Esa Salmela

Magnesium substitution in elective coronary artery surgery: A double-blind clinical study

Magnesium may be beneficial in the control of ventricular ectopy and supraventricular tachyarrhythmias after coronary artery bypass graft (CABG) surgery, but it is not known whether a high-dose magnesium regimen is superior to a regimen keeping the patient normomagnesemic. A prospective randomized and double-blind clinical comparison was performed in 81 elective CABG patients in order to assess the effects of two different magnesium infusion regimens on electrolyte balance and postoperative arrhythmias. Forty-one patients (high-dose group, H) received 4.2 +/- 0.7 g (mean +/- SD), of magnesium sulfate before cardiopulmonary bypass, followed by an infusion of 11.9 +/- 2.8 g of magnesium chloride until the first postoperative (PO) morning, and a further 5.5 +/- 1.0 g until the second PO morning. Forty patients (low-dose group, L) received magnesium sulfate only after bypass to a total of 2.9 +/- 0.5 g at the first, and 1.4 +/- 0.1 g at the second PO morning. A blood cardioplegia technique was used in both groups, including bolus doses of magnesium chloride to a total of 2.4 +/- 0.6 g and 2.3 +/- 0.6 g to H and L patients, respectively. Continuous Holter tape-recording was used for 12 to 15 hours preoperatively, and for 48 hours postoperatively. Serum magnesium peaked in H patients on the first PO morning at 1.60 +/- 0.25 mmol/L, whereafter it declined to the normal level on the third PO morning. Patients in the L group were normomagnesemic, except after the start of bypass.(ABSTRACT TRUNCATED AT 250 WORDS)

Preoperative C-reactive protein and outcome after coronary artery bypass surgery

BACKGROUND C-reactive protein (CRP) is a predictor of early and late outcome after coronary angioplasty, but there is scant data on its impact on the outcome after coronary artery bypass grafting (CABG). METHODS The predictive value of preoperative CRP was evaluated in a series of 764 patients who underwent on-pump CABG. RESULTS During the in-hospital stay, 13 patients (1.7%) died, 45 (4.5%) developed low cardiac output syndrome, and 28 (3.7%) suffered minor or major cerebrovascular complications. Patients with a preoperative serum concentration of CRP>/=1.0 mg/dL had a higher risk of overall postoperative death (5.3% vs 1.1%, p = 0.001), cardiac death (4.4% vs 0.8%, p = 0.002), low cardiac output syndrome (8.8% vs 3.7%, p = 0.01), and any cerebrovascular complication (4.4% vs 3.5%, p = 0.66). Preoperative serum concentration of CRP>/=1.0 mg/dL was significantly more frequent among patients with history of myocardial infarction, diabetes, lower limb ischemia, low left ventricular ejection fraction, NYHA class IV, and in those undergoing urgent or emergency operation. At multivariate analysis, preoperative serum concentration of CRP >/= 1.0 mg/dL (p = 0.01, O.R.: 6.97) and left ventricular ejection fraction (p = 0.01, O.R.: 0.95) were independent predictors of postoperative death. Postoperative mortality rate was 0.3% among patients with preoperative CRP < 1.0 mg/dL and an ejection fraction >/=50%, whereas it was 21.4% among those with a preoperative CRP >/= 1.0 mg/dL and an ejection fraction less than 50% (p < 0.0001). CONCLUSIONS Preoperative serum concentration of CRP in patients undergoing on-pump coronary artery bypass surgery is an important determinant of postoperative outcome.

Options for the management of poststernotomy mediastinitis

The management of 27 consecutive deep sternotomy wound infections is reviewed. In 22 cases the initial treatment was debridement, sternal refixation and dilute antibiotic irrigation via multiple irrigation-suction catheters. In the nine cases (41%) in which these measures failed, more extensive sternal and costal cartilage debridement and closure with a muscle flap were performed. Five cases were initially managed with major reconstructive surgery. For reconstruction, a bilateral pectoralis major myocutaneous flap was used alone in eight cases, while in six the flap was insufficient to obliterate the whole poststernectomy space, and was supplemented with rectus abdominis muscle. Early mediastinitis can be effectively treated with thorough wound debridement and mediastinal irrigation, but if there is a two-week delay from the initial sternotomy to manifestation of infection, radical debridement with muscle flap closure should be seriously considered.

