Aortic and mitral prosthetic valve replacement in age groups 61-65 & 66-70 years

Prosthesis choice for aortic and mitral valve replacements in patients aged 61-70 years is difficult. We evaluated prostheses in age groups 61-65 and 66-70 years. Freedom from major thromboembolism and hemorrhage was greater for bioprostheses than mechanical prostheses in both age groups after aortic valve replacement, but only in the younger age group after mitral valve replacement. Freedom from valve-related re-operation was greater after mitral valve replacement with mechanical prostheses in both age groups, but no difference after aortic valve replacement. Valve type was predictive of major thromboembolism and hemorrhage, except in older patients undergoing mitral valve replacement. Bioprostheses are favored for aortic valve replacement in both age groups, but the risk of re-operation with a bioprosthesis in the mitral position in patients aged 61-65 years favors a mechanical prosthesis. Prosthesis choice is less definite in those aged 66-70 years.     

Performance of bioprostheses and mechanical prostheses in age group 61-70 years

BACKGROUND AND AIM OF THE STUDY: The performance of bioprostheses (BP) and mechanical prostheses (MP) from valve-related composites of complications and combined major thromboembolism and hemorrhage were considered in order to facilitate decision-making for the patient age group of 61-70 years. METHODS: The aortic valve replacement (AVR) population (BP, n = 619; MP, n = 303) was differentiated by age, concomitant coronary artery bypass, diabetes mellitus, chronic obstructive pulmonary disease (COPD) and preoperative renal failure. The mitral valve replacement (MVR) population (BP, n = 353; MP, n = 312) was differentiated by valve type, age, concomitant coronary artery bypass, ejection fraction, NYHA and preoperative renal failure. RESULTS: Actual freedom from reoperation for AVR was 92.1 +/- 1.5% for BP and 98.7 +/- 6.6% for MP, and for MVR was 74.5 +/- 2.6% for BP and 93.8 +/- 2.2% (12 years) for MP. Actual freedom from major thromboembolism and hemorrhage for AVR was 85.1 +/- 1.7% for BP and 76.9 +/- 3.6% for MP, and for MVR was 82.7 +/- 2.4% for BP and 76.7 +/- 3.8% (12 years) for MP. Linearized rates were undifferentiated for major thromboembolism. The hemorrhage rate for AVR-BP was 0.55%/pt-yr and for AVR-MP was 2.3%/pt-yr (p < 0.0001); for MVR-BP, the rate was 0.69%/pt-yr and for MVR-MP was 1.85%/pt-yr (p = 0.0011). The only predictor of AVR reoperation was age, and predictors for MVR reoperation were prosthesis type and follow up NYHA class. Predictors of AVR major thromboembolism and hemorrhage were prosthesis type, age, diabetes mellitus and COPD. There were no predictors of MVR major thromboembolism and hemorrhage. CONCLUSION: For the age group of 61-70 years, MP are recommended for MVR to protect from BP reoperation, whilst for AVR BP are recommended to protect from anticoagulant hemorrhage. Freedom from reoperation for AVR was undifferentiated for BP and MP at 12-15 years.     

Reducing cerebral emboli during cardiopulmonary bypass

Neurologic injury is a common complication of cardiac surgery and is associated with significant morbidity, mortality, and resource utilization. The incidence varies widely according to the definition used, patient age, and complexity of surgery. The manifestations of neurologic injury are broad, ranging from subtle neurocognitive dysfunction to frank stroke. An increasing amount of evidence points to cerebral embolization during cardiopulmonary bypass (CPB) as the principal etiologic factor of these neurologic complications. Cerebral emboli may be composed of atherosclerotic debris, calcium, air, fat, platelet thrombi, or CPB tubing. Advancements in perfusion technology, CPB techniques and surgical strategies may lead to a reduction in neurologic injury during cardiac surgery. In the current paper, we discuss the pathophysiology of neurologic injury after cardiac surgery and methods of reducing cerebral embolization. Reducing emboli and neurologic injury during CPB requires a multidisciplinary approach that includes several simple diagnostic and therapeutic strategies. Reducing cerebral emboli should be a major goal for future research in the fields of cardiac anesthesia, surgery and perfusion.     

The effects of steroids on the occurrence of postoperative atrial fibrillation after coronary artery bypass grafting surgery: a prospective randomized trial

OBJECTIVE: Atrial fibrillation remains one of the most common postoperative complications of coronary artery bypass grafting. Despite many clinical studies, there is still no consensus regarding the best prevention strategy for atrial arrhythmia. A randomized, double-blind, placebo-controlled trial was conducted to determine the effect of steroids on the occurrence of atrial fibrillation after elective coronary artery bypass grafting. METHODS: Eighty-eight consecutive patients were prospectively entered in this study. No patient had documented or suspected arrhythmias before surgery. Forty-three patients received 1 g of methylprednisolone before surgery and 4 mg of dexamethasone every 6 hours for 1 day after surgery, and 43 patients received only placebo. The primary end point was the overall occurrence of postoperative atrial fibrillation. RESULTS: Postoperative atrial fibrillation occurred in 9 (21%) of the 43 patients in the steroid group, as compared with 22 (51%) of the 43 patients in the placebo group ( P = .003). Minor postoperative complications occurred in 15 steroid patients (35%) and in 6 patients (14%) receiving placebo ( P = .01). Major complications occurred in 4 patients who received steroids (9%) and in 2 patients (5%) who received placebo ( P = .68; for all complications, P = .05). CONCLUSIONS: Prophylactic short-term steroid administration in patients undergoing coronary artery bypass grafting significantly reduced postoperative atrial fibrillation. In this study, there was no significant difference between the steroid group and the placebo group with regard to the length of hospital stay; however, the steroid group had more complications, which may contribute to prolonged hospitalization.