Visit-to-Visit Heart Rate Variability in the Prediction of Clinical Outcomes of Patients with Atrial Fibrillation.

BACKGROUND: Visit-to-visit heart rate variability (VVV-HR) has been associated with adverse cardiovascular outcomes. We aimed to determine the predictive value of VVV-HR for adverse clinical outcomes in patients with nonvalvular atrial fibrillation (AF). METHODS: We used data from a prospective multicenter AF registry of 27 hospitals in Thailand during 2014 to 2017. After the baseline visit, patients were followed up every 6 months until 3 years. VVV-HR was calculated from the standard deviation of heart rate data from baseline visit and every follow-up visit. VVV-HR was categorized into four groups according to the quartiles. Clinical outcomes were all-cause death, ischemic stroke/systemic embolism (SE), and heart failure. Cox proportional hazard models were used for multivariable analysis. RESULTS: There were a total of 3,174 patients (mean age: 67.7 years; 41.8% female). The incidence rates of all-cause death, ischemic stroke/SE, and heart failure were 3.10 (2.74-3.49), 1.42 (1.18-1.69), and 2.09 (1.80-2.42) per 100 person-years respectively. The average heart rate was 77.8 ± 11.0 bpm and the average of standard deviation of heart rate was 11.0 ± 5.9 bpm. VVV-HR Q4 was an independent predictor of all-cause death, ischemic stroke/SE, and heart failure with adjusted hazard ratios of 1.45 (95% confidence interval: 1.07-1.98), 2.02 (1.24-3.29), and 2.63 (1.75-3.96), respectively. VVV-HR still remained a significant predictor of clinical outcomes when analyzed based on coefficient of variation and variability independent of mean. CONCLUSION: VVV-HR is an independent predictor for adverse clinical outcomes in patients with AF. A J-curve appearance was demonstrated for the effect of VVV-HR on all-cause death.

SAMe-TT2R2 score for prediction of suboptimal time in therapeutic range in a Thai population with atrial fibrillation.

INTRODUCTION: International normalised ratio (INR) control is an important factor in patients with non-valvular atrial fibrillation (NVAF) being treated with warfarin. INR control was previously reported to be poorer among Asians compared to Westerners. We aimed to validate the SAMe-TT2R2 score for prediction of suboptimal INR control (defined as time in therapeutic range [TTR] < 65% in the Thai population) and to investigate TTR among Thai NVAF patients being treated with warfarin. METHODS: INR data from patients enrolled in a multicentre NVAF registry was analysed. Clinical and laboratory data was prospectively collected. TTR was calculated using the Rosendaal method. Baseline data was compared between patients with and without suboptimal INR control. Univariate and multivariate analyses were performed to identify variables independently associated with suboptimal INR control. RESULTS: A total of 1,669 patients from 22 centres located across Thailand were included. The average age was 69.1 ± 10.7 years, and 921 (55.2%) were male. The mean TTR was 50.5% ± 27.5%; 1,125 (67.4%) had TTR < 65%. Univariate analysis showed hypertension, diabetes mellitus, heart failure, renal disease and SAMe-TT2R2 score to be significantly different between patients with and without optimal TTR. The SAMe-TT2R2 score was the only factor that remained statistically significant in multivariate analysis. The C-statistic for the SAMe-TT2R2 score in the prediction of suboptimal TTR was 0.54. CONCLUSION: SAMe-TT2R2 score was the only independent predictor of suboptimal TTR in NVAF patients being treated with warfarin. However, due to the low C-statistic, the score may have limited discriminative power.

Molecular investigation by whole exome sequencing revealed a high proportion of pathogenic variants among Thai victims of sudden unexpected death syndrome.

