Population characteristics and diagnosis rate of chronic kidney disease by eGFR and proteinuria in Japanese clinical practice: an observational database study.

Chronic kidney disease (CKD) guidelines recommend early identification and intervention to delay the progression of CKD. The Kidney Disease: Improving Global Outcomes (KDIGO) heatmap is widely used for risk evaluation in CKD management; however, real-world evidence on clinical characteristics based on the KDIGO heatmap remains limited worldwide including Japan. In order to understand the management of CKD including its diagnostic rates in a Japanese clinical setting on the basis of KDIGO heatmap, we utilized a medical record database that contains estimated glomerular filtration rate (eGFR) and urine protein data. Adult individuals (≥ 18 years) with two eGFR results of < 90 mL/min/1.73 m2, 90-360 days apart, were included. Approximately half of patients (452,996/788,059) had proteinuria test results and 6.9% (54,073) had quantitative results. CKD diagnosis rate in patients without proteinuria data was 5.9%, with a lower rate (2.9%) in stage G2; the corresponding rates with quantitative test results were 43.5% and 31.3%, respectively. The most frequent comorbidities were hypertension, diabetes, and cardiovascular disease, and their prevalence increased as the eGFR and proteinuria stages progressed. This study revealed a low rate of proteinuria assessment, especially using quantitative methods, and diagnosis in individuals with suspected CKD. With emerging treatment options to prevent CKD progression and complication onset, there is a need for early evaluation and diagnosis of CKD.

Dapagliflozin Utilization in Chronic Kidney Disease and Its Real-World Effectiveness Among Patients with Lower Levels of Albuminuria in the USA and Japan.

INTRODUCTION: Sodium-glucose cotransporter 2 inhibitors such as dapagliflozin have been proven effective for slowing chronic kidney disease (CKD) progression in large outcomes trials that mainly included patients with higher levels of albuminuria. Understanding the real-world utilization and effectiveness of these drugs among patients with CKD with lower levels of albuminuria can inform clinical decision-making in this population. METHODS: Claims data from the USA and Japan were used to describe patients with CKD and urinary albumin-to-creatinine ratio (UACR) < 200 mg/g who were eligible for dapagliflozin 10 mg treatment (initiators and untreated) following its approval for CKD. A quantile regression analysis was performed to evaluate the effect of dapagliflozin 10 mg initiation versus no initiation on estimated glomerular filtration rate (eGFR) slope in a propensity score-matched cohort, using a prevalent new-user design. RESULTS: Dapagliflozin initiators (n = 20,407) mostly had stage 3-4 CKD (69-81% across databases). The most common comorbidities were type 2 diabetes, hypertension and cardiovascular disease. At baseline, a renin-angiotensin system inhibitor was prescribed in 53-81% of patients. Eligible but untreated patients were older and had a higher eGFR and lower comorbidity burden than initiators. Following dapagliflozin initiation, the differences in median eGFR slope between initiators and matched non-initiators were 1.07 mL/min/1.73 m2/year (95% confidence interval [CI] 0.40-1.74) in all patients with UACR < 200 mg/g and 1.28 mL/min/1.73 m2/year (95% CI - 1.56 to 4.12) in patients with UACR < 200 mg/g without type 2 diabetes. CONCLUSIONS: Dapagliflozin 10 mg was prescribed to a broad range of patients with CKD. In patients with UACR < 200 mg/g, dapagliflozin initiation was associated with a clinically meaningful attenuation of eGFR slope compared with non-initiation. These findings supplement available clinical efficacy evidence and suggest that dapagliflozin effectiveness may extend to patients with CKD and UACR < 200 mg/g. Graphical Abstract and Video Abstract available for this article. (Video Abstract 245964 kb).

A survey on the patient journey in Fabry disease in Japan.

