The effects of N-acetylcysteine on pulmonary functions in patients undergoing on-pump coronary artery surgery: a double blind placebo controlled study

OBJECTIVE

To investigate the effects of N-acetylcysteine (NAC) on pulmonary function tests and arterial blood gases in patients undergoing on-pump coronary artery surgery.

PATIENTS AND METHODS

The effect of NAC was assessed within the scope of a prospective, single center, double-blind, placebo-controlled, parallel group study. Eighty-two patients undergoing coronary artery bypass grafting were randomized into two groups to receive either placebo (group 1, n = 40) or NAC (group 2, n=42). Both the NAC group and the placebo-receiving control group also included a COPD subgroup consisting of patients with an FEV1/FVC ratio of < 0.7 and an FEV1 value of 50-80%. Pulmonary function tests were performed preoperatively and on postoperative day 60.

RESULTS

Both groups were similar with respect to age, gender, preoperative risk factors, ejection fraction (EF), mean cross-clamp time, ventilation time, intensive care unit (ICU) stay, atrial fibrillation (AF) and hospital stay (p > 0.05). Postoperative FVC and FEV1 values in group 1 and the postoperative FEV1, FEV1/FVC and FEF 25-75 values in group 2 were lower in comparison to their preoperative values. However, in both group 1 and 2, the decreases observed in these parameters were not statistically significant (p > 0.05). In the COPD subgroup of group 1, a postoperative decrease was observed in the FEV1 and FEF25-75 values, with the FEV1 decreasing by 4.55%, and the FEF25-75 decreasing by 4.2% (p < 0.05). In the COPD subgroup of group 2, no significant decrease was observed in the pulmonary function test values (p > 0.05).

CONCLUSIONS

This study demonstrated that NAC administration in COPD patients undergoing on-pump coronary artery surgery resulted in the preservation of pulmonary functions.

Giant left atrial thrombus formation in patient with a previous coronary artery bypass grafting

Free-floating left atrial ball thrombus is a rare condition. We report a giant left atrial ball thrombus which was removed under surgery uneventfully, in a 48-year-old male patient with the presence of sinus rhythm and no valvular disease with previous off-pump coronary artery bypass surgery.

Plasminogen activator inhibitor-1 levels in patients with primary varicose vein

AIM

Plasmin is involved in extracellular matrix remodeling by activating some matrix metallo-proteinases and degrading extracellular matrix; therefore component of fibrinolytic system such as tissue plasminogen activator and plasminogen activators inhibitors (PAI-1) might have a role in the pathogenesis of vascular remodeling. In our study we aimed to investigate the levels of PAI-1 levels in patients with primary varicose veins (VV) and in their age and gender matched control group.

METHODS

Forty-one consecutive patients with peripheral varicose veins and 37 healthy age and gender-matched control subjects were included in the study from the outpatient cardiology and cardiovascular surgery clinic. Study population consisted of 41 consecutive patients who met the inclusion criteria and diagnosed as having class II primary VV according to CEAP classification. Routine biochemical and hematological analysis were performed in all patients and control subjects.

RESULTS

Plasma levels of PAI-1 were found to be lower in patients than those in control subjects (5.19±2.2 ng/mL vs. 6.47±2.6 ng/mL, P=0.025). Logistic regression analysis revealed that only the plasma levels of PAI-1 were found to be independently but inversely associated with the presence of primary VVs (Odds ratio: 0.80 CI: 0.64-0.99, P=0.04).

CONCLUSION

We have shown that PAI-1 levels are significantly decreased in patients with pVVs and it has an independent association with the presence of pVVs. However, its exact relation and role via matrix metlalloproteinases on the pathogenesis of the disease remains to be elucidated in further studies.