Repair of an aneurysm of the left main coronary artery

Coronary artery aneurysms are rare, especially in the left main coronary artery. Coronary artery aneurysms may rupture or cause myocardial infarction. There are only a few reports of coronary artery aneurysms of the left main coronary artery treated surgically. We report a case in which an arterial graft from the internal iliac (hypogastric) artery was used for the reconstruction of a congenital coronary artery aneurysm of the left main coronary artery. After a follow-up of 5 years, the patient is well and in good condition.

A Retrospective Comparative Study of Aortic Valve Replacement with St. Jude Medical and Medtronic-Hall Prostheses: A 20-year Follow-up Study

Objective - To compare the long-term clinical outcome of patients who underwent aortic valve replacement with St. Jude Medical and Medtronic-Hall mechanical prostheses. Design - From June 1978 to June 1982, 43 Medtronic-Hall and 48 St. Jude Medical mechanical valves were implanted in 90 consecutive patients with aortic valve disease, and their clinical outcome was retrospectively assessed. Results - At 20 years in the St. Jude Medical group and in the Medtronic-Hall group the actuarial rates of overall survival were 50 and 49% ( p = NS), of cardiovascular survival 66 and 63% ( p = NS), of valve-related survival 95 and 91% ( p = NS), of freedom from major valve-related complications 83 and 45% ( p = 0.005), from major cerebrovascular events 93 and 71% ( p = 0.06), from valve thrombosis 97 and 89% ( p = NS), from aortic valve reoperation 93 and 88% ( p = NS), from major bleeding 96 and 82% ( p = 0.04), and from endocarditis 93 and 82% ( p = NS), respectively. The linearized rate of overall major aortic valve prosthesis-related complications was 3.47%/year in the Medtronic-Hall valve group and 1.53%/year in the St. Jude Medical valve group ( p = 0.003). Multivariate analysis showed that the type of prosthesis was predictive of freedom from valve-related complications ( p = 0.01; 2.849; C.I. 95%: 1.246-6.516). Conclusion - The aortic St. Jude Medical mechanical valve seems to be associated with a slightly lower rate of longterm valve-related morbidity than the aortic Medtronic-Hall mechanical valve. Because of the small patient population and the retrospective nature of the study, the choice between these two prostheses should not be made only on the basis of these findings. However, these results suggest a reappraisal for further comparative studies with such an extended follow-up.

Predictors of postoperative mortality after mitral valve repair: analysis of a series of 164 patients.

Background. Mitral valve repair (MVR) has been shown to achieve good long-term results. However, this procedure is associated with relevant immediate postoperative mortality. The aim of this study is to identify those preoperative variables associated with an increased risk of 30-d postoperative death. Methods. One hundred and sixty-four patients underwent MVR at our institution from January 1993 to December 2000. Results. Eleven patients (6.7%) died during the immediate postoperative outcome, a median of 14 d after surgery (range, 1–29 d). One patient (1.3%) out of 80 who underwent MVR as lone procedure died on postoperative day 14 of cardiac tamponade. The mortality rate in those who underwent MVR associated with other procedures was 11.9%. Multivariable analysis (154 patients included in the analysis) showed that patients’ age (p=0.006, for an increase of 10 units: OR 4.33, 95% CI 1.53–12.27), history of prior cardiac surgery (p=0.006, OR 118.56, 95% CI 4.03–3491.14) and NYHA functional class (p=0.011, OR 5.66, 95% CI 1.49–21.49) were significantly associated with an increased risk of postoperative death. The receiver operating characteristics (ROC) curve showed that patients’ age had an area under the curve of 0.762 (95% CI 0.622–0.901, p=0.004), its best cut-off value being 65 years (mortality, 13.4% vs 2.1%, p=0.008, sensitivity 81.8%, specificity 62.1%, accuracy 63.4%). None of the patients older than 65 and with a history of prior cardiac surgery survived the operation. Conclusions. MVR is associated with a relevant 30-d mortality risk in patients older than 65 years, with advanced NYHA functional class and a history of prior cardiac surgery.