INTRODUCTION: Sudden unexpected death syndrome (SUDS) is an important cause of death in young healthy adults with a high incident rate in Southeast Asia; however, there are no molecular autopsy reports about these victims. We performed a combination of both a detailed autopsy and a molecular autopsy by whole exome sequencing (WES) to investigate the cause of SUDS in Thai sudden death victims. MATERIALS AND METHODS: A detailed forensic autopsy was performed to identify the cause of death, followed by a molecular autopsy, in 42 sudden death victims who died between January 2015 and August 2015. The coding sequences of 98 SUDS-related genes were sequenced using WES. Potentially causative variants were filtered based on the variant functions annotated in the dbNSFP database. Variants with inconclusive clinical significance evidence in ClinVar were resolved with a variant prediction algorithm, metaSVM, and the frequency data of the variants found in public databases, such as the 1000 Genome Project, ESP6500 project, and the Exome Aggregation Consortium (ExAc) project. RESULTS: Combining both autopsy and molecular autopsy enabled the potential identification of cause of death in 81% of the cases. Among the 25 victims with WES data, 72% (18/25) were found to have potentially causative SUDS mutations. The majority of the victims had at a mutation in the TTN gene (8/18 = 44%), and only one victim had an SCN5A mutation. CONCLUSIONS: WES can help to identify the genetic causes in victims of SUDS and may help to further guide investigations into their relatives to prevent additional SUDS victims.

Characteristics and Outcomes of Treatment for Non-ST-Segment Elevation Acute Coronary Syndrome: Results from a Single Center Registry.

BACKGROUND: Acute coronary syndrome (A CS) is a leading health burden worldwide. The Siriraj non-ST-segment elevation acute coronary syndrome (NST E-A CS) registry was established in 2012. Here, we report in-hospital outcomes and one-year outcomes from patients in the registry. OBJECTIVE: To investigate and report characteristics and outcomes of treatment for NSTE-ACS at one year from a single center MATERIAL AND METHOD: All patients admitted to Siriraj Hospital with diagnosis of NSTE-ACS were enrolled. Baseline demographic information, presenting signs and symptoms, electrocardiogram, and blood chemistry were recorded. In-hospital complications and outcomes of treatment were also collected and recorded. After being discharged from the hospital, patients were followed-up for one year. RESULTS: Two-hundred patients were evaluated between January 2012 and August 2013. A majority of patients (65.5%) presented with angina. Median TIMI risk score was 4. Thirty-two percent of patients had GR ACE risk score greater than 140. In-hospital mortality was 3.5% (95% CI 2.0-7.0). The most common complication was heart failure (36.5%). Three patients had CVA during admission. At one year the mortality rate was 5% (95% CI 3.0-9.0). Unplanned readmission rate was 9.5%. CONCLUSION: Most patients in the registry were high-risk ACS patients. In-hospital mortality and one-year mortality rates were 3.5% and 5%, respectively. Results from this study were comparable to results reported by previous studies from the Western world

Determining the Site of Accessory Pathways in Orthodromic Reciprocating Tachycardia by Using the Response to Right Ventricular Pacing.

BACKGROUND: Postpacing interval (PPI) after right ventricular (RV) pacing entrainment minus tachycardia cycle length (TCL) with a correction for atrioventricular (AV) node delay (corrected PPI-TCL) was useful to differentiate atrioventricular node reentrant tachycardia (AVNRT) from orthodromic reciprocating tachycardia (ORT). However, the value of corrected PPI-TCL in determining the site of the accessory pathway (AP) in ORT has not been investigated. The purpose of this study was to assess whether the corrected PPI-TCL is useful in differentiating ORT using a left-sided AP from a right-sided AP. METHODS: We studied 52 patients with ORT using a left-sided AP and 13 patients with a right-sided AP. The PPI was measured upon cessation of the RV pacing at a cycle length 10-40 ms shorter than the TCL. The corrected PPI-TCL was calculated from the subtraction of the increment in AV nodal conduction time of the first PPI from the PPI-TCL. RESULTS: The mean corrected PPI-TCL was 83 ± 20 ms in patients with ORT using a left-sided AP and 27 ± 19 ms in patients with a right-sided AP (P ≤ 0.001). All patients with ORT using a left-sided AP except three patients with left septal AP and none of the patients with ORT using a right-sided AP had a corrected PPI-TCL > 55 ms. CONCLUSIONS: The corrected PPI-TCL after the RV pacing entrainment is useful to guide differentiating ORT using a left-sided AP from a right-sided AP.

