Bilateral versus Single Internal-Thoracic-Artery Grafts at 10 Years.

BACKGROUND: Multiple arterial grafts may result in longer survival than single arterial grafts after coronary-artery bypass grafting (CABG) surgery. We evaluated the use of bilateral internal-thoracic-artery grafts for CABG. METHODS: We randomly assigned patients scheduled for CABG to undergo bilateral or single internal-thoracic-artery grafting. Additional arterial or vein grafts were used as indicated. The primary outcome was death from any cause at 10 years. The composite of death from any cause, myocardial infarction, or stroke was a secondary outcome. RESULTS: A total of 1548 patients were randomly assigned to undergo bilateral internal-thoracic-artery grafting (the bilateral-graft group) and 1554 to undergo single internal-thoracic-artery grafting (the single-graft group). In the bilateral-graft group, 13.9% of the patients received only a single internal-thoracic-artery graft, and in the single-graft group, 21.8% of the patients also received a radial-artery graft. Vital status was not known for 2.3% of the patients at 10 years. In the intention-to-treat analysis at 10 years, there were 315 deaths (20.3% of the patients) in the bilateral-graft group and 329 deaths (21.2%) in the single-graft group (hazard ratio, 0.96; 95% confidence interval [CI], 0.82 to 1.12; P=0.62). Regarding the composite outcome of death, myocardial infarction, or stroke, there were 385 patients (24.9%) with an event in the bilateral-graft group and 425 patients (27.3%) with an event in the single-graft group (hazard ratio, 0.90; 95% CI, 0.79 to 1.03). CONCLUSIONS: Among patients who were scheduled for CABG and had been randomly assigned to undergo bilateral or single internal-thoracic-artery grafting, there was no significant between-group difference in the rate of death from any cause at 10 years in the intention-to-treat analysis. Further studies are needed to determine whether multiple arterial grafts provide better outcomes than a single internal-thoracic-artery graft. (Funded by the British Heath Foundation and others; Current Controlled Trials number, ISRCTN46552265 .).

Influence of baseline left ventricular function on the clinical outcome of surgical ventricular reconstruction in patients with ischaemic cardiomyopathy.

AIMS: The Surgical Treatment for Ischemic Heart Failure (STICH) trial demonstrated no overall benefit when surgical ventricular reconstruction (SVR) was added to coronary artery bypass grafting (CABG) in patients with ischaemic cardiomyopathy. The present analysis was to determine whether, based on baseline left ventricular (LV) function parameters, any subgroups could be identified that benefited from SVR. METHODS AND RESULTS: Among the 1000 patients enrolled, Core Lab measures of baseline LV function with adequate quality were obtained in 710 patients using echocardiography, in 352 using cardiovascular magnetic resonance, and in 344 using radionuclide imaging. The relationship between LV end-systolic volume index (ESVI), end-diastolic volume index, ejection fraction (EF), regional wall motion abnormalities, and outcome were first assessed only by echocardiographic measures, and then by 13 algorithms using a different hierarchy of imaging modalities and their quality. The median ESVI and EF were 78.0 (range: 22.8-283.8) mL/m2 and 28.0%, respectively. Hazard ratios comparing the randomized arms by subgroups of LVESVI and LVEF measured by echocardiography found that patients with smaller ventricles (LVESVI <60 mL/m2) and better LVEF (≥33%) may have benefitted by SVR, while those with larger ventricles (LVESVI >90 mL/m(2)) and lower LVEF (≤25%) did worse with SVR. Algorithms using all three imaging modalities found a weaker relationship between LV global function and the effects of SVR. The extent of regional wall motion abnormality did not influence the effects of SVR. CONCLUSIONS: Subgroup analyses of the STICH trial suggest that patients with less dilated LV and better LVEF may benefit from SVR, while those with larger LV and poorer LVEF may do worse. Clinical Trial Registration #: NCT00023595.

Statistical agreement of left ventricle measurements using cardiac magnetic resonance and 2D echocardiography in ischemic heart failure.

