Ayman A. Hussein

Radiofrequency ablation of atrial fibrillation under therapeutic international normalized ratio: A safe and efficacious periprocedural anticoagulation strategy

BACKGROUND The best periprocedural anticoagulation strategy at the time of pulmonary vein isolation (PVI) is not known. Most centers stop administering warfarin (Coumadin) and use bridging with heparin or enoxaparin. OBJECTIVE The purpose of this study was to evaluate the efficacy and safety of PVI under therapeutic international normalized ratio (INR). METHODS Between January 2005 and December 2008, PVI was performed in 3,052 patients with therapeutic INR (> or =1.8) at the time of ablation. All patients were evaluated for ischemic strokes and bleeding complications. RESULTS Mean INR was 2.53 +/- 0.62. Only 3 (0.098%) patients had ischemic strokes. One patient had a hemorrhagic stroke on the third day postablation but recovered completely by 1-week follow-up. Bleeding complications occurred in 34 (1.11%) patients; most were minor (0.79%). Major hemorrhagic complications occurred in 10 (0.33%) patients (tamponade in 5, hematomas requiring intervention in 2, transfusion necessary in 3). CONCLUSION In a large patient population, continuation of Coumadin at a therapeutic INR at the time of PVI without use of heparin or enoxaparin for bridging is a safe and efficacious periprocedural anticoagulation strategy. It is an acceptable and potentially better alternative to strategies that use bridging with heparin or enoxaparin.

Use of dabigatran for periprocedural anticoagulation in patients undergoing catheter ablation for atrial fibrillation

Background—Pulmonary vein isolation (PVI) for atrial fibrillation is associated with a transient increased risk of thromboembolic and hemorrhagic events. We hypothesized that dabigatran can be safely used as an alternative to continuous warfarin for the periprocedural anticoagulation in PVI. Methods and Results—A total of 999 consecutive patients undergoing PVI were included; 376 patients were on dabigatran (150 mg), and 623 patients were on warfarin with therapeutic international normalized ratio. Dabigatran was held 1 to 2 doses before PVI and restarted at the conclusion of the procedure or as soon as patients were transferred to the nursing floor. Propensity score matching was applied to generate a cohort of 344 patients in each group with balanced baseline data. Total hemorrhagic and thromboembolic complications were similar in both groups, before (3.2% versus 3.9%; P=0.59) and after (3.2% versus 4.1%; P=0.53) matching. Major hemorrhage occurred in 1.1% versus 1.6% (P=0.48) before and 1.2% versus 1.5% (P=0.74) after matching in the dabigatran versus warfarin group, respectively. A single thromboembolic event occurred in each of the dabigatran and warfarin groups. Despite higher doses of intraprocedural heparin, the mean activated clotting time was significantly lower in patients who held dabigatran for 1 or 2 doses than those on warfarin. Conclusions—Our study found no evidence to suggest a higher risk of thromboembolic or hemorrhagic complications with use of dabigatran for periprocedural anticoagulation in patients undergoing PVI compared with uninterrupted warfarin therapy.

Natural History and Long-Term Outcomes of Ablated Atrial Fibrillation

Background—Atrial fibrillation (AF) ablation is increasingly used in clinical practice. We aimed to study the natural history and long-term outcomes of ablated AF. Methods and Results—We followed 831 patients after pulmonary vein isolation (PVI) performed in 2005. We documented clinical outcomes using our prospective AF registry with most recent update on this group of patients in October 2009. In the first year after ablation, 23.8% had early recurrence. Over long-term follow-up (55 months), only 8.9% had late arrhythmia recurrence defined as occurring beyond the first year after ablation. Repeat ablations in patients with late recurrence revealed conduction recovery in at least 1 of the previously isolated PVs in all of them and right-sided triggers with isoproterenol testing in 55.6%. At last follow-up, clinical improvement was 89.9% (79.4% arrhythmia-free off antiarrhythmic drugs and 10.5% with AF controlled with antiarrhythmic drugs). Only 4.6% continued to have drug-resistant AF. It was possible to safely discontinue anticoagulation in a substantial proportion of patients with no recurrence in the year after ablation (CHADS score ⩽2, stroke incidence of 0.06% per year). The procedure-related complication rate was very low. Conclusions—Pulmonary vein isolation is safe and efficacious for long-term maintenance of sinus rhythm and control of symptoms in patients with drug-resistant AF. It obviates the need for antiarrhythmic drugs, negative dromotropic agents, and anticoagulants in a substantial proportion of patients.