Background: Fabry disease (FD) is a rare X-linked lysosomal storage disease caused by a deficiency in α-galactosidase that is frequently diagnosed late after disease onset. While previous studies have focused on the multisystem manifestations that can lead to delayed or incorrect diagnosis and management, none have investigated the entire patient journey, and few have examined the patient's disease experience. Objective: To investigate the path to diagnosis from disease onset, and the impact of the disease on daily life, among individuals with FD in Japan. Methods: A nationwide survey of patients with FD receiving enzyme replacement therapy (ERT) was conducted between March 27 and June 11, 2018. Participants were recruited via patient support groups or physicians. Respondents completed a questionnaire eliciting information on sociodemographic status, self-perceived health status, initial and current clinical manifestations, the process of diagnosis, and impact on their life. Responses were analyzed descriptively. Results: Data from 40 respondents were analyzed (17 males and 23 females; 77.5% aged ≥30 years). Mean ERT duration was 7.7 years. Mean time from disease onset to diagnosis was 18.7 years (16.7 years [males] vs 20.3 years [females]). The final diagnosis was made most commonly by pediatricians (38%). Forty percent of respondents felt relieved and 30% felt anxious when diagnosed, and when initiating ERT, 48% felt more positive about their daily life. Nevertheless, 85% reported that treatment affected their lives/work, and most (73%) experienced difficulties in their relationships with others. Conclusion: Efforts are needed to achieve early diagnosis of patients with FD in Japan, to improve clinician awareness, and improve the psychosocial issues associated with FD.

Familial Hypercholesterolemia in Patients with Acute Coronary Syndrome: Genetic Insights from EXPLORE-J.

AIM: Genetic testing can provide a definitive diagnosis of familial hypercholesterolemia (FH). However, accessibility of genetic testing may be limited in certain countries where it is not considered "standard of care," including Japan. In addition, mutations responsible for FH cannot be identified in approximately 30% of patients. METHODS: EXPLORE-J is a multicenter, prospective, observational study of patients presenting with acute coronary syndrome (ACS). The genetic data were analyzed and adjudicated as pathogenic, indeterminate, or nondetectable pathogenic variant. RESULTS: Of 1,944 patients, 431 underwent genetic screening. Overall, most patients had nonpathogenic variants of LDLR, LDLRAP1, or PCSK9 (n=396, 91.9%). Of the 25 (5.8%) patients with pathogenic variants, variants of the LDLR gene and the PCSK9 gene were seen in 10 and 15 patients, respectively. Indeterminate variants were observed in 10 (2.3%) patients. Of the 431 patients, eight (1.9%) met the criteria for a diagnosis of FH using the Japanese Atherosclerosis Society (JAS) 2017 guidelines. When genetic data were incorporated, 33 (7.7%) patients met the JAS guidelines. No patients with FH pathogenic variants satisfied the JAS clinical criteria for a diagnosis of FH. CONCLUSIONS: The results revealed a higher prevalence of genetic mutations of FH among Japanese patients with ACS and a low sensitivity of the FH diagnostic criteria of the JAS 2017 guidelines. These findings highlight the difficulties of FH diagnosis in patients with ACS in the acute phase and suggest the importance of genetic testing and family history.

Glycemic control status, diabetes management patterns, and clinical characteristics of adults with type 1 diabetes in Japan: Study of Adults' Glycemia in T1DM subanalysis.

AIMS/INTRODUCTION: Type 1 diabetes is rare in the general Japanese population, but becoming more common in adults with increased longevity owing to advancements in treatment. We aimed to examine the current state of glycemic control and diabetes management using real-world data on Japanese adults with type 1 diabetes in different age groups. MATERIALS AND METHODS: This was a subanalysis of Japanese participants from a multinational, cross-sectional, observational study of adults with type 1 diabetes aged ≥ 26 years conducted in 2018 (Study of Adults' Glycemia in T1DM). Glycemic control achievement rate and goal setting, incidence of hypoglycemia, and diabetes management of individuals aged 26‒44 years, 45‒64 years, and ≥ 65 years were summarized. RESULTS: The data on 528 participants were analyzed. The mean glycated hemoglobin (HbA1c) value was 7.8% (61.3 mmol/mol). Of the participants, 25.8% achieved an HbA1c level of < 7.0% (26-44 years, 33.7%; 45‒64 years, 18.9%; and ≥ 65 years, 24.3%). In total, 71.4% participants reported ≥ 1 symptomatic hypoglycemic episode within the last 3 months, and 5.5% participants reported ≥ 1 severe hypoglycemic episode within the last 6 months. A less stringent individualized goal was set for participants aged ≥ 65 years; they had the lowest incidence of ≥ 1 symptomatic hypoglycemic episode. Insulin pumps and continuous glucose monitoring were used in 23.5% and 33.9% participants, respectively. CONCLUSION: Glycemic control was suboptimal; the low incidence of severe hypoglycemia suggests careful glycemic control, balancing benefits and risks, particularly in Japanese adults aged ≥ 65 years with type 1 diabetes. SUPPLEMENTARY INFORMATION: The online version contains supplementary material available at 10.1007/s13340-021-00504-7.