BACKGROUND: The aim of this study was to compare cardiac magnetic resonance imaging (CMR) with 2-dimensional echocardiography (2D echo) in the assessment of left ventricle (LV) function parameters and mass in patients with ischemic heart disease and severely depressed LV function. Although 2D echo is commonly used to assess LV indices, CMR is the state-of-the-art technique. Agreement between these 2 methods in these patients has not been well established. MATERIAL/METHODS: LV indexed end systolic and diastolic volumes (EDVi and ESVi), indexed mass (LVMi) and ejection fraction (EF) were assessed in 67 patients (12 women), using 2D echo and CMR. RESULTS: According to statistical analysis (Bland-Altman), 2D echo underestimated LV EDV and ESV and overestimated EF and LVMi compared to CMR. The highest correlation between 2D echo and CMR was found for EDVi (R2=0.73, p<0.0001) and ESVi (R2=0.69, p<0.0001) and the lowest for EF (R2=0.21, p=0.001) and LVMi (R2=0.20, p=0.002). The maximal differences between 2D echo and CMR were found for highest mesurements of LV volumes and mass, and for lowest EF values. CONCLUSIONS: There is moderate to strong correlation between CMR and 2D echo in the assessment of LV function parameters and mass in patients with ischemic heart failure. Between-method agreement depends on the degree of LV dysfunction. The results of assessment of the severely damaged LV obtained by the use of 2D echo should be interpreted with caution.

[POL-TAVI First--Polish report on transcatheter aortic valve implantation (TAVI) of Edwards-Sapien prosthesis in the first 19 high risk patients with severe aortic stenosis and comorbidities]. / Nasze forum--kardiolodzy i kardiochirurdzy razem Raport POL-TAVI FIRST z zastosowania przezcewnikowej implantacji zastawki aortalnej typu Edwards-Sapien u pierwszych w Polsce 19 chorych z grupy bardzo duzego ryzyka, z ciezka stenoza aortalna i chorobami obciazajacymi rokowanie.

Patients with severe symptomatic aortic stenosis, who from November 2008 to March 2009 were treated with Edwards-Sapien transcatheter aortic valve implantation (TAVI) within the POL-TAVI First Polish Registry, were included in the analysis. Nineteen patients aged 78+/-4.8 years with high operation risk and Logistic EuroSCORE 25+/-7.6% were reported (74% were females). In 15 (79%) patients the valve was implanted transapically (TA), in the other four (21%)--via the femoral arterial access (TF). The valve was successfully implanted in 16 (84%) patients, in one patient aortic valvuloplasty alone was performed. During in-hospital period two patients died (one during periprocedural period and another one--two months after the implantation). During the mean follow-up of 5+/-1.5 months (except for one patient who is still in hospital) all patients are in NYHA class I or II. Results of the initial series of 19 TAVI patients in Poland are satisfactory, and the trial will be continued with careful medical and economical analysis.

Perivascular tissue of internal thoracic artery releases potent nitric oxide and prostacyclin-independent anticontractile factor.

OBJECTIVE: It has been recently suggested that perivascular tissue (PVT) releases hypothetic adipocyte- or adventitia-derived relaxing factor. The aim of the study was to assess anticontractile properties of perivascular tissue of human internal thoracic artery (ITA) and to check if this activity is nitric oxide (NO)- or prostacyclin-dependent. We also analyzed the influence of pleural adipose tissue on ITA reactivity. METHODS: Human ITA rings were studied in vitro. First, skeletonized and pedicled ITA reactivity to serotonin and angiotensin II was compared. In subsequent experiments fragments of ITA were skeletonized and divided into two preparations. One was incubated alone, the other together with PVT or pleural adipose tissue floating freely in the bath. First, concentration-response curves to either serotonin or angiotensin II were constructed. Tissue was then transferred from one bath to the other and concentration-response curves were reconstructed. The same protocol was applied with the inhibition of NO synthase with L-NMMA (10(-4)M) and cyclooxygenase with indomethacin (10(-5)M). RESULTS: Skeletonization augmented contractile response to serotonin (E(max) 16.6+/-1.85 mN vs 43.8+/-3.87 mN; pedicled vs skeletonized ITA, respectively; p<0.001) and angiotensin II (E(max) 10.9+/-1.07 mN vs 26.6+/-1.45 mN, respectively; p<0.001). PVT presence in the bath caused decrease of E(max) from 40.8+/-5.01 to 20.1+/-2.69 mN for serotonin; p<0.001 and from 31.4+/-3.75 to 13.0+/-1.60 mN for angiotensin II, p<0.001 (PVT(-) vs PVT(+), respectively). PVT did not change ITA sensitivity (EC(50)) to serotonin or angiotensin II. Pleural adipose tissue did not change the contractile response of ITA to serotonin (E(max) 37.2+/-4.95 mN vs 36.3+/-4.83 mN, pleural fat+and pleural fat-, respectively; p=0.9). NO and prostacyclin inhibition failed to abolish anticontractile properties of perivascular tissue. PVT with cyclooxygenase and NO synthase inhibition decreased E(max) of serotonin from 46.6+/-3.03 to 28.2+/-4.02 mN, p<0.001 and E(max) of angiotensin II from 27.2+/-2.00 to 16.4+/-2.10 mN, p<0.001. CONCLUSIONS: Perivascular tissue of ITA releases potent, soluble, nitric oxide and prostacyclin-independent anticontractile factor. The pleural adipose tissue does not influence ITA reactivity to vasoconstrictors. Preservation of perivascular tissue may protect against vasospasm of ITA graft in clinical settings.

