Atrial Fibrillation Ablation Success Rate - A Retrospective Multicenter Study.

Atrial fibrillation (AF) has become a major health and economic burden. Pulmonary veins isolation (PVI) based ablation for rhythm control of AF is well established. Furthermore, recent studies show its superiority over anti-arrhythmic therapy. However, most of these studies were performed in highly experienced centers, that may not necessarily reflect real world outcomes. We evaluated the outcome (success rate and complications) of 300 consecutive procedures, performed on 291 patients (during 2014-2015) of a major HMO. All had undergone PVI for AF by experienced electrophysiologists in 8 medical centers (85% RF technique). Data were retrospectively collected using computerized medical records. Variables included demographic and clinical characteristics, acute procedural success and complications, long term success rate based on multiple ECGs and Holter monitoring. The average age was 63 years, 61% were male, 79% had paroxysmal AF. Sinus rhythm at 2 years was considered success. The overall success rate of maintaining sinus rhythm at 2 years was 56%. Success rate correlated significantly with age and standard risk factors. Those patients in whom the index procedure was the first ablation, success rate was 78%. Sixty-one patients underwent a second ablation with success rate of 64%, 32 underwent a 3rd/4th procedure with success rate of 56%. The probability to be in sinus rhythm after 2 years regardless of the number of ablations was 78%. Thirty-five percent of the patients were still on anti-arrhythmic therapy at 2 years post procedure. Complication rate was 6.6% (2.5% serious), among them 2 deaths, 1 procedure related. PVI in a real-world large unselected population is a valid therapeutic option for AF with an overall 2-year success rate of 56%. In our group higher complication rate was observed compared to the reported rate in the literature. The use of cryo-ablation for PVI and further improvements in both technique and experience may improve both efficacy and safety profile.

Does levonorgestrel-releasing intrauterine system increase breast cancer risk in peri-menopausal women? An HMO perspective.

PURPOSE: To evaluate the association between levonorgestrel-releasing intrauterine system (LNG-IUS) use and breast cancer (BC) risk. METHODS: A cohort of all Maccabi Healthcare Services (MHS) female members aged 40-50 years between 1/2003 and 12/2013 was used to identify LNG-IUS users as "cases," and 2 age-matched non-users as "controls." Exclusion criteria included: prior BC diagnosis, prior (5 years pre-study) and subsequent treatment with other female hormones or prophylactic tamoxifen. Invasive tumors were characterized by treatments received (chemotherapy, hormonal therapy, trastuzumab, or combination thereof). RESULTS: The analysis included 13,354 LNG-IUS users and 27,324 controls (mean age: 44.1 ± 2.6 vs. 44.9 ± 2.8 years; p < 0.0001). No significant differences in 5-year Kaplan-Meier (KM) estimates for overall BC risk or ductal carcinoma in situ occurrence were observed between groups. There was a trend towards higher risk for invasive BC in LNG-IUS users (5-year KM-estimate: 1.06% vs. 0.93%; p = 0.051). This difference stemmed primarily from the younger women (40-45 years; 0.88% vs. 0.69%, p = 0.014), whereas in older women (46-50 years), it was non-significant (1.44% vs. 1.21%; p = 0.26). Characterization of invasive BC by treatment demonstrated that LNG-IUS users had similar proportions of tumors treated with hormonal therapy, less tumors treated with trastuzumab, (7.5% vs. 14.5%) and more tumors treated with chemotherapy alone (25.8% vs. 14.9%; p = 0.041). CONCLUSIONS: In peri-menopausal women, LNG-IUS was not associated with an increased total risk of BC, although in the subgroup of women in their early 40's, it was associated with a slightly increased risk for invasive tumors.

Trends in annual drug expenditure - a 16 year perspective of a public healthcare maintenance organization.

BACKGROUND: Modern drug therapy accounts for a major share of health expenditure and challenges public provider resources. The objective of our study was to compare drug expenditure trends for ten major drug classes over 16 years at Maccabi Healthcare Services (MHS), the 2(nd) largest healthcare organization in Israel. METHODS: A retrospective analysis of drug expenditure per HMO beneficiary between the years 1998-2014. Trends in annual mean drug expenditures per MHS member were compared among 10 major drug classes. RESULTS: Average annual drug expenditure per beneficiary increased during the study period from 429.56 to 474.32 in 2014 (10.4 %). Ten drug classes accounted for 58.0 % and 77.8 % of total drug cost in 1998 and 2014, respectively. The overall distribution of drug expenditure among drug classes differed significantly between 1998 and 2014 (p < 0.001), mainly due to the increase in expenditure for cancer drugs, from 6.8 % of total drug cost to 30.3 %. In contrast, expenditures for cardiovascular drugs decreased during the same period from 16.0 to 2.7 %. Moreover, the median annual increase in net drug costs per HMO member during 1998-2014 was largest for cancer drugs (NIS 6.18/year; IQR, 1.70-9.92/year), about two-fold that of immunosuppressants, the second fastest growing drug class (NIS 2.81; IQR, 0.58-7.43/year). CONCLUSIONS: The continuous rise in anti-cancer drug expenditure puts a substantial burden on the medication budgets of public health organizations. Coordinated measures involving policy makers, physicians, and pharmaceutical companies will be required for efficient cost containment.

