Influence of sternal size and inadvertent paramedian sternotomy on stability of the closure site: a clinical and mechanical study.

BACKGROUND: The influence of sternal size and of inadvertent paramedian sternotomy on stability of the closure site is not well defined. METHODS: Data on 171 consecutive patients undergoing cardiac surgery through a midline sternotomy were prospectively collected. Intraoperative measurements of sternal dimension included thickness and width at the manubrium, the third and fifth intercostal spaces; paramedian sternotomy was defined as width of one side of the sternum equaling 75% or more of the entire width, at any of the three levels. The chest was closed with simple peristernal steel wires and inspected to detect deep wound infection and/or instability for 3 postoperative months. The sternal factors and several patient/surgery-related factors were included in a multivariate analysis model to identify factors affecting stability. An electromechanical traction test was conducted on 6 rewired sternal models after midline or paramedian sternotomy and separation data were analyzed. RESULTS: Chest instability was detected in 12 (7%) patients and wound infection in 2 (1.2%). Patient weight (P = .03), depressed left ventricular function (P = .04), sternum thickness (indexed to body weight, P = .03), and paramedian sternotomy (P = .0001) were risk factors of postoperative instability; paramedian sternotomy was the only independent predictor (P = .001). The electromechanical test showed more lateral displacement of the two rewired sternal halves after paramedian than midline sternotomy (P = .002); accordingly, load at fracture point was lower after paramedian sternotomy (220 +/- 20 N vs 545 +/- 25 N, P = 0.001). CONCLUSIONS: Inadvertent paramedian sternomoty strongly affects postoperative chest wound stability independently from sternal size, requiring prompt reinforcement of chest closure.

Troponin I release after CABG surgery using two different strategies of myocardial protection and systemic perfusion.

BACKGROUND: Controversies still exist over the optimal temperature for blood cardioplegia and systemic perfusion. This study investigates the effect of temperature of blood cardioplegia and systemic perfusion on the release of troponin I and other biochemical markers. METHODS: One hundred and fifty-four consecutive patients were randomly assigned to one of two cardioplegic and systemic perfusion strategies of cold blood cardioplegia with moderate systemic hypothermia (27 degrees C) or tepid blood cardioplegia with mild systemic hypothermia (33 degrees C). Cardiac troponin I and other biochemical markers were measured at baseline, at the end of surgery, at 12 hours and daily thereafter. A two-way ANCOVA for repeated measure was performed to test the effect of cardioplegia on enzyme release independently of variables that were different between the two groups. RESULTS: The time course of dismission of troponin I, creatine kinase MB, and lactate dehydrogenase were significantly lower with tepid blood cardioplegia and mild systemic perfusion independently of the number of distal anastomoses, CPB time, cross clamp time or total volume of cardioplegia. There were no differences between the two groups in the release of total creatine kinase, aspartate transaminase and alanine transferase. CONCLUSIONS: Both strategies of myocardial protection and systemic perfusion guarantee subclinical minor myocardial damage. The strategy of tepid whole blood cardioplegia and mild systemic hypothermia seems to preserve myocardium better than whole blood cold cardioplegia.

[Aortocoronary bypass in severe left ventricular dysfunction: 9 years of clinical experience and mid-term results]. / Il bypass aortocoronarico nella disfunzione ventricolare sinistra severea: nove anni di esperienza clinica e risultati a medio termine.

