1150.0). None of patients died postoperatively. Excessive drainage (> 850 mL) was found in 13 (13%) patients and 22 (22%) subjects required transfusions. Prolonged mechanical ventilation (> 12 h) was necessary in 15 (15%) patients and respiratory failure occurred in 2 (2%) of them. Postoperative AF was present in 34 (34%) subjects. Perioperative myocardial infarction was diagnosed in 2 (2%) persons. Low cardiac output was present in 9 (9%) patients. Haemodynamic support with the use of IABP was necessary in 7 (7%) patients and inotropic drugs were used in 61 (61%) subjects. Stroke or delirium was diagnosed in 1 (1%) subject. The NT-proBNP level correlated with the operative risk estimated by logistic and additive EuroSCORE: r = 0.558 (95% CI 0.406-0.680; p < 0.001) and r = 0.551 (95% CI 0.397-0.674; p < 0.001), respectively. The NT-proBNP level correlated significantly with the length of Intensive Care Unit (ICU) stay and hospital stay: r = 0.412 (95% CI 0.238-0.566; p < 0.001) and r = 0.547 (95% CI 0.393-0.672; p < 0.001), respectively. The NT-proBNP level was a predictor of postoperative prolonged mechanical ventilation, respiratory failure, AF, IABP use, inotropic support and postoperative platelet transfusions (p < 0.05 for all). However, good or very good diagnostic accuracy was found only in relation to mechanical ventilation (AUROC = 0.854), respiratory insufficiency (AUROC = 0.867), IABP use (AUROC = 0.889), and milrinone use (AUROC = 0.929). CONCLUSIONS: Preoperative assessment of NT-proBNP level in CABG patients could be a valuable diagnostic method for predicting several postoperative complications, especially pulmonary outcomes and requirement for haemodynamic support, and it correlated with the length of ICU stay and hospital stay.

Perioperative blood pressure variability in patients undergoing coronary artery bypass grafting: its magnitude and determinants.

OBJECTIVES: The study aimed to assess the magnitude and determinants of perioperative blood pressure (BP) variability in patients undergoing coronary artery bypass grafting (CABG) with the use of extracorporeal circulation (ECC). METHODS: Two hundred patients were enrolled, 41 women (21%) and 159 men (79%), aged 6 1± 8 years. A direct method of intraoperative BP measurement was used with a cannula placed in the radial artery, and BP was recorded at intervals of 5 min at three stages of the CABG: from cannula placement to the start of ECC, during ECC, and post-ECC until the transfer of patient to the postoperative room. BP variability was assessed using coefficient of variation (in percentage) for systolic, diastolic, mean, and pulse pressures. Impact of sex, age, and comorbidities was determined. RESULTS: Greater changes in BP during CABG were observed in diastolic BP (4/19%) than in systolic BP (11/15%) and the greatest BP variability was associated with pulse pressure (20/72%). The greatest variability of BP parameters was found during ECC (15/72%). Higher BP lability was found in women (13/83%), younger patients (11/78%), and those without diabetes (11/78%), hypertension (11/82%), or obesity (11/71%), and smoking habit increased the variability during CABG (11/89%). All trends were similar for all types of BP. CONCLUSION: Special attention in perioperative anesthetic management should be given not only to elder patients with many comorbid conditions, but also to younger and healthier participants because the latter are characterized by greater variations of BP during CABG.

Intracoronary adiponectin at reperfusion reduces infarct size in a porcine myocardial infarction model.

Reperfusion injury (RI) remains an important limitation of myocardial revascularization. The aim of the present study was to evaluate the influence of the intracoronary injection of adiponectin on RI and cardiomyocyte death in a porcine myocardial infarction model. Acute infarction in 14 Polish domestic pigs was induced by inflation of an over the wire balloon (OTW) catheter in the medial left anterior descending artery for 60 min. The study group consisted of 7 pigs in which intracoronary adiponectin (50 µg) was infused through the OTW catheter immediately before reperfusion. The control group (n=7) was administered placebo. Animals were sacrificed after two days of follow-up. The infarct area (IA) was stained with tetrazoline and the area at risk (AAR) with intracoronary administration of Evans Blue dye before euthanasia. Hearts in each group had similar AARs (46.2±9.9% vs. 48.4±6.2% of the whole myocardium, p=ns). The IA/AAR% and IA were smaller in the study group when compared to the control (24.7±4.0% vs. 45.3±22.5%, p=0.005; and 11.7±4.9% vs. 20.5±5.6%, p=0.01, respectively). These outcomes corresponded well with the peak troponin levels after 12 h (109.9±60.9 ng/ml vs. 185.5±39.4 ng/ml, p=0.017). After two days there was a significantly higher LVEF in the study group (51.4±8.5% vs. 33.9±8.6%, p=0.002). There was also a trend toward lower apoptosis enhancement in the viable myocardium in the study group (3.11±2.3 vs. 8.92±6.3; p=0.07). The administration of adiponectin into the infarct- related artery is safe and feasible. The treatment significantly reduced the infarct size.

