{"product_id":"catheter-ablation-for-persistent-atrial-fibrillation-what-the-star-af-ii-trial-means-for-patients","title":"Catheter Ablation for Persistent Atrial Fibrillation: What the STAR AF II Trial Means for Patients","description":"\u003cp\u003eSUMMARY: In this randomized trial involving 589 patients with persistent atrial fibrillation, adding extra ablation (either targeting complex electrical signals or creating additional linear scars) to standard pulmonary-vein isolation did not improve freedom from recurrent atrial fibrillation at 18 months. Success rates were 59% with isolation alone, 49% with isolation plus electrogram ablation, and 46% with isolation plus lines (P=0.15). The simpler procedure also took less time. This suggests that the extra ablation approaches may not provide additional benefit for persistent AF.\u003c\/p\u003e\n\n\u003ch1\u003eCatheter Ablation for Persistent Atrial Fibrillation: What the STAR AF II Trial Means for Patients\u003c\/h1\u003e\n\n\u003ch2\u003eTable of Contents\u003c\/h2\u003e\n\u003cul\u003e\n\u003cli\u003e\u003ca href=\"#ddn-key-points\"\u003eKey Points\u003c\/a\u003e\u003c\/li\u003e\n\n  \u003cli\u003e\u003ca href=\"#background\"\u003eWhat Is Persistent Atrial Fibrillation and Why Is It Harder to Treat?\u003c\/a\u003e\u003c\/li\u003e\n  \u003cli\u003e\u003ca href=\"#methods\"\u003eHow the Study Was Conducted\u003c\/a\u003e\u003c\/li\u003e\n  \u003cli\u003e\u003ca href=\"#findings\"\u003eKey Findings: Did Extra Ablation Help?\u003c\/a\u003e\u003c\/li\u003e\n  \u003cli\u003e\u003ca href=\"#implications\"\u003eWhat This Means for Patients\u003c\/a\u003e\u003c\/li\u003e\n  \u003cli\u003e\u003ca href=\"#limitations\"\u003eStudy Limitations\u003c\/a\u003e\u003c\/li\u003e\n  \u003cli\u003e\u003ca href=\"#recommendations\"\u003eQuestions to Ask Your Doctor\u003c\/a\u003e\u003c\/li\u003e\n  \u003cli\u003e\u003ca href=\"#ddn-faq\"\u003eFrequently Asked Questions\u003c\/a\u003e\u003c\/li\u003e\n\u003cli\u003e\u003ca href=\"#source\"\u003eSource Information\u003c\/a\u003e\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003c!-- ddn:keypoints:start --\u003e\n\u003ch2 id=\"ddn-key-points\"\u003eKey Points\u003c\/h2\u003e\n\u003cul\u003e\n\u003cli\u003eIn 589 patients with persistent atrial fibrillation, adding electrogram or linear ablation to pulmonary-vein isolation did not significantly reduce recurrent AF at 18 months.\u003c\/li\u003e\n\u003cli\u003eFreedom from recurrent AF at 18 months was 59% with isolation alone, 49% with isolation plus electrograms, and 46% with isolation plus lines.\u003c\/li\u003e\n\u003cli\u003eProcedure time was significantly shorter with pulmonary-vein isolation alone than with the more extensive approaches in this trial.\u003c\/li\u003e\n\u003cli\u003eSerious complications were rare: tamponade, stroke or transient ischemic attack, and one atrioesophageal fistula across all groups.\u003c\/li\u003e\n\u003cli\u003ePatients with persistent AF should discuss with an electrophysiologist whether isolation alone is appropriate, given individual anatomy and symptom burden.\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003c!-- ddn:keypoints:end --\u003e\n\n\n\u003ch2 id=\"background\"\u003eWhat Is Persistent Atrial Fibrillation and Why Is It Harder to Treat?\u003c\/h2\u003e\n\n\u003cp\u003eAtrial fibrillation (AF) is an irregular, often rapid heart rhythm that originates in the upper chambers of the heart (the atria). In \u003cstrong\u003eparoxysmal atrial fibrillation\u003c\/strong\u003e, episodes come and go and usually stop on their own within 7 days. \u003cstrong\u003ePersistent atrial fibrillation\u003c\/strong\u003e is defined as a sustained episode lasting more than 7 days and is more difficult to treat successfully.\u003c\/p\u003e\n\n\u003cp\u003eCatheter ablation is a minimally invasive procedure in which a doctor threads a thin tube (catheter) through blood vessels to the heart and uses heat (radiofrequency energy) to create small scars. These scars block abnormal electrical signals that cause AF. For paroxysmal AF, ablation is very effective. Most triggers for paroxysmal AF come from the \u003cstrong\u003epulmonary veins\u003c\/strong\u003e — the four veins that bring oxygen-rich blood from the lungs to the left atrium. Ablation therefore focuses on creating circular scars around these veins to electrically isolate them from the rest of the heart.