Sex and Racial Differences in High-Density Lipoprotein Levels in Acute Coronary Syndromes.

BACKGROUND: This study aimed to assess sex and racial differences related to high-density lipoprotein cholesterol (HDL-C) levels in those presenting with acute coronary syndromes (ACS). METHODS: Records from patients with ACS presenting to the Emergency Department of University of Florida Hospital Jacksonville from 2009 to 2012, were reviewed. Detailed medical history was obtained. HDL-C levels were measured within 72 h of presentation. Pearson chi-square and Wilcoxon rank sum tests were used to compare groups in univariate analysis. Analysis of variance was performed to determine independent predictors of higher HDL-C levels using variable selection. RESULTS: Of 2400 patients screened, 614 (382 men and 232 women) met inclusion criteria. Hypertension, chronic kidney disease or prior CAD history was similar between sexes and races. Women were more likely to be older (62.4 vs 58.4 years), diabetic (56.5 vs 36.5%) and have higher body mass index (31.2 vs 30.1 kg/m2). Blacks were more likely to be diabetic (50.3 vs 41.3%). After adjusting for all clinical markers, women and blacks along with absence of CAD or diabetes, were significantly associated with higher HDL-C levels. CONCLUSIONS: High HDL-C levels (> 40 mg/dL), considered cardio-protective, were seen in women and blacks with ACS more often than in men and whites. Significant differences in HDL-C levels between sexes were seen in whites but not in blacks. Relevance and quality of HDL-C levels in racial groups need further study as this may have important implications in the interpretation of current guidelines.

Lipid Management and 2-Year Clinical Outcomes in Japanese Patients with Acute Coronary Syndrome: EXPLORE-J.

AIM: The prevalence of atherosclerotic cardiovascular (CV) disease has risen in Japan due to increasing metabolic risk factors, including dyslipidemia. A positive linear correlation between low-density lipoprotein cholesterol (LDL-C) levels, incidence of CV events, and preventive effects of lipid-lowering therapy (LLT) is well established; however, data in Japan are limited. This analysis evaluated current lipid management practices and risk of recurrent CV events in Japanese post-acute coronary syndrome (ACS) patients. METHODS: EXPLORE-J is a multicenter, 2-year observational study of hospitalized ACS patients in Japan. RESULTS: At 2-year follow-up (n=1944, mean age 66 years, 80.3% male), the cumulative incidence of major adverse cardiovascular events (MACE; death associated with myocardial infarction/cerebrovascular accident [CVA] and other CV death, non-fatal ACS, and non-fatal CVA requiring hospitalization during the observation period) was 6.2%; respective incidences of CV death, non-fatal ACS, and CVA were 0.7%, 4.5%, and 1.7%. Statin, intensive statin, and ezetimibe were prescribed for 93.6%, 8.2%, and 3.9% at visit (V)1 (Day[D]1＋14), and 92.3%, 10.5%, and 11.6% of patients at V5 (D730±30 days), respectively. Mean LDL-C was reduced from first post-ACS measurement (121.3 mg/dL) to V5 (79.8 mg/dL). A limited number of patients achieved LDL-C ＜70 mg/dL from V1-V5 (14.4%-34.6%); those with a greater LDL-C reduction by V1 had a lower probability of MACE, indicating the benefits of early LDL-C reduction post ACS. CONCLUSIONS: Guideline-recommended LDL-C target achievement post ACS in Japan is suboptimal, suggesting the need for LLT intensification. Additional analyses by risk stratification of the study population and the benefits of lipid management are planned.

