A 51-year-old Caucasian man with a history notable for dyslipidemia and paroxysmal Atrial Fibrillation (AF) presents to the clinic for second opinion regarding his AF. Patient reports history of AF since two years and has been refractory to drug therapy including Sotalol and Dofetilide. He was symptomatic with palpitations and significant fatigue. The patient's current medications included Metoprolol tartrate 100 mg twice a day, Atorvastatin 10 mg daily, Aspirin 325 mg daily. The risks to an ablation were discussed in details including but not limited to bleeding, infection, stroke, heart attack, phrenic nerve paresis, atrioesophageal fistula and thrombus formation. He elected to proceed and was scheduled for the following month.
Physical exam: Pleasant middle-aged male in no acute distress. Blood pressure135/85 mm Hg, heart rate 84 beats/minute, respiratory rate 18, body mass index 37kg/m2, and pulse oximetry 90%. Breath sounds are diminished, heart sounds are distant, with an unremarkable exam. He had no evidence of jugular venous distension, or lower extremity edema.
Laboratory testing: normal hematology, chemistry profile, thyroid-stimulating hormone. Arterial blood gas (ABG) analysis findings; pH=7.30; pCO2=55 mm Hg; pO2=60mmHg; bicarbonate=31.
Echocardiogram: The left and right ventricles are normal in size. The LV ejection fraction appears to be 55 to 60%. Evidence of grade II diastolic dysfunction. The right atrial cavity is normal in size, left atrial cavity is moderately enlarged. There are no major valvular abnormalities.
Nocturnal Polysomnography: Moderate sleep apnea with apnea-hypopnea index of 20 episodes/hour with several hypopneic episodes.
Atrial fibrillation with an average ventricular response at rest of about 84/min (range about 70-120/min). Relatively low voltage is present diffusely, a non-specific finding that may be seen with obesity. Borderline left axis deviation is also present.11
How would you manage Atrial Fibrillation in this patient once OSA is discovered?
The correct answer is: A. Start treatment with CPAP and proceed with ablation
There is a high prevalence of OSA in patients with AF. Several studies have found that the association between OSA and AF is independent of shared risks factors such as obesity and hypertension.1,2,3 Possible mechanisms by which OSA increases AF development and recurrence including hypoxia, hypercapnia, autonomic dysregulation, endothelial dysfunction, oxidative stress, inflammation and structural changes in the heart.4,5 Recurrence of AF after catheter ablation presents an important limitation in the treatment of AF.4 A recent meta-analysis demonstrated that OSA patients have a 25% greater risk of AF recurrence after catheter ablation than those without OSA (risk ratio 1.25, p = 0.003).4 Non-invasive positive pressure ventilation (NIPPV) is currently the gold standard of OSA treatment, and has a significant impact on reducing AF recurrence after PVI. Fein et all reported a higher AF recurrence rate in patients with undiagnosed/untreated OSA compared to patients without OSA. CPAP-treated patients (daily for a minimum of 3 months) had the similar AF recurrence rate as patients without OSA.6
Current guidelines recommend catheter ablation for patients with symptomatic paroxysmal AF refractory or intolerant to at least one Class I or III antiarrhythmic medication.7 Success rate of single procedure of ablation in patients with paroxysmal AF (PAF) is higher (68% vs. 51%) than those with non-paroxysmal atrial fibrillation (NPAF).8 Male sex, hypertension, hyperlipidemia, NPAF, AF duration, higher BMI, structural or valvular heart disease and left ventricular systolic dysfunction are possible predictors of AF recurrence after ablation. Longer lasting AF episodes are correlated with irreversible remodeling of LA and subsequently lower success rate of procedure.8,9 Therefore, the best approach for this patient would be to start treatment with CPAP and proceed with ablation. Oxygen therapy improves oxygen saturation in patients with OSA, however it has been shown to increase duration of apnea-hypopnea events.10 Thus, answer option C would be incorrect.
To our knowledge, there is no study which demonstrates time period between initiation of NIPPV and optimal time for ablation. The beneficial effects of NIPPV for AF management stem from long term compliance and not from acute short term improvement. Therefore, answer option B or D is not correct.
It is important to note that although the correct choice A is reasonable, no randomized controlled trials have been published to actually support that approach with evidence. There are a number of meta-analysis of observational studies available, which are prone to bias.
This topic highlights the importance of screening patients with AF for OSA prior to ablation and ensure their compliance with CPAP therapy.
Braga B, Poyares D, Cintra F, Guilleminault C, Cirenza C, Horbach S, Macedo D, Silva R, Tufik S, De Paola AA. Sleep-disordered breathing and chronic atrial fibrillation. Sleep Med 2009;10:212–216.
Gami AS, Hodge DO, Herges RM, Olson EJ, Nykodym J, Kara T, Somers VK. Obstructive sleep apnea, obesity, and the risk of incident atrial fibrillation. J Am Coll Cardiol 2007;49:565–571
Ng CY, Liu T, Shehata M, et al. Meta-analysis of obstructive sleep apnea as predictor of atrial fibrillation recurrence after catheter ablation. Am J Cardiol 2011; 108:47.
Jelic S, Padeletti M, Kawut SM, Higgins C, Canfield SM, Onat D,Colombo PC, Basner RC, Factor P, LeJemtel TH. Inflammation, oxidative stress, and repair capacity of the vascular endothelium in obstructive sleep apnea. Circulation 2008;117:2270 –2278.
Fein AS, Shvilkin A, Shah D, Haffajee CI, das S, Kumar K, Kramer DB, Zimetbaum PJ, Buxton AE, Josephson ME, Anter E. Treatment of obstructive sleep apnea reduces the risk of atrial fibrillation recurrence after catheter ablation. J Am Coll Cardiol 2013;62:300–5.
January CT, Wann L, Alpert JS, et al. 2014 AHA/ACC/HRS Guideline for the Management of Patients With Atrial Fibrillation: Executive Summary: A Report of the American College of Cardiology/American Heart Association Task Force on Practice Guidelines and the Heart Rhythm Society. J Am Coll Cardiol 2014;64(21):2246-2280. doi:10.1016/j.jacc.2014.03.021.
Ganesan AN, Shipp NJ, Brooks AG, Kuklik P, Lau DH, Lim HS, Sullivan T, Roberts-Thomson KC, Sanders P. Long-term outcomes of catheter ablation of atrial fibrillation: a systematic review and meta-analysis. J Am Heart Assoc. 2013;2:e004549. doi: 10.1161/JAHA.112.004549.
Zakrzewska-Koperska J, Derejko P, Walczak F, Urbanek P, Bodalski R, Orczykowski M, Kalińczuk L, Jedynak Z, Michałowska I, Oręziak A, Bilińska M,Przybylski A, Szumowski L. Early stage of left atrium remodelling predicts better outcome in long-term follow-up of atrial fibrillation ablation. Kardiol Pol 2014;72(10):925-33. doi: 10.5603/KP.a2014.0112. Epub 2014, May 20
Mehta V, Vasu TS, Phillips B, Chung F. Obstructive sleep apnea and oxygen therapy: a systematic review of the literature and meta-analysis. J Clin Sleep Med 2013;9(3):271-9. doi: 10.5664/jcsm.2500.
Nathanson L A, McClennen S, Safran C, Goldberger AL. ECG Wave-Maven: Self-Assessment Program for Students and Clinicians. http://ecg.bidmc.harvard.edu.