Plasma B-Type Natriuretic Peptide Levels and Recurrent Arrhythmia After Successful Ablation of Lone Atrial Fibrillation

Background— Plasma B-type natriuretic peptide (BNP) is abnormally elevated in patients with lone atrial fibrillation (AF). The exact significance and prognostic implications of this elevation have yet to be determined. Little is known about BNP in lone AF patients undergoing arrhythmia ablation. We sought to determine the relationship between BNP levels and the risk of recurrent arrhythmia after ablation of lone AF. Methods and Results— We followed up 726 patients with lone AF undergoing first-time arrhythmia ablation. All had BNP levels measured on the day of ablation with of the point-of-care Triage Meter assay (Biosite Diagnostics, San Diego, CA). At baseline, factors associated with elevated BNP levels in multivariable linear regression analysis (with log BNP being the dependent variable) were older age (&bgr; regression coefficient for +1-year change, 0.025; P<0.0001), longer duration of AF (&bgr; for +1-year change, 0.031; P=0.01), nonparoxysmal AF (versus paroxysmal; &bgr;, 0.52; P<0.0001), and larger left atrial size (&bgr; for +1-cm2 change, 0.040; P<0.0001). The BNP levels were strongly associated with arrhythmia recurrence in univariate- (hazard ratio for +1-log-BNP change, 2.32; 95% confidence interval, 2.11 to 2.74; P<0.001) and covariate- (hazard ratio for +1-log-BNP change, 2.13; 95% confidence interval, 2.06 to 2.38; P<0.001) adjusted Cox proportional hazards analysis. The covariate-adjusted hazard ratios for recurrent arrhythmia were 1.6, 2.7, 4.3, and 5.7 for the second, third, fourth, and fifth quintiles, respectively, compared with patients in the lowest quintile (P for trend across quintiles <0.001). Conclusions— B-type natriuretic peptide levels correlate with AF burden (chronicity, altered hemodynamics, and anatomic remodeling) in patients with lone AF and are strong predictors of recurrent arrhythmia after ablation. Elevated BNP levels may reflect increased cardiac chamber wall stress and/or intrinsic atrial disease, thus increasing the risk of arrhythmia recurrence.

Peripheral Arterial Disease and Progression of Coronary Atherosclerosis

OBJECTIVES The purpose of this analysis was to characterize the progression of coronary atherosclerosis in patients with concomitant peripheral arterial disease (PAD). BACKGROUND Peripheral arterial disease is associated with adverse cardiovascular outcomes. The impact of concomitant PAD on coronary atherosclerosis progression in patients with coronary artery disease has not been well established. METHODS The burden and progression of coronary atherosclerosis was investigated in 3,479 patients with coronary artery disease with (n = 216) and without (n = 3,263) concomitant PAD who participated in 7 clinical trials that employed serial intravascular ultrasound imaging. RESULTS Patients with PAD had a greater percent atheroma volume (40.4 ± 9.2% vs. 38.5 ± 9.1%, p = 0.002) and percentage of images containing calcium (35.1 ± 26.2% vs. 29.6 ± 24.2%, p = 0.002), in association with smaller lumen volume (275.7 ± 101.6 mm(3) vs. 301.4 ± 110.3 mm(3), p < 0.001) and vessel wall volume (467.7 ± 166.8 mm(3) vs. 492.9 ± 169.8 mm(3), p = 0.01). On serial evaluation, patients with PAD demonstrated greater progression of percent atheroma volume (+0.58 ± 0.38 vs. +0.23 ± 0.3%, p = 0.009) and total atheroma volume (-0.17 ± 2.69 mm(3) vs. -2.05 ± 2.15 mm(3), p = 0.03) and experienced more cardiovascular events (26.3% vs. 19.8%, p = 0.03). In patients with PAD and without PAD, respectively, achieving levels of low-density lipoprotein cholesterol <70 mg/dl was associated with less progression of percent atheroma volume (+0.16 ± 0.27% vs. +0.76 ± 0.20%, p = 0.04; and +0.05 ± 0.14% vs. +0.29 ± 0.13%, p < 0.001) and total atheroma volume (-3.0 ± 1.9 mm(3) vs. +1.0 ± 1.4 mm(3), p = 0.04; and -3.3 ± 1.1 mm(3) vs. -1.6 ± 1.0 mm(3), p < 0.001). CONCLUSIONS Patients with concomitant PAD harbor more extensive and calcified coronary atherosclerosis, constrictive arterial remodeling, and greater disease progression. These changes are likely to contribute to adverse cardiovascular outcomes. The benefit for all patients achieving low levels of low-density lipoprotein cholesterol supports the need for intensive lipid lowering in patients with PAD.