[Clinical significance of transesophageal and epiaortal echocardiography of ascending aorta in risk estimation of neurological complications in coronary artery by-pass patients]. / Znaczenie badania echokardiograficznego przezprzelykowego i epiaortalnego aorty wstepujacej w prognozowaniu ryzyka powiklan neurologicznych u chorych poddanych zabiegowi pomostowania tetnic wiencowych.

UNLABELLED: Advanced atherosclerotic changes in aortal wall are an important factor in taking decision to use minimal-invasive method of coronary artery by-pass grafting. There are some methods for diagnosing atherosclerotic changes in ascending aorta, i.e.: roentgenogram, computer tomography, magnetic resonance imaging, transthoracic echocardiography and especially transesophageal echocardiography and epiaortal echocardiography. THE AIM OF THE STUDY: To define usefulness of transesophageal and epiaortal echocardiography as a method of prognosing neurological complications in patients during coronary artery by-pass grafting. MATERIAL AND METHODS: Study group consisted of 32 consecutive patients who had coronary surgery in II Chair and Department of Cardiosurgery, Silesian Medical University in Katowice due to ischemic heart disease in whom before the surgery ascending aorta wall was evaluated with transesophageal and epiaortal echocardiography and then monitoring of microembolism was performed. Transesophageal examination was performed with Philips Sonos 7500 device with 5 MHz transducer in anesthetized patient. Ascending aorta from level of aortic valve to the aortic arch in long and short axis was evaluated. Epiaortal echocardiography was performer with 7.5 MHz vesseltransducer and Hewlett-Packard Sonos 100 CF H-P device immediately after chest opening. Transesophageal echocardiography of ascending aorta evaluated: intima-media complex thickness and presence of atherosclerotic plaques and calcifications. Microembolism monitoring was performed in 18 patients before and during surgery. Using 2 MHz transducer placed in left and right temporal region number of microembolic incidents were evaluated. RESULTS: Analysis of relationship between aortic wall thickness and microembolic signals during cardiopulmonary by-pass was performed. During cardiopulmonary by-pass microembolic signals (from 7 to 698 signals) were detected in 7 patients. During analysis number of microembolic signals was normalized to cardiopulmonary by-pass duration time. CONCLUSIONS: There was found correlation between number of microembolic signals during cardiopulmonary by-pass and thickness of aortic posterior wall in all of it's levels, using epiaortal method in short axis. This same was found using lateral wall measurements. There was no correlation between aortic wall thickness evaluated with transesophageal echocardiography and numbers of microembolic signals.

[Mitral annuloplasty ring dehiscence after blunt chest trauma]. / Oderwanie sztucznego pierscienia mitralnego w wyniku tepego urazu klatki piersiowej.

A case of recurrent severe mitral regurgitation following blunt chest trauma with deceleration injury in a 61-year-old woman is presented. The patient had undergone previous CABG and mitral annuloplasty with the use of a flexible (Duran) ring. At reoperation, partial dehiscence of the annuloplasty ring, which had become rigid, was found. This was successfully repaired.

Randomized comparison of stentless versus stented valves for aortic stenosis: effects on left ventricular mass.