BACKGROUND: Compared with medical therapy alone, coronary artery bypass surgery improves survival in patients with coronary disease and left ventricular dysfunction. Many of these patients have a hibernating myocardium secondary to chronic ischemia with the potential for improvement in left ventricular function and heart failure symptoms following revascularization therapy. Cardiac transplantation remains the treatment of choice for patients with severe congestive heart failure. METHODS: From January 1992 to June 2000, 351 consecutive patients (318 men, 33 women, mean age 62.8 +/- 8.9 years) with a left ventricular ejection fraction (EF) < or = 35% and with multivessel coronary artery disease underwent isolated coronary artery bypass grafting. Preoperatively 226 patients were in CCS class III-IV and 113 in NYHA class III-IV. The mean number of grafts was 3.4 +/- 0.8/patient and complete revascularization was achieved in 98.6% of cases. The internal mammary artery was used in 341 patients (97.2%) and in 328 (96%) as a graft for the left anterior descending artery. Follow-up was obtained in 97% of the patients and on average lasted 42 +/- 28 months. RESULTS: The hospital mortality was 5.9%. At multivariate analysis urgent operation (p < 0.01) and a lower EF (25.9% in deaths vs 29.1%, p < 0.05) were predictors of an increased operative mortality. EF (assessed postoperatively at transthoracic echocardiography in survivors) improved from 28.9 +/- 5.7 to 34.4 +/- 7.7% (p < 0.0001). At 1, 3, 5, 7, and 9 years respectively, the all-cause survival was 93 +/- 1.5, 85 +/- 2.2, 77 +/- 3.1, 69 +/- 4.9, and 60 +/- 7.3% and the freedom from cardiac death was 94 +/- 1.4, 89 +/- 1.9, 88 +/- 2, 80 +/- 4.7, and 76 +/- 5.7% with an improvement in the anginal and congestive heart failure status (p < 0.0001). CONCLUSIONS: In patients with coronary artery disease and severe left ventricular dysfunction, after evaluation of the clinical presentation, of the usefulness of vessels as grafts and of the presence of myocardial viability, 1) coronary artery bypass grafting can be performed with a low mortality and a good mid-term survival, 2) improvement in left ventricular function can be documented after coronary bypass surgery, 3) the internal mammary artery can be safely used as a graft, 4) the quality of life is improved as demonstrated by the improvement in the anginal and congestive heart failure status.

Left ventricular pseudoaneurysm and mitral valve regurgitation. Conservative surgical therapy.

A patient with posterolateral left ventricular pseudoaneurysm, severe mitral regurgitation and coronary artery disease is reported. Mitral valve insufficiency was almost completely cured by simple closure of the left ventricular defect by edge to edge apposition along the long axis of the heart.

Coronary flow reserve early and late after minimally invasive coronary artery bypass grafting in patients with totally occluded left anterior descending coronary artery.

BACKGROUND: The impairment of flow reserve of the left anterior descending coronary artery in the early postoperative period in patients receiving a left internal thoracic artery graft has been related to the effects of cardiopulmonary bypass. Indeed, the late improvement in flow has been attributed to a late increase in left internal thoracic artery diameter. METHODS: We evaluated 12 patients who underwent minimally invasive direct coronary artery bypass surgery with the internal thoracic artery used to graft an occluded left anterior descending artery without extracorporeal circulation. Early and 6 months after the operation, patients underwent a second angiogram of the left internal thoracic artery graft and assessment of coronary flow reserve by use of an intracoronary 0.014-inch Doppler guide wire. RESULTS: At the late study, coronary flow reserve had increased compared with the early postoperative data from 1.8 +/- 0.4 (standard deviation) to 2.5 +/- 0.6 (P =.002) because of a significant decrease in baseline averaged peak velocity (32.4 +/- 6.2 vs 21.3 +/- 6.4 cm/s, P =.002), whereas the hyperemic values were similar (51 +/- 6 vs 53.7 +/- 21.9 cm/s, P =.6). The diameters of the thoracic artery (2.1 +/- 0.3 vs 2.2 +/- 0.3 mm, P =. 7) and the left anterior descending coronary artery (1.8 +/- 0.1 vs 1.8 +/- 0.2 mm, P =.5), as well as myocardial oxygen consumption (106 +/- 14 vs 101 +/- 16 mm Hg. beats/min. 10(-2), P =.5), were unchanged. CONCLUSIONS: Our findings suggest that the late improvement in coronary flow reserve is independent of the diameter of the graft and probably reflects an early distal coronary vessel dysfunction, which normalizes with time.

Beneficial impact of isoflurane during coronary bypass surgery on troponin I release.