Pre-operative trans-thoracic doppler ultrasonography evaluation and intraoperative manual evaluation of the left internal thoracic artery in patients with type 2 diabetes with coronary artery disease

Patients with coronary artery disease, with (n = 25) and without (n = 59) type 2 diabetes, who were scheduled to undergo coronary artery bypass grafting were enrolled in this prospective study. The left internal thoracic artery (LITA) was assessed for graft suitability before surgery by trans-thoracic Doppler ultra sonography and during surgery by manual measurement. Significant differences were seen between preoperative and intra-operative LITA blood flow rates and LITA diameters, and the values of each at the two time points showed significant correlation, suggesting that pre-operative measurements largely related to intra-operative conditions. The pre-operative and intra-operative LITA blood flow rates and LITA diameters were not significantly different between patients with and without type 2 diabetes. Pre-operative LITA blood flow was monophasic in three patients without diabetes and the LITA grafts of these patients were deemed unsuitable for implantation during surgery. It is concluded that type 2 diabetes does not seem to have a negative effect on the suitability of LITA grafts. In addition, trans-thoracic Doppler ultrasonography is an easy, cost-effective, reproducible and non-invasive examination method, which may help in the evaluation of LIMA function and contribute to graft selection.

On-pump coronary artery bypass surgery in high-risk patients aged over 65 years (EuroSCORE 6 or more): impact on early outcomes

The results of on-pump coronary artery bypass graft (CABG) surgery in 166 high-risk elderly patients (EuroSCORE 6 or more; over age 65 years [mean 71.8 years]) were compared with 176 low-risk elderly patients (EuroSCORE below 6; over age 65 years [mean 68.8 years]). There was no significant difference in hospital mortality or number of grafts between the two groups. Rates of inotropic agent use, intra-aortic balloon pump insertion and atrial fibrillation, and the duration of intensive care unit and hospital stay were significantly higher in high-risk than low-risk patients. There were no significant differences in the incidence of major complications between the two groups. The results suggest that, in selected patients, on-pump CABG can be safely performed in high-risk patients over 65 years old with no effect on mortality.

Atrial fibrillation after coronary artery bypass grafting in elderly patients: incidence and risk factor analysis

OBJECTIVE

New-onset atrial fibrillation (AF) is the most frequent arrhythmic complication after coronary artery bypass grafting (CABG). Elderly patients who undergo this operation may have a different risk profile from the general population. The aim of this study was to identify risk factors for post-CABG AF in the elderly population.

METHODS

Between September 2001 and December 2005, 426 elderly patients (age >/= 65 years) underwent CABG at our center. Ninety-one developed post-CABG AF (AF group), and the other 335 (no-AF group) did not develop this complication. Multivariate analysis (odds ratio, +/- 95 % CI, P value) was used to identify independent clinical predictors of post-CABG AF.

RESULTS

The incidence of post-CABG AF in elderly patients during the study period was 21.4 %. Multivariate analysis identified age (OR 1.07, P < 0.009), age >/= 75 years (OR 1.77, P < 0.042), preoperative renal insufficiency (OR 5.09, P < 0.035), EuroSCORE (OR 1.18, P < 0.038), and cross-clamping time (OR 1.02, P < 0.012) as predictors of AF occurrence. The AF group had a significantly longer mean intensive care unit (ICU) stay (3.8 +/- 4.7 vs. 2.5 +/- 1.3 days for AF vs. no-AF; P = 0.0001), and a significantly higher proportion of patients with prolonged (>/= 6 days) ICU stays (8.8 % vs. 3.2 %, respectively; P = 0.033). Hospital mortality was 3.2 % in the no-AF group and 2.2 % in the AF group ( P = 0.74).

CONCLUSION

This study of elderly patients reveals some novel predictors of post-CABG AF, most notably preoperative renal insufficiency and EuroSCORE. It is important to identify risk factors for post-CABG AF in all patient groups as this knowledge might lead to better prevention of this problem and its potential consequences.

Complete myocardial revascularization using arterial grafts only in patients with unstable angina: impact on early outcome

OBJECTIVE

The aims of this study were 1) to assess early clinical outcomes for patients with unstable angina (UA) who undergo urgent/emergent coronary artery bypass grafting (CABG); and 2) to evaluate the feasibility and safety of complete revascularization using strictly arterial grafts in this patient group.

