Monahan, Kristi H.

Background: The frequency of pulmonary vein stenosis (PVS) after ablation for atrial fibrillation has decreased, but it remains a highly morbid condition. Although treatment strategies including pulmonary vein dilation and stenting have been described, the long-term impacts of these interventions are unknown. We evaluated the presentation of severe PVS, and examined the risk for restenosis after intervention using either balloon angioplasty (BA) alone or BA with stenting. Methods: This was a prospective, observational study of 124 patients with severe PVS evaluated between 2000 and 2014. Results: All 124 patients were identified as having severe PVS by computed tomography in 219 veins. One hundred two patients (82%) were symptomatic at diagnosis. The most common symptoms were dyspnea (67%), cough (45%), fatigue (45%), and decreased exercise tolerance (45%). Twenty-seven percent of patients experienced hemoptysis. Ninety-two veins were treated with BA, 86 were treated with stenting, and 41 veins were not treated. A 94% acute procedural success rate was observed and did not differ by initial management. Major procedural complications occurred in 4 of the 113 patients (3.5%) who underwent invasive assessment, and minor complications occurred in 15 patients (13.3%). Overall, 42% of veins developed restenosis including 27% of veins (n=23) treated with stenting and 57% of veins (n=52) treated with BA. The 3-year overall rate of restenosis was 37%, with 49% of BA-treated veins and 25% of stented veins developing restenosis (hazard ratio, 2.77; 95% confidence interval, 1.72–4.45; P <0.001). After adjustment for age, CHA2DS2-VASc score, hypertension, and the time period of the study, there was still a significant difference in the risk of restenosis for BA versus stenting (hazard ratio, 2.46; 95% confidence interval, 1.47–4.12; P <0.001). Conclusions: The diagnosis of PVS is challenging because of nonspecific symptoms and the need for dedicated pulmonary vein imaging. There is no difference in acute success by type of initial intervention; however, stenting significantly reduces the risk of subsequent pulmonary vein restenosis in comparison with BA.

Background The mechanisms of atrial fibrillation (AF) are highly divergent. The prevalence of AF increases significantly with age, and underling mechanisms might vary with age. Endothelial dysfunction may be associated with AF and atrial arrhythmia recurrence after catheter ablation. We tested the hypothesis that the impact of endothelial dysfunction on arrhythmia recurrence following catheter ablation is age dependent. Methods and Results This study enrolled 92 participants with AF undergoing catheter ablation. Endothelial function was assessed by peripheral arterial tonometry before ablation, and the natural logarithmic transformation of reactive hyperemia index was calculated. Endothelial dysfunction was defined as a natural logarithmic transformation of reactive hyperemia index <0.618 (median). Participants were followed for atrial tachycardia, flutter, and fibrillation recurrence for a median of 14 months. The mean age was 57±10 years. There was significant interaction between age and endothelial dysfunction in association with recurrence of AF ( P =0.029) and any atrial arrhythmia ( P =0.015), and the risk associated with endothelial dysfunction for arrhythmia recurrence was higher in younger versus older participants. Participants were divided into 2 age groups at a threshold of 60 years. Among participants aged ≤60 years, multivariate Cox proportional hazards analysis revealed the independent association between endothelial dysfunction and increased risk of arrhythmia recurrence (hazard ratio for AF 4.18 [95% CI 1.33–15.82], P =0.014, and for any atrial arrhythmia 3.62 [95% CI 1.29–11.81], P =0.014). Kaplan–Meier analysis showed that participants with endothelial dysfunction had significantly higher rates of recurrence of AF ( P =0.01) and any atrial arrhythmia ( P =0.002). Conclusions The risk associated with endothelial dysfunction for arrhythmia recurrence following catheter ablation was age dependent and was higher in younger participants.

BACKGROUND The implications of hypotension occurring during dobutamine stress echocardiography have not been elucidated. We observed in some patients that hyperdynamic left ventricular function developed during dobutamine stress echocardiography and hypothesized that intracavitary obstruction was occurring and might account for hypotension in some patients. METHODS AND RESULTS Fifty-seven consecutive patients undergoing dobutamine stress echocardiography underwent pulsed-wave and continuous-wave Doppler examination of the left ventricular cavity at rest and at peak dobutamine infusion. The development of an intraventricular gradient with dobutamine stress was defined as a late-peaking left ventricular Doppler velocity profile that exceeded basal velocity by at least 1 m/sec. During dobutamine stress testing, left ventricular outflow velocity or intracavitary velocity increased in all patients. Obstruction occurred in 12 patients (21%, group 1). Group 2 was the remaining 45 patients. Peak velocities in group 1 ranged from 2.0 to 5.0 m/sec (mean, 3.5 m/sec), and the mean increase from velocity at rest was 2.3 m/sec. The mean change in systolic blood pressure was significantly lower in patients in group 1 (-15 versus 4 mm Hg, p = 0.02). When the 18 patients with an ischemic response to stress testing (evidenced by new or worsening wall motion abnormalities) were excluded from analysis, systolic blood pressure response was still significantly different for the two groups (-19 versus 2 mm Hg, p = 0.03). CONCLUSIONS Dynamic left ventricular obstruction is a new observation; it may develop frequently in patients undergoing dobutamine stress echocardiography. Obstruction rather than ischemia may explain a decrease in blood pressure during dobutamine stress echocardiography.