BACKGROUND: Experimental studies indicate that isoflurane, a commonly used volatile anesthetic, mimics the cardioprotective effects of ischemic preconditioning, probably through ATP-sensitive K+ (KATP) channel activation. The aim of this study was to evaluate the impact of isoflurane during coronary bypass surgery (CABG) on troponin I release. MATERIAL AND METHODS: Forty consecutive patients with chronic stable angina and multivessel disease undergoing isolated CABG were randomized to a control (16 men and 4 women, aged 51 to 73 years, mean 62) or isoflurane (15 men and 5 women, aged 51 to 77 years, mean 65) group before aortic cross-clamping and cardioplegia. Serum levels of troponin I and creatine kinase (CK)-MB, as markers of ischemic injury, were obtained at 24 hours after CABG. Regional wall motion score and left ventricular ejection fraction (LVEF) at transthoracic echocardiography were assessed 5 days postoperatively. Comparisons between groups were performed in the entire population and, subsequently, in those patients with preoperative LVEF < 50%. RESULTS: There were no significant differences between isoflurane-treated patients and controls in cross-clamp time (49 +/- 14 vs 51 +/- 13 min, p = ns), peak values of troponin I (0.9 +/- 0.7 vs 1.4 +/- 1.3 ng/ml, p = ns) and CK-MB (62 +/- 27 vs 64 +/- 27 U/l, p = ns), or postoperative echocardiographic score (26 +/- 7 vs 22 +/- 5, p = ns) and LVEF (53 +/- 10 vs 55 +/- 7%, p = ns). When the comparisons were restricted to those patients with preoperative LVEF < 50%, at 24 hours the isoflurane-treated patients exhibited a smaller release of troponin I and of CK-MB than controls (1.1 +/- 0.7 vs 2.3 +/- 1.3 ng/ml, p = 0.03, and 39 +/- 10 vs 57 +/- 22 U/l, p = 0.04, respectively). CONCLUSIONS: Isoflurane reduces myocardial injury in patients with impaired left ventricular function undergoing CABG; thus, it can be safely used as an additional cardioprotective tool during routine CABG in high-risk patients with poor left ventricular function.

Mid-term results of conventional bypass surgery for complex proximal left anterior descending coronary artery stenoses.

BACKGROUND: The significant involvement of proximal left anterior descending (LAD) coronary artery affects patient prognosis and must be treated. Recently, as alternative methods to conventional coronary bypass (CABG), minimally invasive direct coronary artery bypass grafting (MIDCAB) and percutaneous transluminal coronary angioplasty with stent implantation (PTCA/S) have been proposed to reduce costs and patient discomfort. The aim of this study was to obtain early and medium-term results of CABG in patients with complex LAD disease in whom the expected results with PTCA/S or MIDCAB would have been suboptimal. METHODS: We retrospectively examined one hundred consecutive patients subjected to isolated CABG who received either a single graft to LAD or several grafts to LAD and diagonal branches. The choice of CABG was due to poor expectable results with PTCA/S or MIDCAB because of anatomical characteristics of the lesion, inclusion in ongoing randomized study comparing surgical versus non-surgical revascularization, or preference on the part of the cardiologist or patient. RESULTS: Left internal mammary artery (LIMA) was grafted to LAD in 99 (99%) patients; 65 (65%) patients received at least one saphenous graft to the diagonal branches. No death was observed within 30 days from the operation. One (1%) patient had a perioperative non-Q myocardial infarction (MI). At a mean follow-up time of 38 +/- 16 months (range 2-60), there were no cardiac deaths and no new MI. Six patients complained of recurrent angina: in all cases but one (vein graft failure to a diagonal branch), there were no clinical or diagnostic signs suggesting other graft failures. The probability of freedom from early and late events, including cardiac death, MI and recurrence of angina regardless of site, was 99% at 1 year and 86% at 5 years. CONCLUSIONS: At present, conventional CABG seems to be the "gold standard palliation" of LAD disease in most cases. It can be performed safely with excellent early and medium-term results in terms of freedom from cardiac events. Its comparison with percutaneous transluminal techniques and MIDCAB needs to be addressed in further prospective studies.

