Systematic Approach Revealed SERPING1 Splicing-Affecting Variants to be Highly Represented in the Czech National HAE Cohort

Hereditary angioedema due to C1 inhibitor deficiency (C1-INH-HAE) is a rare and life-threatening condition characterized by recurrent localized edema. We conducted a systematic screening of SERPING1 defects in a cohort of 207 Czech patients from 85 families with C1-INH-HAE. Our workflow involved a combined strategy of sequencing extended to UTR and deep intronic regions, advanced in silico prediction tools, and mRNA-based functional assays. This approach allowed us to detect a causal variant in all families except one and to identify a total of 56 different variants, including 5 novel variants that are likely to be causal. We further investigated the functional impact of two splicing variants, namely c.550 + 3A > C and c.686-7C > G using minigene assays and RT-PCR mRNA analysis. Notably, our cohort showed a considerably higher proportion of detected splicing variants compared to other central European populations and the LOVD database. Moreover, our findings revealed a significant association between HAE type 1 missense variants and a delayed HAE onset when compared to null variants. We also observed a significant correlation between the presence of the SERPING1 variant c.-21 T > C in the trans position to causal variants and the frequency of attacks per year, disease onset, as well as Clinical severity score. Overall, our study provides new insights into the genetic landscape of C1-INH-HAE in the Czech population, including the identification of novel variants and a better understanding of genotype-phenotype correlations. Our findings also highlight the importance of comprehensive screening strategies and functional analyses in improving the C1-INH-HAE diagnosis and management.

Nonprocedural bleeding after left atrial appendage closure versus direct oral anticoagulants: A subanalysis of the randomized PRAGUE-17 trial

INTRODUCTION

Observational studies have shown low bleeding rates in patients with atrial fibrillation (AF) treated by left atrial appendage closure (LAAC); however, data from randomized studies are lacking. This study compared bleeding events among patients with AF treated by LAAC and nonvitamin K anticoagulants (NOAC).

METHODS

The Prague-17 trial was a prospective, multicenter, randomized trial that compared LAAC to NOAC in high-risk AF patients. The primary endpoint was a composite of a cardioembolic event, cardiovascular death, and major and clinically relevant nonmajor bleeding (CRNMB) defined according to the International Society on Thrombosis and Hemostasis (ISTH).

RESULTS

The trial enrolled 402 patients (201 per arm), and the median follow-up was 3.5 (IQR 2.6-4.2) years. Bleeding occurred in 24 patients (29 events) and 32 patients (40 events) in the LAAC and NOAC groups, respectively. Six of the LAAC bleeding events were procedure/device-related. In the primary intention-to-treat analysis, LAAC was associated with similar rates of ISTH major or CRNMB (sHR 0.75, 95% CI 0.44-1.27, p = 0.28), but with a reduction in nonprocedural major or CRNMB (sHR 0.55, 95% CI 0.31-0.97, p = 0.039). This reduction for nonprocedural bleeding with LAAC was mainly driven by a reduced rate of CRNMB (sHR for major bleeding 0.69, 95% CI 0.34-1.39, p = .30; sHR for CRNMB 0.43, 95% CI 0.18-1.03, p = 0.059). History of bleeding was a predictor of bleeding during follow-up. Gastrointestinal bleeding was the most common bleeding site in both groups.

CONCLUSION

During the 4-year follow-up, LAAC was associated with less nonprocedural bleeding. The reduction is mainly driven by a decrease in CRNMB.

Left Atrial Appendage Closure versus Non-Warfarin Oral Anticoagulation in Atrial Fibrillation: 4-Year Outcomes of PRAGUE-17

BACKGROUND

The PRAGUE-17 trial demonstrated that left atrial appendage closure (LAAC) was non-inferior to non-warfarin oral anticoagulants (NOAC) for preventing major neurological, cardiovascular or bleeding events in high-risk patients with atrial fibrillation (AF).

OBJECTIVE

To assess the pre-specified long-term (4-year) outcomes in PRAGUE-17.

METHODS

PRAGUE-17 was a randomized non-inferiority trial comparing percutaneous LAAC (Watchman or Amulet) with NOACs (95% apixaban) in non-valvular AF patients with a history of cardioembolism, clinically-relevant bleeding, or both CHA₂DS₂-VASc > 3 and HASBLED > 2. The primary endpoint was a composite of cardioembolic events (stroke, transient ischemic attack, or systemic embolism), cardiovascular death, clinically-relevant bleeding, or procedure/device-related complications (LAAC group only). The primary analysis was modified intention-to-treat (mITT).

