Left Atrial Radiofrequency Ablation Associated with Valve Surgery: Midterm Outcomes

Long-term cardiac remodeling associated with heart failure following left-ventricular valve replacement surgery: A retrospective study

To investigate long-term cardiac remodeling and prognosis of patients post-left-ventricular valve replacement, and explored related risk factors of heart failure and management strategies. Retrospective cohort of patients with left-ventricular valve replacement between 2005 and 2007. Major adverse cardiac events were recorded, including death, hospitalization, stroke, and New York Heart Association (NYHA) functional classifications. Cardiac remodeling was assessed by comparing pre-operative, post-operative, and follow-up echocardiographic images. (1).. Two hundred fifty-seven patients who received left-ventricular mitral, aortic, or double-valve replacement surgery were followed up for 10.4 ± 1.5 years with an all-cause mortality rate 18.7% and an incidence of heart failure that significantly restricted daily life (NYHA III or IV) 21.3%. (2).. There were no significant differences in classic cardiac-remodeling variables between baseline and long-term follow-up, such as left-ventricular diameter (47.9 ± 8.3 vs 49.9 ± 8.0 mm, P = .14) and left-ventricular ejection fraction (58.6 ± 9.6% vs 57.0 ± 10.3%, P = .34), whereas there were significant differences in terms of left-atrial anteroposterior diameter (LA) (39.7 ± 9.5 vs 49.0 ± 14.3 mm, P < .001) and tricuspid regurgitation (TR) (1.4 ± 1.0 vs 2.2 ± 1.2, P < .001). Multivariable logistic regression analysis showed that LA ≥ 50 mm (P = .011) and more than moderate tricuspid regurgitation (TR > 2) (P = .012) were associated with poor prognoses for long-term consequences of heart failure. Both LA and TR progressed with the length of time after surgery. LA enlargement and TR after left-ventricular valve replacement surgery were time-dependent events, which represented cardiac remodeling and were closely related to post-operative long-term consequences of heart failure. It is important to be cognizant of and to explore long-term preventive and treatment strategies for adverse cardiac events in patients following left-ventricular valve replacement.

The Need for Consistent Predictors of Success for Surgical Ablation of Atrial Fibrillation

Objective

As with any medical therapy, identification of consistent and reliable outcome predictors is essential to understanding the efficacy of surgical ablation for atrial fibrillation. We originally intended to conduct a meta-analysis on atrial fibrillation surgical ablation to identify clinical factors that are most often associated with success. However, these studies are greatly heterogeneous. We conducted a systematic review to identify trends in outcome predictors and to provide recommendations for more uniform data analysis and reporting.

Methods

Relevant studies published between January 2005 and September 2013 were identified. To minimize heterogeneity, data were extracted only from multivariate analyses of outcome predictors. The initial approach for meta-analytic analyses was abandoned for a systematic review approach.

Results

From 604 initial citations, 19 studies with 5200 patients were included in the review. Systematic review of multivariable atrial fibrillation recurrence rates after surgical ablation revealed that studies were statistically heterogeneous, but atrial fibrillation recurrence after surgical ablation in mid-term follow-up was most often predicted by left atrium size, duration of atrial fibrillation, fine-wave atrial fibrillation, age of patient, and atrial fibrillation type.

Conclusions

The innate heterogeneity of published data precludes a meta-analysis for predictors of surgical ablation success. Of the few published studies that allow comparison, the most consistent predictors of failure were enlarged left atrium and long atrial fibrillation duration. These results underscore the need for consistent and reliable outcome predictors. We strongly recommend the development of a standardized system of measurement for consistent clinical parameters that can be used in outcome analyses for surgical ablation of atrial fibrillation.

Late outcome of surgical radiofrequency ablation for persistent valvular atrial fibrillation in China: a single-center study

Background

Atrial fibrillation (AF) adversely affects surgical outcomes of cardiac valve surgery. Surgical ablation is an effective way to treat valvular AF. The aim of this study was to evaluate the late outcome of surgical radiofrequency ablation and explore the risk factors of AF recurrence in Chinese patients undergoing cardiac valve surgery.

Methods

Three hundred ninety six consecutive patients with persistent valvular AF were enrolled in this study. They underwent concomitant modified Maze IV and were completed follow-ups. Cox survival regression model was used to screen independent risk factors for predicting late recurrence of AF.

Results

During the follow-up period of 28 (6 ~ 61) months, AF recurred in 151 patients (38.1%). In multivariate survival regression, factors predictive of AF late recurrence were AF duration, pre-operative serum B-type natriuretic peptide (BNP), pre-operative heart rate and left atrial diameter (LAD), post-operative atrial tachyarrhythmias and AF at discharge. According to receiver operating characteristic curve analysis, the best cutoff values for AF duration, BNP, heart rate and LAD were 66.5 months, 251 pg/ml, 82 beats/min and 67.9 mm, respectively.

Conclusions

Longer AF duration, larger LAD, higher BNP level and lower heart rate indicated a poor late outcome of surgical radiofrequency ablation in persistent AF patients undergoing cardiac valve surgery. Therefore, indication to radiofrequency ablation should be carefully considered in these patients.

Electronic supplementary material

The online version of this article (doi:10.1186/s13019-017-0627-z) contains supplementary material, which is available to authorized users.

A brief overview of surgery for atrial fibrillation

The Maze procedure was the first surgical technique developed to ablate, rather than isolate, atrial fibrillation and was first performed clinically in 1987. The experimental and clinical electrophysiological maps on which the Maze procedure was based demonstrated the presence of two or more large (5-6 cm diameter) macro-reentrant circuits during established atrial fibrillation (AF). Eleven years later, focal triggers were identified, primarily in and around the pulmonary veins, and were shown to be responsible for the induction of individual episodes of AF. Thus, it became clear that episodes of paroxysmal AF could be treated in most patients by isolating or ablating the region of the pulmonary veins, but that once AF became non-paroxysmal and thus dependent upon the macro-reentrant circuits for its maintenance, it would still be necessary to perform some type of additional procedure to interrupt those circuits. Approximately 100,000 patients who undergo coronary artery bypass grafting (CABG), aortic valve replacement (AVR) or mitral valve surgery in the US also have associated AF, but only 20% of them undergo a concomitant procedure to ablate the AF. However, multiple studies have demonstrated that treating the AF at the time of these other primary operations results in an improved quality of life, fewer long-term strokes and improved long-term survival while adding no risk to the overall surgical procedure. Moreover, the major cardiology and surgery societies recommend that concomitant AF surgery be performed in all cases when feasible. Patients undergoing CABG and AVR who have paroxysmal AF should undergo pulmonary vein isolation, while those with non-paroxysmal AF (persistent or long-standing persistent AF) should have a Maze procedure. Patients undergoing mitral valve surgery who have either paroxysmal AF or non-paroxysmal AF should undergo a Maze procedure.