Improved outcomes and complications of atrial fibrillation catheter ablation over time: learning curve, techniques, and methodology

Introduction and objectives

The outcomes of atrial fibrillation ablation procedures vary widely between different centers. Our objective was to analyze the results and complications of this procedure in our center and identify factors predicting the efficacy and safety of atrial fibrillation ablation.

Methods

In total, 726 atrial fibrillation ablation procedures were performed in our center between 2002 and 2009. Beginning in January 2008, a protocol for anticoagulation and conscious sedation was systematically applied. Outcomes and complications could therefore be compared in 2 well-differentiated groups: group A included 419 procedures performed prior to 2008 and group B included 307 procedures completed after 2008 using the new protocol.

Results

During an average follow-up of 8.7 months, 60.9% of patients were arrhythmia-free after one or repeat procedures. After only 1 procedure, the success rate was 41% and significantly higher in group B (51.6% vs 35.2% in group A; P=.001). There were 31 major complications (4.2%), 26 in group A (6.2%) and 5 in group B (1.6%) (P=.002). The implementation of the new protocol was an independent predictor of the absence of complications (odds ratio=0.406; 95% confidence interval, 0.214-0.769; P<.006).

Conclusions

Systematic application of an anticoagulation and conscious sedation protocol is associated with improved results and fewer complications of atrial fibrillation ablation. Factors not evaluated in the present study, such as operator experience and ongoing improvements in atrial fibrillation ablation technology, could have influenced these findings.Full English text available from:www.revespcardiol.org     

Seasonal effect of GnIH on gonadotrope functions in the pituitary of goldfish

Gonadotropin-inhibitory hormone (GnIH) inhibits gonadotropin release in birds and mammals. To investigate its role in teleosts, we examined the effects of synthetic goldfish (g)GnIH on pituitary LH-β and FSH-β subunit, and gGnIH receptor (gGnIH-R) mRNA levels and LH secretion in goldfish. Intraperitoneal injections of gGnIH increased pituitary LH-β and FSH-β mRNA levels at early to late gonadal recrudescence, but reduced serum LH and pituitary gGnIH-R mRNA levels, respectively, at early to mid-recrudescence and later stages of recrudescence. Static incubation with gGnIH elevated LH secretion from dispersed pituitary cell cultures from prespawning fish, but not at other recrudescent stages; suppressed LH-β mRNA levels at early recrudescence and prespawning but elevated LH-β at mid-recrudescence; and consistently attenuated FSH-β mRNA in a dose-specific manner. Results indicate that in goldfish, regulation of LH secretion and gonadotropin subunit mRNA levels are dissociated in the presence of gGnIH and dependent on maturational status and administration route.     

Cellular adaptation contributes to calorie restriction-induced preservation of skeletal muscle in aged rhesus monkeys

We have previously shown that a 30% reduced calorie intake diet delayed the onset of muscle mass loss in adult monkeys between ~16 and ~22 years of age and prevented multiple cellular phenotypes of aging. In the present study we show the impact of long term (~17 years) calorie restriction (CR) on muscle aging in very old monkeys (27-33 yrs) compared to age-matched Control monkeys fed ad libitum, and describe these data in the context of the whole longitudinal study. Muscle mass was preserved in very old calorie restricted (CR) monkeys compared to age-matched Controls. Immunohistochemical analysis revealed an age-associated increase in the proportion of Type I fibers in the VL from Control animals that was prevented with CR. The cross sectional area (CSA) of Type II fibers was reduced in old CR animals compared to earlier time points (16-22 years of age); however, the total loss in CSA was only 15% in CR animals compared to 36% in old Controls at ~27 years of age. Atrophy was not detected in Type I fibers from either group. Notably, Type I fiber CSA was ~1.6 fold greater in VL from CR animals compared to Control animals at ~27 years of age. The frequency of VL muscle fibers with defects in mitochondrial electron transport system enzymes (ETS(ab)), the absence of cytochrome c oxidase and hyper-reactive succinate dehydrogenase, were identical between Control and CR. We describe changes in ETS(ab) fiber CSA and determined that CR fibers respond differently to the challenge of mitochondrial deficiency. Fiber counts of intact rectus femoris muscles revealed that muscle fiber density was preserved in old CR animals. We suggest that muscle fibers from CR animals are better poised to endure and adapt to changes in muscle mass than those of Control animals.     

