Predictors of recurrence following catheter ablation of atrial fibrillation using an irrigated-tip ablation catheter

INTRODUCTION: The aims of this study were to identify predictors of recurrence after catheter ablation of atrial fibrillation (AF) and to report the safety and efficacy of catheter ablation of AF using an irrigated-tip ablation catheter. METHODS AND RESULTS: Seventy-five consecutive patients (51 men [68%]; age 54 +/- 13 years) with symptomatic drug-refractory paroxysmal (42 patients), persistent (21 patients), or permanent (12 patients) AF underwent catheter ablation of AF using an irrigated-tip ablation catheter and a standard ablation strategy, which involved electrical isolation of all pulmonary veins (PVs) and creation of a cavotricuspid linear lesion. At 10.5 +/- 7.5 months of follow-up following a single (n = 75) or redo ablation procedure (n = 11), 39 (52%) of the 75 patients were free of AF, 10 were improved (13%), and 26 had experienced no benefit from the ablation procedure (35%). Seventy-six percent of patients with paroxysmal AF were free from recurrent AF. The most significant complications were two episodes of pericardial tamponade, mitral valve injury in one patient, two strokes, and complete but asymptomatic PV stenosis in one patient. Cox proportional hazards multivariate regression analysis identified the presence of persistent AF, permanent AF, and age >50 years prior to the ablation are the only independent predictors of AF recurrence after the first PV isolation procedure. CONCLUSION: Catheter ablation of AF using a strategy involving isolation of all PVs and creation of a linear lesion in the cavotricuspid isthmus using cooled radiofrequency energy is associated with moderate efficacy and an important risk for complications. The best results of this procedure are achieved in the subset of patients who are younger than 50 years and have only paroxysmal AF.     

Normal reference values for the adult right ventricle by magnetic resonance imaging

The purpose of this study was to establish reference ranges for magnetic resonance imaging (MRI) measurements of the adult right ventricle stratified by gender. Cardiovascular MRI is increasingly used for evaluating the right ventricle in congenital and acquired heart disease, but gender-specific normative values are currently unavailable. Study participants included 500 subjects free of clinical cardiovascular disease who were participants in the Multi-Ethnic Study of Atherosclerosis (MESA). All subjects underwent MRI according to a standard protocol. The endocardial margins of the right ventricle were manually contoured on short-axis images, and right ventricular (RV) volumes were calculated using a summation-of-disks method. RV dimensions were measured on 4-chamber gradient-echo images and in the short-axis plane. Except for the ejection fraction, all unadjusted RV parameters were significantly greater in men than in women (p <0.001). In the entire study population, RV volumes and linear dimensions each correlated significantly with height (r = 0.38 to 0.64, p = 0.001 for all) and body surface area (r = 0.41 to 0.64, p = 0.001 for all). Gender differences persisted after adjustment for subject height. After adjustment for body surface area, volumetric variables remained significantly greater (p = 0.001) in men than in women. Even after adjusting for body surface area and height, Chinese participants had significantly lower RV volumes compared with Caucasians. In conclusion, gender-specific normal values for the adult right ventricle by MRI are presented. Cardiovascular MRI measures of RV volumes and linear dimensions differ significantly according to gender and body size. These values will be useful to differentiate RV health from diseases that result in abnormal RV structure and function.     

Ethnic differences of the presence and severity of coronary atherosclerosis

BACKGROUND: Although cardiovascular risk factor levels are substantially different in Caucasians, African-American, Hispanics, and Asians, the relative rates of coronary heart disease in these groups are not consistent with these differences. The objective of the study is to assess the differences in the prevalence and severity of coronary artery calcification, as a measure of atherosclerosis, in these different ethnic groups. METHODS: Electron-beam tomography was performed in 16,560 asymptomatic men and women (Asians=1336, African-Americans=610, Hispanics=1256) aged >or=35 years referred by their physician for cardiovascular risk evaluation. The study population encompassed 70% males, aged 52+/-8 years. RESULTS: Caucasians were more likely to present with dyslipidemia (p<0.0001), while African-Americans and Hispanics had a higher prevalence of smoking, diabetes, and hypertension (all p<0.001). After adjustment for age, gender, risk factors, and treatment for hypercholesterolemia, compared with Caucasians, the relative risks for men having coronary calcification were 0.64 (95% CI: 0.48-0.86) in African-Americans, 0.88 (95% CI: 0.67-1.15) in Hispanics, and 0.66 (95% CI: 0.55-0.80) in Asians. After similar adjustments, the relative risks for women having coronary calcification, were 1.58 (95% CI: 1.13-2.19) for African-Americans, 0.84 (95% CI: 0.66-1.06) in Hispanics, and 0.71 (95% CI: 0.56-0.89) in Asian women. After adjusting for age and risk factors using multivariable analysis, African-American men were least likely to have any coronary calcium while African-American women had significantly higher OR of any calcification. Asian men and women had significantly lower OR of any calcification. There was no significant difference in prevalence or severity of atherosclerosis between Hispanics and Caucasians, in men or women. CONCLUSIONS: Our study results demonstrate significant difference in the presence as well as severity of calcification according to ethnicity, independent of atherosclerotic risk factors. Results from this study (physician referred) closely parallel the results from MESA (population based, measured risk factors). Ethnic specific data on the predictive value of differing coronary calcium scores are needed.     

