Atrial fibrillation after coronary artery bypass surgery: risk factors and management

Background: atrial fibrillation [AF] after coronary artery bypass surgery continues to be one of the most common postoperative complications [15-35%]. This increases the postoperative risk of heart failure, morbidity and mortality

Patients and methods: in this study, over the last 3 years, 500 coronary artery bypass surgical patients without preoperative AF were observed, those who developed postoperative atrial fibrillation were studied in order to assess the risk factors, complications and management in an attempt to avoid or decrease this postoperative complication and sequelae

Results: the most important risk factors which increase the risk of post-operative atrial fibrillation were namely advanced age, male gender, hypertension, diabetes, low ejection fraction, use of cardiopulmonary bypass, and advanced coronary artery disease

Conclusion: in order to decrease the risk of postoperative atrial fibrillation, we recommend starting antiarrythmogenic [calcium channel blockers, amiodarone, or digoxin] preoperatively in patients with known risk factors and if possible to operate by off pumping technique. Early initiation of therapy to revert to normal sinus rhythm1 whether pharmacologically or electrical cardioversion is mandatory. In persistent atrial fibrillation, anticoagulation or antiplatelet therapy is recommended. Antiarrythmogenic therapy up to for life could be considered, and digoxin in cases of congestive cardiac failure

Moderate mitral regurgitation with coronary artery disease: decision to operate on the mitral valve or not, with coronary bypass graft surgery

Background: ischemic [functional] mitral valve regurgitation is associated with a higher hospital morbidity and mortality rates especially when left untreated during coronary artery bypass graft surgery. In cases of moderate mitral regurgitation and coronary artery disease, operative strategy continues to be debated between coronary artery bypass [CABG] grafting alone and concomitant valve reconstructive surgery. Controversy still exists regarding the potential to alter postoperative cardiac functional results [and overall survival] by applying mitral valve surgical procedures during the performance of CABG surgery

Objective: to know the predictive factors to decide when mitral valve surgery is mandatory along with coronary artery bypass graft in cases of ischemic moderate mitraI regurge. Does it really impact the result of surgery?

Patients and Methods: we present in our study 100 patients operated upon for CABG in the National Heart Institute Cairo with coexisting ischemic moderate ischemic mitral valve regurge [IMR].They were divided into 2 groups: group I included 50 CABG patients with moderate mitral regurgitation in whom no surgical intervention has been done to the mitral valve, and group II 50 patients mitral valve surgery has been performed with the CABG [CABG +MVR]. The 2 groups were matched by age, sex and risk factors. Postoperative follow up was carried out for a mean time of 8 months +/- 2.3 SD

Results: postoperative follow up of our patients revealed that age and sex did not affect the outcome [p-value >0.05] not statistically significant. Left atrial [LA] size, end systolic dimension [ESD] and end diastolic dimension [EDD] improved significantly in both groups. Fraction shortening [FS], ejection fraction [FS] and number of patients with persistent atrial fibrillation [AF] improved significantly [p-value <0.05] in group I [CABG alone]. While in group II [CABG+MVR] they improved with high statistical significance [p-value<0.005]. Pulmonary artery pressure [PAP] improved with high statistical significance in both groups, but with better improvement in group IX. The NYHA class of dyspnea improved with high statistical significance in group I [p-value <0.005], while in group II it improved with a higher statistical significance [p-value <0.004]

Conclusion : In patients with coronary ischemia causing ischemic moderate mitral regurge, the performance of mitral reparative surgical procedures in association with CABG surgery is preferable in cases of congestive heart failure as it improves the postoperative performance of cardiac function and helps the patient to carry a better life style

Surgical repair of congenital isolated subaortic membrane: Operative technical options and results

Immediate results after operative treatment of subaortic membrane have been generally good with low operative mortality and good preservation of systolic function Residual gradients after operation may be due to inadequate resection, but dynamic outflow obstruction almost contributes significantly to this finding. The hypothesis that discrete subaortic stenosis [SAS] is a dynamic, progressive disorder of the LVOT is supported serial hemodynamic and angiographic investigations. These data support the concept that in patients, who develop SAS, there may be a preexisting nidus that is stimulated by hemodynamic forces. Resection of extensive subaortic fibrous tissue may still leave behind tissue that has a propensity for forming a recurrent obstruction. To find the best surgical management of the subaortic membrane in an attempt to reach best results, minimal gradient, with least residual complications or risk of recurrence. This study is prospective trial that was conducted in the National Heart Institute in Cairo, Egypt in the period between January 2003 and January 2005, 105 patients with isolated congenital subaortic membrane in the study. All patients were evaluated preoperatively and monitored postoperatively in the intensive care unit, in the ward until discharge, 15 days, 1 month, and 6 months after surgery. All residual complications or recurrences were noted. Surgical complete resection of congenital subaortic membrane is a successful operation; with statistically significant improvement in dyspnea functional class, decrease in systolic gradient across the LV naorta, and gradual decrease in septal wall thickness. But it still carries the risk of residual LVOT restenosis and risk of recurrence. So it is preferable to do at least a septal myotomy to decrease these complications. Complete resection of congenital subaortic membrane has generally good late post operative results. It is preferable to perform at least myotomy as routine, and in cases of severe septal hypertrophy to do myomectomy [this seems to be a more aggressive approach]. But it acceptable to decrease the risk of residual or recurrence of the LVOT

Effect of the long-term treatment with oral anti-coagulant on bone density

Oral anticoagulant such as sodium warfarin has been the standard oral anticoagulant used in a variety of clinical settings [e.g. atrial fibrillation, post valve replacement therapy, deep venous thrombosis [DVT],. But because vitamin K also interacts with osteocalcin a protein vital for bone formation warfarin's antagonism of vitamin K has the potential to affect bone strength as well. Osteoporotic fractures occur when the bones become so weakened that minor trauma causes breakage. To find out the effect of long-term warfarin therapy on bone density scans. This study is a case-control analytic study that was conducted in the National Heart Institute, Cairo Egypt. This study included 50 patients receiving oral anti-coagulant [warfarin]. Another 50 normal control subjects [not using warfarin] matched by age and sex were included in the study. Patients with renal and/or hepatic impairment were excluded. Data were collected retrospectively from the patient's medical records and history taking. The anticoagulation status was monitoring through assessment of the prothrombin time expressed as the International Normalized Ratio [INR]. Bone mineral densitometry was assessed from the heel using the [LUNAR EXPRESS ACHILLES] Densitometer. The Z-score is defined as the number of SD above or below the mean using age and sex-matched reference data. There was no significant difference between the studied patients and controls regarding their mean age and sex distribution [P > 0.05]. The mean duration of warfarin therapy was 6.94 +/- 3.8 years and the mean dose of warfarin therapy was 6.58 +/- 3.6 mg. The mean Z-score of the studied patients was 0.31 +/- 0.13 and while, it was 0.20 +/- 0.11 for the controls and the difference between the two groups was significant [P < 0.05]. There was significant positive correlation between age of the studied patients and Z-score [r = 0.607, P < 0.001]. There was also significant positive correlation between duration of warfarin therapy and Z-score [r = 0.318, P < 0.05]. There was no significant correlation between the dose of warfarin and Z=score [r = 0.044, P > 0.05]. Results of the study showed that there was no significant difference between males and females warfarin users regarding their mean age, dose of warfarin, and duration of therapy [P > 0.05]. Z-score was significantly higher among males than that among females [P < 0.05]. Long-term warfarin therapy is associated with decrease in bone density. The most independent predictor of decrease bone mass was the patients age, and duration of therapy. Dose of warfarin seems to have no effect on bone density in our study group