\u003c\/p\u003e\n\n\u003cp\u003ePersistent AF is more challenging. The abnormal signals are not only in the pulmonary veins but also throughout the left atrium, which has developed \"substrate\" — tissue changes that help keep AF going. Because of this, guidelines have suggested that doctors should consider more extensive ablation in addition to pulmonary-vein isolation. The two most common extra techniques are:\u003c\/p\u003e\n\n\u003cul\u003e\n  \u003cli\u003e\n\u003cstrong\u003eAblation of complex fractionated electrograms (CFEs):\u003c\/strong\u003e targeting small areas in the atrium that show rapid, disorganized electrical activity.\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003eLinear ablation:\u003c\/strong\u003e creating long lines of scar tissue across the roof of the left atrium and between the mitral valve and the pulmonary veins (the mitral isthmus).\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003cp\u003eHowever, before this trial, there were limited randomized data to prove that these additional ablation strategies actually improve outcomes. The \u003cstrong\u003eSTAR AF II\u003c\/strong\u003e (Substrate and Trigger Ablation for Reduction of Atrial Fibrillation Trial Part II) was designed to answer this question directly.\u003c\/p\u003e\n\n\u003ch2 id=\"methods\"\u003eHow the Study Was Conducted\u003c\/h2\u003e\n\n\u003ch3\u003eTrial Design and Participants\u003c\/h3\u003e\n\n\u003cp\u003eThe study was a multicenter, randomized trial conducted at 48 experienced centers in 12 countries. It was sponsored by St. Jude Medical, a medical device company. The trial was approved by ethics committees at each center, and all patients gave written informed consent.\u003c\/p\u003e\n\n\u003cp\u003eA total of \u003cstrong\u003e589 patients\u003c\/strong\u003e with persistent atrial fibrillation were enrolled between November 2010 and July 2012. Patients were eligible if they were \u003cstrong\u003e18 years or older\u003c\/strong\u003e, had \u003cstrong\u003esymptomatic persistent AF\u003c\/strong\u003e (a sustained episode lasting more than 7 days), had AF that was \u003cstrong\u003erefractory to at least one antiarrhythmic medication\u003c\/strong\u003e, and were undergoing ablation for the \u003cstrong\u003efirst time\u003c\/strong\u003e.\u003c\/p\u003e\n\n\u003cp\u003eKey exclusion criteria were:\u003c\/p\u003e\n\u003cul\u003e\n  \u003cli\u003eParoxysmal (episodic) atrial fibrillation\u003c\/li\u003e\n  \u003cli\u003eSustained AF lasting more than \u003cstrong\u003e3 years\u003c\/strong\u003e\n\u003c\/li\u003e\n  \u003cli\u003eA left atrial diameter of \u003cstrong\u003e60 mm or greater\u003c\/strong\u003e (severely enlarged left atrium)\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003ch3\u003eRandomization and Ablation Strategies\u003c\/h3\u003e\n\n\u003cp\u003ePatients were randomly assigned in a \u003cstrong\u003e1:4:4 ratio\u003c\/strong\u003e to one of three ablation strategies:\u003c\/p\u003e\n\n\u003col\u003e\n  \u003cli\u003e\n\u003cstrong\u003ePulmonary-vein isolation alone\u003c\/strong\u003e (67 patients) — ablation around each pulmonary vein until electrical signals from the veins could not enter the atrium (entrance block) and pacing inside the vein could not exit (exit block).\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003ePulmonary-vein isolation plus complex fractionated electrogram ablation\u003c\/strong\u003e (263 patients) — after isolation, doctors used validated automated software to identify and ablate areas with rapid or continuous electrical activity until AF terminated or all such areas were eliminated.\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003ePulmonary-vein isolation plus linear ablation\u003c\/strong\u003e (259 patients) — after isolation, doctors created additional lines of scar across the left atrial roof and the mitral valve isthmus, and confirmed conduction block with pacing maneuvers.