Clinical implications of conduction abnormalities and arrhythmias after transcatheter aortic valve implantation

The Role of ECG Strain Pattern in Prognosis after TAVI: A Sub-Analysis of the DIRECT Trial

BACKGROUND

The presence of an electrocardiographic (ECG) strain pattern-among other ECG features-has been shown to be predictive of adverse cardiovascular outcomes in asymptomatic patients with aortic stenosis. However, data evaluating its impact on symptomatic patients undergoing TAVI are scarce. Therefore, we tried to investigate the prognostic impact of baseline ECG strain pattern on clinical outcomes after TAVI.

METHODS

A sub-group of patients of the randomized DIRECT (Pre-dilatation in Transcatheter Aortic Valve Implantation Trial) trial with severe aortic stenosis who underwent TAVI with a self-expanding valve in one single center were consecutively enrolled. Patients were categorized into two groups according to the presence of ECG strain. Left ventricular strain was defined as the presence of ≥1 mm convex ST-segment depression with asymmetrical T-wave inversion in leads V5 to V6 on the baseline 12-lead ECG. Patients were excluded if they had paced rhythm or left bundle branch block at baseline. Multivariate Cox proportional hazard regression models were generated to assess the impact on outcomes. The primary clinical endpoint was all-cause mortality at 1 year after TAVI.

RESULTS

Of the 119 patients screened, 5 patients were excluded due to left bundle branch block. Among the 114 included patients (mean age: 80.8 ± 7), 37 patients (32.5%) had strain pattern on pre-TAVI ECG, while 77 patients (67.5%) did not exhibit an ECG strain pattern. No differences in baseline characteristics were found between the two groups. At 1 year, seven patients reached the primary clinical endpoint, with patients in the strain group demonstrating significantly higher mortality in Kaplan-Meier plots compared to patients without left ventricular strain (five vs. two, log-rank p = 0.022). There was no difference between the strain and no strain group regarding the performance of pre-dilatation (21 vs. 33, chi-square p = 0.164). In the multivariate analysis, left ventricular strain was found to be an independent predictor of all-cause mortality after TAVI [Exp(B): 12.2, 95% Confidence Intervals (CI): 1.4-101.9].

CONCLUSION

Left ventricular ECG strain is an independent predictor of all-cause mortality after TAVI. Thus, baseline ECG characteristics may aid in risk-stratifying patients scheduled for TAVI.

Permanent Pacing After Transcatheter Aortic Valve Implantation: Incidence, Predictors and Evolution of Left Ventricular Function

Background

Transcatheter aortic valve implantation (TAVI) is a well-established procedure; however, atrioventricular block requiring permanent pacemaker implantation (PPI) is a common complication.

Objectives

To determine the incidence, predictors and clinical outcomes of PPI after TAVI, focusing on how PPI affects left ventricular ejection fraction (LVEF) after TAVI.

Methods

The Brazilian Multicenter TAVI Registry included 819 patients submitted to TAVI due to severe aortic stenosis from 22 centers from January/2008 to January/2015. After exclusions, the predictors of PPI were assessed in 670 patients by use of multivariate regression. Analysis of the ROC curve was used to measure the ability of the predictors; p < 0.05 was the significance level adopted.

Results

Within 30 days from TAVI, 135 patients (20.1%) required PPI. Those patients were older (82.5 vs. 81.1 years; p = 0.047) and mainly of the male sex (59.3% vs 45%; p = 0.003). Hospital length of stay was longer in patients submitted to PPI (mean = 15.7 ± 25.7 vs. 11.8 ± 22.9 days; p < 0.001), but PPI affected neither all-cause death (26.7% vs. 25.6%; p = 0.80) nor cardiovascular death (14.1% vs. 14.8%; p = 0.84). By use of multivariate analysis, the previous presence of right bundle-branch block (RBBB) (OR, 6.19; 3.56-10.75; p ≤ 0.001), the use of CoreValve^® prosthesis (OR, 3.16; 1.74-5.72; p ≤ 0.001) and baseline transaortic gradient > 50 mm Hg (OR, 1.86; 1.08-3.2; p = 0.025) were predictors of PPI. The estimated risk of PPI ranged from 4%, when none of those predictors was present, to 63%, in the presence of all of them. The model showed good ability to predict the need for PPI: 0.69 (95%CI: 0.64 - 0.74) in the ROC curve. The substudy of 287 echocardiograms during the 1-year follow-up showed worse LVEF course in patients submitted to PPI (p = 0.01).