Humanistic and economic burden of cardiovascular disease related comorbidities and hypoglycaemia among patients with type 2 diabetes in Japan.

AIM: This study aims to examine the humanistic and economic burden of cardiovascular disease (CVD)-related comorbidities and hypoglycaemia among respondents with type 2 diabetes (T2D) in Japan. METHODS: This study used the Japan National Health and Wellness Survey 2016 database. Respondents who self-reported a physician-diagnosed T2D were included. Respondents with or without the condition of interest (CVD-related comorbidities or hypoglycaemia) were compared via generalized linear models in terms of the outcome variables: (1) health-related quality of life (HRQoL), (2) work productivity and activity impairment, (3) healthcare resource utilization and (4) economic costs. RESULTS: A total of 1478 survey respondents reported a diagnosis of T2D (mean age 63.6 ±â€¯10.6 years, mean HbA1c 6.91 ±â€¯1.1%). Of whom, 804 subjects (54.4%) had at least one CVD related comorbidities, and 369 subjects (29.3%) reported experiences of hypoglycaemia episodes. Patients with CVD-related comorbidities or hypoglycaemia episodes had worse HRQoL, more work and activity impairment, increased health care visits, and higher costs. CONCLUSIONS: CVD related comorbidities and hypoglycaemia remains a significant humanistic and economic burden in patients with T2D. The findings suggested that appropriate T2D management with proper medication choice are important to control CVD related comorbidities and hypoglycaemia among T2D patients to alleviate the burden.

Efficacy and safety of alirocumab 150mg every 4 weeks in hypercholesterolemic patients on non-statin lipid-lowering therapy or lowest strength dose of statin: ODYSSEY NIPPON.

BACKGROUND: Alirocumab, a fully human monoclonal antibody to proprotein convertase subtilisin/kexin type 9, given every 2 weeks (Q2W), significantly reduced low-density lipoprotein cholesterol (LDL-C) levels in Japanese hypercholesterolemic patients on background statin. We evaluated alirocumab 150mg every 4 weeks (Q4W) in patients on lowest-dose statin or non-statin lipid-lowering therapy (LLT). METHODS: ODYSSEY NIPPON was a double-blind study conducted in Japanese patients with LDL-C ≥100mg/dL (heterozygous familial hypercholesterolemia or non-familial hypercholesterolemia with coronary heart disease) or ≥120mg/dL (non-familial hypercholesterolemia, Japan Atherosclerosis Society category III) on atorvastatin 5mg/day or non-statin LLT. Patients were randomized (1:1:1) to subcutaneous alirocumab 150mg Q4W, alirocumab 150mg Q2W, or placebo for the 12-week double-blind treatment period (DBTP), followed by a 52-week open-label treatment period (OLTP). At entry into the OLTP, patients received alirocumab 150mg Q4W, with possible up-titration to 150mg Q2W at Week 24. RESULTS: Least-square mean percent change in LDL-C from baseline at Week 12 (primary efficacy endpoint) was -43.8% for alirocumab Q4W, -70.1% for Q2W, and -4.3% for placebo. During the OLTP, mean LDL-C change from baseline was -45.1% at Week 20, with a further reduction at Week 36, with achieved levels maintained to Week 64. Percent of patients with ≥1 adverse event (DBTP) was 51.9% with alirocumab Q4W, 47.2% with Q2W, and 46.4% with placebo. Most common adverse events were infections and infestations (25.9%, 22.6%, 17.9%, respectively), gastrointestinal disorders (13.0%, 9.4%, 12.5%), nervous system disorders (5.6%, 7.5%, 10.7%), and general disorders and administration-site conditions (3.7%, 11.3%, 5.4%). CONCLUSIONS: Hypercholesterolemic Japanese patients who tolerate only lowest-strength dose statin or non-statin LLT can achieve robust LDL-C reduction with alirocumab 150mg Q4W, in addition to their current LLT. Alirocumab 150mg Q4W dosing was efficacious and generally well tolerated without new safety concerns. (ClinicalTrials.gov number: NCT02584504).