2017 HRS expert consensus statement on cardiovascular implantable electronic device lead management and extraction

Fred M. Kusumoto, MD, FHRS, FACC, Chair, Mark H. Schoenfeld, MD, FHRS, FACC, FAHA, CCDS, Vice-Chair, Bruce L. Wilkoff, MD, FHRS, CCDS, Vice-Chair, Charles I. Berul, MD, FHRS, Ulrika M. Birgersdotter-Green, MD, FHRS, Roger Carrillo, MD, MBA, FHRS, Yong-Mei Cha, MD, Jude Clancy, MD, Jean-Claude Deharo, MD, FESC, Kenneth A. Ellenbogen, MD, FHRS, Derek Exner, MD, MPH, FHRS, Ayman A. Hussein, MD, FACC, Charles Kennergren, MD, PhD, FETCS, FHRS, Andrew Krahn, MD, FRCPC, FHRS, Richard Lee, MD, MBA, Charles J. Love, MD, CCDS, FHRS, FACC, FAHA, Ruth A. Madden, MPH, RN, Hector Alfredo Mazzetti, MD, JoEllyn Carol Moore, MD, FACC, Jeffrey Parsonnet, MD, Kristen K. Patton, MD, Marc A. Rozner, PhD, MD, CCDS, Kimberly A. Selzman, MD, MPH, FHRS, FACC, Morio Shoda, MD, PhD, Komandoor Srivathsan, MD, Neil F. Strathmore, MBBS, FHRS, Charles D. Swerdlow, MD, FHRS, Christine Tompkins, MD, Oussama Wazni, MD, MBA

Cardiomyocyte Injury Assessed by a Highly Sensitive Troponin Assay and Sudden Cardiac Death in the Community: The Cardiovascular Health Study

OBJECTIVES This study sought to determine the association between markers of cardiomyocyte injury in ambulatory subjects and sudden cardiac death (SCD). BACKGROUND The pathophysiology of SCD is complex but is believed to be associated with an abnormal cardiac substrate in most cases. The association between biomarkers of cardiomyocyte injury in ambulatory subjects and SCD has not been investigated. METHODS Levels of cardiac troponin T, a biomarker of cardiomyocyte injury, were measured by a highly sensitive assay (hsTnT) in 4,431 ambulatory participants in the Cardiovascular Health Study, a longitudinal community-based prospective cohort study. Serial measures were obtained in 3,089 subjects. All deaths, including SCD, were adjudicated by a central events committee. RESULTS Over a median follow-up of 13.1 years, 246 participants had SCD. Baseline levels of hsTnT were significantly associated with SCD (hazard ratio [HR] for +1 log(hsTnT): 2.04, 95% confidence interval [CI]: 1.78 to 2.34]. This association persisted in covariate-adjusted Cox analyses accounting for baseline risk factors (HR: 1.30, 95% CI: 1.05 to 1.62), as well as for incident heart failure and myocardial infarction (HR: 1.26, 95% CI: 1.01 to 1.57). The population was also categorized into 3 groups based on baseline hsTnT levels and SCD risk [fully adjusted HR: 1.89 vs. 1.55 vs. 1 (reference group) for hsTnT ≥12.10 vs. 5.01 to 12.09 vs. ≤ 5.00 pg/ml, respectively; p trend = 0.005]. On serial measurements, change in hsTnT levels was also associated with SCD risk (fully adjusted HR for +1 pg/ml per year increase from baseline: 1.03, 95% CI: 1.01 to 1.06). CONCLUSIONS The findings suggest an association between cardiomyocyte injury in ambulatory subjects and SCD risk beyond that of traditional risk factors.

Inflammation and sudden cardiac death in a community-based population of older adults: The Cardiovascular Health Study

