Intraprocedural high-degree atrioventricular block or complete heart block in transcatheter aortic valve replacement recipients with no prior intraventricular conduction disturbances.

BACKGROUND: Conduction disturbances are the most frequent complication of transcatheter aortic valve replacement (TAVR). However, no data exists regarding the outcomes of intraprocedural high-degree atrioventricular block (HAVB) or complete heart block (CHB) in patients without previous conduction disturbances. OBJECTIVES: The aim of this study was to evaluate the outcomes of intraprocedural-HAVB/CHB in patients without previous intraventricular conduction disturbances. METHODS: The occurrence of intraprocedural-HAVB/CHB was assessed in 676 consecutive patients undergoing TAVR, and two groups were established according to its duration: persistent-HAVB/CHB (PHAVB/CHB) and transient-HAVB/CHB (THAVB/CHB), not present at the end of the procedure. RESULTS: Intraprocedural-HAVB/CHB occurred in 50 patients (7.4%), being persistent in 32 (64.0%), and transient in 18 (36.0%). The use of Medtronic Corevalve Revalving System (MCRS) and a greater oversizing of the valve increased the risk of intraprocedural-HAVB/CHB (p < 0.001). Permanent pacemaker implantation (PPI) was more frequent in the PHAVB/CHB than in the THAVB/CHB group (96.9% vs. 33.3%; p < 0.001). At 1-month follow-up, the PHAVB/CHB group showed a 98% ventricular pacing rate (VPR) compared to 16% in the THAVB/CHB group (p < 0.001), and similar VPR were observed at 1-year follow-up (98% vs. 37%, p < 0.001). Left ventricular ejection fraction (LVEF) decreased at 1-year follow-up in patients with PHAVB/CHB (-3.9 ± 1.8%, p = 0.003). CONCLUSIONS: In TAVR recipients with no prior intraventricular conduction disturbances, intraprocedural-HAVB/CHB occurred in 7.4% of cases. HAVB/CHB was persistent in most cases and determined a high rate of PPI post-TAVR. Very high VPR at 1- and 12-month follow-up were observed, which in turn was associated with a negative effect on LVEF. These results support early PPI and close follow-up in patients developing intraprocedural-PHAVB/CHB.

Late Cerebrovascular Events Following Transcatheter Aortic Valve Replacement.

OBJECTIVES: This study sought to determine the incidence, clinical characteristics, associated factors, and outcomes of late cerebrovascular events (LCVEs) (>30 days post-procedure) following transcatheter aortic valve replacement (TAVR). BACKGROUND: Scarce data exist on LCVEs following TAVR. METHODS: This was a multicenter study including 3,750 consecutive patients (mean age, 80 ± 8 years; 50.5% of women) who underwent TAVR and survived beyond 30 days. LCVEs were defined according to the Valve Academic Research Consortium 2 (VARC 2) criteria. RESULTS: LCVEs occurred in 192 (5.1%) patients (stroke, 80.2%; transient ischemic attack, 19.8%) after a median follow-up of 2 (1 to 4) years. Late stroke was of ischemic, hemorrhagic, and undetermined origin in 80.5%, 18.8%, and 0.7% of patients, respectively. Older age, previous cerebrovascular disease, higher mean aortic gradient at baseline, the occurrence of stroke during the periprocedural TAVR period, and the lack of anticoagulation (novel oral anticoagulants or vitamin K antagonists) post-TAVR were independent factors associated with late ischemic stroke/transient ischemic attack (p < 0.05 for all). Echocardiographic data at the time of the LCVE showed no signs of valve thrombosis or degeneration in the vast majority (97%) patients. Late stroke was disabling in 107 (69.5%) patients (ischemic, 68%; hemorrhagic, 79%), and associated with an in-hospital mortality rate of 29.2%. CONCLUSIONS: LCVEs occurred in 5.1% of TAVR recipients after a median follow-up of 2 years. LCVEs were ischemic in most cases, with older age, previous cerebrovascular events, higher mean aortic gradient at baseline, the occurrence during the periprocedural TAVR period, and lack of anticoagulation (but not valve thrombosis/degeneration) determining an increased risk. Late stroke was disabling in most cases and associated with dreadful early and midterm outcomes.

The QT Interval Dynamic in a Human Experimental Model of Controlled Heart Rate and QRS Widening.

Background: there is increasing interest for computing corrected QT intervals in patients with prolonged depolarization. We aimed to analyze the effect of prolonged QRS in the QT and in the diagnostic accuracy of frequency-correction. Methods and Results: in 28 patients admitted for self-expanding aortic valve implantation, sequential pacing was performed in the AAI mode in two different phases: before and immediately after the release of the prosthesis. We evaluated the accuracy of the Bazett, Fridericia, Framingham and Hodges formulas with the reference of the QT at 60 bpm (QTc/deviation). The widening of the QRS was the main contributor to the QT prolongation (Pearson 0.79; CI95%: 0.75-0.84). Prolongation in other intervals (ST segment and T-wave) significantly contribute in the higher frequency range (p < 0.05). The Bazett's formula displayed the highest QTc/deviation, while Framingham and Hodges retrieved the lowest QTc/deviation and the best fit (p < 0.001). In addition, the Bazett's formula displayed the highest correlation between variations in the QTc/deviation and the widening of the QRS (Pearson coefficient -0.54; p < 0.001) in comparison with the Fridericia, Framingham and Hodges formulas (-0.51, -0.37 and -0.38 respectively; p < 0.001). There was also a linear effect of the heart rate in the QTc/deviation obtained with the Bazett's formula (p = 0.015), not observed for other formulas. Conclusions: The prolonged depolarization of the ventricles introduces direct and linear prolongation in the QT interval, but also a non-linear distortion in cardiac repolarization that contributes for QT prolongation at the higher frequency range. The Bazett's formula displays significantly higher sensitivity to prolongation of ECG intervals.

Self-expanding transcatheter aortic valve implantation for degenerated Mitroflow bioprosthesis: Early outcomes.

BACKGROUND: The aim of this study was to assess the safety and effectiveness of valve in valve (VIV) TAVI with the autoexpandable valve, specifically in patients with failed Mitroflow (MF) bioprosthetic aortic valves. METHODS: Pilot, single center, observational and prospective study that included 45 consecutive patients with symptomatic failed MF bioprosthetic aortic valve, referred for VIV TAVI. The safety primary endpoint was a composite of early events at 30 days, defined by VARC-2 criteria. The efficacy primary endpoint was the device success (no procedural mortality, correct positioning of a single prosthetic heart valve into the proper anatomical location and absence of moderate/severe prosthetic aortic valve regurgitation). We also analysed patient-prosthesis mismatch (PPM) parameters. RESULTS: Between March 2012 to December 2017, 45 symptomatic patients (age 79.9 ±â€¯6.5 years) with degenerated MF valves (numbers 19: 33.3%; 21: 28.9%; 23: 24.4%; 25: 13.3%) underwent CoreValve (n = 11) or Evolut R (n = 34) implantation (23 and 26 mm sizes). The STS predicted risk of mortality was 6.3 ±â€¯6.3%. The safety primary endpoint occurred in 4 patients (8.8%). The efficacy endpoint was present in all patients (100%). There were no coronary occlusions or procedural deaths. The number of patients with any degree of PPM raised from 51.1% (pre-TAVI) to 60% (post-TAVI). CONCLUSIONS: Self-expanding TAVI for degenerated MF bioprosthesis has favourable early outcomes. The VIV procedure has provided an important gateway to avoiding high-risk redo surgery and is now a potential option for MF failed surgically aortic implanted valves.