Reliable focal and rotational activations in CARTOFINDER mapping using the OctaRay catheter.

INTRODUCTION: The aim of the current study was to elucidated the reliable atrial fibrillation (AF) drivers identified by CARTOFINDER using OctaRay catheter. METHODS AND RESULTS: The reliability of focal and rotational activations identified by CARTOFINDER using OctaRay catheter was assessed by the sequential recordings in each site of both atrium before and after pulmonary vein isolation (PVI) in 10 persistent AF patients. The outcome measures were the reproducibility rate during the sequential recordings and the stability rate between pre- and post-PVI as reliable focal and rotational activations. The study results were compared with those under use of PentaRay catheter (N = 18). Total 68928 points of 360 sites in OctaRay group and 24 177 points of 311 sites in PentaRay were assessed. More focal activation sites were identified in OctaRay group than PentaRay group (7.9% vs. 5.7%, p < .001), although the reproducibility rate and the stability rate were significantly lower in OctaRay group (45.3% vs. 58.9%, p < .001; 11.2% vs. 28.4%, p < .001). Meanwhile, the prevalence of reproducible focal activation sites among overall points was comparable (3.6% vs. 3.3%, p = .08). Regarding rotational activation, more rotational activation sites were identified in OctaRay group (5.1% vs. 0.2%, p < .001), and the reproducibility rate and the stability rate were significantly higher in OctaRay group (45.2% and 12.5% vs. 0.0%, p < .001). Both reliable focal and rotational activation sites were characterized by significantly shorter AF-cycle length (CL) and higher repetition of focal and rotational activations during the recordings compared with the sites of non or unreliable focal and rotational activations. CONCLUSION: In CARTOFINDER, OctaRay catheter could identify reliable focal activation with high resolution and reliable rotational activation compared with PentaRay catheter. The repetitive focal and rotational activations with short AF-CL could be the potential target during ablation.

Long-Term Effects of Proton Pump Inhibitors in Patients Undergoing Percutaneous Coronary Intervention in High-Risk Subgroups.

BACKGROUND: Proton pump inhibitors (PPIs) reportedly reduce upper gastrointestinal bleeding (UGIB) in patients undergoing percutaneous coronary intervention (PCI). However, whether the benefits of PPIs differ in high-risk subgroups is unknown. METHODS AND RESULTS: Among 24,563 patients undergoing first PCI in the CREDO-Kyoto registry Cohort-2 and -3, we evaluated long-term effects of PPI for UGIB, defined as GUSTO moderate/severe bleeding, in several potential high-risk subgroups. In the study population, 45.6% of patients were prescribed PPIs. Over a median 5.6-year follow-up, PPIs were associated with lower adjusted risk of UGIB (hazard ratio [HR] 0.64; 95% confidence interval [CI] 0.50-0.80; P<0.001) and a non-significant but numerically lower risk of any gastrointestinal bleeding (HR 0.84; 95% CI 0.71-1.01; P=0.06). PPIs were not associated with a lower risk of GUSTO moderate/severe bleeding (HR 1.04; 95% CI 0.94-1.15; P=0.40) or a higher adjusted risk of myocardial infarction or ischemic stroke (HR 1.00; 95% CI 0.90-1.12; P=0.97), but were associated with higher adjusted mortality risk (HR 1.18; 95% CI 1.09-1.27; P<0.001). The effects of PPIs for UGIB, myocardial infarction or ischemic stroke, and all-cause death were consistent regardless of age, sex, acute coronary syndrome, high bleeding risk, oral anticoagulant use, and type of P2Y12inhibitor. CONCLUSIONS: PPIs were associated with a lower risk of UGIB and a neutral risk of ischemic events regardless of high-risk subgroup.

Prognostic Importance of B-Type Natriuretic Peptide Level in Patients Undergoing Catheter Ablation for Atrial Fibrillation.

