Please assess the completion status of the following clinical trial:

Trial Title: Heart Rate Regularization in Patients With Permanent Atrial Fibrillation Post Marketing Study

Study Design Characteristics:
- Allocation: RANDOMIZED
- Intervention Model: CROSSOVER
- Observational Model: None
- Primary Purpose: TREATMENT
- Time Perspective: None
- Masking: DOUBLE
- Phase: PHASE4
- Number of Arms: 2.0

Eligibility Criteria:
Inclusion Criteria:~* Patient has signed informed consent form~* Patient with permanent atrial fibrillation, standard indication for VVI(R) pacing, and at least 1 episode of rate irregularity in the last month~* New York Heart Association (NYHA) Class I, II, III~* Patient is able to comply with follow-up times and will comply with the protocol~* \> 18 years of age~Exclusion Criteria:~* Paroxysmal atrial fibrillation~* NYHA Class IV~* Left ventricular ejection fraction (LVEF) \< 35~* Patients with unstable angina~* Patients who have experienced an acute myocardial infarction or received coronary artery revascularization (CABG), or coronary angioplasty (PTCA) within 3 months prior to enrolment~* Patient candidate for cardiac surgery, or coronary angioplasty (PTCA)~* Patients who experienced a cardiovascular accident (CVA) or transient ischemic attack (TIA) with permanent disability~* Life expectancy \< 12 months due to other medical conditions~* Pregnancy~* The patient is enrolled in any concurrent (drug and/or device) study

- Gender: ALL
- Minimum Age: 18 Years
- Maximum Age: None
- Healthy Volunteers: f

Study Arms:
- 1. VRS ON (Type: EXPERIMENTAL): Patients with permanent atrial fibrillation implanted with VVI(R) pacemaker Vitatron model C20 SSIR or T20 SSIR were randomized to Function Ventricular Rate Stabilization (VRS) ON or OFF.~This arm (1) is randomized to Function Ventricular Rate Stabilization ON.
- 2. VRS OFF (Type: NO_INTERVENTION): Patients with permanent atrial fibrillation implanted with VVI(R) pacemaker Vitatron model C20 SSIR or T20 SSIR were randomized to Function Ventricular Rate Stabilization (VRS)ON or OFF.~This arm (2) is randomized to Function Ventricular Rate Stabilization OFF.

Based on this trial design, predict the completion outcome and termination type (if applicable).