A Novel Computational Tool for Mining Real-Life Data: Application in the Metastatic Colorectal Cancer Care Setting.

BACKGROUND: Randomized clinical trials constitute the gold-standard for evaluating new anti-cancer therapies; however, real-life data are key in complementing clinically useful information. We developed a computational tool for real-life data analysis and applied it to the metastatic colorectal cancer (mCRC) setting. This tool addressed the impact of oncology/non-oncology parameters on treatment patterns and clinical outcomes. METHODS: The developed tool enables extraction of any computerized information including comorbidities and use of drugs (oncological/non-oncological) per individual HMO member. The study in which we evaluated this tool was a retrospective cohort study that included Maccabi Healthcare Services members with mCRC receiving bevacizumab with fluoropyrimidines (FP), FP plus oxaliplatin (FP-O), or FP plus irinotecan (FP-I) in the first-line between 9/2006 and 12/2013. RESULTS: The analysis included 753 patients of whom 15.4% underwent subsequent metastasectomy (the Surgery group). For the entire cohort, median overall survival (OS) was 20.5 months; in the Surgery group, median duration of bevacizumab-containing therapy (DOT) pre-surgery was 6.1 months; median OS was not reached. In the Non-surgery group, median OS and DOT were 18.7 and 11.4 months, respectively; no significant OS differences were noted between FP-O and FP-I, whereas FP use was associated with shorter OS (12.3 month; p <0.002; notably, these patients were older). Patients who received both FP-O- and FP-I-based regimens achieved numerically longer OS vs. those who received only one of these regimens (22.1 [19.9-24.0] vs. 18.9 [15.5-21.9] months). Among patients assessed for wild-type KRAS and treated with subsequent anti-EGFR agent, OS was 25.4 months and 18.7 months for 124 treated vs. 37 non-treated patients (non-significant). Cox analysis (controlling for age and gender) identified several non-oncology parameters associated with poorer clinical outcomes including concurrent use of diuretics and proton-pump inhibitors. CONCLUSIONS: Our tool provided insights that confirmed/complemented information gained from randomized-clinical trials. Prospective tool implementation is warranted.

The impact of the Oncotype DX Recurrence Score on treatment decisions and clinical outcomes in patients with early breast cancer: the Maccabi Healthcare Services experience with a unified testing policy.

The Oncotype DX Recurrence Score is a validated prognosticator in oestrogen receptor positive (ER+) breast cancer. Our retrospective analysis of a prospectively defined cohort summarises the clinical implications associated with Oncotype DX testing according to the Maccabi Healthcare Services (MHS) policy. The MHS eligibility criteria for testing included ER+ N0/pN1mic invasive tumours, discussion of test implications with an oncologist, ductal carcinoma 0.6-1 cm Grade 2-3, HER2 negative ductal carcinomas with 1.1-4.0 cm Grade 1-2, or lobular carcinoma. Large (> 1 cm) Grade 3 tumours could have grade reassessed. We linked Recurrence Score results with patients' information and used chi-squared tests to assess the associations thereof. Between January 2008 and December 2011, tests were performed on 751 patients (MHS-eligible, 713); 54%, 38%, and 8% of patients had low, intermediate, and high Recurrence Score results, respectively. Recurrence Score distribution varied significantly with age (P = 0.002), with increasing Recurrence Score values with decreasing age. The proportion of patients with high Recurrence Score results varied by grade/size combination and histology, occurring in 32% of small (≤ 1 cm) Grade 3 and 3% of larger (1.1-4 cm) Grade 1 ductal tumours and only in 2% of lobular carcinomas. Chemotherapy was administered to 1%, 13%, and 61% of patients with low, intermediate, and high Recurrence Score results, respectively (P < 0.0001), but only to 2% of intermediate score patients ≥ 65 years. Luteinising-hormone-releasing hormone agonists with tamoxifen were used in 27% of low Recurrence Score patients ≤ 50 years. With a median follow-up of 26 months, no systemic recurrences were documented, whereas four patients exhibited locoregional recurrences. In summary, in this low-to-moderate risk patient population, testing identified 46% of patients as intermediate/high risk. Treatment decisions were influenced by Recurrence Score results and patients' age. The current MHS policy seems to achieve the goal of promoting chemotherapy use according to the test results in a prespecified patient population.