BACKGROUND: This study assessed the prognostic importance of B-type natriuretic peptide (BNP) concentrations for clinical events after catheter ablation for atrial fibrillation (AF).Methods and Results: We enrolled 1,750 consecutive patients undergoing initial AF ablation whose baseline BNP data were available from a large-scale multicenter observational cohort (TRANQUILIZE-AF Registry). The prognostic impact of BNP concentration on clinical outcomes, including recurrent tachyarrhythmias and a composite of heart failure (HF) hospitalization or cardiac death, was evaluated. Median baseline BNP was 94.2 pg/mL. During a median follow-up of 2.4 years, low BNP (<38.3 pg/mL) was associated with lower rates of recurrent atrial tachyarrhythmias than BNP concentrations ≥38.3 pg/mL (19.9% vs. 30.6% at 3 years; P<0.001) and HF (0.8% vs. 5.3% at 3 years; P<0.001). Multivariable Cox regression analyses revealed that low BNP was independently associated with lower risks of arrhythmia recurrence (hazard ratio [HR] 0.63; 95% confidence interval [CI] 0.47-0.82; P<0.001) and HF (HR 0.17; 95% CI 0.04-0.71; P=0.002). The favorable impact of low BNP on arrhythmia recurrence was prominent in patients with paroxysmal, but not non-paroxysmal, AF, particularly among those with long-standing AF. CONCLUSIONS: Low BNP concentrations had a favorable impact on clinical outcomes after AF ablation. The heterogeneous impact of baseline BNP concentrations on arrhythmia recurrence for the subgroups of patients divided by AF type warrants future larger studies with longer follow-up periods.

Dual Antiplatelet Therapy Duration After Multivessel Optimal Intravascular Ultrasound-Guided Percutaneous Coronary Intervention.

BACKGROUND: There is a scarcity of data evaluating contemporary real-world dual antiplatelet therapy (DAPT) strategies after percutaneous coronary intervention (PCI).Methods and Results: In the OPTIVUS-Complex PCI study multivessel cohort enrolling 982 patients undergoing multivessel PCI, including left anterior descending coronary artery using intravascular ultrasound (IVUS), we conducted 90-day landmark analyses to compare shorter and longer DAPT. DAPT discontinuation was defined as withdrawal of P2Y12inhibitors or aspirin for at least 2 months. The prevalence of acute coronary syndrome and high bleeding risk by the Bleeding Academic Research Consortium were 14.2% and 52.5%, respectively. The cumulative incidence of DAPT discontinuation was 22.6% at 90 days, and 68.8% at 1 year. In the 90-day landmark analyses, there were no differences in the incidences of a composite of death, myocardial infarction, stroke, or any coronary revascularization (5.9% vs. 9.2%, log-rank P=0.12; adjusted hazard ratio, 0.59; 95% confidence interval, 0.32-1.08; P=0.09) and BARC type 3 or 5 bleeding (1.4% vs. 1.9%, log-rank P=0.62) between the off- and on-DAPT groups at 90 days. CONCLUSIONS: The adoption of short DAPT duration was still low in this trial conducted after the release of the STOPDAPT-2 trial results. The 1-year incidence of cardiovascular events was not different between the shorter and longer DAPT groups, suggesting no apparent benefit of prolonged DAPT in reducing cardiovascular events even in patients who undergo multivessel PCI.

Instability of rotational activation as atrial fibrillation drivers: Assessment by ExTRa Mapping system.