\u003c\/li\u003e\n\u003c\/ol\u003e\n\n\u003cp\u003eRandomization was performed using an automated telephone system and was stratified by study site. \u003cstrong\u003ePatients were unaware\u003c\/strong\u003e of which ablation strategy they received. Doctors, of course, knew which procedure they were performing.\u003c\/p\u003e\n\n\u003ch3\u003eProcedures and Follow-Up\u003c\/h3\u003e\n\n\u003cp\u003eBefore ablation, patients stopped taking antiarrhythmic medications and took oral anticoagulation (blood thinners) for at least 4 weeks. The ablation itself used radiofrequency energy delivered through a catheter with an open, irrigated tip, guided by a 3D mapping system (EnSite Velocity, St. Jude Medical).\u003c\/p\u003e\n\n\u003cp\u003eDuring the first 3 months after ablation (the \"blanking period\"), patients could take antiarrhythmic medications. After that, their use was discouraged. Patients with recurrent AF after the blanking period could restart antiarrhythmic drugs or undergo a repeat ablation using the same randomized strategy, which was recommended 3 to 6 months after the initial procedure.\u003c\/p\u003e\n\n\u003cp\u003eFollow-up assessments were performed at \u003cstrong\u003ebaseline and at 3, 6, 9, 12, and 18 months\u003c\/strong\u003e. At each visit, patients had:\u003c\/p\u003e\n\u003cul\u003e\n  \u003cli\u003eClinical assessment\u003c\/li\u003e\n  \u003cli\u003e12-lead electrocardiogram (ECG)\u003c\/li\u003e\n  \u003cli\u003e24-hour Holter monitor recording\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003cp\u003eIn addition, patients were given a \u003cstrong\u003etranstelephonic monitor\u003c\/strong\u003e and were asked to transmit rhythm recordings \u003cstrong\u003eweekly\u003c\/strong\u003e and any time they had symptoms like palpitations, dizziness, or shortness of breath. All ECGs and Holter readings were interpreted by clinicians who did not know the treatment assignment. Transtelephonic transmissions were read by independent core laboratory personnel, also blinded to treatment.\u003c\/p\u003e\n\n\u003ch3\u003eStudy Endpoints and Statistical Analysis\u003c\/h3\u003e\n\n\u003cp\u003eThe \u003cstrong\u003eprimary endpoint\u003c\/strong\u003e was freedom from any documented episode of atrial fibrillation lasting longer than 30 seconds after a single ablation procedure, with or without antiarrhythmic medication. Episodes within the first 3-month blanking period were not counted. A repeat left atrial ablation procedure at any time was also counted as a recurrence.\u003c\/p\u003e\n\n\u003cp\u003eMain secondary endpoints included:\u003c\/p\u003e\n\u003cul\u003e\n  \u003cli\u003eFreedom from documented AF after two ablation procedures\u003c\/li\u003e\n  \u003cli\u003eFreedom from any atrial arrhythmia (AF, atrial flutter, or atrial tachycardia) after one and after two procedures\u003c\/li\u003e\n  \u003cli\u003eUse of antiarrhythmic medication\u003c\/li\u003e\n  \u003cli\u003eProcedure time\u003c\/li\u003e\n  \u003cli\u003eIncidence of repeat procedures\u003c\/li\u003e\n  \u003cli\u003eIncidence of periprocedural complications\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003cp\u003eAn independent events committee, unaware of treatment assignments, adjudicated all adverse events.\u003c\/p\u003e\n\n\u003cp\u003eSample-size calculations were based on a pilot study. The expected freedom from AF after one procedure was \u003cstrong\u003e75%\u003c\/strong\u003e for isolation plus electrograms and \u003cstrong\u003e45%\u003c\/strong\u003e for isolation alone. For isolation plus lines, the expected success was estimated from the literature at \u003cstrong\u003e60%\u003c\/strong\u003e. The trial was designed to have \u003cstrong\u003e90% power\u003c\/strong\u003e at a one-sided alpha level of 0.025, and after accounting for a 15% dropout rate, the target enrollment was \u003cstrong\u003e549 patients\u003c\/strong\u003e (61 for isolation alone and 244 each for the other two groups).