Consequence of atrial fibrillation and the risk of embolism after percutaneous mitral commissurotomy: The necessity of the maze procedure

Preoperative study of the surface ECG for the prognosis of atrial fibrillation maze surgery outcome at discharge

The Cox-maze surgery is an effective procedure for terminating atrial fibrillation (AF) in patients requiring open-heart surgery associated with another heart disease. After the intervention, regardless of the patient's rhythm, all are treated with oral anticoagulants and antiarrhythmic drugs prior to discharge. Furthermore, patients maintaining AF before discharge could also be treated with electrical cardioversion (ECV). In view of this, a preoperative prognosis of the patient's rhythm at discharge would be helpful for optimizing drug therapy planning as well as for advancing ECV therapy. This work analyzes 30 preoperative electrocardiograms (ECGs) from patients suffering from AF in order to predict the Cox-maze surgery outcome at discharge. Two different characteristics of the AF pattern have been studied. On the one hand, the atrial activity (AA) organization, which provides information about the number of propagating wavelets in the atria, was investigated. AA organization has been successfully used in previous studies related to spontaneous reversion of paroxysmal AF and to the outcome of ECV. To assess organization, the dominant atrial frequency (DAF) and sample entropy (SampEn) have been computed. On the other hand, the second characteristic studied was the fibrillatory wave (f-wave) amplitude, which has been demonstrated to be a valuable indicator of the Cox-maze surgery outcome in previous studies. Moreover, this parameter has been obtained through a new methodology, based on computing the f-wave average power (fWP). Finally, all the computed indices were combined in a decision tree in order to improve prediction capability. Results for the DAF yielded a sensitivity (Se), a specificity (Sp) and an accuracy (Acc) of 61.54%, 82.35% and 73.33%, respectively. For SampEn the values were 69.23%, 76.00% and 73.33%, respectively, and for fWP they were 92.31%, 82.35% and 86.67%, respectively. Finally, the decision tree combining the three parameters analyzed improved the preoperative prognosis of the Cox-maze outcome with values of Se, Sp and Acc of 100%, 82.35% and 90%, respectively. As a consequence, the analysis of parameters related to the f-wave pattern, extracted from the preoperative ECG, has provided a considerable ability to predict the outcome of AF Cox-maze surgery at discharge.

Mitral stenosis

Mitral stenosis is a common disease that causes substantial morbidity worldwide. The disease is most prevalent in developing countries, but is increasingly being identified in an atypical form in developed countries. All treatments that increase valve area improve morbidity. Mortality improves with surgery; the benefit of percutaneous balloon valvuloplasty to mortality might be similar to that of surgery but needs further study. Percutaneous balloon valvuloplasty is the treatment of choice for patients in whom treatment is indicated, except for those with suboptimum valve morphology, and even these patients are sometimes treated with this procedure if surgery is not feasible or if surgical risk is prohibitive. We review the pathology, diagnosis, and treatment options for patients with mitral stenosis.

Percutaneous balloon commissurotomy reduces incidence of ischemic cerebral stroke in patients with symptomatic rheumatic mitral stenosis

Whether percutaneous balloon commissurotomy reduces cerebral stroke in patients with symptomatic rheumatic mitral stenosis remains obscure. This study enrolled 170 such patients undergoing either medical therapy alone (n=71) or balloon commissurotomy (n=99). In the short term, balloon commissurotomy was successfully accomplished in 99% patients without embolic complications. At follow-up (mean 4.2+/-3.2 years), patients undergoing commissurotomy encountered significantly rarer ischemic stroke than the medicine group (2% vs. 13%, p=0.043). Multivariate Cox regression analysis further confirmed balloon commissurotomy as a negative predictor for ischemic stroke (hazard ratio 0.135, p=0.011). These results lead to the conclusion that percutaneous balloon commissurotomy could substantially decrease the long-term incidence of ischemic cerebral stroke in eligible patients with symptomatic rheumatic mitral stenosis.

Impact of maze and concomitant mitral valve surgery on clinical outcomes

We evaluated the usefulness of the maze procedure among patients with atrial fibrillation undergoing mitral valve surgery. Seven matched-controlled and four randomized trials were identified from Medline English language papers (1995 to 2005). After 2 to 8 years of follow-up in matched-controlled studies, odds ratio and 95% confidence interval (CI) for atrial fibrillation free, embolic events free, and long-term survival for those treated with maze were 12.51 (95% CI: 9.18 to 17.03), 9.35 (95% CI: 5.11 to 17.13), and 2.27 (95% CI: 1.21 to 4.27), respectively. Correspondingly, after 1 to 1.5 years of follow-up in randomized trials, they were 9.01 (95% CI: 4.21 to 19.3), 5.19 (95% CI: 0.50 to 53.6), and 0.49 (95% CI: 0.12 to 1.93), respectively. The addition of the maze procedure to mitral valve surgery was more likely to maintain patients in sinus rhythm and may lower embolic events, including stroke, but did not necessarily improve long-term survival.

Important contributions to cardiothoracic surgery by Japanese thoracic and cardiac surgeons

Cardiothoracic surgeons in Japan have made outstanding contributions to our knowledge and therapy of diseases and anomalies of the heart, lungs, esophagus, chest wall and diaphragm. It is an honor for me to address this subject at the 57th Annual Meeting of the Japanese Association for Thoracic Surgery in Sapporo because your President, Tomio Abe, is a valued friend and colleague who worked with me and my group as a Research Fellow at Washington U. from 1970-1973. He was recommended by Prof. Juro Wada, then the Chief in Sapporo. I was privileged to meet Prof. Wada at U.S. meetings. One of Prof. Wada's many contributions was the first cardiac transplant in Japan. Dr. Abe's work in St. Louis led to 12 publications and he was the first author of two papers. Since, his contributions expanded to more than 550 publications on treatment of complex congenital heart diseases, ventricular assistance, myocardial protection, valvular heart disease and aortic aneurysms. An operation for correction of Taussig-Bing malformation reported in 1984 is now referred to as the Abe operation. Torikata, in 1925, introduced "free thoracotomy" with no differential pressure. In 1933, Ohsawa successfully resected the esophagus with immediate reconstruction-the first in the world. Wada, in 1963, developed a thermodisc oxygenator and in 1966 the first tilting disc heart valve-the Wada Cutter Valve and other contributions as a worldwide ambassador for Japanese Surgery. Kawata, et al. showed better ventricular function after patch reconstruction of left ventricular aneurysms. Ueda, et al. revived retrograde cerebral perfusion for repair of aortic arch aneurysms. Nakayama, Akiyama and Isono made important contributions to esophageal cancer surgery. Kimoto, et al., in 1956, performed open cardiac surgery under direct vision with brain cooling by irrigation. Sakakibara, et al., Hikasa, et al., Atsumi, et al., and Takano and Akutsu made contributions to cardiac surgery. There were many other contributions by Japanese Surgeons.