BACKGROUND: ExTRa Mapping™ has developed to visualize rotational activation as atrial fibrillation (AF) drivers. The current study was sought to evaluate the instability of AF drivers by ExTRa Mapping™. METHODS: Variation of nonpassively activated ratio (%NP) among three-time repetitive recordings before and after pulmonary vein isolation (PVI) in left atrium was assessed in 26 persistent AF patients. The recoding time was set at 5 or 8 s for the respective patients. The outcome measures included %NP at each recording, mean value of the three-time recordings, and the instability index, which was defined as maximum difference per mean %NP × 100 (%). RESULTS: Total 683 sites 2049 recordings were assessed. Mean %NP was 33.3(23.3-42.7)%, and higher in sites with severe (≥50%) and patchy low voltage area than those without, but not in those with severe complex fractionated atrial electrogram area. There was significant correlation between actual and mean %NP (R = 0.86, P < .001), but maximum difference among the repetitive recordings was 16(10-24)%. The instability index of %NP was 55.9(30.9-83.6)%, and significantly lower at the recordings of 8 s compared with 5 s (50.6[28.6-78.4]% vs. 60.4[35.0-90.0]%, P = .004). Furthermore, it was higher at sites with lower reliability of the recordings. After PVI, mean %NP significantly decreased (28.7[18.3-36.7]% vs. 37.7[28.7-45.7]%, P < .001), but the instability index significantly increased compared with those before PVI (60.0[35.0-92.7]% vs. 48.9[29.1-75.0]%, P = .001). CONCLUSION: Rotational activation as AF drivers assessed by ExTRa Mapping™ is unstable, and repetitive and longer recording is required for the reliable assessment even after PVI.

Matched comparison of catheter ablation versus conservative management for atrial fibrillation.

It is still controversial whether catheter ablation for atrial fibrillation (AF) could improve clinical outcomes in general AF population. Among 4398 patients with diagnosis of AF in the outpatient department of Kyoto University Hospital between January 2005 and March 2015, we identified 537 pairs of patients who received first-time catheter ablation (ablation group) or conservative management (conservative group), matched for age, gender, AF duration, AF type, AF symptoms, and previous heart failure (HF). The primary outcome measure was a composite of cardiovascular death, HF hospitalization, ischemic stroke, or major bleeding. Most baseline characteristics were well balanced between the 2 groups, except for the higher prevalence of low body weight, history of malignancy, and severe chronic kidney disease in the conservative group. Median follow-up duration was 5.3 years. The cumulative 5-year incidence of the primary outcome measure was significantly lower in the ablation group than in the conservative group (5.2% versus 15.6%, log-rank P < 0.001). Even after adjusting for the imbalances in the baseline characteristics, the lower risk of the ablation group relative to the conservative group for the primary outcome measure remained highly significant (HR 0.32, 95% CI 0.21-0.47, P < 0.001). Ablation compared with conservative management was also associated with significantly lower risks for the individual components of the primary outcome. In this matched analysis in AF patients, ablation as compared with conservative management was associated with better long-term clinical outcomes, although we could not deny the possibility of selection bias and unmeasured confounding.

Limitations of lesion quality estimated by ablation index: An in vitro study.

LIMITATIONS OF THE ABLATION INDEX BACKGROUND: Ablation index (AI) is a novel marker of lesion quality from radiofrequency (RF) catheter ablation. However, AI reliability has not been fully validated by experimental data. The aim of the present study is to validate AI reliability for estimating lesion size using different settings for RF parameters: contact angle, power delivery, and contact force (CF). METHODS AND RESULTS: We evaluated the lesion size in porcine hearts (N = 108) after RF application at three different contact angles to the myocardium: perpendicular (90°), oblique (45°), and parallel (0°). At each angle, RF power at 25, 30, and 35 W was applied at target CF values of 5, 15, and 30 g as measured by the CF sensor to reach target AIs of 300, 400, 500, and 600. AI value was significantly correlated with lesion depth, width, and volume (R = 0.84, 0.82, and 0.87, respectively, all P < 0.001). Lesion depth decreased with smaller contact angles (45° and 0°). Furthermore, high-power RF energy (35 W) resulted in a significantly smaller lesion volume compared with standard-power energy (30 W). There were no significant differences in lesion size among CF settings. CONCLUSIONS: AI was strongly correlated with lesion depth, width, and volume, but only within a small range of contact angles and RF power delivery settings.

Optimal cutoff value of bipolar low-voltage in electroanatomic voltage mapping during atrial fibrillation rhythm.