Background— The efficacy of radiofrequency ablation for atrial fibrillation (AF) in patients with left ventricular (LV) systolic dysfunction and isolated diastolic dysfunction is uncertain. Methods and Results— A prospective cohort of patients with normal and abnormal LV function underwent ablation for antiarrhythmic drug (AAD)-refractory AF. Three groups were compared: 111 patients with systolic dysfunction, defined as LV ejection fraction (LVEF) ≤40%; 157 patients with isolated diastolic dysfunction but preserved LVEF ≥50%; and 100 patients with normal LV function. The primary end point was AAD-free AF elimination at 1 year after ablation. This end point was achieved in 62% of patients with systolic dysfunction, 75% of those with diastolic dysfunction, and 84% of controls ( P =0.007). AF control on or off AADs was achieved in 76% of patients with systolic dysfunction, 85% of those with diastolic dysfunction, and 89% of controls ( P =0.08). In the systolic dysfunction group, 49% experienced an increase in LVEF by ≥5% after ablation, of which 64% achieved normal LVEF. In the diastolic dysfunction group, 30% of patients demonstrated at least 1 grade improvement in diastolic dysfunction. Multivariable analysis demonstrated an increased relative risk of arrhythmia recurrence of 1.8 (95% CI, 1.1 to 3.1; P =0.02) in systolic dysfunction and 1.7 (1.0 to 2.7; P =0.04) in isolated diastolic dysfunction compared with normal function. Conclusions— Although an ablative approach for AF in patients with systolic or diastolic dysfunction is associated with an increased long-term recurrence risk, there is potential for substantial quality-of-life improvement and LV functional benefit.

Background— Obesity is a risk factor for atrial fibrillation and other cardiovascular conditions. Our objective was to determine whether catheter-based ablation effectively treated atrial fibrillation in obese patients. Methods and Results— Five hundred twenty-three consecutive patients with symptomatic, medication-refractory atrial fibrillation underwent catheter ablation. Patients were grouped by body mass index (lean, <25 kg/m 2 ; overweight, 25 to 29.9 kg/m 2 ; obese, ≥30 kg/m 2 ). Outcome and quality of life were measured with a general health survey (Medical Outcomes Study 36-item Short-Form General Health Survey [SF-36]); patients were assessed before ablation and at 3 and 12 months after the procedure. Two hundred twenty-eight study patients (44%) were overweight, and 201 (38%) were obese. Twelve months after curative ablation, 72% of patients were free of atrial fibrillation without the use of antiarrhythmic agents; 84% were arrhythmia free when those receiving medication were included. Atrial fibrillation was eliminated in 75%, 72%, and 70% of the lean, overweight, and obese patients, respectively, at 12 months ( P =0.41, trend test). SF-36 scores were lower for patients with higher body mass index ( P <0.05) at baseline. SF-36 scores improved in every functional domain for all body mass index groups after ablation. The mean SF-36 total physical score increased from 59±20 at baseline to 77±19 in 12 months ( P <0.001). The total mental health score improved from 66±18 to 79±16 in 12 months ( P <0.001). Conclusions— Catheter ablation of atrial fibrillation was effective in obese patients. Coexistence of atrial fibrillation and obesity indicated lower SF-36 scores, but the improvement in quality of life was consistent across all body mass index categories.

Background— Although segmental or circumferential ablation is effective in eliminating pulmonary vein (PV)–mediated atrial fibrillation (AF), this procedure may be complicated by the occurrence of PV stenosis. Methods and Results— To establish the clinical presentation, diagnostic manifestations, and interventional management of PV stenosis, 23 patients with stenosis of 34 veins complicating ablation of AF were evaluated. Each patient became symptomatic 103±100 days after undergoing ablation. In 8 veins, the ablation producing the PV stenosis was a repeated procedure for continued AF. Nineteen patients presented with dyspnea on exertion, 7 with dyspnea at rest, 9 with cough, and 6 with chest pain. On multirow spiral computed tomography examination, the narrowest lumen of the affected PVs measured 3±2 mm compared with 13±3 mm at baseline ( P ≤0.001). The relative perfusion of affected lung segments on isotope scans was reduced to 4±3% of total perfusion compared with 22±10% in unaffected segments. At percutaneous intervention, these veins showed 80±13% stenosis, with a mean gradient of 12±5 mm Hg. This was significantly reduced to a residual stenosis of 9±8% ( P ≤0.001) and a residual gradient of 3±4 mm Hg ( P ≤0.001). Twenty veins were treated with balloon dilatation alone, whereas 14 veins were stented with standard 10-mm-diameter bare-metal stents. Although the symptomatic response was nearly immediate and impressive, 14 patients developed in-stent or in-segment restenosis, requiring repeated interventions in 13. Conclusions— Percutaneous intervention produces rapid and dramatic symptom relief in patients with highly symptomatic PV stenosis after radiofrequency ablation for AF. Nevertheless, alternative treatment methods will be required to decrease recurrent in-stent or in-segment restenosis.