PATIENTS AND METHODS

Between September 2001 and May 2005, a total of 961 patients underwent CABG at our center. One hundred and sixty-seven (17.4 %) of these individuals underwent urgent or emergent CABG because of UA, and 794 (82.6 %) underwent elective CABG for stable angina (SA). Of the 167 patients with UA, 59 (35.3 %) underwent complete revascularization using arterial grafts only (AO subgroup: internal thoracic arteries and radial arteries) and the other 108 received a combination of arterial and venous grafts (AV subgroup: 1 internal thoracic artery plus saphenous vein grafts).

RESULTS

The UA group had a significantly higher proportion of women and a significantly higher rate of left main coronary artery disease than the SA group ( P = 0.016 and P = 0.0001, respectively). Cardiopulmonary bypass time was significantly longer in the UA group ( P = 0.01). Higher proportions of the UA group required inotropic support ( P = 0.001), intra-aortic balloon pump support ( P = 0.001), and re-exploration for bleeding or cardiac tamponade ( P = 0.005). This group also had a significantly longer mean time on mechanical ventilation ( P = 0.001) and a longer mean intensive care unit stay ( P = 0.01). The rates of operative mortality (first 30 days) in the SA and UA groups were 1.8 % and 6 %, respectively ( P = 0.001). There were no statistical differences between the AO and AV subgroups with respect to any of the preoperative or intraoperative findings. The AO group had a significantly shorter mean intensive care unit stay than the AV group ( P = 0.05). The AV group had a roughly fivefold higher operative mortality than the AO group (8.3 % vs. 1.7 %, respectively), but this difference was not statistically significant ( P = 0.17).

CONCLUSION

Urgent or emergent CABG in the setting of UA is associated with increased but acceptable rates of mortality and morbidity. Complete myocardial revascularization using arterial grafts only (combinations of internal thoracic and radial arteries) is feasible and safe in this patient group.

Midterm experience with the Sorin Bicarbon heart valve prosthesis for rheumatic disease

BACKGROUND

In this study, we present a single center experience with Bicarbon bileaflet valve in 307 patients with rheumatic heart disease.

METHODS

Between August 1998 and September 2000, 307 patients underwent heart valve replacement using the Bicarbon bileaflet valve (Sorin Biomedica, Saluggia, Italy) with an average age of 47.19+/-13.21 years (range 14 to 80 years), consisting of 147 males and 160 females at Alkan Hospital, Cardiovascular Surgery Department. Aortic valve replacement (AVR) was performed in 77 patients, mitral valve replacement (MVR) in 156 patients and double valve replacement (DVR) in 74 patients.

RESULTS

The early mortality rate was 3.3% (10/307) and there was no late mortality. The actuarial survival rate, including hospital mortality, was 96.74+/-1.01% for the whole group, 96.5+/-1.5% for the MVR group, 97.4+/-1.8% for the AVR group and 97.3+/-1.9% for the DVR group at 35 months. One patient had obstructive valve thrombosis with MVR. The 35 months actuarial freedom from valve thrombosis was 99.58+/-0.4% for the whole group. Four patients were reoperated and the 35 months actuarial freedom from reoperation was 98.53+/-0.7% for the whole group, 98.65+/-0.9% for the MVR group, 96.73+/-02% for the DVR group and 100% for the AVR group. No instances of perivalvular leak, hemolysis, endocarditis or embolism were observed during the entire follow-up period. Mean follow-up duration was 16.5+/-7.9 months (ranged 4 to 35 months).

CONCLUSION

We have presented our mid-term results with the Sorin Bicarbon bileaflet valve in patients with rheumatic heart disease, which provided good clinical performance combined with meticulous patient care and advanced surgical techniques.

Clinical experience with Sorin Bicarbon valve in patients with tight mitral valve stenosis and elevated pulmonary hypertension (early and mid-term results)

BACKGROUND

The results of mitral valve replacement (MVR) with Sorin mechanical valves in patients who had tight mitral stenosis with high pulmonary artery pressure were reviewed.