\u003c\/p\u003e\n\n\u003cp\u003eStatistical comparisons among the three groups were performed using the log-rank test with two degrees of freedom, and post hoc pairwise analyses used the Holm method. A two-sided P value of less than 0.05 was considered statistically significant.\u003c\/p\u003e\n\n\u003ch2 id=\"findings\"\u003eKey Findings: Did Extra Ablation Help?\u003c\/h2\u003e\n\n\u003ch3\u003eFollow-Up and Adherence\u003c\/h3\u003e\n\n\u003cp\u003eOf the 589 randomized patients, \u003cstrong\u003e21 patients did not receive any ablation\u003c\/strong\u003e after randomization, and \u003cstrong\u003e19 more dropped out\u003c\/strong\u003e before completing the 3-month blanking period. These patients were not included in the outcome analyses. Therefore, the primary analysis included \u003cstrong\u003e61 patients in the isolation-alone group, 244 in the isolation-plus-electrograms group, and 244 in the isolation-plus-lines group\u003c\/strong\u003e.\u003c\/p\u003e\n\n\u003cp\u003eOf the patients who did receive ablation, \u003cstrong\u003e90% completed the 18-month follow-up\u003c\/strong\u003e. Adherence to Holter monitoring at each visit was \u003cstrong\u003e85%\u003c\/strong\u003e. Adherence to at least weekly transtelephonic transmission during the 18 months was \u003cstrong\u003e75%\u003c\/strong\u003e, with no significant differences among the groups.\u003c\/p\u003e\n\n\u003ch3\u003ePrimary Outcome: Recurrence of Atrial Fibrillation\u003c\/h3\u003e\n\n\u003cp\u003eAfter 18 months, the primary outcome — freedom from any documented AF recurrence lasting more than 30 seconds after one ablation procedure — was reported for:\u003c\/p\u003e\n\n\u003cul\u003e\n  \u003cli\u003e\n\u003cstrong\u003e59%\u003c\/strong\u003e of patients in the pulmonary-vein isolation alone group (36 of 61)\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003e49%\u003c\/strong\u003e of patients in the isolation plus electrograms group (119 of 244)\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003e46%\u003c\/strong\u003e of patients in the isolation plus lines group (112 of 244)\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003cp\u003eThe overall comparison among the three groups was \u003cstrong\u003enot statistically significant (P = 0.15)\u003c\/strong\u003e. In other words, adding either complex fractionated electrogram ablation or linear ablation did not significantly improve freedom from recurrent AF compared to pulmonary-vein isolation alone.\u003c\/p\u003e\n\n\u003ch3\u003eSecondary Outcomes\u003c\/h3\u003e\n\n\u003cp\u003eThere were also no significant differences among the three groups for the main secondary endpoints:\u003c\/p\u003e\n\n\u003cul\u003e\n  \u003cli\u003e\n\u003cstrong\u003eFreedom from AF after one procedure without antiarrhythmic drugs:\u003c\/strong\u003e 48% (isolation alone), 37% (isolation plus electrograms), 33% (isolation plus lines) — P = 0.11\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003eFreedom from any atrial arrhythmia after one procedure with or without drugs:\u003c\/strong\u003e 49%, 41%, and 37% — P = 0.15\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003eFreedom from any atrial arrhythmia after one procedure without drugs:\u003c\/strong\u003e 41%, 33%, and 29% — P = 0.08\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003eFreedom from documented AF after two procedures:\u003c\/strong\u003e 72%, 60%, and 58% — P = 0.18\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003eFreedom from any atrial arrhythmia after two procedures:\u003c\/strong\u003e 61%, 50%, and 48% — P = 0.24\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003eDocumented atrial flutter or tachycardia after one procedure:\u003c\/strong\u003e 11%, 11%, and 14% — P = 0.57\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003eDocumented atrial flutter or tachycardia after two procedures:\u003c\/strong\u003e 11%, 13%, and 12% — P = 0.98\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003cp\u003eOne noteworthy post hoc finding: when the researchers specifically compared pairs of groups without adjusting for multiple comparisons using the Holm method, they found that patients assigned to \u003cstrong\u003eisolation plus lines\u003c\/strong\u003e had \u003cstrong\u003esignificantly less freedom from AF and from atrial arrhythmias without antiarrhythmic medications\u003c\/strong\u003e than patients assigned to \u003cstrong\u003eisolation alone\u003c\/strong\u003e (P = 0.04 for both comparisons). This was an unplanned analysis, so it should be interpreted cautiously, but it does suggest that adding linear ablation might actually be worse in some respects.