BACKGROUND: Aortic valve replacement (AVR) is the established treatment for severe aortic stenosis. In response to the long-term results of aortic homografts, stentless porcine valves were introduced as an alternative low-resistance valve. We conducted a randomized trial comparing a stentless with a stented porcine valve in adults with severe aortic stenosis. METHODS AND RESULTS: The primary outcome was change in left ventricular mass index (LVMI) measured by transthoracic echocardiography and, in a subset, by cardiovascular MR. Measurements were taken before valve replacement and at 6 and 12 months. Patients undergoing AVR with an aortic annulus < or =25 mm in diameter were randomly allocated to a stentless (n=93) or a stented supra-annular (n=97) valve. There were no significant differences in mean LVMI between the stentless versus stented groups at baseline (176+/-62 and 182+/-63 g/m2, respectively) or at 6 months (142+/-49 and 131+/-45 g/m2, respectively), although within-group changes from baseline to 6 months were highly significant. Changes in LVMI measured by cardiovascular MR (n=38) were consistent with the echo findings. There was a greater reduction in peak aortic velocity (P<0.001) and a greater increase in indexed effective orifice area (P<0.001) in the stentless group than in the stented group. There were no differences in clinical outcomes between the 2 valve groups. CONCLUSIONS: Despite significant differences in indexed effective orifice area and peak flow velocity in favor of the stentless valve, there were similar reductions in left ventricular mass at 6 months with both stented and stentless valves, which persisted at 12 months.

Plasma ANP and renin-angiotensin-aldosterone system as new parameters describing the hemodynamics of the circulatory system after implantation of stented or stentless aortic valves.

BACKGROUND AND AIM OF THE STUDY: Aortic valve replacement (AVR) in patients with a small aortic root involves the occurrence of patient-prosthesis mismatch (PPM). Recent reports have shown that a reduced effective orifice area index (EOAI) may not be the sole factor responsible for this complication. The study aim was to analyze the activity of atrial natriuretic peptide (ANP)/renin-angiotensin-aldosterone (RAA) after implantation of stented or stentless valves. METHODS: Between 2001 and 2003, a total of 30 patients operated on at the authors' institution received either a stentless Freestyle bioprosthesis (group A; n = 15) or a stented Mosaic bioprosthesis (group B; n = 15). The demographics of both groups were similar, and all patients underwent echocardiography preoperatively, and at one, six and 12 months postoperatively. The activity of the RAA system and plasma ANP level were measured in all patients preoperatively and at one and six months postoperatively. RESULTS: At one month after AVR, statistically significant inter-group differences were noted in plasma renin activity (group A, 3.7 +/- 2.1 ng/ml/h; group B, 5.6 +/- 0.8 ng/ml/h; p <0.05; control value 0.3-5.3 ng/ml/h). For ANP, statistically significant differences were present at one month after surgery (group A, 36.3 +/- 5.1 pg/ml; group B, 62.9 +/- 9.2 pg/ml; p <0.005; control value 27.3-37.2 pg/ml). On echocardiography, the ejection fraction, aortic valve gradient, EOAI and left ventricular mass index (LVMI) were assessed. A statistically significant difference was identified for the LVMI at 12 months postoperatively (group A, 216 +/- 13 g/m2; group B, 240 +/- 18 g/m2; p <0.05). In terms of other parameters both groups were similar. CONCLUSION: The implantation of an aortic valve prosthesis affects the hemodynamics of the entire circulatory system, and thus the activity of natriuretic systems. Whilst stentless valves allowed much more rapid normalization of circulatory system hemodynamics (one month), no difference compared to preoperative was identified after six months. Natriuretic peptides appear to provide more sensitive (long-term) but less specific (short-term) assessment of circulatory system behavior than echocardiography.

Left internal mammary artery improves 5-year survival in patients under 40 subjected to surgical revascularization.

BACKGROUND: The population of young patients under 40 requiring coronary bypass surgery is characterized by an extremely and unusually rapid progression of coronary heart disease. The aim of the present study was to assess the clinical status and quality of life in these patients after surgery in relation to the type of conduit used to revascularize the left anterior descending artery (LAD). METHODS: One hundred seventeen patients under 40 (range, 30-40 years) underwent coronary artery bypass grafting (CABG) at our institution between 1991 and 1999. Ninety-one patients received LIMA to LAD graft (group A), and in 26 patients the saphenous vein was used to graft this vessel (group B). Seventy-eight patients (63 in group A and 15 in group B) were assessed after a mean time of 71 +/- 26 months. They were asked to fill out a questionnaire aimed at their subjective assessment of their quality of life as compared with their preoperative status. RESULTS: Five-year actuarial survival was higher in patients with LIMA to LAD graft (log rank test: P < .004). The functional status of patients in group B was significantly worse in comparison to group A: respectively, CCS 2.2 +/- 1.1 versus 1.5 +/- 0.7; (P = .02), NYHA 2.2 +/- 1.1 versus 1.3 +/- 0.5; (P = .002). Patients in group B more frequently required reinstitution of nitroglycerine treatment (93% versus 56%; P = .025). We failed to show differences between the 2 groups as far as subjective quality of life is concerned. In summary, 63% of patients perceived it to be worse, 29% to be better, and 8% felt it had not changed. CONCLUSION: The use of LIMA is crucial in patients undergoing CABG under the age of 40 in order to achieve the best possible surgical results. Quicker recurrence of coronary disease symptoms is observed when a vein is used to graft the LAD. It may reflect an earlier progress of atherosclerosis in venous grafts.

