Evaluation of the effect of prior antiarrhythmic drug use on the success of atrial fibrillation catheter ablation.

WHAT IS KNOWN AND OBJECTIVE: Current guidelines recommend catheter ablation (CA) for atrial fibrillation (AF) refractory to at least one antiarrhythmic drug (AAD), but do not specify an adequate number of AADs to be trialed prior to considering ablation. The objective of this study was to evaluate the effect of CA success based on the number of AADs failed in patients with paroxysmal or persistent AF. METHODS: This retrospective cohort study evaluated patients with paroxysmal or persistent AF who underwent an initial CA at a community hospital. Patients with unknown AAD histories, those who did not achieve acute procedural success, or who were lost to follow-up or death unrelated to thromboembolic stroke within 6 months post-ablation were excluded. Catheter ablation success was defined as freedom from AF. The primary outcome was the incidence of AF or atrial flutter captured on an electrocardiogram or other recording device at 3, 6, 9 and 12 months after the procedure. RESULTS AND DISCUSSION: Overall, 99 out of 103 patients completed 1 year of follow-up. Of those patients, 34 of 99 (34.3%) experienced AF recurrence within 1-year post-ablation. There was no significant difference among the categories of number of failed AADs and the recurrence of AF within 12 months post-ablation for zero AADs, 1 AADs and ≥2 AADs (41.7%, 31.3% and 40%, respectively; P = 0.658). WHAT IS NEW AND CONCLUSION: The results of this study do not support preferentially performing CA on patients who have failed a certain number of AADs. Results are limited by the nature of the study design and a small sample size. Conclusive results would best be addressed by a prospective randomized trial.

Conventional coronary artery disease risk factors and coronary artery calcium detected by electron beam tomography in 30,908 healthy individuals.

PURPOSE: Electron beam tomography (EBT) is a noninvasive measure of coronary artery calcium (CAC), a marker for atherosclerosis. In this study we examined the association between conventional risk factors for coronary artery disease (CAD) and CAC. METHODS: EBT CAC screening was performed on 30,908 asymptomatic individuals aged 30 to 90 years. Prior to EBT screening, individuals provided demographic and CAD risk factor information. EBT utilized a C-100 EBT scanner, and the amount of CAC was determined using the Agatston scoring method. RESULTS: The results of this study demonstrate that for both men and women, all conventional risk factors were significantly associated with the presence of any detectable CAC, and the mean CAC score increased in proportion to the number of CAD risk factors. In age-adjusted (multivariable) logistic regression analysis, cigarette use, histories of hypercholesterolemia, diabetes, and hypertension were each significantly associated with mild to extensive CAC scores (> or =10.0). CONCLUSION: CAD risk factors are associated with higher atherosclerotic plaque burden in both men and women. The odds ratios associated with each risk factor relative to the extent of CAC are similar to those reported for the development of clinical CAD, suggesting the existence of an association between CAC (subclinical disease) and CAD (clinical disease).

Paradoxical increase in ventricular torsion and systolic torsion rate in type I diabetic patients under tight glycemic control.

OBJECTIVES: This study sought to characterize the early features of diabetic cardiomyopathy by magnetic resonance imaging (MRI) tagging. BACKGROUND: The earliest manifestations of diabetic cardiomyopathy have not been well established, especially under tight glycemic management. We hypothesized that torsion measurements would identify subclinical contractile alterations in type I diabetics with normal left ventricular ejection fraction, mass, blood pressure, and aggressive glycemic control. We also sought to characterize the influence of elevated resting heart rates (HRs) of diabetics on torsion. METHODS: Sixteen patients with type I diabetes and 10 control patients underwent cine and tagged MRI with a 1.5-T scanner. Torsion, strain, and their rates were measured. To quantify the influence of chronotropic and inotropic stimulation on torsion, nine healthy volunteers underwent MRI tagging at rest, after atropine injection, and after exercise. RESULTS: Diabetic patients (hemoglobin A1c, 6.8 +/- 0.4%) had a higher resting HR (77.0 +/- 12.4 beats/min vs. 59.0 +/- 5.6 beats/min; p < 0.01), higher maximal torsion by 23% (3.5 +/- 0.9 degrees/cm vs. 2.7 +/- 0.4 degrees/cm; p < 0.01) and higher maximal systolic torsion rate (TR-s) by 25% (0.013 +/- 0.003 degrees/cm/s vs. 0.010 +/- 0.002 degrees/cm/s, p = 0.01). Torsion did not significantly change with chronotropic stimulation (p = 0.30). CONCLUSIONS: In diabetics under tight glycemic control, we observed a surprising increase in torsion and TR-s unrelated to chronotropic influences of HR. We propose that increased torsion and TR-s could represent early predictive markers of the propensity to cardiac dysfunction in asymptomatic type I diabetics. Furthermore, these findings seem fundamental to the diabetic state itself and unaccounted for by other comorbidities.

Construction and validation of an automated model for the early identification of patients hospitalized for heart failure.

In order to institute early hospital-wide interventions, we constructed a reliable automated model for identifying newly admitted patients with congestive heart failure using electronically captured administrative and clinical data.