RESULTS

We randomized 402 AF patients (201 per group, age 73.3±7.0 years, 65.7% male, CHA₂DS₂-VASc 4.7+1.5, HASBLED 3.1+0.9). After 3.5 years median follow-up (1,354 patients-years), LAAC was non-inferior to NOAC for the primary endpoint by mITT (subdistribution hazard ratio[sHR] 0.81, 95% CI 0.56-1.18; p=0.27; p for non-inferiority=0.006). For the components of the composite endpoint, the corresponding sHRs (and 95% CIs) were 0.68 (0.39-1.20; p=0.19) for cardiovascular death, 1.14 (0.56-2.30; p=0.72) for all-stroke/TIA, 0.75 (0.44-1.27; p=0.28) for clinically-relevant bleeding, and 0.55 (0.31-0.97; p=0.039) for non-procedural clinically-relevant bleeding. The primary endpoint outcomes were similar in the per-protocol [sHR 0.80 (95% CI 0.54-1.18), p=0.25] and on-treatment [sHR 0.82 (95% CI 0.56-1.20), p=0.30] analyses.

CONCLUSION

In long-term follow-up of PRAGUE-17, LAAC remains non-inferior to NOACs for preventing major cardiovascular, neurological or bleeding events. Furthermore, non-procedural bleeding was significantly reduced with LAAC.

The effect of left atrial appendage closure on heart failure biomarkers: A PRAGUE-17 trial subanalysis

INTRODUCTION

The randomized PRAGUE-17 trial demonstrated noninferiority of left atrial appendage closure (LAAC) to non-vitamin K anticoagulants (NOACs) for the prevention of major cardiovascular or cerebrovascular events. However, the left atrial appendage is an important source of natriuretic peptides and plays a role in left atrial reservoir function. Changes of heart failure (HF) biomarkers after LAAC compared to NOAC has not been studied. The aim of the study was to compare the changes in concentrations of HF biomarkers between LAAC and NOAC patients.

METHODS

Of 402 patients randomized in the PRAGUE-17 trial, biomarkers were analyzed in 144 patients (73 in the NOAC and 71 in the LAAC group). Both groups had similar baseline characteristics. Serum concentration of NT-proBNP, NT-proANP, Galectin-3, and GDF-15 were measured at baseline (before the procedure in the LAAC group), at the 6-month (and at 24-month for NT-proBNP) follow-up timepoint.

RESULTS

There were no significant differences in baseline, 6 month, and delta (δ = baseline - 6 month) concentrations of NT-proANP between the groups (NOAC: baseline 2.6 [0.5; 4.9], 6-month 3.1 [1.8; 4.8], p = .068; LAAC: baseline 3.3 [1.1; 4.6], 6-month 2.6 [0.9; 5.3], p = .51; p value for δ in concentrations between groups = 0.42). Similarly, there were no significant differences in baseline, 6, 24 months, and delta concentrations of NT-proBNP between the groups (NOAC: baseline 461.0 [113.5; 1342.0], 6 month 440.0 [120.5; 1291.5], 24 month 798 [274; 2236], p = .39; LAAC: baseline 421.0 [100.0; 1320.0], 6 month 601.0 [145.0; 1230.0], 24 month 855 [410; 1367], p = .28; p value for δ in concentrations between groups = 0.73 at 6 months, and 0.58 at 24 months). Finally, no significant differences were present in baseline, 6 month, and δ concentrations of Galectin-3 and GDF-15 between the two groups.

CONCLUSION

LAAC did not significantly influence the levels of HF biomarkers 6 months after the procedure.

P814Analysis of patients with tako-tsubo syndrome in terms of the triggering mechanism

Introduction

Tako-tsubo syndrome (TTS) might be caused by two different trigger mechanisms. There is very little data available on patient characteristics and prognosis regarding the trigger mechanisms.

Purpose

Comparison of patients with TTS in terms of different trigger factor – emotional stress vs. psychical stress caused by severe non-cardiac condition.

Method

Data were obtained from the Tako-tsubo registry of patients hospitalized in Cardiocenter University Hospital from 2013 to 2018, in total 86 patients were diagnosed with TTS. The patients were divided into 2 groups according to the triggering cause, that we thoroughly examined in each case. In the first group, there were patients with TTS triggered by emotional stress (such as death in the family or anxiety disorders) and in the second group there were patients whose TTS was caused primarily by non-cardiac conditions of various etiology, such as neurological, infectious or postoperative issues.

Results

Out of 86 patients, there were 20 (23,3%) patients excluded, for we weren't able to establish the triggering cause. In 26 (30,2%) patients, the trigger was psychological and 40 (46,5%) patients suffered from non-cardiac condition. According to the collected data there were no significant differences amongst basic demographic facts. Women represented the majority in both groups – 92% vs 95%, age of 70,6±0,8 vs 71,9±0,7 years (p=0,650). There were no significant differences in the hs-TnT 624ng/l ± 49,9 vs 610,2±17,3ng/l (p=0,959). There were significant differences discovered in the average NT-proBNP level – 2691±220,5pg/ml vs 10610±599pg/ml (p<0,05). The patients with non-cardiac conditions developed acute complications more frequently, especially a respiratory failure requiring mechanical ventilation 20% vs 3,8% (p<0,05). In total, 8 (9,3%) patients with TTS died, of whom all had a physical stress factor of p<0,05.

Conclusion

Physical stress in patients with severe non-cardiac conditions is a more frequent trigger for TTS than emotional stress. Patients with TTS induced by physical stress have a significantly worse prognosis.