Recovery of LV contractility in man is enhanced by preischemic administration of enflurane.

BACKGROUND: Volatile anesthetics enhance postischemic functional recovery in animal models; this effect has not been investigated in man. METHODS: Twenty-two patients undergoing coronary surgery were randomized to enflurane administration (0.5% to 2%) for 5 minutes to reduce systolic blood pressure by 20% to 25% immediately before cardioplegic arrest. Left ventricular contractility was assessed by pressure-area relations using echocardiographic automated border detection during inflow occlusion before and after cardiopulmonary bypass. Linear regression analysis in 16 patients with paired data sets assessed changes in contractility. RESULTS: The relation was highly linear (r = 0.95+/-0.02). A change of slope versus the change in x intercept was detected in controls (mean difference, 16.1 mm Hg/cm2, 95% confidence limits, 5.9 to 26.3; 2.2 cm2, 95% confidence limits, -1.1 to 5.5; p = 0.007), which was different from those of treated patients (mean difference, 0.7 mm Hg/cm2, 95% confidence limits, -2.2 to 3.7; -0.06 cm2, 95% confidence limits, -1.6 to 1.5; p > 0.2). Analysis of covariance in the overall group confirmed a significant effect of treatment (p = 0.002). CONCLUSIONS: Enflurane enhances postischemic functional recovery, possibly through pharmacologic preconditioning of myocardium.

Cyanoacrylate glue as an alternative to an additional suture line in the repair of type A aortic dissection.

We describe the use of cyanoacrylate glue in conjunction with gelatin-resorcinol-formalin glue for the treatment of type A aortic dissection. Instead of placing an additional suture line 2-3 cm from the edges of the aortic stumps to create a large pocket for gluing, we have been using a cyanoacrylate adhesive for approximating the walls of the true and false lumina without the risk of tearing them. Moreover, the simplicity and quickness of the procedure enables application of the cyanoacrylate glue even deeper into the aortic arch, creating a wider area for gluing the dissected layers.

Residual aortic valve regurgitation after aortic root remodeling without a direct annuloplasty.

BACKGROUND: Aortic insufficiency secondary to degenerative aneurysms of the ascending aorta can be surgically treated with replacement of the valve or with remodeling of the aortic root. METHODS: In 15 patients who underwent aortic root remodeling from January 1994 to December 1996, we evaluated the postoperative aortic regurgitation and correlated it with several anatomic and functional variables. Operative success was defined as a residual aortic regurgitation less than or equal to 1 on a scale of 0 to 4. RESULTS: Root dimensions and aortic incompetence decreased significantly after the operation (p < 0.0001). The difference between preoperative and postoperative root diameters (p = 0.0006) and the presence of Marfan's syndrome (p < 0.0001) were independently predictive of persisting significant aortic insufficiency. Operative success was obtained in patients with a difference between preoperative and postoperative root diameters smaller than 30 mm. CONCLUSIONS: Aortic root remodeling is effective in reducing aortic regurgitation. Severe aortic root dilatation may result in excessive geometric alteration, leading to suboptimal results. The choice of a larger graft contributes to avoiding excessive geometric constraint of a profoundly diseased aortic root. Indication to undergo root remodeling should be evaluated cautiously in patients with Marfan's syndrome.

Regression of left ventricular hypertrophy after aortic valve replacement for aortic stenosis with different valve substitutes.