Real-World Data to Identify Hypercholesterolemia Patients on Suboptimal Statin Therapy.

AIM: Statins are generally well-tolerated but some patients develop adverse events and down-titrate or discontinue statins. It is important to understand the frequency of dyslipidemia patients with the inability to continue statins. The aim of the present study was to identify the frequency of high-risk dyslipidemia patients who are unable to take or not taking statins for any reason using Japanese hospital claims database. METHODS: 2,527,405 dyslipidemia patients with atherosclerotic cardiovascular disease were investigated between April 2008 and September 2017. Definition 1 included statin discontinuation or down-titration with non-statin lipid modifying therapy (LMT) prescription, rhabdomyolysis or muscle-related symptoms with statin down-titration or discontinuation, or prescription for ≥3 statin types. Definition 2 included all components of Definition 1 in addition to statin down-titration or discontinuation for any reason. Patients never given statins but who started non-statin LMT were considered as Definition 3. The achievement rate of the target LDL-C level was investigated. RESULTS: Among 54,296 patients with statin prescription, 2.32% and 48.38% patients were identified as Definition 1 and 2, respectively. Of eligible patients, 13.16% patients were identified as Definition 3. The achievement rate of target LDL-C level was lower in patients meeting each definition than not satisfying each definition. CONCLUSIONS: There is a proportion of high-risk dyslipidemia patients unable to take or not taking statins for any reason, and it is associated with lower achievement rates of target LDL-C levels. Suboptimal management of LDL-C is directly associated with residual cardiovascular risk and implementation of alternative therapeutic options in addition to existing LMT is warranted.

Investigation into Lipid Management in Acute Coronary Syndrome Patients from the EXPLORE-J Study.

AIMS: The EXPLORE-J study aimed to assess lipid management in patients hospitalized for acute coronary syndrome (ACS) and their cardiovascular risk despite undergoing standard therapy. Here, we focused on background characteristics of patients in the EXPLORE-J study to elucidate the current lipid-lowering therapy and its issues in Japan. METHODS: In this multicenter, prospective, observational study (UMIN000018946), consecutive Japanese ACS patients who required hospitalization were registered between April 2015 and August 2016. Background and lipid profile data collected within 14 days of hospitalization were analyzed according to risk factors such as diabetes mellitus status. RESULTS: In total, 1944 patients were analyzed (80.3% male). The mean and standard deviation (SD) age and body mass index of all patients were 66.0 years (SD: 12.2) and 24.24 kg/m2 (SD: 3.59), respectively. The most common lipid-modifying medication used at the time of ACS was statins (27.3%). The low-density lipoprotein cholesterol (LDL-C) level (first measurement after hospitalization) of patients overall was 121.2 mg/dL (SD: 39.7); 30.3% had an LDL-C level ＜100 mg/dL (current target level for secondary prevention of cardiovascular events in Japan), compared with 52.1% of patients with a previous history of coronary artery disease (CAD), and 57.2% of patients with a history of CAD and diabetes. CONCLUSIONS: Many patients were not meeting Japanese LDL-C target levels at the time of ACS, and a large proportion of patients meeting target levels developed ACS; therefore, more stringent management and further evaluation of the target LDL-C levels is warranted in high-risk patients and those with previous history of CAD.

Prevalence of familial hypercholesterolemia in patients with acute coronary syndrome in Japan: Results of the EXPLORE-J study.