BACKGROUND: Electroanatomic voltage mapping (EAVM) of the left atrium (LA) with multielectrodes is usually acquired during sinus rhythm (SR), and the feasibility of EAVM during atrial fibrillation (AF) rhythm is unclear. METHODS: We performed EAVM of LA during both SR and AF rhythm in 44 patients undergoing catheter ablation for AF and validated the optimal cutoff value of low-voltage area (LVA) during AF rhythm for detecting LVA defined as bipolar voltages ≤0.5 mV during SR. RESULTS: In each session, mean 829 and 552 points were acquired by multielectrodes during SR and AF rhythm, respectively. Mean proportion of LVA was 4.9% among LA surface area of 276.2 cm2 . Differences of LVA proportions between SR and AF rhythm were 5.8% (P < 0.001), 4.2% (P < 0.001), 2.7% (P < 0.001), 1.2% (P = 0.01), and -0.5% (P = 0.17) at the cutoff value of 0.4, 0.35, 0.3, 0.25, and 0.2 mV during AF rhythm, respectively. There was a good correlation between LVA proportions during SR and AF rhythm with cutoff value of 0.2 mV (R = 0.88, P < 0.001) and 37 patients (84.1%) had the discrepancy of LVA proportions within 3%. Furthermore, there was no significant difference between LVA proportions at each segment of LA. The discrepancy was relatively large in patients with large LA dimension and LVA during SR. CONCLUSION: EAVM during AF rhythm was feasible and the optimal cutoff value of LVA was 0.2 mV for detecting LVA ≤ 0.5 mV during SR. However, the evidence is restricted to patients with relatively small LVA.

Real-time surveillance of left atrial appendage thrombus during contrast computed tomography imaging for catheter ablation: THe Reliability of cOMputed tomography Beyond UltraSound in THROMBUS detection (THROMBUS) study.

Left atrial contrast computed tomography (LA-CT) as well as transesophageal echocardiography (TEE) can exclude left atrial appendage (LAA) thrombus, but is sometimes unable to evaluate LAA due to incomplete LAA filling. The aim of the current study was to validate the utility of real-time approach of LA-CT with real-time surveillance of LAA-filling defect (FD). We enrolled consecutive 894 patients with LA-CT studies acquired for catheter ablation and compared the diagnostic accuracy in demonstrating LAA-FD between conventional protocol (N = 474) and novel protocol with real-time surveillance of LAA-FD immediately after the initial scanning and, when necessary, adding delayed scanning in the supine or prone position (N = 420). Primary endpoint was severity of LAA-FD classified into the 3 groups: "Grade-0" for complete filling of contrast, "Grade-1" for incomplete filling of contrast, and "Grade-2" for complete FD of contrast. The prevalence of Grade-1 and Grade-2 FD was 17.3% and 11.2% in conventional protocol, whereas there was no patient with Grade-2 FD, and only 1 patient with Grade-1 FD after the additional scanning in novel protocol. In 5 patients with suspected LAA thrombus both by TEE and Grade-2 FD in LA-CT by the conventional protocol, ablation procedure was canceled due to diagnosis of LAA thrombus. Conversely, 4 patients with suspected LAA thrombus by TEE in novel protocol group was proved to have intact LAA by LA-CT with and without additional scanning. This novel approach with real-time surveillance improved the diagnostic accuracy of LA-CT in detecting LAA-FD, suggesting potential superiority of LA-CT over TEE in excluding LAA thrombus.

Effect of 1-Month Dual Antiplatelet Therapy Followed by Clopidogrel vs 12-Month Dual Antiplatelet Therapy on Cardiovascular and Bleeding Events in Patients Receiving PCI: The STOPDAPT-2 Randomized Clinical Trial.