The quality of life in implantable cardioverter defibrillator patients.

BACKGROUND: Implantable cardioverter defibrillators (ICD) are effective for reducing mortality in patients at high risk for sudden cardiac death (SCD). The effects of the devices on psychological status and quality of life were poor especially in the patients who received ICD shocks. This study compared quality of life (QOL) in a group who received an ICD shock with a group who did not receive an ICD shock. MATERIAL AND METHOD: A prospective study enrolled patients with implantable cardioverter defibrillator who came for followup at Siriraj's device clinic between June and December 2010. These patients completed the Medical Outcomes Study Short Form-36 Questionnaire (SF-36) to assess QOL. RESULTS: There were 138 patients, 105 men and 33 women with a mean age of 59 completed the Medical Outcomes Study Short Form-36 Questionnaire. Sixty-seven (48.55%) patients received an ICD shock. Patients who received the shock had worse general health on the Short Form-36 Questionnaire compared with patients who had no shock (Mean 57.2 +/- 21 in shock group vs. 66.1 +/- 18 in non-shock group, p = 0.011). There was no statistically significant difference in mental health between two groups (p = 0.63). In shock group, there was no statistically significant difference in health status between appropriate, inappropriate, and appropriate-inappropriate shock groups. CONCLUSION: General health in patients who had ICD shock was significantly affected in a negative manner when compared to those who had no shock.

Recent onset atrial fibrillation: baseline data from Thai subset of RECORD AF study.

BACKGROUND: The RECORD AF study is the first worldwide, prospective, observational 1-year longitudinal survey of real-life management of patients with recently diagnosed atrial fibrillation (AF). The authors present here the baseline data of Thai subset of the study. MATERIAL AND METHOD: The study enrolled consecutive patients of age > or = 18 years, presenting with and treated for AF (< or = 1 year from diagnosis), visiting office- or hospital-based cardiologists. The main primary objectives were to assess therapeutic success and clinical outcomes in rhythm- and rate-control strategies. RESULTS: Of 209 patients recruited between July and December 2007, 200 were eligible for evaluation (mean age: 62.8 years, SD 12.4; 51% males). Hypertension (49%) and dyslipidemia (36%) were the most common underlying cardiovascular diseases (CVDs). Thirty-six point nine percent of patients were at high risk of stroke (CHADS, score > or = 2). In the previous year 93 (52%) patients were diagnosed with paroxysmal AF and 86 (48%) patients with persistent AF. Rate-control was the main treatment strategy used in 151 (75.50%) of the patients, and was more frequently used in persistent AF (94.20%) than paroxysmal AF (61.3%). The most frequent medication used for rhythm-control strategy was amiodarone (83.7%) and, for rate-control strategy, it was beta-blockers (57%). For antithrombotic medication, antiplatelet agents were used in 92 (46%) patients and oral anticoagulation in 86 (43%) patients. CONCLUSION: For Thai patients with AF, hypertension and dyslipidemia were the most common underlying CVDs, and rate control was the preferred treatment strategy. The prospective 1-year data will provide insights on current AF treatment strategies.

Optimal INR level in Thai atrial fibrillation patients who were receiving warfarin for stroke prevention in Thailand.