BACKGROUND Inflammation is linked to adverse cardiovascular events, but its association with sudden cardiac death (SCD) has been controversial. Older subjects, who are at particular risk for SCD, were underrepresented in previous studies addressing this issue. OBJECTIVE The purpose of this study was to study the association between inflammation and SCD in a community-based population of older adults. METHODS In the Cardiovascular Health Study, 5806 and 5382 participants had measurements of C-reactive protein (CRP) and interleukin-6 (IL6), respectively, and were followed for up to 17 years. SCD risk as a function of baseline IL-6 and CRP was assessed in the overall population and in a group of participants without known prevalent cardiac disease. RESULTS In univariate analyses, both IL-6 (hazard ratio [HR] 1.79 for 1+ log IL-6, 95% confidence interval [CI] 1.50-2.13; 5th vs 1st quintile HR 3.36, 95% CI 2.24-5.05) and CRP (HR 1.31 for 1+ log CRP, 95% CI 1.18-1.45; 5th vs 1st quintile HR 2.00, 95% CI 1.40-2.87) were associated with SCD risk. In covariate-adjusted analyses, accounting for baseline risk factors, incident myocardial infarction, and heart failure, the association with SCD risk persisted for IL-6 (HR 1.26 for 1+ log IL-6, 95% CI 1.02-1.56; 5th vs 1st quintile HR 1.63, 95% CI 1.03-2.56) but was significantly attenuated for CRP (HR 1.13 for 1+ log CRP, 95% CI 1.00-1.28; 5th vs 1st quintile HR 1.34, 95% CI 0.88-2.05). Similar findings were observed in participants without prevalent cardiac disease. CONCLUSION Greater burden of inflammation, assessed by IL-6 levels, is associated with SCD risk beyond traditional risk factors, incident myocardial infarction, and heart failure.

Serial measures of cardiac troponin T levels by a highly sensitive assay and incident atrial fibrillation in a prospective cohort of ambulatory older adults.

BACKGROUND Various mechanisms in cardiac remodeling related to atrial fibrillation (AF) lead to elevated circulating cardiac troponin levels, but little is known about such elevations upstream to AF onset. OBJECTIVE The purpose of this study was to study the association between circulating troponin levels as assessed by a highly sensitive cardiac troponin T (hs-cTnT) assay and incident atrial fibrillation (AF). METHODS In a large prospective cohort of ambulatory older adults [the Cardiovascular Health Study (CHS)], hs-cTnT levels were measured in sera that were collected at enrollment from 4262 participants without AF (2871 with follow-up measurements). Incident AF was identified by electrocardiograms during CHS visits, hospital discharge diagnoses, and Medicare files, including outpatient and physician claims diagnoses. RESULTS Over median follow-up of 11.2 years (interquartile range 6.1-16.5), 1363 participants (32.0%) developed AF. Higher baseline levels of hs-cTnT were associated with incident AF in covariate-adjusted analyses accounting for demographics, traditional risk factors, and incident heart failure in time-dependent analyzes (hazard ratio for 3rd tertile vs undetectable 1.75, 95% confidence interval 1.48-2.08). This association was statistically significant in analyses that additionally adjusted for biomarkers of inflammation and hemodynamic strain (hazard ratio for 3rd tertile vs undetectable 1.38, 95% confidence interval 1.16-1.65). Significant associations were also found when hs-cTnT levels were treated as a continuous variable and when examining change from baseline of hs-cTnT levels and incident AF. CONCLUSION The findings show a significant association of circulating troponin levels in ambulatory older adults with incident AF beyond that of traditional risk factors, incident heart failure, and biomarkers of inflammation and hemodynamic strain.

Radiofrequency ablation of atrial fibrillation in patients with mechanical mitral valve prostheses safety, feasibility, electrophysiologic findings, and outcomes.

OBJECTIVES The purpose of this study was to evaluate the feasibility, safety, and outcomes of radiofrequency ablation of atrial fibrillation (AF) in patients with mechanical mitral valve replacement (MVR). BACKGROUND The role of ablative therapy in patients with MVR is not yet established, with safety concerns and very few outcome data. METHODS Between January 2003 and December 2008, we followed up 81 patients with MVR undergoing first-time AF ablation (compared with 162 age- and sex-matched controls). Arrhythmia recurrences were identified by symptoms with documentation, event monitoring, Holter monitoring, and electrocardiograms. RESULTS All MVR and control patients underwent ablation under therapeutic international normalized ratio. No entrapment of catheters or stroke occurred. There were no differences in terms of procedure-related complications between the groups (p = NS). Patients with MVR had larger atria (p < 0.0001), lower left ventricular ejection fractions (p = 0.0001), and more concomitant atrial flutter at baseline (p < 0.0001). Over a 24-month follow-up, they had higher recurrence rates compared with controls (49.4% vs. 27.7% after a single ablation, p = 0.0006). The creation of flutter lines significantly reduced recurrences in patients with any history of atrial flutter (16.7% vs. 60.9%, p = 0.009). At last follow-up, 82.7% of MVR patients had their arrhythmia controlled (69.1% not receiving antiarrhythmic drugs). CONCLUSIONS Radiofrequency ablation is feasible and safe for patients with MVR. It allowed restoration of sinus rhythm in a substantial proportion of patients undergoing ablation. An abnormal atrial substrate underlies recurrences in these patients. The ablation procedure needs to be further refined with a focus on extra pulmonary vein triggers and concomitant flutters to improve outcomes.