BACKGROUND AND AIMS: Prevalence of familial hypercholesterolemia (FH), a common genetic disorder with a high risk for coronary artery disease (CAD), is high among CAD patients; however, data on FH prevalence among acute coronary syndrome (ACS) patients are limited. EXPLORE-J is the largest registry to diagnose FH among Japanese ACS patients using the 2012 Japan Atherosclerosis Society guidelines. METHODS: This prospective study consecutively recruited patients between April 2015 and August 2016 at 59 sites. Low-density lipoprotein cholesterol (LDL-C) levels, family history of premature CAD, presence of tendon xanthomas, and Achilles tendon radiograms were recorded at baseline. The prevalence rate of FH in patients with ACS was estimated with 95% CI. RESULTS: Of 1944 analyzed patients (mean age, 66.0 years; men, 80.3%), 52 (2.7% [95% CI: 2.0-3.5]) had FH. Thirty-one (1.6%) had LDL-C ≥180 mg/dL and Achilles tendon thickness (ATT) ≥9 mm, 8 (0.4%) had LDL-C ≥180 mg/dL and family history of premature CAD, 10 (0.5%) had ATT ≥9 mm and family history of premature CAD, and 3 (0.2%) met all the criteria. FH patients were younger than those without FH (59.5 [12.5] vs. 66.2 [12.1] years; p < 0.001). More patients with premature ACS (men, <55 years; women, <65 years) than without (4.7% [95% CI: 2.9-7.2] vs. 2.1% [1.4-3.0]) had FH. CONCLUSIONS: FH prevalence is at least five-fold higher in ACS patients than in the general population, especially in patients with premature ACS onset and ATT ≥9 mm. FH screening in ACS patients is therefore clinically important and critical.

Treatment Patterns and Lipid Profile in Patients with Familial Hypercholesterolemia in Japan.

AIM: To evaluate the epidemiology and real-world treatment patterns associated with lipid-modifying therapies (LMTs) among groups of Japanese patients with familial hypercholesterolemia (FH). METHODS: A retrospective observational study was conducted using an electronic hospital-based administrative claims database and electronic medical records. Patients with existing diagnosis of FH (FH-D) and patients with suspected FH (FH-S) defined by low-density lipoprotein cholesterol (LDL-C) ≥190 mg/dL were included, and medical records of hospitals across Japan were analyzed to assess the diagnostic status, management of LDL-C levels, and treatment patterns. RESULTS: Among the 3,495 patients who met the inclusion criteria, 193 patients were FH-D and 3,339 patients were FH-S. Among them, 83.5% had not achieved the LDL-C of ＜100 mg/dL recommended for patients with FH at the index date. Mean LDL-C levels for all patients and for FH-D and FH-S patients were 145.8 mg/dL, 119.2 mg/dL, and 147.6 mg/dL, respectively. 44.5% of the patients were not currently treated with LMTs. High-intensity statins were used only in 19.2% and 2.3% of the FH-D and FH-S patients, respectively. Furthermore, among the FH-D and FH-S statin-treated patients, 61 (69.3%) and 1,059 (89.7%) remained on monotherapy even when their LDL-C was ≥100 mg/dL. CONCLUSIONS: Treatment and management of LDL-C in Japanese FH patients remain suboptimal. The results suggest that FH is underdiagnosed in real-world, routine clinical practice in Japan. There is an urgent need to improve the diagnostic rate of FH and to provide the appropriate therapy to achieve the recommended LDL-C levels of ＜100 mg/dL or a more than 50% reduction for patients with FH in Japan.

Efficacy and safety of alirocumab in patients with hypercholesterolemia not adequately controlled with non-statin lipid-lowering therapy or the lowest strength of statin: ODYSSEY NIPPON study design and rationale.