Conclusion

BRD prévio, gradiente aórtico médio > 50 mmHg e CoreValve® são preditores independentes de implante de MPD pós-TAVI. Ocorreu implante de MPD em aproximadamente 20% dos casos de TAVI, o que prolongou a internação hospitalar, mas não afetou a mortalidade. O implante de MPD afetou negativamente a FEVE pós-TAVI.

Timing of Onset and Outcome of New Conduction Abnormalities Following Transcatheter Aortic Valve Implantation: Role of Balloon Aortic Valvuloplasty

INTRODUCTION AND OBJECTIVES

Little is known about the timing of onset and outcome of conduction abnormalities (CA) following balloon-expandable transcatheter aortic valve implantation. The aim of this study was to examine the timing of CA and determine the impact of balloon aortic valvuloplasty (BAV) on the persistence of these abnormalities.

METHODS

A total of 347 patients were included. Of these, 75 had a continuous electrocardiogram recording and a 6-lead electrocardiogram at each step of the procedure.

RESULTS

In the transcatheter aortic valve implantation population undergoing continuous electrocardiogram monitoring, new-onset left bundle branch block (LBBB) or third-degree atrioventricular block occurred in 48 (64%) and 16 (21.3%) patients, with 51.5% of CA occurring before valve implantation. Left bundle branch block persisted more frequently at hospital discharge (53.8 vs 22.7%; P=.028) and at 1-month follow-up (38.5 vs 13.6%; P=.054) when occurring before valve implantation. Balloon aortic valvuloplasty prior to valve implantation was used in 264 (76.1%) patients, and 78 (22.5%) had persistent LBBB or complete atrioventricular block requiring pacemaker implantation. Persistent LBBB or unresolved atrioventricular block at 1 month occurred more frequently in the BAV group (76.1 vs 47.6%; P=.021), and the use of BAV was associated with a lack of CA resolution (OR, 3.5; 95%CI, 1.17-10.43; P=.021).

CONCLUSIONS

In patients undergoing a balloon-expandable transcatheter aortic valve implantation, more than half of CA occurred before valve implantation. Early occurrence of CA was associated with a higher rate of persistence at 1-month follow-up. The use of BAV was associated with an increased risk of CA persistence.

Atrial Fibrillation Is Associated With Increased Mortality in Patients Undergoing Transcatheter Aortic Valve Replacement: Insights From the Placement of Aortic Transcatheter Valve (PARTNER) Trial

BACKGROUND

This study sought to evaluate the impact of atrial fibrillation (AF) on clinical outcomes in patients undergoing transcatheter aortic valve replacement.

METHODS AND RESULTS

Data were evaluated in 1879 patients with baseline and discharge ECGs who underwent transcatheter aortic valve replacement in the Placement of AoRTic TraNscathetER Valve (PARTNER) trial. A total of 1262 patients manifested sinus rhythm (SR) at baseline/SR at discharge, 113 SR baseline/AF discharge, and 470 AF baseline/AF discharge. Patients who converted from SR to AF by discharge had the highest rates of all-cause mortality at 30 days (P<0.0001 across all groups; 14.2% SR/AF versus 2.6% SR/SR; adjusted hazard ratio [HR]=3.41; P=0.0002) and over 2-fold difference at 1 year (P<0.0001 across all groups; 35.7% SR/AF versus 15.8% SR/SR; adjusted HR=2.14; P<0.0001). The presence of AF on baseline or discharge ECG was a predictor of 1-year mortality (adjusted HR=2.14 for SR/AF group and HR=1.88 for AF/AF groups; P<0.0001 for both groups versus SR/SR). For patients discharged in AF, those with lower ventricular response (ie, <90 bpm) experienced less 1-year all-cause mortality (HR=0.74; P=0.04).

CONCLUSIONS

After transcatheter aortic valve replacement, the presence of AF at discharge, and particularly, the conversion to AF by discharge and higher ventricular response are associated with increased mortality. These data underscore the deleterious impact of AF, as well as the need for targeted interventions to improve clinical outcomes, in patients undergoing transcatheter aortic valve replacement.

CLINICAL TRIAL REGISTRATION

URL: http://www.clinicaltrials.gov. Unique identifier: NCT00530894.