Importance: Very short mandatory dual antiplatelet therapy (DAPT) after percutaneous coronary intervention (PCI) with a drug-eluting stent may be an attractive option. Objective: To test the hypothesis of noninferiority of 1 month of DAPT compared with standard 12 months of DAPT for a composite end point of cardiovascular and bleeding events. Design, Setting, and Participants: Multicenter, open-label, randomized clinical trial enrolling 3045 patients who underwent PCI at 90 hospitals in Japan from December 2015 through December 2017. Final 1-year clinical follow-up was completed in January 2019. Interventions: Patients were randomized either to 1 month of DAPT followed by clopidogrel monotherapy (n=1523) or to 12 months of DAPT with aspirin and clopidogrel (n=1522). Main Outcomes and Measures: The primary end point was a composite of cardiovascular death, myocardial infarction (MI), ischemic or hemorrhagic stroke, definite stent thrombosis, or major or minor bleeding at 12 months, with a relative noninferiority margin of 50%. The major secondary cardiovascular end point was a composite of cardiovascular death, MI, ischemic or hemorrhagic stroke, or definite stent thrombosis and the major secondary bleeding end point was major or minor bleeding. Results: Among 3045 patients randomized, 36 withdrew consent; of 3009 remaining, 2974 (99%) completed the trial. One-month DAPT was both noninferior and superior to 12-month DAPT for the primary end point, occurring in 2.36% with 1-month DAPT and 3.70% with 12-month DAPT (absolute difference, -1.34% [95% CI, -2.57% to -0.11%]; hazard ratio [HR], 0.64 [95% CI, 0.42-0.98]), meeting criteria for noninferiority (P < .001) and for superiority (P = .04). The major secondary cardiovascular end point occurred in 1.96% with 1-month DAPT and 2.51% with 12-month DAPT (absolute difference, -0.55% [95% CI, -1.62% to 0.52%]; HR, 0.79 [95% CI, 0.49-1.29]), meeting criteria for noninferiority (P = .005) but not for superiority (P = .34). The major secondary bleeding end point occurred in 0.41% with 1-month DAPT and 1.54% with 12-month DAPT (absolute difference, -1.13% [95% CI, -1.84% to -0.42%]; HR, 0.26 [95% CI, 0.11-0.64]; P = .004 for superiority). Conclusions and Relevance: Among patients undergoing PCI, 1 month of DAPT followed by clopidogrel monotherapy, compared with 12 months of DAPT with aspirin and clopidogrel, resulted in a significantly lower rate of a composite of cardiovascular and bleeding events, meeting criteria for both noninferiority and superiority. These findings suggest that a shorter duration of DAPT may provide benefit, although given study limitations, additional research is needed in other populations. Trial Registration: ClinicalTrials.gov Identifier: NCT02619760.

Impact of Pre-Existing Bradycardia on Subsequent Need for Pacemaker Implantation After Radiofrequency Catheter Ablation for Atrial Fibrillation.

BACKGROUND: The incidence of subsequent need for permanent pacemaker implantation (PMI) after radiofrequency catheter ablation (RFCA) for atrial fibrillation (AF) in real world patients with and without pre-existing bradycardia has not yet been fully evaluated. Methods and Results: A total of 1,131 consecutive patients undergoing first-time RFCA for AF who had no previous or planned device implantation, were enrolled in the present study. Of 799 paroxysmal AF (PAF) patients, 121 (15.1%) had sinus node dysfunction (SND). Of 332 non-PAF patients, 73 (22.0%) had slow ventricular response (VR), defined as heart rate <80 beats/min at rest without any rate-control drugs. The 5-year cumulative incidence of PMI after RFCA in PAF patients with and without SND was 14.8% and 1.7%, respectively (P<0.001). The 5-year cumulative incidence of PMI after RFCA in non-PAF patients with and without slow VR was 14.8% and 4.7%, respectively (P<0.001). SND and female gender in PAF patients, as well as slow VR and age ≥75 years in non-PAF patients, were independent and additive predictors of PMI. The 5-year cumulative incidence of PMI was 26.3% in female PAF patients with SND and 33.3% in elderly non-PAF patients with slow VR. CONCLUSIONS: PMI was avoided in >85% of patients undergoing RFCA for PAF with pre-existing SND, although care should be taken for female patients. Decision-making regarding RFCA for non-PAF patients with slow VR, especially in the elderly, should be cautious.