OBJECTIVE: Stentless biologic aortic valves are less obstructive than stented biologic or mechanical valves. Their superior hemodynamic performances are expected to reflect in better regression of left ventricular hypertrophy. We compared the regression of left ventricular hypertrophy in 3 groups of patients undergoing aortic valve replacement for severe aortic stenosis. Group I (10 patients) received stentless biologic aortic valves, group II (10 patients) received stented biologic aortic valves, and group III (10 patients) received bileaflet mechanical aortic valves. METHODS: Echocardiographic evaluations were performed before the operation and after 1 year, and the results were compared with those of a control group. Left ventricular diameters and function, left ventricular wall thickness, and left ventricular mass were assessed by echocardiography. RESULTS: Group I patients had a significantly lower maximum and mean transprosthetic gradient than the other valve groups (P = .001). One year after operation there was a significant reduction in left ventricular mass for all patient groups (P < .01), but mass did not reach normal values (P = .05). Although the rate of regression in the interventricular septum and posterior wall thickness differed slightly among groups, their values at follow-up were comparable and still higher than control values (P = .002). The ratio between interventricular septum and posterior wall and the ratio between wall thickness and chamber radius did not change significantly at follow-up. CONCLUSIONS: Because the number of patients was relatively small, we could not use left ventricular mass regression after I year to distinguish among patients undergoing aortic valve replacement for aortic stenosis by means of valve prostheses with different hemodynamic performances.

Autograft from quadrangular resection for floppy valve repair in endocarditis.

We present a case of reconstruction of the anterior leaflet in mitral valve prolapse and subacute bacterial endocarditis in which the resected prolapsing segment of the posterior leaflet was used as patch material. Competence of the valve was achieved with no recurrence of infection. Quadrangular resection of the posterior leaflet supplies presumably viable patch material for valve repair, which is particularly useful in bacterial endocarditis and when pliability is required.

Levels of troponin I and cardiac enzymes after reinfusion of shed blood in coronary operations.

BACKGROUND: Reinfusion of shed blood after coronary artery bypass grafting might increase the levels of cardiac enzymes with consequent difficulties in the diagnosis of perioperative myocardial infarction. METHODS: Thirty consecutive patients undergoing coronary artery bypass grafting who bled at least 400 mL within the first 4 hours after operation underwent reinfusion of shed blood. Thirty consecutive patients who were not autotransfused served as control. All patients underwent enzyme determination (total creatine kinase, MB fraction, lactate dehydrogenase, and troponin I) in the shed blood and in circulating blood preoperatively, at arrival in the intensive care unit, and 6, 24, and 48 hours after operation. RESULTS: The shed blood contained significantly higher concentration of cardiac enzymes than the circulating blood at all time intervals (p = 0.0001). The levels of creatine kinase, its MB fraction, and lactate dehydrogenase in circulating blood were significantly elevated in patients receiving autotransfusion up to 24 hours after autotransfusion. The blood levels of troponin I were not significantly different between the two group of patients at all time points. The percent fraction of MB did not increase after autotransfusion. CONCLUSIONS: The measurement of cardiac troponin I is a useful marker for the diagnosis of perioperative myocardial infarction in patients undergoing transfusion of shed blood after coronary operation.

Extent and pattern of regression of left ventricular hypertrophy in patients with small size CarboMedics aortic valves.

OBJECTIVE: To assess the extent and pattern of regression of left ventricular hypertrophy after valve replacement for aortic stenosis, we studied 26 patients receiving either 19 or 21 mm CarboMedics valves (group I, 13 patients) or either 23 or 25 mm CarboMedics valves (group II, 13 patients). The studies were done before the operation and after 3 years, and results were compared with those of 10 control patients. METHODS: Left ventricular end-diastolic and end-systolic diameters and volumes, ejection fraction and fractional shortening, and interventricular septum and posterior wall thickness were measured. The ratio between interventricular septum and posterior wall thickness, the ratio between left ventricular wall thickness and left ventricular chamber radius, and the left ventricular mass were then calculated. RESULTS: At follow-up there was a significant reduction in the left ventricular mass, interventricular septum, and posterior wall thickness for both patient groups (p < 0.01). However, only the posterior wall thickness reached normal values; the interventricular septum and the left ventricular mass indices were still significantly greater than in the control group (p < 0.01). Because of the incomplete regression of interventricular septal hypertrophy, the ratio between interventricular septum and posterior wall thickness was similar between both patient groups but it was significantly higher than in control subjects (p < 0.01). The ratio between wall thickness and chamber radius did not decrease significantly in group II patients, in whom it remained above the control values. CONCLUSION: Having a bileaflet aortic prosthesis of one size larger did not seem to significantly influence the pattern and the extent of regression of left ventricular hypertrophy after an intermediate period of follow-up.