\u003c\/p\u003e\n\n\u003ch3\u003eProcedural Details\u003c\/h3\u003e\n\n\u003cp\u003eAt the time of ablation, \u003cstrong\u003e79% of patients were in spontaneous atrial fibrillation\u003c\/strong\u003e. Successful pulmonary-vein isolation was achieved in \u003cstrong\u003e97%\u003c\/strong\u003e of all patients, with no significant differences between groups.\u003c\/p\u003e\n\n\u003cp\u003eIn the isolation plus electrograms group, complex fractionated electrograms were \u003cstrong\u003esuccessfully eliminated in 80% of patients\u003c\/strong\u003e. In 11% of cases, the electrograms were not mapped according to protocol because AF was no longer inducible after pulmonary-vein isolation. In 9%, all complex fractionated electrograms could not be eliminated.\u003c\/p\u003e\n\n\u003cp\u003eIn the isolation plus lines group, all patients had the required lines performed, but only \u003cstrong\u003e74%\u003c\/strong\u003e showed complete conduction block across both lines.\u003c\/p\u003e\n\n\u003cp\u003e\u003cstrong\u003eProcedure time was significantly shorter for pulmonary-vein isolation alone\u003c\/strong\u003e than for the other two procedures (P \u0026lt; 0.001). Exposure to fluoroscopy (X-ray imaging) was also significantly lower for isolation alone (P \u0026lt; 0.001 for both comparisons).\u003c\/p\u003e\n\n\u003cp\u003eRepeat ablation was performed in:\u003c\/p\u003e\n\u003cul\u003e\n  \u003cli\u003e\n\u003cstrong\u003e21%\u003c\/strong\u003e of patients in the isolation-alone group\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003e26%\u003c\/strong\u003e of patients in the isolation plus electrograms group\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003e33%\u003c\/strong\u003e of patients in the isolation plus lines group\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003cp\u003eThe difference between groups was not significant (P = 0.10).\u003c\/p\u003e\n\n\u003ch3\u003eComplications\u003c\/h3\u003e\n\n\u003cp\u003eSerious complications in the trial included:\u003c\/p\u003e\n\u003cul\u003e\n  \u003cli\u003e\n\u003cstrong\u003eTamponade\u003c\/strong\u003e (compression of the heart due to fluid in the sac around it) — occurred in \u003cstrong\u003e3 patients\u003c\/strong\u003e\n\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003eStroke or transient ischemic attack\u003c\/strong\u003e (\"mini-stroke\") — occurred in \u003cstrong\u003e3 patients\u003c\/strong\u003e\n\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003eAtrioesophageal fistula\u003c\/strong\u003e (an abnormal connection between the heart and the esophagus, a rare but very serious complication) — occurred in \u003cstrong\u003e1 patient\u003c\/strong\u003e\n\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003cp\u003eThe report notes that an independent events committee adjudicated all adverse events, and the numbers above represent the total across all treatment groups.\u003c\/p\u003e\n\n\u003ch3\u003eBaseline Patient Characteristics\u003c\/h3\u003e\n\n\u003cp\u003eThe three groups were well balanced at the start of the trial. Across all groups, the average age was \u003cstrong\u003e58 to 61 years\u003c\/strong\u003e, \u003cstrong\u003e76% to 81%\u003c\/strong\u003e of patients were male, and the average left ventricular ejection fraction (a measure of heart pumping function) was \u003cstrong\u003e55% to 57%\u003c\/strong\u003e. The average left atrial diameter was \u003cstrong\u003e44 to 46 mm\u003c\/strong\u003e. Time from first AF diagnosis averaged \u003cstrong\u003e3.6 to 4.3 years\u003c\/strong\u003e.