Prevalence and significance of clinically unsuspected pulmonary embolism: detection using coronary computed tomography angiography.

BACKGROUND AND AIM: Clinically unsuspected pulmonary embolism can be detected using coronary computed tomography (CT), but the clinical significance of unsuspected pulmonary embolism remains unclear. METHODS: Pulmonary embolism was assessed using consecutive coronary CT from March 2003 to June 2007 to assess 1077 patients. Coronary CT was performed using a 16-row multidetector CT (MDCT) scanner with ECG-gating. A radiologist and a cardiologist retrospectively assessed the images of pulmonary arteries to arrive at a consensus diagnosis. RESULTS: Unsuspected pulmonary embolism was detected in 32/1,077 (3.0%) patients. No significant difference was observed with regard to death and acute pulmonary embolism between patients with and without unsuspected pulmonary embolism at five years (6.7% vs. 4.1%, p = 0.61). Prior cardiac surgery within three months of diagnosis of pulmonary embolism was an independent risk factor for unsuspected pulmonary embolism, which was detected in 10/89 (11%) of such patients. The absence of anticoagulant therapy was a risk factor (p = 0.015) for unsuspected pulmonary embolism post-cardiac surgery. Although only one out of 10 patients received anticoagulant therapy, none of the 10 experienced critical events. Five of the 10 patients underwent repeated coronary CT, and the embolus disappeared regardless of its size and location in four of the five patients who did not receive anticoagulant therapy. CONCLUSIONS: The prevalence of unsuspected pulmonary embolism detected using coronary CT was 3.0%. Prior cardiac surgery within three months of diagnosing pulmonary embolism was an independent risk factor for unsuspected pulmonary embolism. The long-term clinical outcomes of patients with unsuspected pulmonary embolism were favorable.

One-year lung function decline in sarcoidosis.

BACKGROUND: The definition of progressive pulmonary fibrosis is based on a 1-year lung function decline. OBJECTIVES: To evaluate the epidemiology and clinical relevance of 1-year lung function decline in sarcoidosis. METHODS: A retrospective observational study at a general sarcoidosis clinic. RESULTS: Of the 198 patients, 42 (18.4 %) had a 1-year lung function decline (absolute 12-month decline in percentage predicted forced vital capacity [%FVC] of ≥5 % or percentage predicted diffusion capacity for carbon monoxide [%DLCO] of ≥10 %). A 1-year lung function decline was associated with a 2-year lung function decline (a relative 24-month decline in %FVC of ≥10 % or %DLCO of ≥15 %), which occurred in 13 (7.4 %) of the 175 patients with 24-month follow-up results. A 1-year lung function decline was not associated with survival; a 2-year lung function decline predicted mortality. CONCLUSIONS: Compared with a 24-month decline, a 12-month decline in lung function did not predict worse survival in sarcoidosis.

Variation in the frozen lesion size according to the non-occluded application duration and technique for cryoballoon ablation.

OBJECTIVE: The frozen lesion formation created by cryoballoon ablation, especially with non-occluded applications, has not been fully evaluated. This study aimed to validate the lesion size under different cryoballoon ablation settings: application duration, push-up technique, and laminar flow. METHODS: The frozen lesion size was evaluated immediately after ending the freezing with three different application durations (120, 150, and 180 seconds) in porcine hearts (N = 24). During the application, the push-up technique was applied at 10, 20, and 30 seconds after starting the freezing with or without laminar flow. RESULTS: The lesion size was significantly correlated with the nadir balloon temperature (P<0.001). The lesion volume became significantly larger after 150 seconds than 120 seconds (1272mm3 versus 1709mm3, P = 0.004), but not after 150 seconds (versus 1876mm3 at 180 seconds, P = 0.29) with a comparable nadir balloon temperature. Furthermore, the lesion volume became significantly larger with the push-up technique with the largest lesion size with a 20-second push-up after the freezing (1193mm3 without the push-up technique versus 1585mm3 with a push-up at 10 seconds versus 1808mm3 with a push-up at 20 seconds versus 1714mm3 with a push-up at 30 seconds, P = 0.04). Further, the absence of laminar flow was not associated with larger lesion size despite a significantly lower nadir balloon temperature. CONCLUSION: The frozen lesion size created by cryoballoon ablation became larger with longer applications at least 150 seconds and with a push-up technique especially at 20 seconds after the freezing.