BACKGROUND: Statins are generally well-tolerated and serious side effects are infrequent, but some patients experience adverse events and reduce their statin dose or discontinue treatment altogether. Alirocumab is a highly specific, fully human monoclonal antibody to proprotein convertase subtilisin/kexin type 9 (PCSK9), which can produce substantial and sustained reductions of low-density lipoprotein cholesterol (LDL-C). METHODS: The randomized, double-blind, placebo-controlled, parallel-group, phase 3 ODYSSEY NIPPON study will explore alirocumab 150 mg every 4 weeks (Q4W) in 163 Japanese patients with hypercholesterolemia who are on the lowest-strength dose of atorvastatin (5 mg/day) or are receiving a non-statin lipid-lowering therapy (LLT) (fenofibrate, bezafibrate, ezetimibe, or diet therapy alone). Hypercholesterolemia is defined as LDL-C ≥ 100 mg/dL (2.6 mmol/L) in patients with heterozygous familial hypercholesterolemia or non-familial hypercholesterolemia with a history of documented coronary heart disease, or ≥120 mg/dL (3.1 mmol/L) in patients with non-familial hypercholesterolemia classified as primary prevention category III (i.e. high-risk patients). During the 12-week double-blind treatment period, patients will be randomized (1:1:1) to receive alirocumab subcutaneously (SC) 150 mg Q4W alternating with placebo for alirocumab Q4W, or alirocumab 150 mg SC every 2 weeks (Q2W), or SC placebo Q2W. The primary efficacy endpoint is the percentage change in calculated LDL-C from baseline to week 12. The long-term safety and tolerability of alirocumab will also be investigated. DISCUSSION: The ODYSSEY NIPPON study will provide insights into the efficacy and safety of alirocumab 150 mg Q4W or 150 mg Q2W among Japanese patients with hypercholesterolemia who are on the lowest-strength dose of atorvastatin, or are receiving a non-statin LLT (including diet therapy alone). TRIAL REGISTRATION: ClinicalTrials.gov number: NCT02584504.

External validation of the HIT Expert Probability (HEP) score.

The diagnosis of heparin-induced thrombocytopenia (HIT) can be challenging. The HIT Expert Probability (HEP) Score has recently been proposed to aid in the diagnosis of HIT. We sought to externally and prospectively validate the HEP score. We prospectively assessed pre-test probability of HIT for 51 consecutive patients referred to our Consultative Service for evaluation of possible HIT between August 1, 2012 and February 1, 2013. Two Vascular Medicine fellows independently applied the 4T and HEP scores for each patient. Two independent HIT expert adjudicators rendered a diagnosis of HIT likely or unlikely. The median (interquartile range) of 4T and HEP scores were 4.5 (3.0, 6.0) and 5 (3.0, 8.5), respectively. There were no significant differences between area under receiver-operating characteristic curves of 4T and HEP scores against the gold standard, confirmed HIT [defined as positive serotonin release assay and positive anti-PF4/heparin ELISA] (0.74 vs 0.73, p = 0.97). HEP score ≥ 2 was 100 % sensitive and 16 % specific for determining the presence of confirmed HIT while a 4T score > 3 was 93 % sensitive and 35 % specific. In conclusion, the HEP and 4T scores are excellent screening pre-test probability models for HIT, however, in this prospective validation study, test characteristics for the diagnosis of HIT based on confirmatory laboratory testing and expert opinion are similar. Given the complexity of the HEP scoring model compared to that of the 4T score, further validation of the HEP score is warranted prior to widespread clinical acceptance.

Spontaneous dissociated firing from the pulmonary veins during ablation of paroxysmal atrial fibrillation: implications and impact on arrhythmia-free survival.

BACKGROUND: Following pulmonary vein isolation (PVI) for the treatment of paroxysmal atrial fibrillation (AF), spontaneous dissociated firing (DiFi) from the isolated veins may be observed. Little is known about the significance and prognostic implications of this phenomenon. We sought to determine the relationship between DiFi and ablation outcomes. METHODS: The study population consisted of 156 paroxysmal AF patients who underwent first time PVI and were found to have spontaneous DiFi from the pulmonary veins (PVs). Their outcomes were compared to a population of 156 propensity-matched controls from our prospectively maintained AF ablation data registry. RESULTS: DiFi was most frequently observed from the right superior PV and occurred in 89 patients (57.1%). After 24 months of follow-up, patients with DiFi had better success rates compared to those with silent veins after isolation (88.5% vs 75%, P = 0.002). The overall distribution of types of recurrent arrhythmia was similar between DiFi patients and their matched controls (P = NS). During repeat ablations, DiFi patients were less likely to have PV conduction recovery (60% vs 93.3%, P = 0.02). Importantly, none of the veins with DiFi during index procedures was found to have conduction recovery. CONCLUSION: In patients with paroxysmal AF undergoing ablation, DiFi from the PVs after their isolation was associated with improved ablation outcomes. It is possible that DiFi is an indicator of successful durable isolation of the PVs. The findings suggest that confirmation of exit block may be warranted to improve AF ablation outcomes.