Angiotensin-converting enzyme inhibitors reveal non-NO-, non-prostacycline-mediated endothelium-dependent relaxation in internal thoracic artery of hypertensive patients.

BACKGROUND: We have shown that treatment of hypertension with ACE inhibitors (ACE-I) enhances relaxation to acetylcholine in human internal thoracic artery (ITA) above this in nonhypertensive patients receiving no ACE-I. Present study assesses the endothelium-dependent responses mediated by neither NO nor prostacyclin in human ITA. METHODS: We compared isolated ITA rings from hypertensive patients treated with ACE-I (ACE-I group) with those from normotensive patients on no ACE-I (control group). Relaxation to acetylcholine was assessed before and after inhibition of NO synthase and cyclooxygenase with L-NMMA and indomethacin, respectively. RESULTS: The maximal relaxation in ACE-I group was 79+/-3.3% and was depressed by incubation with L-NMMA and indomethacin to 41+/-2.7% (p<0.001); pD(2)=7.7+/-0.1 vs. 7.4+/-0.8 (p=0.265). The maximal relaxation to acetylcholine was lower in the control group: 65+/-3.3% (p=0.01); pD(2)=7.5+/-0.1 (p=0.07). Incubation with L-NMMA and indomethacin produced contraction to acetylcholine with a maximum of 43+/-7% (p<0.001); pD(2)=5.3+/-0.3 (p<0.001). The area under the concentration-response curve for acetylcholine-induced relaxation in ACE-I group equaled [arbitrary units] 596+/-71 and after incubation with L-NMMA and indomethacin 281+/-40 (p=0.002). Estimated LNMMA- and indomethacin-resistant relaxation, absent in control group, accounted for 47+/-4% of relaxation to acetylcholine in ACE-I group. Estimated NO- and prostacyclin-mediated relaxation was higher in control group than ACE-I group: 628+/-74 vs. 315+/-47 (p=0.009). CONCLUSIONS: The results suggest that therapy with ACE-I improves endothelial function of hypertensive patients mainly by enhancing the endothelium-derived hyperpolarizing factor (EDHF) (and not NO)-mediated responses. It seems that it reveals measurable non-NO- non-PGI-mediated endothelium-dependent relaxation otherwise absent in conduit arteries.

Skeletonization of internal thoracic artery affects its innervation and reactivity.

OBJECTIVE: The studies showing the superior characteristics of ITA graft and its impact on the clinical results of coronary artery surgery were performed with ITA harvested almost exclusively as a pedicle. This study assesses the impact of ITA skeletonization on its innervation and reactivity. METHODS: Segments of skeletonized and non-skeletonized ITA were stained with antibodies against protein S-100 to look for the presence of sympathetic nerve fibers. The functional studies were performed on segments of discarded human pedicled ITA that were divided into two 3mm rings, one skeletonized and another non-skeletonized. We compared concentration-effect relationships for the contraction to norepinephrine and endothelium-dependent relaxation to acetylcholine and bradykinin, as well as endothelium-independent relaxation to sodium nitroprusside in skeletonized and non-skeletonized segments of the same ITA. RESULTS: Skeletonized ITA was devoid of protein S-100 positive nerve fibers. It contracted stronger (maximal response 37.0+/-2.04 vs. 25.4+/-1.83mN (P<0.001)) and was twice as sensitive to norepinephrine: pD(2) 6.03+/-0.10 vs. 5.70+/-0.12 (P=0.035). The endothelium-dependent relaxation responses did not differ between skeletonized and non-skeletonized ITA rings. The skeletonized ITA rings appeared over 10 times more sensitive to sodium nitroprusside: pD(2) 6.66+/-0.20 vs. 5.59+/-0.37 (P=0.012)-potency ratio 11.61. The maximal responses did not differ significantly: 112.0+/-6.71 vs. 129.4+/-16.4% (P=0.33). CONCLUSIONS: Skeletonization results in sympathectomy of ITA. It has no effect on endothelium-dependent relaxation but increases reactivity of ITA to norepinephrine. This augmented response to alpha-agonist is small, in comparison with over a ten-fold increase in sensitivity to sodium nitroprusside. Pedicled and skeletonized ITA are functionally significantly different vessels when studied in vitro.