Long-term outcome after mitral valve repair

Background. Several studies reported excellent long-term results after mitral valve repair for regurgitation, however a number of patients still experience recurrent mitral valve regurgitation which requires reoperation. We have evaluated the long-term outcome of a consecutive series of patients who underwent mitral valve repair for regurgitation in an attempt to identify the risk factors associated with late failures. Patients and methods. One-hundred and sixty-four patients underwent mitral valve repair for ischemic and degenerative mitral valve regurgitation. Seventy-two patients underwent echocardiographic evaluation a median of 5.6 years after surgery. Results. Ten-year survival freedom from any fatal cardiac event was 75.9% and survival freedom from redo mitral valve surgery was 93.8%. Multivariable analysis showed that residual mitral valve regurgitation grade > 1 as assessed during the immediate postoperative period (at 10-year, 60.6% vs. 95.7%, p = 0.001, RR 20.7, 95%C.I. 3.4–125.3) and chronic obstructive pulmonary disease/asthma (at 10-year 66.8% vs. 95.2%, p = 0.013, RR 12.0, 95%C.I. 1.7–85.2) were predictors of redo mitral valve surgery. The same findings were observed also among patients with myxomatous degenerative disease. At echocardiographic follow-up, no significant improvement was detected in terms of left ventricular ejection fraction, whilst mitral valve regurgitation grade (median, 3 to 1), New York Heart Association class (median, 2 to 1) and left atrium diameter (median, 50 to 44 mm) decreased significantly. Conclusions. This study confirms the excellent clinical long-term results after mitral valve repair. An adequate repair technique is advocated in order to decrease the immediate postoperative rate of residual regurgitation > 1 as this is a main determinant of late failures requiring redo mitral valve surgery. Further studies are required to better define the possible causative role of chronic obstructive pulmonary disease and any underlying connective tissue metabolic disorder in late failures after mitral valve repair.

Pulmonary artery blood temperature at admission to the intensive care unit is predictive of outcome after on‐pump coronary artery bypass surgery

Objective—To evaluate whether pulmonary artery blood (PA) temperature on admission to the intensive care unit (ICU) is predictive of postoperative outcome after isolated on‐pump coronary artery bypass grafting (CABG). Design—A retrospective study on 1639 patients who underwent isolated on‐pump CABG in whom PA temperature at admission to the ICU was available for review. Results—Thirty‐three patients (2.0%) died during the in‐hospital stay and 87 patients (5.3%) developed low cardiac output syndrome. PA temperature at admission to the ICU was significantly associated with an increased risk of overall postoperative death (p = 0.002), cardiac death (p = 0.03), and low cardiac output syndrome (p < 0.0001), and was significantly correlated with prolonged length of ICU stay (p < 0.0001) and postoperative bleeding (p = 0.001). Patients with high PA temperature had significantly more severe comorbidities, and longer aortic cross‐clamping and cardiopulmonary bypass time. The receiver operating characteristic curve showed that PA temperature at admission to the ICU in predicting postoperative death had an area under the curve of 0.660 (p = 0.002) and its best cut‐off value was 36.4°C (sensitivity: 63.6%, specificity: 65.2%). When the PA temperature at admission to the ICU was ≥36.4°C, the postoperative mortality and low cardiac output syndrome rates were 3.6 and 8.3%, whereas they were 1.1 and 3.7% when the PA temperature at admission to the ICU was <36.4°C (p  =  0.001, p < 0.0001), respectively. Conclusion—Patients having a PA temperature ≥36.4°C at admission to the ICU after CABG seem to be at higher risk of poor postoperative outcome.

Does angiographic severity of coronary artery disease predict postoperative outcome after coronary artery bypass surgery

Objective—It is not clear whether the severity of coronary artery disease as assessed on angiography has an impact on the postoperative outcome after coronary artery bypass surgery (CABG). Design—The angiographic status of 15 coronary arteries/segments of 2233 patients who underwent isolated on‐pump CABG was graded according to the following criteria: 1 = no stenosis; 2 = stenosis <50%; 3 = stenosis of 50–69%; 4 = stenosis of 70–89%; 5 = stenosis of 90–99%; 6 = vessel occlusion; and 7 = vessel is not visualized. Results—Thirty‐seven patients (1.7%) died during the in‐hospital stay and 108 (4.8%) developed postoperatively low cardiac output syndrome. Multivariate analysis showed that along with other risk factors the overall coronary angiographic score was predictive of postoperative death (p = 0.03; OR: 1.027, 95% CI: 1.003–1.052) and of low cardiac output syndrome (p = 0.04; OR: 1.172, 95% CI: 1.010–1.218). The status of the proximal segment of the left circumflex coronary artery, the diagonal arteries and the left obtuse marginal arteries was most closely associated with adverse postoperative outcome. Conclusion—The angiographic status of coronary arteries has an impact on the immediate outcome after CABG.