A new external stent - intimal proliferation and apoptosis in the vein graft in the animal model.

BACKGROUND: We have previously showed that the extravascular dacron mesh stent wrapped around a vein graft and implanted into the arterial system prevented the hypertrophy of the graft's wall, impeded the overgrowth of the intima and decreased the proliferation rate of venous graft cellular elements. AIM: To determine the role of cellular proliferation and apoptosis in the process of remodelling in the stent in an animal model in a 12-week period. METHODS: Male sheep (n = 21) received by transplantation the hybrid graft (group 1) or carotid artery radial vein grafts (group 2). A hybrid graft was composed of a radial vein, collagen fibrin glue and highly flexible torlen/dacron mesh tubing. Grafts were retrieved on day 5, 9 and then week 4, 6, 8, 10, 12, respectively. A proliferation process was assessed using a Ki-67 antigen kit. The presence of apoptosis was detected using a TUNEL kit, strictly according to the manufacturer's manual. RESULTS: The number of proliferating cells has presented a decreasing trend in both groups, whereas the mean quantity of apoptotic cells increased over a 12-week period (p < 0.001) in both groups. Proliferation was more prominent during the first 5 weeks in both groups. The trend had a tendency to reverse during the last 7 weeks of observation. The ratio of proliferating to apoptotic cells differed between groups (1.6 vs. 1.9 on day 5 and 0.2 vs. 0.6 in week 12, in group 1 and group 2, respectively). No linear correlation between proliferation and apoptosis was observed (p > 0.05). CONCLUSIONS: Different kinetics in the trico hybrid graft group in comparison with the radial vein graft group was observed, with a more prominent cellular turnover in the trico hybrid graft. Apoptosis in an unprotected vein wall was overcomed by the proliferation process. In trico hybrid vein grafts, beneficial remodelling of the intimal layer was predominantly dependent on inhibition of intimal proliferation rather than the effect of changes of the apoptosis ratio. There was no linear correlation between proliferation and apoptosis in the investigated grafts.

Diazoxide protects myocardial mitochondria, metabolism, and function during cardiac surgery: a double-blind randomized feasibility study of diazoxide-supplemented cardioplegia.

OBJECTIVES: The study was designed to assess whether diazoxide-mediated cardioprotection might be used in human subjects during cardiac surgery. METHODS: Forty patients undergoing coronary artery bypass grafting were randomized to receive intermittent warm blood antegrade cardioplegia supplemented with either diazoxide (100 micromol/L) or placebo (n = 20 in each group). Mitochondria were assessed before and after ischemia and reperfusion in myocardial biopsy specimens. Myocardial oxygen and glucose and lactic acid extraction ratios were measured before ischemia and in the first 20 minutes of reperfusion. Hemodynamic data were collected, and troponin I, creatine kinase-MB, and N-terminal prohormone brain natriuretic peptide levels were measured. All outcomes were analyzed by using mixed-effects modeling for repeated measures. RESULTS: No deaths, strokes, or infarcts were observed. Patients received, on average, 36.2 +/- 1.2 mg of diazoxide and 37.3 +/- 1.9 mg of placebo (P = .6). Diazoxide added to cardioplegia prevented mitochondrial swelling (8899 +/- 474 vs 9273 +/- 688 pixels before and after the procedure, respectively; P = .6) compared with that seen in the placebo group (8474 +/- 163 vs 11,357 +/- 759 pixels, P = .004). No oxygen debt was observed in the diazoxide group. Glucose consumption and lactic acid production returned to preischemic values faster in the diazoxide group. The following hemodynamic parameters differed between the diazoxide and placebo groups, respectively, in the postoperative period: cardiac index, 3.0 +/- 0.09 versus 2.6 +/- 0.09 L . min(-1) . m(-2) (P = .002); left cardiac work index, 2.81 +/- 0.07 versus 2.31 +/- 0.07 kg/m(2) (P < .001); oxygen delivery index, 420 +/- 14 versus 377 +/- 13 mL . min(-1) . m(-2) (P = .03); and oxygen extraction ratio, 29.3% +/- 1.1% versus 32.6% +/- 1.1% (P = .02). Postoperative myocardial enzyme levels did not differ, but N-terminal prohormone brain natriuretic peptide levels were lower in the diazoxide group (120 +/- 27 vs 192 +/- 29 pg/mL, P = .04). CONCLUSIONS: Supplementing blood cardioplegia with diazoxide is safe and improves myocardial protection during cardiac surgery, possibly through its influence on the mitochondria.