Effect of coronary artery bypass graft in patients with unstable angina on left ventricular remodelling in medium-term follow-up.

INTRODUCTION: Left ventricular remodelling is a process of change in size, shape, wall thickness and heart function, initiated by a noxious stimulus such as ischaemia. Methods of pharmacological and surgical inhibition or reversal of remodelling are being sought. AIM: To assess the influence of coronary artery bypass grafting on echocardiographic measures of left ventricular size and shape in medium-term follow-up. METHODS: In a group of 30 patients three echocardiographic examinations were performed: before CABG operation, 3 months after and 20 months after the operation. Left ventricular area and volumes as well as indices of sphericity, thinning and expansion were calculated. RESULTS: After the operation, left ventricular areas measured in short axis and in apical four-chamber view increased among patients with a history of myocardial infarction. Improvement in the sphericity index occurred after the operation in patients with a history of myocardial infarction in whom the ejection fraction before the operation was less than 50%. CONCLUSIONS: The left ventricular remodelling process progresses after coronary artery bypass grafting in patients with a history of myocardial infarction. Inhibition of remodelling may be expected in patients without myocardial infarction, with preserved left ventricular systolic function.

[Mediastinal abscess as a remote complication of CABG combined with temporary cardiac pacing--a case report]. / Ropien sródpiersia jako odlegle powiklanie pomostowania tetnic wiencowych z zastosowaniem czasowej stymulacji serca. Opis przypadku.

A case of a 74 year old patient with a history of CABG with temporary epicardial cardiac pacing, is described. Five years later the patient developed wound infection. Computerised tomography revealed the presence of mediastinal abscess containing surgical material. The patients underwent surgical removal of the abscess with a distal part of an epicardial pacing lead which was left after CABG and was the most probable cause of infection.

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.

[New face of modified reperfusion: postconditioning]. / Nowe oblicze modyfikowanej reperfuzji: postconditioning.

In this review authors describe the mechanisms and possibilities of attenuation of ischaemia reperfusion injury in the myocardium. They describe modified reperfusion (postconditioning) and discuss its use in basic and clinical research. The proposed effects of modified reperfusion on the reperfusion injury were also depicted and compared to the mechanisms and action of ischemic preconditioning.

Diazoxide provides protection to human myocardium in vitro that is concentration dependent.

BACKGROUND: Diazoxide has been shown to confer significant myocardial protection in many experiments. This study was designed to assess its influence on the structural injury and functional recovery of human myocardium subjected to hypoxia/reoxygenation in vitro. METHODS: The isolated electrically driven human right atrial trabeculae, obtained during cardiac surgery, were studied. The tissue bath was oxygenated with 95% oxygen and 5% carbon dioxide, hypoxia being obtained by replacing oxygen with argon. The influence of diazoxide on atrial contractility was studied first. Next, the two trabeculae from one atrial appendage were studied simultaneously, adding diazoxide to the tissue bath 10 minutes before hypoxia in one, with another serving as a control. We tested 10(-4.5) mol/L and 10(-4) mol/L diazoxide in three sets of experiments testing 30, 60, and 90 minutes of hypoxia. We continued reoxygenation for 120 minutes (in 60-minute and 90-minute hypoxia experiments) and subsequently tested reaction to 10(-4) mol/L norepinephrine. Apart from continuous recording of the contraction force, we measured the troponin I release into the tissue bath after ischemia and reoxygenation. RESULTS: Diazoxide exerted a negative inotropic effect in human atrial muscle (pD(2)=3.96 +/- 0.18). Both concentrations of diazoxide studied resulted in better functional recovery of atrial trabeculae subjected to 30 minutes of hypoxia. With longer hypoxia, only the higher diazoxide concentration provided significant protection as assessed by contractility. After 120 minutes of reoxygenation, only diazoxide-treated muscle was viable enough to respond to norepinephrine. Only 10(-4) mol/L diazoxide resulted in lower troponin I release during hypoxia and reoxygenation. CONCLUSIONS: This study shows that diazoxide provides significant concentration-dependent protection against hypoxia/reoxygenation injury to human myocardium in vitro.