OBJECTIVE: To determine the optimal International Normalized Ratio (INR) level in Thai atrialfibrillation (AF) patients who received warfarin. MATERIAL AND METHOD: This retrospective study enrolled 230 AF patients that received warfarin in Siriraj Hospital between January 1, 2005 andDecember 31, 2009 and collected the INR level at the time of the event, the numbers of ischemic stroke, and bleeding events. The incidence density of ischemic stroke or bleeding events was calculated by dividing the number of ischemic stroke or bleeding event in each INR level with the summation of the time that each patient stayed in each INR group. The patients with a prosthetic valve were excluded. The INR range was classified into six groups (less than 1.5, 1.5 to 1.9, 2.0 to 2.4, 2.5 to 2.9, 3.0 to 3.4, and greater than 3.4). The optimal INR level was defined as the lowest incidence density of ischemic stroke and bleeding complications. RESULTS: Two hundred thirty AF patients (the mean age 68 ± 12 years) were enrolled, contributing to 737.54 patient-years of observation period. Of the 230 patients, nine patients experienced 12 ischemic events (1.6 per 100 patient-years) and 54 patients experienced 57 bleeding events (7.7 per 100 patient-years). The percentage of patient-time spent within INR 2 to 3, INR less than 2, and INR more than 3 were 40.75, 46.22, and 13.03%, respectively. The INR level more than 3.4 increased both major and minor bleeding events (p = 0.001). The INR level of 3.0 to 3.4 increased the minor bleeding events (p = 0.03). The INR level less than 1.5 increased incidence of ischemic stroke (p = 0.03). The overall event rate was lowest in the INR range from 1.5 to 2.9, which is significantly different from that of lNR more than 2.9 (p < 0.0001), but trend lower than INR less than 1.5 without being statistically significant (p = 0.198). CONCLUSION: An INR of 1.5-2.9 appeared to be associated with the lowest incidence rate of bleeding or ischemic stroke in a cohort of Thai AFpatients receiving warfarin therapy for stroke prevention.

The relationship between plasma NT-proBNP level and pacing mode in the patient with implanted permanent pacemaker.

BACKGROUND AND OBJECTIVE: Plasma BNP is current one of the prognostic markers for cardiovascular disease including congestive heart failure. The objective of the present study was to evaluate the level of plasma NT-proBNP in patients who have had permanent pacemaker implantation. MATERIAL AND METHOD: The clinical characteristics and the plasma NT-proBNP level were recorded and obtained from 284 patients with implanted permanent pacemaker followed-up at the Pacemaker Clinic, Siriraj Hospital. The factors associated with abnormal NT-proBNP level were analyzed. RESULTS: Among 284 patients who participated in the present study, 140 patients had NT-proBNP in normal range (level of < 300 pg/ml). 68 patients had NT-proBNP level between 300 to 900 pg/m/ and 76 patients had NT-proBNP level > 900 pg/ml. There were significant correlations between log NT-proBNP with patient's age, left ventricular ejection fraction and serum creatinine level with age and serum creatinine showing positive correlation and left ventricular ejection fraction having a negative correlation. From multiple regression analysis, three factors were associated with high NT-proBNP level: older age, serum creatinine level and ventricular based pacing. The patients with ventricular based pacing mode had higher NT-proBNP level than patients with atrial based pacing mode even after being adjusted for age and serum creatinine adjusted CONCLUSION: In the patient with permanent pacemaker three factors are associated with high NT-proBNP level. These are older age, serum creatinine level, and ventricular based pacemaker.

Comparison of the incidence of imidapril and enalapril induced cough.

BACKGROUND: Imidapril is an angiotensin converting enzyme (ACE) inhibitor without a sulfhydril group which has been shown from previous study to have low incidence of ACE inhibitor induced cough. OBJECTIVE: To compare the incidence of cough between two ACE inhibitors, imidapril and enalapril. MATERIAL AND METHOD: A comparative cross over study was performed in 119 patients with hypertension or left ventricular dysfunction. Patients were assigned to one of the two treatment groups, either a group receiving imidapril or enalapril for 4 weeks (Period I) and then these same groups were crossed over to receive either enalapril or imidapril for 4 weeks (Period II). The occurrence of cough during treatment was monitored by interviewing the patients. RESULTS: The incidence of cough was 44 % while on imidapril treatment and 66% while on enalapril treatment (p = 0.0014). The antihypertensive effects of two drugs were not different. CONCLUSION: The incidence of cough was significantly less under imidapril than under enalapril treatment, while there was no difference in the antihypertensive effects between the two ACE inhibitors.

Simultaneous use of implantable cardioverter-defibrillators and left ventricular assist devices in patients with severe heart failure.

