Real-world data of radiofrequency catheter ablation in paroxysmal atrial fibrillation: Short- and long-term clinical outcomes from the prospective multicenter REAL-AF Registry.

BACKGROUND: The safety and long-term efficacy of radiofrequency (RF) catheter ablation (CA) of paroxysmal atrial fibrillation (PAF) has been well established. Contemporary techniques to optimize ablation delivery, reduce fluoroscopy use, and improve clinical outcomes have been developed. OBJECTIVE: The purpose of this study was to assess the contemporary real-world practice approach and short and long-term outcomes of RF CA for PAF through a prospective multicenter registry. METHODS: Using the REAL-AF (Real-world Experience of Catheter Ablation for the Treatment of Symptomatic Paroxysmal and Persistent Atrial Fibrillation; ClincalTrials.gov Identifier: NCT04088071) Registry, patients undergoing RF CA to treat PAF across 42 high-volume institutions and 79 experienced operators were evaluated. The procedures were performed using zero or reduced fluoroscopy, contact force sensing catheters, wide area circumferential ablation, and ablation index as a guide with a target of 380-420 for posterior and 500-550 for anterior lesions. The primary efficacy outcome was freedom from all-atrial arrhythmia recurrence at 12 months. RESULTS: A total of 2470 patients undergoing CA from January 2018 to December 2022 were included. Mean age was 65.2 ±11.14 years, and 44% were female. Most procedures were performed without fluoroscopy (71.5%), with average procedural and total RF times of 95.4 ± 41.7 minutes and 22.1±11.8 minutes, respectively. At 1-year follow-up, freedom from all-atrial arrhythmias was 81.6% with 89.7% of these patients off antiarrhythmic drugs. No significant difference was identified comparing pulmonary vein isolation vs pulmonary vein isolation plus ablation approaches. The complication rate was 1.9%. CONCLUSION: Refinement of RF CA to treat PAF using contemporary tools, standardized protocols, and electrophysiology laboratory workflows resulted in excellent short- and long-term clinical outcomes.

Impact of Atrial Fibrillation on Exercise Capacity and Mortality in Heart Failure With Preserved Ejection Fraction: Insights From Cardiopulmonary Stress Testing.

BACKGROUND: Atrial fibrillation (AF) has been objectively associated with exercise intolerance in patients with heart failure with reduced ejection fraction; however, its impact in patients with heart failure with preserved ejection fraction has not been fully scrutinized. METHODS AND RESULTS: We identified 1744 patients with heart failure and ejection fraction ≥50% referred for cardiopulmonary stress testing at the Cleveland Clinic (Cleveland, OH), 239 of whom had AF. We used inverse probability of treatment weighting to balance clinical characteristics between patients with and without AF. A weighted linear regression model, adjusted for unbalanced variables (age, sex, diagnosis, hypertension, and ß-blocker use), was used to compare metabolic stress parameters and 8-year total mortality (social security index) between both groups. Weighted mean ejection fraction was 58±5.9% in the entire population. After adjusting for unbalanced weighted variables, patients with AF versus those without AF had lower mean peak oxygen consumption (18.5±6.2 versus 20.3±7.1 mL/kg per minute), oxygen pulse (12.4±4.3 versus 12.9±4.7 mL/beat), and circulatory power (2877±1402 versus 3351±1788 mm Hg·mL/kg per minute) (P<0.001 for all comparisons) but similar submaximal exercise capacity (oxygen consumption at anaerobic threshold, 12.0±5.1 versus 12.4±6.0mL/kg per minute; P =0.3). Both groups had similar peak heart rate, whereas mean peak systolic blood pressure was lower in the AF group (150±35 versus 160±51 mm Hg; P<0.001). Moreover, AF was associated with higher total mortality. CONCLUSIONS: In the largest study of its kind, we demonstrate that AF is associated with peak exercise intolerance, impaired contractile reserve, and increased mortality in patients with heart failure with preserved ejection fraction. Whether AF is the primary offender in these patients or merely a bystander to worse diastolic function requires further investigation.

Burden of cardiovascular disease in chronic obstructive pulmonary disease.

BACKGROUND: Chronic obstructive pulmonary disease (COPD) and atherosclerotic vascular disease share several etiopathogenic factors. PURPOSE: To compare the prevalence of self-reported cardiovascular and cerebrovascular disease (CCVD) between COPD and non-COPD subjects using the National Health and Nutrition Examination Survey (NHANES) database. Among subjects without pre-existent CCVD, the short-term and lifetime risks of future CCVD were also compared between the two groups. METHODS: Pooled NHANES 2007-2010 data were analyzed in May 2012 and April 2013. Based on predicted Framingham risk, subjects without self-reported CCVD were classified as follows: high short-term risk, low short-term/high lifetime risk, and low short-term/low lifetime risk for future CCVD. RESULTS: Estimated self-reported CCVD prevalence was 20.0% and 7.4% in COPD and non-COPD groups, respectively (p<0.001). On multivariable analysis, COPD was an independent risk factor for prevalent self-reported CCVD (prevalence ratio=1.4, 95% CI=1.1, 1.8). Among subjects without CCVD, there were significant differences in predicted future CCVD risk between the two groups. In the non-COPD group, prevalence of high short-term risk, low short-term/high lifetime risk, and low short-term/low lifetime risk was 18.9%, 62.7%, and 18.4%, respectively. In the COPD group, corresponding prevalence estimates were 35.8%, 53.2%, and 11.1%, respectively. Men and women had significantly different risk factor profiles for future CCVD. CONCLUSIONS: The prevalence of self-reported CCVD was significantly higher in subjects with COPD than in those without COPD. Among subjects without pre-existent CCVD, the risk of future CCVD was significantly higher in the COPD group than in the non-COPD group.

Translating metabolomics to cardiovascular biomarkers.

Metabolomics is the systematic study of the unique chemical fingerprints of small molecules or metabolite profiles that are related to a variety of cellular metabolic processes in a cell, organ, or organism. Although messenger RNA gene expression data and proteomic analyses do not tell the whole story of what might be happening in a cell, metabolic profiling provides direct and indirect physiologic insights that can potentially be detectable in a wide range of biospecimens. Although not specific to cardiac conditions, translating metabolomics to cardiovascular biomarkers has followed the traditional path of biomarker discovery from identification and confirmation to clinical validation and bedside testing. With technological advances in metabolomic tools (such as nuclear magnetic resonance spectroscopy and mass spectrometry) and more sophisticated bioinformatics and analytical techniques, the ability to measure low-molecular-weight metabolites in biospecimens provides a unique insight into established and novel metabolic pathways. Systemic metabolomics may provide physiologic understanding of cardiovascular disease states beyond traditional profiling and may involve descriptions of metabolic responses of an individual or population to therapeutic interventions or environmental exposures.