Hemodynamic performances of small diameter carbomedics and St. Jude valves.

BACKGROUND AND AIMS OF THE STUDY: Optimal hemodynamic performances are of paramount importance when implanting a mechanical valve in patients with a small aortic annulus. A Doppler echocardiographic study was performed to compare the hemodynamic performances of small CarboMedics and St. Jude valves. MATERIALS AND METHODS: Twenty-nine patients receiving either a 19 mm (n = 10) or a 21 mm (n = 10) CarboMedics valve or a 19 mm (n = 9) St. Jude Med HP valve were evaluated. A Doppler echocardiographic study was performed at rest and two minutes after treadmill exercise with the Bruce protocol. Peak and mean gradients across the valve were estimated; effective orifice area, performance index and discharge coefficient were calculated. Heart rate, blood pressure and cardiac output were all significantly increased with exercise. RESULTS: Peak and mean gradients at rest were significantly higher (p < 0.05) in the 19 mm CarboMedics valve (40.2 +/- 15 mmHg and 22.6 +/- 9 mmHg, respectively) when compared either with 21 mm CarboMedics valve (27.6 +/- 6.8 mmHg and 14.2 +/- 3.4 mmHg, respectively) or with the 19 mm St. Jude HP valve (23.6 +/- 10.4 mmHg and 13.6 +/- 5 mmHg, respectively). Peak and mean gradients were not modified with exercise for the 19 mm CarboMedics valve and significantly increased for the 21 mm CarboMedics and the 19 mm St. Jude HP valves. Although these values were still higher in the 19 mm CarboMedics valve, they did not reach the level of statistical significance when compared with the other two valve groups. CONCLUSIONS: The 19 mm St. Jude HP valve shows hemodynamic performances at rest that are similar to those of the 21 mm CarboMedics valve and superior to those of the 19 mm CarboMedics valve. With exercise both sizes of the CarboMedics valve show an in vivo discharge coefficient close to one, testifying to a full utilization of the internal orifice area.

Early postoperative myocardial ischemia after coronary artery bypass grafting. Detrimental effects of nitroglycerine infusion.

This study was aimed at assessing the incidence and mechanisms of myocardial ischemia early after coronary artery bypass grafting and the effects of treatment with nitroglycerine. The electrocardiogram of 35 patients (29 males and 6 females, mean age 61 +/- 8 years) with stable angina and multivessel coronary disease, was monitored continuously for 24 hours after uncomplicated coronary artery bypass grafting. Patients were randomized to receive nitroglycerin infusion or placebo. Fourteen of the 35 patients (40%) had 24 transient ischemic episodes (mean duration 11.8 +/- 3.5 min; range 6-20 min with ST segment elevation in 6, ST segment depression in 7 and both ST segment elevation and depression in 1. Seventy-five per cent of the ischemic episodes occurred within the first 6 postoperative hours. The mean ejection fraction prior to surgery and the mean number of stenosed vessels and of the implanted grafts were similar in patients with and without postoperative ischemia (57 +/- 5 vs 57 +/- 6%, p = 0.86; 2.7 +/- 0.5 vs 2.8 +/- 0.4, p = 0.52 and 3.0 +/- 0.9 vs 3.2 +/- 0.7, p = 0.51, respectively) as well as total bypass time and cross-clamp time (123 +/- 38 vs 124 +/- 18 min, p = 0.89 and 67 +/- 20 vs 70 +/- 14 min, p = 0.68, respectively). The values of heart rate and systolic blood pressure at the onset of the ischemic episodes were similar to those recorded 15 min before (103 +/- 16 vs 106 +/- 18 b/min, p = 0.36 and 119 +/- 12 vs 121 +/- 14 mmHg, p = 0.48). Ischemic episodes were recorded in 9 of the 16 patients (56%) randomized to receive nitroglycerine and in 5 only of the 19 patients (26%) randomized to receive placebo (p = 0.05). Thus, transient ischemic episodes occurring early after coronary artery bypass grafting are not preceded by an increase in myocardial oxygen consumption; they appear to be due, therefore, to a primary reduction in coronary blood flow. Treatment with nitroglycerine is associated with a higher prevalence of ischemic episodes, thus suggesting that myocardial ischemia is unlikely to be caused by spasm of large epicardial vessels or grafts. Myocardial ischemia may be caused, instead, by extracorporeal circulation-induced alterations enhanced by the hypotensive effects of nitroglycerine.