More patients who are receiving therapy with a left ventricular assist device (LVAD) also have an implantable cardioverter-defibrillator (ICD). The aim of the present study was to describe the outcomes and device interactions of simultaneous therapy with an ICD and a LVAD. We evaluated 76 patients with class IV heart failure (age 52 + or - 12 years, left ventricular ejection fraction 0.13 + or - 0.05%, 88% men, 61% nonischemic cardiomyopathy) with both an ICD and a LVAD. The median follow-up with both devices was 156 days. A LVAD with a pulsatile and continuous flow pump was used in 53 (70%) and 23 (30%) patients, respectively. Of the 76 patients, 12 (16%) received a total of 54 ICD therapies. Of the ICD therapies, 88% were appropriate. Of the 76 patients, 55 (72%) underwent heart transplantation a median of 146 days after LVAD implantation. Twelve patients (16%) died during simultaneous ICD and LVAD therapy. Interactions between the LVAD and ICD occurred in 2 patients (2.7%) with continuous flow pumps (HeartMate II). In both cases, telemetry failure occurred after LVAD implantation with 2 different models of ICDs from the same manufacturer. No ICD therapies occurred because of device-related interactions. In conclusion, simultaneous ICD and LVAD therapy in patients with severe congestive heart failure is safe and clinically feasible. Interactions between the devices are uncommon and appear limited to specific models of ICDs.

A randomized assessment of the incremental role of ablation of complex fractionated atrial electrograms after antral pulmonary vein isolation for long-lasting persistent atrial fibrillation.

OBJECTIVES: This study sought to determine whether ablation of complex fractionated atrial electrograms (CFAEs) after antral pulmonary vein isolation (APVI) further improves the clinical outcome of APVI in patients with long-lasting persistent atrial fibrillation (AF). BACKGROUND: Ablation of CFAEs has been reported to eliminate persistent AF. However, residual pulmonary vein arrhythmogenicity is a common mechanism of recurrence. METHODS: In this randomized study, 119 consecutive patients (mean age 60 +/- 9 years) with long-lasting persistent AF underwent APVI with an irrigated-tip radiofrequency ablation catheter. Antral pulmonary vein isolation resulted in termination of AF in 19 of 119 patients (Group A, 16%). The remaining 100 patients who still were in AF were randomized to no further ablation and underwent cardioversion (Group B, n = 50) or to ablation of CFAEs in the left atrium or coronary sinus for up to 2 additional hours of procedure duration (Group C, n = 50). RESULTS: Atrial fibrillation terminated during ablation of CFAEs in 9 of 50 patients (18%) in Group C. At 10 +/- 3 months after a single ablation procedure, 18 of 50 (36%) in Group B and 17 of 50 (34%) in Group C were in sinus rhythm without antiarrhythmic drugs (p = 0.84). In Group A, 15 of 19 patients (79%) were in sinus rhythm. A repeat ablation procedure was performed in 34 of 100 randomized patients (for AF in 30 and atrial flutter in 4). At 9 +/- 4 months after the final procedure, 34 of 50 (68%) in Group B and 30 of 50 (60%) in Group C were in sinus rhythm without antiarrhythmic drugs (p = 0.40). CONCLUSIONS: Up to 2 h of additional ablation of CFAEs after APVI does not appear to improve clinical outcomes in patients with long-lasting persistent AF.

Relationship between the spectral characteristics of atrial fibrillation and atrial tachycardias that occur after catheter ablation of atrial fibrillation.

BACKGROUND: During catheter ablation of complex fractionated atrial electrograms, persistent atrial fibrillation (AF) may convert to an atrial tachycardia (AT). OBJECTIVE: The purpose of this study was to investigate the possible mechanisms of AT by examining the spectral and electrophysiologic characteristics of AF and ATs that occur after catheter ablation of AF. METHODS: The subjects of this study were 33 consecutive patients with persistent AF who had conversion of AF to AT during ablation of AF (group I) and 20 consecutive patients who underwent ablation of persistent AT that developed more than 1 month after AF ablation (group II). Spectral analysis of the coronary sinus (CS) electrograms and lead V(1) was performed during AF at baseline, before conversion, and during AT. The spatial relationship between the AT mechanism and ablation sites was examined. RESULTS: A spectral component with a frequency that matched the frequency of AT was present in the baseline periodogram of AF more often in group I (52%) than in group II (20%, P = .02). Ablation resulted in a decrease in the dominant frequency of AF but not in the frequency of the spectral component that matched the AT. There was a significant direct relationship between the baseline dominant frequency of AF and the frequency of AT in the CS in group I (r = 0.76, P <.0001) but not in group II (r = 0.38, P = .09). ATs were macroreentrant in 64% and 60% of patients in groups I and II, respectively (P = .8). The AT site was more likely to be distant (>1 cm) from AF ablation sites in group I (70%) than in group II (35%, P = .007). CONCLUSION: The findings of this study suggest that ATs observed during ablation of AF often may be drivers of AF that become manifest after elimination of higher-frequency sources and fibrillatory conduction.