Lipid peroxidation and vitamin E in human coronary atherosclerotic lesions.

BACKGROUND: We aimed to assess the oxidant/antioxidant status within the ex vivo human coronary endarterectomy samples. METHODS: To achieve this, we measured products of lipid oxidation (malondialdehyde, 7-ketocholesterol), lipids (cholesterol, cholesteryl esters) and vitamin E in endarterectomy samples. RESULTS: Content of malondialdehyde in the plaque ranged from 0.23 to 37.36 microg/g. Unesterified cholesterol content ranged from 0.30 to 1.94 mg/g. It was 9.04+/-4.32% of total cholesterol. Total cholesterol content ranged from 1.73 to 23.69 mg/g. Cholesteryl palmitate content ranged from 0.57 to 19.10 mg/g, which is 11.43-60.86% of the total esters (mean+/-SD 40.27+/-18.42%). Cholesteryl oleate content ranged from 0.24 to 5.76 mg/g, being 9.97-21.81% of total esters (mean+/-SD 14.35+/-4.51%). Cholesteryl linoleate content ranged from 1.05 to 8.21 mg/g, being 17.84-45.15% of total esters (mean+/-SD 30.78+/-11.69%). Cholesteryl arachidonate content ranged from 0.51 to 4.20 mg/g, which is 7.56-22.87% of total esters (mean+/-SD 14.60+/-5.60%). The cholesteryl linoleate/cholesteryl oleate ratio (CL/CO) ranged from 1.01 to 4.33. Content of 7-ketocholesterol in the plaque ranged from 0.0 to 577.5 ng/g of wet weight. The 7-ketocholesterol/total cholesterol ratio was 0.003+/-0.003% (range from 0.0% to 0.008%). The 7-ketocholesterol/unesterified cholesterol ratio was 0.024+/-0.023% (range from 0.0% to 0.066%). The plaque content of vitamin E ranged from 0.0 to 40.9 microg/g of wet weight. CONCLUSION: The present study, comprising measurements of lipids, products of lipid peroxidation and vitamin E in 12 human coronary endarterectomy samples, lends the evidence for ongoing lipid peroxidation within an atherosclerotic lesion.

Total arterial revascularization for multiple vessel coronary artery disease: with or without cardiopulmonary bypass.

BACKGROUND: To assess the usefulness of off-pump technique for more technically demanding coronary artery bypass procedures using exclusively arterial conduits. METHODS: Analysis of perioperative data of 324 consecutive patients in whom total arterial revascularization for multiple- vessel coronary artery disease was performed--181 cases on-pump and 143 cases off-pump. RESULTS: On average in the on-pump group 2.7 +/- 0.8 (range, 2-5) grafts per patient were constructed versus 2.4 +/- 0.7 (range, 2-4) grafts per patient in the off-pump group (P < .001). Of the total number of 490 anastomoses performed on-pump, 83 (17%) were side-to-side and of 349 anastomoses performed off-pump, 51(15%) were side-to-side, a nonsignificant difference (P = .4). The aorta was used as a site for proximal anastomosis of 1 or more arterial conduits in 105 patients (58%) who underwent on-pump surgery and in 57 patients (40%) who underwent off-pump surgery (P = .002). In the off-pump group, the right internal thoracic artery (RITA) was rarely (12%) routed through the transverse sinus to circumflex branches compared with the on-pump group (34%) (P = .017). RITA in off-pump patients was more often used to revascularize the anterior wall (47% versus 29%; P = .08). We observed no difference in mortality (1.7% versus 0%; P = .3), incidence of perioperative myocardial infarction (8.8% versus 7.7%; P = .8), stroke (1.7% versus 1.4%; P = .8), or atrial fibrillation (24% versus 19%; P = .3). We observed less inotropic support and less blood-product use in off-pump patients. CONCLUSION: Total arterial revascularization for multiple-vessel coronary artery disease may be safely performed off-pump. We observed tendency to somewhat smoother postoperative course in the off-pump group.