Muscle pain and serum creatine kinase are not associated with low serum 25(OH) vitamin D levels in patients receiving statins.

OBJECTIVE: Vitamin D deficiency has been associated in some studies with nonspecific musculoskeletal pain and, more specifically, with statin-induced myalgia, which was ameliorated by high-dose vitamin D supplements. Our objective was to explore the association between vitamin D status and statin-induced myalgia and elevation of serum creatine kinase (CK). DESIGN: Retrospective cohort study, based on the electronic database of a health maintenance organization. PATIENTS: Six thousand eight hundred and eight patients (71·5% women) to whom statins were dispensed during 2008 and who had ≥1 CK and 25-hydroxy vitamin D (25OHD) levels measured during statin exposure. Of these, 376 patients (5·5%) had switched from a first-line statin to atorvastatin because of muscle pain (n = 220) or other reasons (n = 156). Measurements; In the entire cohort, we compared serum CK levels among serum 25OHD quartiles. In addition, we compared CK and 25OHD levels among patients with myalgia, other switchers and nonswitchers. RESULTS: The median 25OHD level in the entire cohort was 21·8 ng/ml [interquartile range (IQR), 16·3-27·4]. CK levels were marginally lower in patients in the lowest 25OHD quartile [median CK (IQR) in 25OHD quartiles 1-4, 87 (61-130), 90 (65-131), 91 (65-132) and 91 (67-131) IU/ml, respectively; P = 0·007]. 25OHD levels in statin switchers were similar to those in nonswitchers; moreover, there were no differences in 25OHD among switchers with muscle pain and other switchers. CONCLUSION: Our findings do not support an association between low 25OHD levels and statin-induced myalgia or CK elevation.

Hyperkalemia and renal function during monotherapy and dual renin-angiotensin blockade in the community setting.

BACKGROUND: In controlled trials, dual therapy with angiotensin-converting enzyme inhibitors (ACE-I) and angiotensin receptor blockers (ARBs) is associated with hyperkalemia and decreased renal function, but there is no information about these adverse effects in clinical practice. OBJECTIVE: The aim of this study was to assess the incidence of hyperkalemia and decreased renal function during dual therapy (ACE-I plus ARB) in a community-based setting. METHODS: In a retrospective cohort database study, we identified patients who received ARBs added to ongoing ACE-I therapy and who had at least 1 measurement of serum creatinine and potassium during each treatment period. We compared rates of hyperkalemia (>5.5 mmol/L) during equal periods of monotherapy and dual therapy and the rate of a significant rise in serum creatinine (≥0.5 mg/dL) between study periods. We assessed the impact of potential confounders on outcomes by logistic regression analysis. RESULTS: Among 425 patients (median follow-up 19 months for each treatment period), hyperkalemia was 2-fold more common during dual therapy than monotherapy (11.1% and 5.6% of patients, respectively) (relative risk = 1.96; 95% CI, 1.22-3.14; P < 0.001). In 77 patients with reduced renal function on monotherapy (serum creatinine ≥1.5 mg/dL), the rate of hyperkalemia was 20.8/100 patient-years, resulting in a number needed to harm of 10.1 patients, compared with 52.6 patients among those with preserved renal function. Mean serum creatinine between treatment periods increased >0.5 mg/dL in 7.5% of patients, more commonly in patients with decreased (18.2%) than with preserved (5.2%) baseline renal function (P < 0.001). CONCLUSION: In the community setting, dual therapy was associated with hyperkalemia and a decrease in renal function. The absolute risks were especially high among patients with reduced baseline renal function.

Potent CYP2D6 Inhibiting drugs do not increase relapse rate in early breast cancer patients treated with adjuvant tamoxifen.