Intraoperative antifibrinolysis and blood-saving techniques in cardiac surgery. Prospective trial of 3 antifibrinolytic drugs.

Sixty consecutive patients undergoing elective open-heart surgery were prospectively enrolled in a study to compare the efficacy of 3 different antifibrinolytic drugs to reduce postoperative bleeding and to reduce homologous blood requirements in combination with blood-saving techniques and restrictive indications for blood transfusion. The patients were randomized to 1 of 4 intraoperative treatment regimens: 1) control (no antifibrinolytic therapy); 2) epsilon-aminocaproic acid (10 g IV at induction of anesthesia, followed by infusion of 2 g/h for 5 hours); 3) tranexamic acid (10 mg/kg IV within 30 minutes after induction of anesthesia, followed by infusion of 1 mg/kg per hour for 10 hours); or 4) high-dose aprotinin (2 million KIU IV at induction of anesthesia and 2 million KIU added to the extracorporeal circuit, followed by infusion of 500 thousand KIU/h during surgery). Hemoconcentration and reinfusion of blood drained from the operative field and the extracorporeal circuit after operation were used in all patients. Indications for blood transfusion were hypotension, tachycardia, or both, with hemoglobin values < 8.5 g/dL; or severe anemia with hemoglobin values < 7 g/dL. Compared with the blood loss in the control group, patients receiving aprotinin and epsilon-aminocaproic acid showed significantly less postoperative blood loss at 1 hour (control, 128 +/- 94 mL; aprotinin, 54 +/- 47 mL, p = 0.01; and epsilon-aminocaproic acid, 69 +/- 35 mL, p = 0.03); this trend continued at 24 hours after operation (control, 724 +/- 280 mL; aprotinin, 344 +/- 106 mL, p < 0.0001; and epsilon-aminocaproic acid, 509 +/- 148 mL, p = 0.01). Aprotinin was significantly more efficient than epsilon-aminocaproic acid (p=0.002). Tranexamic acid did not have a statistically significant effect on blood loss. Homologous blood requirements were not significantly different among the groups; postoperative hematologic values and coagulation times were also comparable. Despite the efficacy of aprotinin and epsilon-aminocaproic acid shown in the present study, the blood requirements were not significantly different from those that are found when transfusions are restricted, autotransfusions are used, and blood from the operative field and extracorporeal circuit is concentrated and reinfused. Therefore, intraoperative antifibrinolysis may not be indicated in routine cardiac surgery when other blood-saving techniques are adopted.

Determinants of myocardial ischemia during percutaneous transluminal coronary angioplasty in patients with significant narrowing of a single coronary artery and stable or unstable angina pectoris.

Previous studies have assessed the determinants of collateral vessel recruitment during coronary occlusion in patients undergoing percutaneous transluminal coronary angioplasty (PTCA). However, the determinants of severity of myocardial ischemia after sudden coronary occlusion do not necessarily coincide with those responsible for collateral vessel recruitment. The aim of this study was to assess the determinants of severity of myocardial ischemia during balloon inflation by recording surface and intra-coronary electrocardiograms (ECGs). In 62 consecutive patients with 1-vessel disease and without previous myocardial infarction undergoing successful PTCA for stable (n = 33) or unstable (n = 29) angina pectoris, the summation of the absolute values of ST-segment shifts from baseline on the intracoronary and surface ECG at the end of the first 2-minute inflation was obtained as an index of the severity of myocardial ischemia. Stenosis severity before PTCA was measured using computerized coronary angiography, while the grade of collateral filling was scored according to Rentrop's classification. The mean (+/- 1 SD) ST-segment shift at the end of balloon inflation was less in patients with than without collateral vessels (12 +/- 10 vs 23 +/- 15 mm, p < 0.05). Despite a similar prevalence of collateral vessels (34% vs 24%, p = NS), the mean ST-segment shift was also less in patients with unstable than stable angina (15 +/- 9 vs 24 +/- 17 mm, p < 0.05). However, the mean ST-segment shift was not associated with the severity of coronary stenosis before PTCA (r = 0.0004, p = NS).(ABSTRACT TRUNCATED AT 250 WORDS)

