Surgical Ablation of Atrial Fibrillation in High-Risk Patients: Success versus Risk.

Background:  Surgical atrial ablation is evaluated by surgeons in relation to the estimated surgical risk. We analyze whether high-risk patients (HRPs) experience risk escalation by ablation procedures.

Methods:  The CASE-Atrial Fibrillation (AF) registry is a prospective, multicenter, all-comers registry of atrial ablation in cardiac surgery. We analyzed the 1-year outcome regarding survival and rhythm endpoints of 1,000 consecutive patients according to the operative risk classification (EuroSCORE II ≤ 2 vs. >2).

Results:  Higher NYHA (New York Heart Association) score, ischemic heart failure, status poststroke, renal insufficiency, chronic obstructive pulmonary disease, and diabetes mellitus were strongly represented in HRPs. HRPs exhibit more left ventricular ejection fraction < 40% (19.2 vs. 8.8%; p < 0.001) but identical left atrial diameter and left ventricular end-diastolic diameter compared with low-risk patients (LRPs). CHA2DS-Vasc-score (2.4 ± 1 vs. 3.6 ± 1.5; p < 0.001), sternotomies, combination surgeries, coronary artery bypass graft, and mitral valve procedures were increased in HRPs. LRPs underwent stand-alone ablations as well. Ablation energy did not differ. Left atrial appendage closure was performed in up to 86.1% (mainly cut-and-sew procedures). Mortality corresponded to the original risk class without an escalation that may be related to ablation, stroke rate, or myocardial infarction. A total of 60.6% of HRPs versus 75.1% of LRPs were discharged in sinus rhythm. Long-term EHRA (European Heart Rhythm Association) score symptoms were lower in HRPs. Repeated rhythm therapies were rare. Additional antiarrhythmics received a minority without group dependency. A total of 1.6 versus 4.1% of HRPs (p = 0.042) underwent long-term stroke; excess mortality was not observed. Anticoagulation remained common in HRPs.

Conclusion:  Surgical risk and long-term mortality are determined by the underlying disease. In HRPs, freedom from AF and symptom relief can be achieved. Preoperative risk scores should not lead to withholding an ablation procedure.