Endoxifen, the most active metabolite of the prodrug tamoxifen, is produced by cytochrome P450 CYP2D6. Breast cancer patients treated with tamoxifen who have reduced CYP2D6 activity, related to either genetic variation or drug inhibition, may have inferior outcomes. To assess the effect of concomitant CYP2D6 inhibiting drug use on clinical outcomes of breast cancer patients treated with adjuvant tamoxifen. We conducted a retrospective database analysis. Women with non-metastatic estrogen receptor positive tumors who had completed adjuvant tamoxifen therapy for 2 years, without treatment with adjuvant aromatase inhibitors or early relapse, were included. Patients were classified as users of CYP2D6 inhibitors if they purchased strong CYP2D6 inhibiting drugs for ≥ 4 consecutive months during tamoxifen treatment. Tumors were classified as "high risk" if adjuvant chemotherapy was prescribed. Primary endpoint was disease free (DFS) and secondary endpoint was overall survival (OS). 902 patients treated with tamoxifen (median duration, 4.9 years) were followed for a median period of 5.9 years. Fifty-nine (6.5%) patients were users of CYP2D6 inhibitors (median duration, 23 months). DFS at 3 years (corresponding to 5 years after tamoxifen initiation) did not differ between users and non-users of CYP2D6 inhibiting drugs (92.7 vs. 93.0%, respectively; adjusted P = 0.44). OS at 3 years was lower in the patients using CYP2D6 inhibiting drugs: 89.4 vs. 93.8%, but after adjustment for age and comorbidities this difference was not significant (P = 0.20). Overall recurrence rates did not differ between users and non-users of CYP2D6 inhibiting drugs (11.8 vs. 19.0% respectively, P = 0.23). Concomitant prolonged therapy with strong CYP2D6 inhibiting drugs does not affect adversely DFS and recurrence rates in tamoxifen-treated early breast cancer patients.

Database evaluation of the effects of long-term rosiglitazone treatment on cardiovascular outcomes in patients with type 2 diabetes.

Recent meta-analyses suggest an increased risk of acute myocardial infarction (AMI) in patients with type 2 diabetes mellitus (T2DM) treated with rosiglitazone. These meta-analyses have drawn considerable criticisms. Retrospective observational studies do not consistently support this association. The objective of this study was to compare rates of adverse cardiovascular outcomes in T2DM patients treated with rosiglitazone alone or combined with metformin or metformin alone. This retrospective study, using the health maintenance organization database, included patients who were dispensed rosiglitazone (alone or with metformin) for at least 6 months as follows: rosiglitazone alone (n = 745), rosiglitazone and metformin (n = 2753), and metformin alone (n = 11 938). Adverse cardiovascular outcomes were new diagnosis of AMI, acute coronary syndrome (ACS), coronary revascularization (CRV), congestive heart failure (CHF), and all-cause mortality. Mean on-treatment follow-up was 30 months. After adjustment for covariates found to be significant in univariate analyses, rosiglitazone was associated only with CHF (hazard ratio [HR] = 2.23; 95% confidence interval [CI]: 1.41-1.95) with no increase of risk for AMI (HR = 1.13; 95%CI: 0.60-2.12), ACS (HR = 0.85; 95% CI: 0.57-1.26), coronary revascularization (HR = 1.22; 95% CI:0.82-1.54), or all-cause mortality (HR = 1.15; 95% CI: 0.85-1.56). In this community-based cohort, 30 months of therapy with rosiglitazone treatment was associated with increased risk of CHF but was not associated with increased risk of AMI, ACS, coronary revascularization, or all-cause mortality.

Database assessment of the effectiveness of brand versus generic rosiglitazone in patients with type 2 diabetes mellitus.

BACKGROUND: To compare the effectiveness of brand rosiglitazone maleate (BRM) versus generic rosiglitazone HCl (GRH) in patients with type 2 diabetes mellitus, using computerized records of a healthcare organization. Retrospective, longitudinal database analysis. MATERIAL/METHODS: Comparison of HbA1C reduction in patients starting treatment with either BRM (n=740) or GRH (n=306) in the years 2004-2005. RESULTS: BRM users were older (63.5+/-11 vs. 61.7+/-10 years p<0.001) and presented more cardiovascular disorders (38% vs. 25%, p<0.001) with no differences in gender distribution, rates of hypertension or use of concomitant oral hypoglycemic drugs. Use of concomitant insulin was more frequent (17.7% vs. 6.2%, p<0.0001), rates of dispensed rosiglitazone doses >4 mg/d (65.3% vs. 48.5%, p<0.001) and treatment duration was longer (9.3+/-6.2 vs. 5.2+/-2.2 months, p<0.001) with the generic formulation. Baseline HbA1C levels were higher (9.0+/-1.5 vs. 8.6+/-1.2%, p<0.001) and the absolute decrease in HbA1C levels was greater in the GRH group (-1.2+/-1.6% vs. -0.5+/-1.7%, p<0.001). On multiple regression analysis, the decrease in HbA1C (dependent variable) was associated mainly with initial HbA1C level (partial r2=0.30). Rosiglitazone formulation (partial r2=0.02), age, treatment duration and concomitant insulin (partial r2=0.006) were all significant but minor predictors, with no effect of rosiglitazone daily dose. Mean regression-predicted decreases in HbA1C (with 95% CL) were not significantly different between the two rosiglitazone formulations: -1.6% (-4.3% to +1.1%) for GRH and -1.1% (-3.8% to +1.6%) for BRM. CONCLUSIONS: In this retrospective database analysis, we found no evidence of different effectiveness of generic vs. brand rosiglitazone in lowering HbA1C levels.