Ischemic preconditioning during coronary angioplasty is prevented by glibenclamide, a selective ATP-sensitive K+ channel blocker.

BACKGROUND: Brief episodes of ischemia render the heart more resistant to subsequent ischemia; this phenomenon has been called ischemic preconditioning. In some animal species, myocardial preconditioning appears to be due to activation of ATP-sensitive K+ (KATP) channels. The role played by KATP channels in preconditioning in humans remains unknown. The aim of this study was to establish whether glibenclamide, a selective KATP channel blocker, abolishes the ischemic preconditioning observed in humans during coronary angioplasty following repeated balloon inflations. METHODS AND RESULTS: Twenty consecutive patients undergoing one-vessel coronary angioplasty were randomized to receive 10 mg oral glibenclamide or placebo. Sixty minutes after glibenclamide or placebo administration, patients were given an infusion of 10% dextrose (8 mL/min) to correct glucose plasma levels or, respectively, an infusion of saline at the same infusion rate. Thirty minutes after the beginning of the infusion, both patient groups underwent coronary angioplasty. The mean values (+/- 1 SD) of ST-segment shifts on the surface 12-lead ECG and the intracoronary ECG were measured at the end of the first and second balloon inflations, both 2 minutes long. In glibenclamide-treated patients, the mean ST-segment shift during the second balloon inflation was similar to that observed during the first inflation (23 +/- 13 versus 20 +/- 8 mm, P = NS), and the severity of cardiac pain was greater (55 +/- 21 versus 43 +/- 23 mm on a scale of 0 to 100, P < .05). Conversely, in placebo-treated patients the mean ST-segment shift during the second inflation was less than that during the first inflation (9 +/- 5 versus 23 +/- 13 mm, P < .001), as was the severity of cardiac pain (15 +/- 15 versus 42 +/- 19 mm, P < .01). Blood glucose levels were significantly reduced 60 minutes after glibenclamide compared with those at baseline (53 +/- 9 versus 102 +/- 10 mg/100 mL, P < .001) in the glibenclamide group; however, before coronary angioplasty, blood glucose levels increased to 95 +/- 19 mg/100 mL, a value similar to that found in placebo group (96 +/- 11 mg/100 mL, P = NS). CONCLUSIONS: In humans, ischemic preconditioning during brief repeated coronary occlusions is completely abolished by pretreatment with glibenclamide, thus suggesting that it is mainly mediated by KATP channels.

[Unstable angina: the point of view of the surgeon]. / L'angina instabile: il parere del chirurgo.

Unstable angina is a serious condition with high risk of early coronary events; coronary revascularization in these patients gives good results but carries higher operative risk than in stable angina patients. Full medical therapy with antiischemic agents may be effective in controlling symptoms and preventing death and is therefore the first treatment of choice; as in stable angina, further treatment is indicated in stabilized patients according to non invasive tests results and coronary angiograms. Non responsive unstable patients have a poor outcome and are candidates for revascularization: angioplasty may be preferred in single or double vessel disease and bypass operation in multivessel disease. However, surgical revascularization in single and double vessel disease with critical proximal stenosis of a large anterior descending gives optimal results in our experience and may be the treatment of choice also in these patients. Because of the higher operative risk in multivessel disease in unstable ischemia, a combined procedure with angioplasty of the "culprit" lesion followed by full revascularization at a later time may be a more favourable option in some patients with multivessel disease.