High-output pacing in mapping of postinfarction ventricular tachycardia.

BACKGROUND: Pace mapping is used to identify critical areas for postinfarction ventricular tachycardia (VT). Unexcitable scar during pacing with standard output can identify borders of the reentry circuit. Unexcitable scar is not thought to contain surviving muscle fibers critical to the circuit. Due to current-to-load mismatch or a deep seated isthmus, higher power might be required in order to obtain capture. OBJECTIVE: The purpose of this study was to evaluate the value of high-output pacing in patients with postinfarction VT. METHODS: In a consecutive series of 18 patients (15 men, age 62 +/- 9, EF 0.29 +/- 0.15) with postinfarction VT, a voltage map was obtained and bipolar pace mapping was performed in areas with low voltage (<1.5 mV) at an output of 10 mA and 2 ms pulse width (PW). High-output capture was defined as capture that failed at these settings but succeeded at higher pacing output. The pacing output was increased to 20 mA at 2 ms, and the PW was increased to 10 ms as required to achieve capture. RESULTS: Seventy-seven VTs were induced. Thirty-nine isthmus sites were identified. Focal areas with high-output capture were observed in 12/18 patients (output: 20 mA; mean PW: 7.3 +/- 3.5 ms). In 9/18 patients, this area was critical for the reentry circuit of 10 clinical VTs (23% of isthmus sites). In one third of patients, isthmus sites were identified only by high-output pacing. CONCLUSION: High-output pacing can be helpful in identifying critical areas of postinfarction VT that otherwise may be missed.

Prevalence and characteristics of continuous electrical activity in patients with paroxysmal and persistent atrial fibrillation.

BACKGROUND: Complex fractionated atrial electrograms (CFAEs) may play a role in the genesis of atrial fibrillation (AF). One type of CFAE is continuous electrical activity (CEA). The prevalence and characteristics of CEA in patients with paroxysmal and persistent AF are unclear. METHODS AND RESULTS: In 44 patients (age = 59 +/- 8 years) with paroxysmal (25) or persistent (19) AF, bipolar electrograms were systematically recorded for > or =5 seconds at 24 left atrial (LA) sites, including 8 antral sites, and 2 sites within the coronary sinus (CS). CEA was defined as continuous depolarization for >1 second with no isoelectric interval. CEA was recorded at the LA septum (79%), antrum (66%), posterior (68%) and anterior walls (67%), roof (66%), base of the LA appendage (61%), inferior wall (61%), posterior mitral annulus (48%), CS (41%), and in the LA appendage (14%). Antral CEA was equally prevalent in patients with paroxysmal (63%) and persistent AF (70%, P = 0.12). In patients with paroxysmal AF, the prevalence of CEA was similar among antral and nonantral LA sites, except for the LA appendage. However, in patients with persistent AF, CEA was more prevalent at the nonantral (80%) than antral sites (70%, P = 0.03). CEA at nonantral sites except the CS was more prevalent in persistent than in paroxysmal AF (80% vs 57%, P < 0.001). The mean duration of intermittent episodes of CEA was longer in persistent than in paroxysmal AF (P < 0.001). CONCLUSIONS: The higher prevalence and duration of CEA at nonantral sites in persistent than in paroxysmal AF is consistent with a greater contribution of LA reentrant mechanisms in persistent AF. However, the high prevalence of CEA at nonantral sites in paroxysmal atrial fibrillation (PAF) suggests that CEA alone is a nonspecific marker of appropriate target sites for ablation of AF. The characteristics of CEA that most accurately identify drivers of AF remain to be determined.