Transcatheter aortic valve replacement-state of the art and a glimpse to the future: 'the Tailored Approach'

Transcatheter aortic valve replacement determined a paradigm shift in the treatment of high-risk patients with severe symptomatic aortic valve stenosis. Notwithstanding the impressive results of the first-generation prostheses, a fast-paced technological evolution is taking place to overcome their limitations, in particular the vascular access damage and the paravalvular leak. Nowadays, with the availability of several different devices, the expert operator can select the right prosthesis for the specific anatomical and clinical situation. As 'One does not fit all', the 'Tailored TAVR Approach' we describe will conceivably become the future of this therapy.

Optimizing clinical outcomes of transcatheter aortic valve implantation patients with comorbidities

Transcatheter aortic valve implantation (TAVI) has revolutionized the management of high-risk or inoperable patients presenting with symptomatic severe aortic stenosis (AS). There are several factors to consider to optimize patient outcomes from TAVI. Before TAVI, patient selection is key and an understanding the effects of common comorbidities on outcomes after TAVI is critical. Some comorbidities share common risk factors with AS (e.g. coronary artery disease), others are directly or indirectly caused or exacerbated by severe AS (e.g. atrial fibrillation, pulmonary hypertension, mitral regurgitation, tricuspid regurgitation and right ventricular dysfunction), whereas others are not directly related to severe AS (e.g. chronic kidney disease and chronic lung disease). Choice of transcatheter heart valve prosthesis, vascular access route and mode of anesthesia are important considerations during TAVI. New onset conduction disturbances and arrhythmias remain a vexing issue after TAVI. The aim of the present review is to provide an overview of these issues.

Arrhythmia Burden in Elderly Patients With Severe Aortic Stenosis as Determined by Continuous Electrocardiographic Recording

Background—

This study sought to evaluate the prevalence of previously undiagnosed arrhythmias in candidates for transcatheter aortic valve replacement (TAVR) and to determine the impact on therapy changes and arrhythmic events after the procedure.

Methods and Results—

A total of 435 candidates for TAVR underwent 24-hour continuous ECG monitoring the day before the procedure. Newly diagnosed arrhythmias were observed in 70 patients (16.1%) before TAVR: paroxysmal atrial fibrillation (AF)/atrial tachycardia (AT) in 28, advanced atrioventricular block or severe bradycardia in 24, nonsustained ventricular tachycardia in 26, and intermittent left bundle-branch block in 3 patients. All arrhythmic events but one were asymptomatic and led to a therapy change in 43% of patients. In patients without known AF/AT, the occurrence of AF/AT during 24-hour ECG recording was associated with a higher rate of 30-day cerebrovascular events (7.1% versus 0.4%; P =0.030). Among the 53 patients with new-onset AF/AT after TAVR, 30.2% had newly diagnosed paroxysmal AF/AT before the procedure. In patients who needed permanent pacemaker implantation after the procedure (n=35), 31.4% had newly diagnosed advanced atrioventricular block or severe bradycardia before TAVR. New-onset persistent left bundle-branch block after TAVR occurred in 37 patients, 8.1% of whom had intermittent left bundle-branch block before the procedure.

Conclusions—

Newly diagnosed arrhythmias were observed in approximately a fifth of TAVR candidates, led to a higher rate of cerebrovascular events, and accounted for a third of arrhythmic events after the procedure. This high arrhythmia burden highlights the importance of an early diagnosis of arrhythmic events in such patients to implement the appropriate therapeutic measures earlier.

Transcatheter aortic valve implantation-induced left bundle branch block: causes and consequences

Transcatheter aortic valve implantation (TAVI) is an alternative treatment option for patients with severe aortic valve stenosis who do not qualify for surgical aortic valve replacement (AVR). Besides its proven clinical benefits, one of the complications of TAVI is the creation of conduction abnormalities, like left bundle branch block (LBBB). New LBBB occurs between 7 and 65% of cases, numbers that differ considerably between devices. In this review, we discuss the possible causes and the clinical significance of TAVI-induced LBBB. Several device- and procedural-related factors seem responsible for the development of LBBB, of which depth of implantation and balloon-annulus diameter ratio are the most important ones. TAVI-induced LBBB negatively affects cardiac function and hospitalization, but its impact on mortality is subject of debate. Future research and registries should implement strict diagnostic criteria for LBBB together with recording of its timing and persistence.