The study population consisted of two cohorts: a discovery set from Heart Center Leipzig (HCL), Germany, and a validation set from Vanderbilt University (VU), US. 1145 patients from The Heart Center Leipzig AF Ablation Registry and 261 from The Vanderbilt AF Ablation Registry were included in this study (Table 1 ). Patients underwent AF catheter ablation according to current guidelines at HCL between January 2007 and December 2011, and at VU between March 2004 and December 2011.
Paroxysmal and persistent AF was defined according to current guidelines [5 (link)]. Paroxysmal AF was defined as self-terminating within 7 days after onset documented by previous routine electrocardiograms (ECG) or Holter ECG. Persistent AF was defined as any AF episode either lasting longer than 7 days or requiring drug or direct current cardioversion for termination.
In all patients, transthoracic and transesophageal echocardiography was performed prior to ablation. At HCL, all class I or III antiarrhythmic medications with the exception of amiodarone were discontinued at least 5 half-lives before the procedure. At VU, antiarrhythmic medications were continued peri-procedurally at the discretion of the individual operator and discontinued 3 months after the procedure.
eGFR was estimated at HCL and VU according to the standard formulas used clinically at each institution. At HCL, the CKD-EPI (Chronic Kidney Disease Epidemiology Collaboration) equation was used: eGFR = 141 × min(Scr/κ, 1)α × max(Scr/κ, 1)−1.209 × 0.993Age × 1.018 [if female] × 1.159[if Black], where Scr is serum creatinine, κ is 0.7 for females and 0.9 for males, α is −0.329 for females and −0.411 for males, min indicates the minimum of Scr/κ or 1, and max indicates the maximum of Scr/κ or 1 [6 (link)]. At VU, eGFR was estimated using the MDRD (modification of diet in renal disease) formula: eGFR = 186 × Scr−1.154 × Age−0.203 × [1.210 if Black] ×[0.742 if female]. As standard clinical practice at VU, an eGFR cutoff of 60 ml/min/1.73 m2 is used where estimates greater than 60 ml/min/1.73 m2 were recorded as 60 ml/min/1.73 m2.
The study was performed according to the Declaration of Helsinki and Institutional Guidelines. Patients provided written informed consent.
Paroxysmal and persistent AF was defined according to current guidelines [5 (link)]. Paroxysmal AF was defined as self-terminating within 7 days after onset documented by previous routine electrocardiograms (ECG) or Holter ECG. Persistent AF was defined as any AF episode either lasting longer than 7 days or requiring drug or direct current cardioversion for termination.
In all patients, transthoracic and transesophageal echocardiography was performed prior to ablation. At HCL, all class I or III antiarrhythmic medications with the exception of amiodarone were discontinued at least 5 half-lives before the procedure. At VU, antiarrhythmic medications were continued peri-procedurally at the discretion of the individual operator and discontinued 3 months after the procedure.
eGFR was estimated at HCL and VU according to the standard formulas used clinically at each institution. At HCL, the CKD-EPI (Chronic Kidney Disease Epidemiology Collaboration) equation was used: eGFR = 141 × min(Scr/κ, 1)α × max(Scr/κ, 1)−1.209 × 0.993Age × 1.018 [if female] × 1.159[if Black], where Scr is serum creatinine, κ is 0.7 for females and 0.9 for males, α is −0.329 for females and −0.411 for males, min indicates the minimum of Scr/κ or 1, and max indicates the maximum of Scr/κ or 1 [6 (link)]. At VU, eGFR was estimated using the MDRD (modification of diet in renal disease) formula: eGFR = 186 × Scr−1.154 × Age−0.203 × [1.210 if Black] ×[0.742 if female]. As standard clinical practice at VU, an eGFR cutoff of 60 ml/min/1.73 m2 is used where estimates greater than 60 ml/min/1.73 m2 were recorded as 60 ml/min/1.73 m2.
The study was performed according to the Declaration of Helsinki and Institutional Guidelines. Patients provided written informed consent.