Calcified versus noncalcified atherosclerosis: Implications for evaluating cardiovascular risk

Although the quantification of coronary arterial calcification (CAC) correlates well with disease burden, calcified plaques only represent a portion of the total plaque burden. Contrast-enhanced multidetector CT angiography has emerged as a promising noninvasive tool to directly examine the coronary artery wall and accurately determine atherosclerotic plaque burden and composition. Published literature on plaque subtypes (noncalcified, mixed, and calcified) suggests that mixed plaque burden is more likely to be associated with high-risk groups, such as those with diabetes mellitus, inflammatory biomarkers, increasing stenotic coronary artery disease, myocardial perfusion defects, higher CAC scores and, more importantly, features of plaque instability such as thin-cap fibroatheroma. One small study suggested that mixed plaque burden can predict cardiovascular outcomes. Based on emerging data, determination of mixed plaque burden appears more promising, but the value of exclusively calcified and noncalcified plaque is less convincing.     

Trends in 30-Day Readmission Rates for Medicare and Non-Medicare Patients in the Era of the Affordable Care Act

Background

Temporal changes in the readmission rates for patient groups and conditions that were not directly under the purview of the Hospital Readmissions Reduction Program (HRRP) can help assess whether efforts to lower readmissions extended beyond targeted patients and conditions.

Cocaine and Marijuana Use Among Young Adults With Myocardial Infarction

Background

Substance abuse is increasingly prevalent among young adults, but data on cardiovascular outcomes remain limited.

Familial Hypercholesterolemia Among Young Adults With Myocardial Infarction

BackgroundThere are limited data on the prevalence and treatment of familial hypercholesterolemia (FH) among U.S. adults who experience a myocardial infarction (MI) at a young age.ObjectivesThis study aimed to evaluate the prevalence of clinically defined FH and examine the rates of statin utilization and low-density lipoprotein cholesterol (LDL-C) achieved 1-year post MI.MethodsThe YOUNG-MI registry is a retrospective cohort study that includes patients who experience an MI at or below age 50 years between 2000 and 2016 at 2 academic centers. Probable or definite FH was defined by the Dutch Lipid Clinic criteria. Outcomes included the proportion of patients classified as probable or definite FH, use of lipid-lowering therapy, and LDL-C achieved 1-year post MI.ResultsThe cohort consisted of 1,996 adults with a median age of 45 years; 19% were women, and 54% had ST-segment elevation MI. Probable/definite FH was present in 180 (9%) of whom 42.8% were not on statins prior to their MI. Of the 1,966 patients surviving until hospital discharge, 89.4% of FH patients and 89.9% of non-FH patients were discharged on statin therapy (p = 0.82). Among FH patients, 63.3% were discharged on high-intensity statin compared with 48.4% for non-FH patients (p < 0.001). At 1-year follow-up, the percent reduction in LDL-C among FH patients was ?44.4% compared with ?34.5% (p = 0.006) in non-FH patients. The proportion of patients with LDL-C ≥70 mg/dl was higher among FH patients (82.2%) compared with non-FH patients (64.5%; p < 0.001).ConclusionsClinically defined FH was present in nearly 1 of 10 patients with MI at a young age. Only two-thirds of FH patients were discharged on high-intensity statin therapy, and the vast majority had elevated LDL-C at 1 year. These findings reinforce the need for more aggressive lipid-lowering therapy in young FH and non-FH patients post-MI.     

Higher Fitness Is Strongly Protective in Patients with Family History of Heart Disease: The FIT Project

Background

Cardiorespiratory fitness protects against mortality; however, little is known about the benefits of improved fitness in individuals with a family history of coronary heart disease. We studied the association between cardiorespiratory fitness and risk of incident coronary heart disease and all-cause mortality, hypothesizing an inverse relationship similar to individuals without a family history of coronary heart disease.