\u003c\/p\u003e\n\n\u003cp\u003eMedical history showed that \u003cstrong\u003e48% to 61%\u003c\/strong\u003e had hypertension, \u003cstrong\u003e9% to 12%\u003c\/strong\u003e had diabetes, \u003cstrong\u003e3% to 11%\u003c\/strong\u003e had coronary disease, \u003cstrong\u003e5% to 9%\u003c\/strong\u003e had a prior stroke or transient ischemic attack, and \u003cstrong\u003e4% to 6%\u003c\/strong\u003e had heart failure. Regarding stroke risk (CHADS2 score), \u003cstrong\u003e31% to 46%\u003c\/strong\u003e had a score of 0, \u003cstrong\u003e37% to 49%\u003c\/strong\u003e had a score of 1, \u003cstrong\u003e9% to 12%\u003c\/strong\u003e had a score of 2, and \u003cstrong\u003e4% to 7%\u003c\/strong\u003e had a score greater than 2. Baseline medications included beta-blockers (56% to 64%), calcium-channel blockers (13% to 18%), amiodarone (19% to 24%), and vitamin K antagonists (72% to 82%), among others.\u003c\/p\u003e\n\n\u003ch2 id=\"implications\"\u003eWhat This Means for Patients\u003c\/h2\u003e\n\n\u003cp\u003eThe most important message from STAR AF II is that \u003cstrong\u003emore extensive ablation is not necessarily better\u003c\/strong\u003e for persistent atrial fibrillation. In this large, randomized trial, adding either complex fractionated electrogram ablation or linear ablation to pulmonary-vein isolation did not reduce the rate of recurrent AF over 18 months. In fact, the numerical trend favored the simpler procedure.\u003c\/p\u003e\n\n\u003cp\u003eThis is reassuring for patients who have persistent AF and are considering catheter ablation. It suggests that \u003cstrong\u003epulmonary-vein isolation alone may be a reasonable first-line approach\u003c\/strong\u003e, and that the additional time, risk, and complexity of substrate modification may not provide meaningful benefit.\u003c\/p\u003e\n\n\u003cp\u003eThe significantly shorter procedure time with pulmonary-vein isolation alone is also important. A shorter procedure generally means less time under anesthesia, lower radiation exposure from fluoroscopy, and potentially fewer complications.\u003c\/p\u003e\n\n\u003cp\u003eHowever, the results do not mean that every patient with persistent AF should receive only pulmonary-vein isolation. Persistent AF is a complex and heterogeneous condition. Some patients may still benefit from additional ablation, particularly if pulmonary-vein isolation alone fails. The study also found that only \u003cstrong\u003e74%\u003c\/strong\u003e of patients who received linear ablation achieved complete conduction block, suggesting that the technique might not have been fully effective in all cases. This could partly explain the lack of benefit.\u003c\/p\u003e\n\n\u003cp\u003eFor patients, the key takeaway is to have a detailed discussion with an electrophysiologist (a heart rhythm specialist) about the risks and benefits of each ablation strategy, taking into account individual anatomy, AF duration, symptom burden, and underlying heart disease.\u003c\/p\u003e\n\n\u003ch2 id=\"limitations\"\u003eStudy Limitations\u003c\/h2\u003e\n\n\u003cp\u003eAs with any clinical trial, this study has limitations that are important to understand:\u003c\/p\u003e\n\n\u003cul\u003e\n  \u003cli\u003e\n\u003cstrong\u003eUnblinded operators:\u003c\/strong\u003e Although patients did not know their treatment assignment, the doctors performing the ablations obviously did. This can introduce bias, although the endpoints were adjudicated by blinded committees.\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003eExperienced centers only:\u003c\/strong\u003e All procedures were performed at 48 experienced centers. Results may not be generalizable to lower-volume or less experienced centers.\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003eFollow-up duration:\u003c\/strong\u003e The trial followed patients for 18 months. Longer-term outcomes may differ.