Diazoxide provides maximal KATP channels independent protection if present throughout hypoxia.

BACKGROUND: It is not clear what the optimal timing of diazoxide administration for cardioprotection in human myocardium is. We aimed to establish it. We next checked whether protection depended on adenosine triphosphate (ATP)-inhibited potassium (KATP) channels. METHODS: Isolated human right atrial trabeculae were subjected to 90-minute hypoxia and 120-minute reoxygenation in vitro, followed by adding 10(-4) M norepinephrine. Diazoxide (100 microM) was added (1) as a 10-minute preconditioning signal with 10-minute washout before hypoxia or (2) 10-minute pretreatment without washout before hypoxia or (3) throughout hypoxia or (4) 10 minutes before and throughout hypoxia or (5) during the first 20 minutes of reoxygenation only. In the control, no diazoxide was added. In another set of experiments, diazoxide (100 microM) was present throughout hypoxia in control, while we tried to inhibit its protective effect with glibenclamide (1, 10, 100 microM) or 5-hydroxydecanoate (100 microM). RESULTS: The presence of diazoxide throughout hypoxia improved recovery of contractility during reoxygenation, allowed for significant response to norepinephrine at the end of reoxygenation, prevented "ischemic contracture" development, and reduced release of troponin I to tissue bath during hypoxia. Adding diazoxide 10 minutes before hypoxia conferred significantly weaker protective effects in all the above respects. We failed to show a protective effect of diazoxide used as a preconditioning signal or during reoxygenation. Neither 5-hydroxydecanoate nor glibenclamide significantly influenced protective effects of diazoxide added during hypoxia. CONCLUSIONS: Administration of diazoxide throughout hypoxia provided maximal protective effect, suggesting that diazoxide may be an important adjunct to cardioplegic solution. The protection offered by diazoxide used during hypoxia appears independent of its influence on KATP channels.

Invasive treatment of coronary artery disease in octogenarians.

INTRODUCTION: There are many patients aged over 80 years among those hospitalised for coronary artery disease (CAD). The unanswered question is whether invasive treatment of such patients is effective and safe. AIM: To assess and compare one-year clinical outcomes after percutaneous coronary angioplasty (PTCA) and surgical coronary artery bypass grafting (CABG) in patients aged over 80 years and in younger patients. METHOD: There were 63 patients aged over 80 years suffering from CAD who underwent either PTCA or CABG. The control group consisted of 40 patients aged 60-65 years treated in the same way. Data on medical history, cardiovascular risk factors, and angiographic findings were analysed. The potential risks of the procedures, post-procedural complications as well as the clinical status at the end of one-year follow-up were evaluated. RESULTS: There were 24 surgical revascularisation procedures and 39 PCIs performed in the very old patients. Stable angina was found in 29 cases, unstable angina in 19 and acute myocardial infarction in 15 patients. There were three in-hospital deaths and 18 periprocedural complications were noted. During the one-year follow-up period six deaths occurred, persistent or recurrent angina was found in 11 patients after PCI and two after CABG. There were no deaths in the control group and the incidence of minor complications was similar to the senile group. In younger patients who underwent CABG, CCS class at one year was lower than in the very old ones. CONCLUSIONS: The invasive treatment of coronary artery disease in octogenarians is feasible with satisfactory results and acceptable procedural risks.

Minimally invasive mitral valve surgery -- first experience in Poland.

BACKGROUND: Minimally invasive cardiac surgery has been introduced to treat various cardiac disorders, predominantly ischaemic heart disease. Its usage in valvular disorders has been only recently proposed. AIM: To assess safety and efficacy of minimally invasive mitral valve surgery. METHODS: The procedure was performed in 10 patients (6 females, 4 males, mean age 59+/-7 years). All but one had preserved left ventricular ejection fraction. Two patients underwent mitral valvuloplasty, and mitral valve replacement was performed in all remaining cases. One procedure was a redo surgery following mitral commisurotomy. RESULTS: In all patients the procedure was effective. Prolongation of cardiopulmonary bypass and aorta cross-clamping time did not increase the complication rate which included one wound infection, one repeated cannulation of the femoral vessels and one minor stroke. Rehabilitation process seemed to be shorter than after standard procedures. CONCLUSIONS: Minimally invasive mitral valve surgery is a safe and alternative method of treatment, and is associated with excellent cosmetic results.

[Pulmonary embolism in a patient with unstable angina treated with surgical revascularisation--a case report]. / Zator tetnicy plucnej w niestabilnej dlawicy piersiowej poddanej chirurgicznej rewaskularyzacji.