Seasonal Effect of Gonadotrophin Inhibitory Hormone on Gonadotrophin‐Releasing Hormone‐induced Gonadotroph Functions in the Goldfish Pituitary

We have shown that native goldfish gonadotrophin inhibitory hormone (gGnIH) differentially regulates luteinsing hormone (LH)‐β and follicle‐stimulating hormone (FSH)‐β expression. To further understand the functions of gGnIH, we examined its interactions with two native goldfish gonadotrophin‐releasing hormones, salmon gonadotrophin‐releasing hormone (sGnRH) and chicken (c)GnRH‐II in vivo and in vitro. Intraperitoneal injections of gGnIH alone reduced serum LH levels in fish in early and mid gonadal recrudescence; this inhibition was also seen in fish co‐injected with either sGnRH or cGnRH‐II during early recrudescence. Injection of gGnIH alone elevated pituitary LH‐β and FSH‐β mRNA levels at early and mid recrudescence, and FSH‐β mRNA at late recrudescence. Co‐injection of gGnIH attenuated the stimulatory influences of sGnRH on LH‐β in early recrudescence, and LH‐β and FSH‐β mRNA levels in mid and late recrudescence, as well as the cGnRH‐II‐elicited increase in LH‐β, but not FSH‐β, mRNA expression at mid and late recrudescence. sGnRH and cGnRH‐II injection increased pituitary gGnIH‐R mRNA expression in mid and late recrudescence but gGnIH reduced gGnIH‐R mRNA levels in late recrudescence. gGnIH did not affect basal LH release from perifused pituitary cells and continual exposure to gGnIH did not alter the LH responses to acute applications of GnRH. However, a short 5‐min GnIH treatment in the middle of a 60‐min GnRH perifusion selectively reduced the cGnRH‐II‐induced release of LH. These novel results indicate that, in goldfish, gGnIH and GnRH modulate pituitary GnIH‐R expression and gGnIH differentially affects sGnRH and cGnRH‐II regulation of LH secretion and gonadotrophin subunit mRNA levels. Furthermore, these actions are manifested in a reproductive stage‐dependent manner.     

Safety and Efficacy of Percutaneous Cryoablation for Small Hepatocellular Carcinomas Adjacent to the Heart

PurposeThis study evaluated the safety and efficacy of percutaneous cryoablation for treatment of the left subdiaphragmatic small hepatocellular carcinomas (HCCs) adjacent to the heart.Materials and MethodsBetween September 2013 and March 2018, 189 consecutive patients underwent cryoablation for small HCCs (≤3 cm); 70 patients (mean: 61.3 ± 10.6 years of age; range: 40–82 years) with left hepatic tumors (22 juxtacardiac and 48 nonjuxtacardiac tumors) were retrospectively analyzed. Patients were divided into juxtacardiac and nonjuxtacardiac tumor groups (tumor margins: ≤10 mm and >10 mm, respectively, from the heart border). The rates of technical success, complete ablation, complications, and local tumor recurrence (LTR) were evaluated.ResultsNo significant intergroup differences were observed in the mean diameter of the tumor (17.9 ± 5.5 mm vs. 17.5 mm ± 5.2, respectively; P = 0.781) and of the ablation zone (41.3 ± 4.2 mm vs. 43.5 ± 5.8 mm, respectively; P = 0.115). Technical success was achieved in all patients. No procedure-related major complications occurred in either group. The median follow-up period was 15 months (range: 3.1–49.6 months). No statistically significant intergroup differences were observed in the rates of complete ablation (90.9% vs. 93.8%, respectively; P = 0.646) and LTR (20% vs. 15.6%, respectively; P = 0.725).ConclusionsCryoablation is a safe treatment modality for patients with juxtacardiac small HCCs, without an increased risk of cardiac complications compared to treatment of HCCs that are nonjuxtacardiac, and with comparable efficacy.     

Factors Associated with Osteoid Osteoma Recurrence after CT-Guided Radiofrequency Ablation

PurposeTo identify clinical and imaging variables associated with symptomatic recurrence of osteoid osteomas (OOs) treated with computerized tomography (CT)–guided radiofrequency (RF) ablation.Materials and MethodsSeventy-one patients treated with the use of CT-guided RF ablation for OO at a single institution from July 2005 to May 2018 were included in this retrospective cohort analysis. Clinical data, including patient age, sex, race, and clinical outcomes, were collected from institutional electronic health records and telephone follow-up. Imaging variables regarding tumor characteristics were gathered from imaging reports and a blinded review of preprocedural images by an experienced musculoskeletal radiologist. Logistic regression, Cox proportional hazards, and Kaplan-Meier analyses were used to identify variables that are significantly associated with symptomatic recurrence, which was defined as pain occurring > 2 weeks after RF ablation.ResultsTen patients (14.1%) experienced symptomatic recurrence at a median of 21.5 months after RF ablation. Univariable logistic regression classified young age (≤ 13 years), female sex, maximum tumor length, and “eccentricity index” (EI) ≥ 3 as predictive variables significantly associated with symptomatic recurrence. Multivariable logistic regression identified female sex and EI ≥ 3 to be significant predictors for symptomatic recurrence. A multivariable proportional hazards Cox regression of time to recurrence revealed EI ≥ 3 to be the only significant predictor of symptomatic recurrence.ConclusionsFemale patients with OOs with an EI ≥ 3 have a greater risk of symptomatic recurrence following RF ablation. The EI is a useful tool to identify OOs with elongated 3-dimensional morphology, which may warrant more extensive ablation.