\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003eMonitoring limitations:\u003c\/strong\u003e Holter monitors recorded only 24 hours at each visit, and transtelephonic monitoring depended on patient adherence (75%). Some short or asymptomatic episodes of AF may have been missed.\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003eSpecific patient population:\u003c\/strong\u003e Patients with AF lasting more than 3 years or a left atrial diameter of 60 mm or greater were excluded. Results may not apply to those with more advanced disease.\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003eVariable completeness of ablation:\u003c\/strong\u003e In the linear ablation group, complete conduction block was achieved in only 74% of patients. This could have affected the outcomes in that group.\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003eSponsorship:\u003c\/strong\u003e The trial was funded by St. Jude Medical, the manufacturer of the mapping system and catheters used. The sponsor reviewed the manuscript but was not involved in study design, writing, or submission.\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003ch2 id=\"recommendations\"\u003eQuestions to Ask Your Doctor\u003c\/h2\u003e\n\n\u003cp\u003eIf you have persistent atrial fibrillation and are considering catheter ablation, here are some questions based on this study that you might ask your doctor:\u003c\/p\u003e\n\n\u003col\u003e\n  \u003cli\u003e\n\u003cstrong\u003eIs pulmonary-vein isolation alone enough for my type of AF?\u003c\/strong\u003e The STAR AF II results suggest that it may be, but your individual situation matters.\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003eDo you recommend additional ablation of complex fractionated electrograms or linear lesions?\u003c\/strong\u003e If so, ask why — and what evidence supports that choice for your specific case.\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003eWhat is your success rate and complication rate?\u003c\/strong\u003e This trial was conducted at experienced centers with a 97% success rate for pulmonary-vein isolation.\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003eWhat are the risks of the procedure?\u003c\/strong\u003e In this trial, serious complications included tamponade, stroke or transient ischemic attack, and atrioesophageal fistula — all rare but possible.\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003eHow long will the procedure take?\u003c\/strong\u003e The simpler pulmonary-vein isolation procedure took significantly less time than the more extensive approaches.\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003eWhat is the plan for managing my stroke risk?\u003c\/strong\u003e Anticoagulation was used before and after ablation in the trial, and should be part of your overall treatment plan.\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003eWhat happens if AF recurs?\u003c\/strong\u003e In the study, repeat ablation was performed in 21% to 33% of patients, and freedom from AF after two procedures was better across all groups.\u003c\/li\u003e\n\u003c\/ol\u003e\n\n\u003cp\u003eThe decision to undergo catheter ablation — and which type of ablation to have — is personal. This study provides strong evidence that additional substrate modification does not routinely improve outcomes for persistent AF. Discussing these findings with your care team can help you make an informed choice that aligns with your goals and values.\u003c\/p\u003e\n\n\u003c!-- ddn:faq:start --\u003e\n\u003ch2 id=\"ddn-faq\"\u003eFrequently Asked Questions\u003c\/h2\u003e\n\u003ch3\u003eWhat is persistent atrial fibrillation and why is it harder to treat than paroxysmal AF?\u003c\/h3\u003e\n\u003cp\u003ePersistent atrial fibrillation is a sustained irregular heart rhythm lasting more than 7 days. It is harder to treat because abnormal electrical signals are not only in the pulmonary veins but also throughout the left atrium, which has developed tissue changes that help keep AF going. This is why doctors previously considered more extensive ablation.\u003c\/p\u003e\n\u003ch3\u003eWhat was the STAR AF II trial testing?