METHODS

During a period of two years, from August 1998 to May 2000, a mitral valve replacement with a Sorin Bicarbon mechanical valve was performed in 51 patients with a diagnosis of tight mitral stenosis associated with severe pulmonary hypertension (preoperative mean systolic pulmonary artery pressure was 72+/-12 mmHg, range from 60 to 105 mmHg). There were 37 women and 14 men; mean age was 47.2+/-12 years. Forty-eight patients (94.12%) were in NYHA functional class III or IV. All the patients discharged from the hospital were submitted to a clinical follow-up program. A 100% follow-up was obtained with a mean of 12.6+/-6.4 months (range 2 to25 months).

RESULTS

Operative mortality was 3.9%, 2 patients who had concomitant CABG died due to low cardiac output. Twelve patients (23.5%) needed an inotropic pharmacological support during the postoperative time. In one patient a re-exploration for bleeding was necessary, and in another one a cerebrovascular accident occurred 3 days after the operation. After 6 months, one patient was reoperated on because of mechanical valve dysfunction due to pannus formation. All survivors underwent a postoperative echocardiographic assessment. The systolic PAP decreased from a mean preoperative value of 72+/-12 mmHg to 39.9+/-12 mmHg. NYHA functional status significantly improved and 86% of the patients were in NYHA functional class I or II.

CONCLUSIONS

The mitral valve replacement with Bicarbon mechanical valve prosthesis shows excellent results in patients with mitral valve stenosis associated with a severe pulmonary hypertension.

Does cardiopulmonary bypass alter plasma level of tumor markers? CA 125 and carcinoembryonic antigen

BACKGROUND

In addition to malignant diseases, acute and chronic inflammations may elevate plasma levels of tumor markers CA 125 and carcinoembryonic antigen (CEA). Cardiopulmonary bypass (CPB) causes a generalized inflammatory response. In this study, we have investigated the effect of CPB on plasma levels of CA 125 and CEA.

METHODS

We measured plasma levels of CA 125 and CEA in patients undergoing coronary artery bypass grafting (CABG) with CPB (Group 1, n = 21), and in patients who underwent off-pump CABG, that is, without CPB (Group 2, n = 16). Blood samples were collected preoperatively, and on postoperative days 1, 6, and 12.

RESULTS

Within both groups, CEA plasma levels were not significantly influenced in any samples. Comparing with preoperative values, CA 125 values elevated significantly on postoperative days 6 and 12 within both groups. It was observed that the elevation of CA 125 plasma levels in these samples were significantly higher in Group 1.

CONCLUSIONS

The results indicate that CPB elevated plasma level of CA 125. However, clinical importance of this finding needed further evaluation.

Double coronary endarterectomy on the beating heart in two patients with porcelain aorta

Patients with porcelain aorta carry a high risk of systemic embolism during coronary artery bypass grafting. Avoiding manipulation of the aorta during operation using the beating heart approach can prevent atheroemboli. In patients with diffuse atherosclerotic coronary artery disease who require endarterectomy, coronary bypass operations can be done safely on the beating heart.

Bloodstream, respiratory, and deep surgical wound infections after open heart surgery

Nosocomial infections are one of the most feared complications after open heart surgery. A large retrospective study was conducted to evaluate the nature and scope of the problem. Between 1992 and 1998, 9352 patients who had undergone open heart surgery were evaluated. Bloodstream infections, pneumonia, and deep sternal wound infections were included. Univariate and logistic regression analyses were conducted to identify the high-risk patients that were likely to become infected. Three hundred forty-six infections in 276 patients were diagnosed. Age, preoperative albumin level, banked blood requirement, duration of operation, diabetes mellitus, previous open heart surgery, moderate or severe pericardial adhesions, obesity, postoperative low cardiac output, and postoperative cerebrovascular accident were found to be significant in univariate and logistic regression analyses for infectious outcome. Univariate analysis also revealed additional significant factors: fresh frozen plasma requirement, duration of cardiopulmonary bypass and cross-clamp, preoperative high levels of blood urea and glucose, presence of occlusive peripheral arterial disease, preoperative history of hypertension, and nasal carriage of Staphylococcus aureus. Methicillin resistant S. aureus was involved in 58.4% of the infections. Risk factors should be individualized for patients and every effort should be carried out to minimize infectious outcome.