Body mass index, obstructive sleep apnea, and outcomes of catheter ablation of atrial fibrillation.

BACKGROUND: Obesity and obstructive sleep apnea (OSA) are associated with atrial fibrillation (AF). The effects of a large body mass index (BMI) and OSA on the results of radiofrequency catheter ablation (RFA) of AF are unclear. OBJECTIVE: To evaluate the effect of BMI and OSA on the efficacy of RFA for AF. METHODS: RFA was performed in 324 consecutive patients (mean age = 57 +/- 11 years) with paroxysmal (234) or chronic (90) AF. OSA was diagnosed by polysomnography in 32 of 324 patients (10%) prior to ablation. Among the 324 patients, 18% had a normal BMI (<25 kg/m(2)), 39% were overweight (BMI >/= 25 kg/m(2) and <30 kg/m(2)), and 43% were obese (>or=30 kg/m(2)). RFA was performed to eliminate complex fractionated atrial electrograms (CFAE) in the pulmonary vein antrum and left atrium. RESULTS: At 7 +/- 4 months after a single ablation procedure, 63% of patients without OSA and 41% with OSA were free from recurrent AF without antiarrhythmic drug therapy (P = 0.02). Multivariate analysis including variables of age, gender, type and duration of AF, OSA, BMI, left atrial size, ejection fraction, and hypertension demonstrated that OSA was the strongest predictor of recurrent AF (OR = 3.04, 95% CI: 1.11-8.32, P = 0.03). There was no association between BMI and freedom from recurrent AF. A serious complication occurred in 3 of 324 patients, with no relationship to BMI. CONCLUSIONS: OSA is a predictor of recurrent AF after RFA independent of its association with BMI and left atrial size. Obesity does not appear to affect outcomes after radiofrequency catheter ablation of AF.

Randomized evaluation of right atrial ablation after left atrial ablation of complex fractionated atrial electrograms for long-lasting persistent atrial fibrillation.

BACKGROUND: With electrogram-guided radiofrequency ablation (RFA) of long-lasting persistent atrial fibrillation (AF), the best results have been reported when complex fractionated electrograms (CFAEs) in both the left (LA) and right (RA) atria were targeted. However, many studies have reported excellent outcomes from RFA of long-lasting persistent AF with the use of other ablation strategies that were limited to the LA. The incremental value of RFA of RA CFAEs is yet to be defined. METHODS AND RESULTS: In 85 patients with long-lasting persistent AF (age=59+/-10 years), RFA was directed at CFAEs in the LA and coronary sinus until AF terminated (19) or all identified LA CFAEs were eliminated. Sixty-six patients who remained in AF were randomly assigned to cardioversion and no further RFA (n=33) or to RFA of RA CFAEs (n=33). RA sites consisted of the crista terminalis (69%), septum (38%), superior vena cava (28%), coronary sinus ostium (22%), and the base of the appendage (31%). AF terminated in 1 (3%) of 33 patients during RA RFA. At 17+/-6 months after a single ablation procedure, 74% of the patients in whom AF terminated during LA RFA were in sinus rhythm. Rates of freedom from AF were similar in the patients randomized to no RFA in the RA (24%) and those randomized to RFA of RA CFAEs (30%, P=0.8). The ablation procedure was repeated in 26 patients (31%) for AF (n=22) or atrial flutter (n=4). At 16+/-7 months after the final procedure, 89% of the patients in whom AF terminated during LA RFA were in sinus rhythm. Among the randomized patients, the proportion of patients who remained in sinus rhythm was similar in patients who did not undergo RFA of RA CFAEs (52%) and those who did (58%, P=0.6). CONCLUSIONS: After RFA of CFAEs in the LA and coronary sinus, ablation of CFAEs in the RA provides little or no increment in efficacy among patients with long-lasting persistent AF.