A case of a 58-year-old female patient with unstable angina is presented. Two weeks earlier the patient suffered from acute myocardial infarction treated with thrombolysis. The patient underwent surgical revascularisation which was complicated by acute pulmonary embolism. Repeated surgery and inspection of pulmonary arteries revealed the presence of thrombus which was successfully removed. The post-operative course was uneventful. The causes and treatment of pulmonary embolism complicating coronary artery by-pass grafting are discussed.

[In-stent thrombosis following coronary artery by-pass grafting - a case report]. / Zakrzepica w stencie powiklaniem zabiegu pomostowania aortalno-wiencowego.

A case of a 60 year old male with a history of myocardial infarction treated with coronary angioplasty with stent implantation, who was admitted to the hospital for coronary artery by-pass grafting (CABG), is presented. The post-operative course was complicated by new acute MI due to the in-stent thrombosis. The patient received aspirin and ticlopidine, and underwent intra-aortic balloon pumping followed-by an effective coronary angioplasty of the infarct-related coronary artery.

Primary OPCAB as a strategy for acute coronary syndrome and acute myocardial infarction.

BACKGROUND: Conventional coronary artery bypass graft (CABG) surgery using cardiopulmonary bypass (CPB) carries higher mortality and morbidity for patients undergoing surgery during acute coronary syndrome (ACS). The aim of this retrospective study was to evaluate potential benefits of avoiding CPB by instead performing off-pump CAB (OPCAB) during surgery on patients in ACS. METHODS: Among 624 patients who underwent OPCAB between January 1999 and June 2001, 143 underwent surgery during ACS (group 1). The ACS patients in group 1 were divided into 2 subgroups: 66 underwent surgery during acute myocardial infarction (AMI group) and 77 during unstable angina classified as class III or IV according to the Braumwald classification (unstable coronary artery disease [CAD] group). Group 2 (the elective CAD group) consisted of 481 patients who underwent isolated elective OPCAB during the same time period. RESULTS: Overall 30-day mortality was 4.9% (n = 7) for the ACS group and 0.83% (n = 4) for the elective CAD group (P < .0001). Differences between groups were found in use of inotropes, intraaortic balloon pump, and subsequent conversion of OPCAB to CPB (P < .0001, P < .01, and P < .03, respectively), as well as use of blood transfusion (P < .0003). Multivariate logistic regression analysis for 641 patients revealed ACS (P < .015), AMI (P < .019), renal failure (P < .017), and left ventricle aneurysm (P < .028) as independent risk factors for 30-day mortality in ACS reoperation (P = .02), whereas in AMI renal failure (P = .02) appeared to be an independent risk factor. CONCLUSIONS: OPCAB is a valuable treatment strategy in ACS patients; however, it carries significant mortality and morbidity. Careful preselection and timing of intervention are required in order for patients to fully benefit from the OPCAB strategy.

Dysfunction of left ventricle as an indication for off-pump coronary artery bypass grafting.

BACKGROUND: Coronary artery bypass grafting (CABG) with cardiopulmonary bypass carries significant risk for patients with severe left ventricular (LV) dysfunction. METHODS: Between 1997 and 2000, 240 patients underwent OPCAB. The patients were retrospectively divided into 2 groups with regard to LV function. Group 1 consisted of 90 patients with ejection fraction (EF) <35% and grou p 2 of 150 patients without severe LV impairment and EF >35%. Patients were compared for preoperative risk factors, perioperative mortality, and postoperative complications. RESULTS: Preoperative expected mortality according to EuroSCORE was higher in group 1, 5.95, compared with group 2, 2.66 (P =.0005). A few preoperative risk factors were more common in group 1: urgent operation (P =.00001), unstable angina (P =.0018), Canadian Cardiovascular Society class (P =.001), myocardial infarction (P =.0001), and peripheral arteriopathy (P =.0006). Mean number of grafts was 1.51 in group 1 and 1.55 in group 2 with the same internal thoracic artery utilization. Perioperative drainage, anesthesia and intubation time, transfusion rate, and use of inotropes were comparable. Actual, nonadjusted mortality was 2.5% in group 1 and 1.4% in group 2 (P = not significant). Overall rates of postoperative complications were comparable; only use of an intraoperative balloon pump was more frequent in group 1 (P =.006). Postoperative stay was shorter in group 1 (P equals). CONCLUSIONS: Off-pump CABG for patients with LV impairment is associated with surgical outcome similar to that among patients with normal LV function, in spite of the presence of unfavorable risk factors. Off-pump surgery with selective anterior (including right main) arterial revascularization can be indicated in the presence of poor LV function.