Establishment and characterization of pheochromocytoma tumor models expressing different levels of trkA receptors.

To date experimental in vivo pheochromocytoma (PC) models have not been available. A major in vitro PC model consists of PC12 cells that respond to nerve growth factor (NGF) by differentiation, mediated by the trkA receptor. We report the establishment of PC12 tumor models expressing low and high levels of trkA receptor in CD1 nude mice. The tumors are characterized by their responsiveness to NGF, karyotype, presence of enolase, and chromaffin granules, as well as dopamine release. These novel PC models facilitate research on the role of the trkA receptor in cancer and the development of trkA-selective anti-cancer agents.

Characterization of nerve growth factors (NGFs) from snake venoms by use of a novel, quantitative bioassay utilizing pheochromocytoma (PC12) cells overexpressing human trkA receptors.

Snake venoms are a very abundant source of nerve growth factors (NGF). NGFs of Elapidae showing 65% sequence homology with mouse or human NGF, while the Viperidae NGF shows N-glycosylation (Asn-21) typical of these mammalian NGFs. Snake NGF-induced neurite outgrowth (neurotropic activity) was measured in the past by using PC12 cell or dorsal root ganglion bioassays. The present study was aimed at comparing, by dose-response experiments, the neurotropic activity of cobra and vipera versus mammalian NGFs, by using a novel bioassay involving PC12 cells genetically engineered to overexpress NGF-trkA receptors of human origin. These cells respond to NGF by differentiation (morphologically expressed as neurite outgrowth) by a process mediated by NGF-trkA receptors. This process was evaluated by two different criteria: (1) elongation of neurites (E), and (2) Percentage of responsive cells (PRC) determined by digital acquisition of data and computer analysis. We found that snake venom NGFs were less potent than mouse NGF, and that cobra NGF was more potent than vipera NGF. These data indicate the following order of NGF activity towards recombinant human trkA receptors: recombinant human NGF>mouse NGF>cobra NGF>vipera NGF. The neurotropic efficacy of these NGFs was found to be similar, reaching 80-90% of maximal activity obtained with all NGF forms. Interestingly, cobra (but not vipera) NGF demonstrated prolonged neurotropic activity compared with mouse NGF. The results of the present study indicate that cobra and vipera venom NGFs represent natural agonists of human trkA-receptor of a lower potency, but of similar efficacy, compared with mammalian NGFs. These compounds are important pharmacological tools to characterize the trkA receptor structure-function relationship, and to develop novel neurotropic drugs.

A quantitative bioassay for nerve growth factor, using PC12 clones expressing different levels of trkA receptors.

Nerve growth factor (NGF) is a neurotrophin required for differentiation, development, and survival of the sympathetic nervous system, with many of its biological effects being mediated via trkA receptors. There is a need for a standard quantitative bioassay for NGF, to be used in basic research and in pharmaceutical studies. The objective of the present research was to develop a selective, quantitative, and reliable bioassay for NGF, using a morphological criterion: neurite cell outgrowth. In addition, we aimed to apply the aforementioned bioassay to measure NGF administered to mice. Pheochromocytoma PC12 cell variants including wild-type cultures, and a trkA-overexpressing stable transfectant PC12-6.24-I, PC12nnr5, and PC12EN lacking trkA receptors, were used. Dose-response curves were generated with NGF beta-subunit (2.5S) purified from mouse submaxillary glands. Our results demonstrated that the bioassay was sensitive to 0.3-20 ng/mL, and selective, as neurite outgrowth was not seen by any other growth factor other than NGF. In addition, variant clones PC12nnr5 and PC12EN, lacking trkA receptors, did not respond to NGF. The bioassay detected NGF in serum of mice injected with NGF. This novel developed bioassay can serve as a model system for various neuroscience purposes.