\u003c\/h3\u003e\n\u003cp\u003eThe trial randomly assigned 589 patients with persistent atrial fibrillation to pulmonary-vein isolation alone, isolation plus complex fractionated electrogram ablation, or isolation plus linear ablation. The goal was to see whether adding extra ablation improved freedom from recurrent atrial fibrillation compared with the simpler procedure alone.\u003c\/p\u003e\n\u003ch3\u003eDid adding extra ablation help patients with persistent atrial fibrillation?\u003c\/h3\u003e\n\u003cp\u003eNo. At 18 months, freedom from recurrent atrial fibrillation was 59% with isolation alone, 49% with isolation plus electrogram ablation, and 46% with isolation plus lines. The differences were not statistically significant (P=0.15). The simpler procedure also took less time and had no worse outcomes in this trial.\u003c\/p\u003e\n\u003ch3\u003eWhat does this trial mean for a patient considering catheter ablation for persistent AF?\u003c\/h3\u003e\n\u003cp\u003ePulmonary-vein isolation alone may be a reasonable first-line approach for persistent atrial fibrillation. Adding substrate modification did not improve outcomes in this trial and increased procedure time. However, persistent AF is complex, so individual anatomy, symptom burden, and underlying heart disease should be discussed with an electrophysiologist before choosing a strategy.\u003c\/p\u003e\n\u003ch3\u003eWhat were the serious complications in this trial?\u003c\/h3\u003e\n\u003cp\u003eSerious complications included tamponade (compression of the heart by fluid) in 3 patients, stroke or transient ischemic attack in 3 patients, and atrioesophageal fistula (an abnormal connection between heart and esophagus) in 1 patient. These events occurred across the whole trial; they are rare but possible during catheter ablation.\u003c\/p\u003e\n\u003ch3\u003eWhat questions should I ask my doctor about persistent AF ablation?\u003c\/h3\u003e\n\u003cp\u003eAsk whether pulmonary-vein isolation alone is enough for your type of AF, why extra ablation might be recommended for you, the doctor's success and complication rates, how long the procedure will take, how stroke risk will be managed, and what the plan is if AF returns. The trial showed repeat ablation was done in 21%–33% of patients, with better freedom from AF after two procedures.\u003c\/p\u003e\n\u003c!-- ddn:faq:end --\u003e\n\n\u003ch2 id=\"source\"\u003eSource Information\u003c\/h2\u003e\n\n\u003cp\u003e\u003cstrong\u003eOriginal article title:\u003c\/strong\u003e Approaches to Catheter Ablation for Persistent Atrial Fibrillation\u003c\/p\u003e\n\n\u003cp\u003e\u003cstrong\u003eAuthors:\u003c\/strong\u003e Atul Verma, M.D., Chen-yang Jiang, M.D., Timothy R. Betts, M.D., M.B., Ch.B., Jian Chen, M.D., Isabel Deisenhofer, M.D., Roberto Mantovan, M.D., Ph.D., Laurent Macle, M.D., Carlos A. Morillo, M.D., Wilhelm Haverkamp, M.D., Ph.D., Rukshen Weerasooriya, M.D., Jean-Paul Albenque, M.D., Stefano Nardi, M.D., Endrj Menardi, M.D., Paul Novak, M.D., and Prashanthan Sanders, M.B., B.S., Ph.D., for the STAR AF II Investigators\u003c\/p\u003e\n\n\u003cp\u003e\u003cstrong\u003eJournal:\u003c\/strong\u003e The New England Journal of Medicine, 2015;372:1812-22. Published May 7, 2015.\u003c\/p\u003e\n\n\u003cp\u003e\u003cstrong\u003eDOI:\u003c\/strong\u003e 10.1056\/NEJMoa1408288\u003c\/p\u003e\n\n\u003cp\u003e\u003cstrong\u003eTrial registration:\u003c\/strong\u003e ClinicalTrials.gov number, NCT01203748\u003c\/p\u003e\n\n\u003cp\u003e\u003cstrong\u003eFunding:\u003c\/strong\u003e St. Jude Medical\u003c\/p\u003e\n\n\u003cp\u003eThis patient-friendly article is based on peer-reviewed research. It is intended for educational purposes and should not replace individualized advice from your healthcare provider.\u003c\/p\u003e","brand":"DiagnosticDetectives.Com","offers":[{"title":"Default Title","offer_id":47439667167388,"sku":null,"price":0.0,"currency_code":"CHF","in_stock":true}],"url":"https:\/\/diagnosticdetectives.ch\/it\/products\/catheter-ablation-for-persistent-atrial-fibrillation-what-the-star-af-ii-trial-means-for-patients","provider":"DiagnosticDetectives.Com","version":"1.0","type":"link"}