Efficacy and safety of Saireito (TJ-114) in patients with atrial fibrillation undergoing catheter ablation procedures: A randomized pilot study.

BACKGROUND: Early arrhythmia recurrences commonly occur after atrial fibrillation (AF) ablation because of irritability and inflammation of left atrium. We hypothesized that short-term use of Saireito would be effective in reducing frequent atrial tachyarrhythmias in the early-phase post-ablation. METHODS: One hundred patients undergoing catheter ablation for symptomatic AF were randomly assigned to either a 30-day use of Saireito or control group. The primary endpoint was total number of episodes of frequent atrial tachyarrhythmias including definite recurrent AF and frequent premature atrial contractions during the 30-day treatment period post-ablation. RESULTS: Three (6.0%) out of 50 patients treated with Saireito discontinued the drug because of adverse symptoms. The Saireito group was associated with a numerically lower number of episodes of frequent atrial tachyarrhythmias than the control group (3.1 versus 5.2 times, P = 0.17). The mean daily episodes of frequent atrial tachyarrhythmias were significantly fewer in the Saireito group during Day-6 to Day-10 (0.12/day versus 0.27/day, P = 0.03), and during Day-11 to Day-15 (0.08/day versus 0.24/day, P = 0.001). The prevalence of adverse symptoms during the 30-day treatment period was significantly higher in the Saireito group (18.0% versus 2.0%, P = 0.005). CONCLUSIONS: Thirty-day use of Saireito following AF ablation was associated with a tendency toward reduced number of episodes of frequent atrial tachyarrhythmias during the treatment period, with more pronounced effect in the first two weeks.

Auxiliary roles of nardilysin in the early diagnosis of acute coronary syndrome: a prospective cohort study, the Nardi-ACS study.

Acute coronary syndrome (ACS) includes myocardial infarction (MI) and unstable angina (UA). MI is defined by elevated necrosis markers, preferably high-sensitivity cardiac troponins (hs-cTn). However, it takes hours for cTn to become elevated after coronary occlusion; therefore, difficulties are associated with diagnosing early post-onset MI or UA. The aim of this prospective cohort study was to examine the diagnostic ability of serum nardilysin (NRDC) for the early detection of ACS. This study consisted of two sequential cohorts, the Phase I cohort, 435 patients presenting to the emergency room (ER) with chest pain, and the Phase II cohort, 486 patients with chest pain who underwent coronary angiography. The final diagnosis was ACS in 155 out of 435 patients (35.6%) in the phase I and 418 out of 486 (86.0%) in the phase II cohort. Among 680 patients who presented within 24 h of onset, 466 patients (68.5%) were diagnosed with ACS. Serum NRDC levels were significantly higher in patients with ACS than in those without ACS. The sensitivity of NRDC in patients who presented within 6 h after the onset was higher than that of hsTnI, and the AUC of NRDC within 1 h of the onset was higher than that of hsTnI (0.718 versus 0.633). Among hsTnI-negative patients (300 of 680 patients: 44.1%), 136 of whom (45.3%) were diagnosed with ACS, the sensitivity and the NPV of NRDC were 73.5 and 65.7%, respectively. When measured in combination with hsTnI, NRDC plays auxiliary roles in the early diagnosis of ACS.